1

M5:

Ove

rvie

w o

f Urb

an W

ater

R

isk

Ass

essm

ent

Shi

rley

Cla

rkP

enn

Sta

te -

Har

risbu

rg

Ris

k A

sses

smen

t Int

rodu

ctio

n

•E

nviro

nmen

tal r

egu

latio

ns a

nd th

e re

sulta

nt

activ

ities

are

des

igne

d to

add

ress

env

ironm

enta

l th

reat

s to

hum

an (

pub

lic)

and

eco

logi

cal h

ealth

. •

Que

stio

n:

–H

ow d

id w

e de

cide

tha

t par

ticul

ar a

ctiv

itie

s an

d/or

po

lluta

nt lo

ads

caus

e an

en

viro

nmen

tal h

ealth

pr

oble

m th

at r

equi

res

addr

ess

ing?

•

Muc

h o

f th

is d

iscu

ssio

n is

bas

ed o

n th

e fo

llow

ing

sour

ces:

–G

uide

lines

for

Eco

log

ical

Ris

k A

sses

smen

t(P

ublis

hed

on M

ay

14, 1

998

, Fed

eral

Reg

iste

r 63

(93)

:268

46-2

6924

)–

Intr

oduc

tion

to C

hem

ical

Exp

osur

e an

d R

isk

Ass

essm

ent

Ris

k A

sses

smen

t Ove

rvie

w

•B

ased

on

two

ele

men

ts: c

hara

cter

izat

ion

of

effe

cts

and

char

acte

rizat

ion

of e

xpos

ure.

•

The

se fo

cus

the

thre

e ph

ases

of r

isk

asse

ssm

ent:

–pr

oble

m fo

rmul

atio

n,

–an

alys

is, a

nd

–ris

k ch

arac

teriz

atio

n.

Ris

k A

sses

smen

t Flo

w C

hart

s

2

Ris

k A

sses

smen

t Ove

rvie

w

•P

robl

em fo

rmul

atio

n:

–Id

ent

ify p

urpo

se, d

efin

e pr

oble

m, d

evel

op p

lan

for

anal

yzin

g an

d ch

arac

teriz

ing

risk

.–

Tw

o pr

oduc

ts: a

sse

ssm

ent e

ndpo

ints

and

con

cept

ual

mod

els.

•A

naly

sis:

–G

uide

d b

y th

e p

rodu

cts

of p

robl

em fo

rmul

atio

n.

–E

valu

ate

dat

a to

de

term

ine

how

, and

if, e

xpo

sure

to

stre

ssor

s is

like

ly to

occ

ur (

char

acte

rizat

ion

of e

xpo

sure

) an

d, g

iven

this

exp

osu

re, t

he p

ote

ntia

l and

type

of e

ffec

ts

that

can

be

exp

ecte

d (c

hara

cter

izat

ion

of e

ffec

ts).

–

Tw

o pr

ofile

s a

s pr

oduc

ts: o

ne fo

r e

xpo

sure

and

one

for

stre

ssor

re

spon

se.

Ris

k A

sses

smen

t Ove

rvie

w

•R

isk

cha

ract

eriz

atio

n:–

Inte

grat

e ex

pos

ure

and

stre

ssor

-res

pon

se p

rofil

es r

isk

estim

atio

n p

roce

ss.

–P

rod

uct:

ris

k de

scrip

tion,

incl

udin

g an

inte

rpre

tatio

n of

ad

vers

ity (

whe

ther

the

ef

fect

s of

the

exp

osur

e ar

e n

egat

ive)

and

des

crip

tions

of u

ncer

tain

ty a

nd

lines

of

evid

ence

.

•Ite

rativ

e pr

oces

s, e

spec

ially

as

one

phas

e ex

pose

s a

data

gap

that

re

quire

s ac

tion!

•

Mon

itorin

g da

ta –

impo

rtan

t in

put t

o al

l ph

ases

of

a ris

k as

sess

men

t. –

Driv

e n

eed

for

risk

asse

ssm

ent

by id

entif

ying

cha

nges

in e

colo

gica

l and

/or

heal

th c

ondi

tion.

–

Use

d to

eva

luat

e a

risk

ass

essm

ent’s

pre

dict

ion

s.

•T

he r

efer

ence

(U

S E

PA

19

98)

from

wh

ich

mu

ch o

f th

is s

ectio

n is

dra

wn

m

akes

a d

istin

ctio

n be

twee

n r

isk

man

ager

s an

d ris

k as

sess

ors.

Th

e te

xt

box

belo

w h

igh

light

s th

e di

ffer

ence

s in

the

two

posi

tions

thro

ugh

the

list

of q

ues

tion

s th

at a

re o

f in

tere

st t

o ea

ch.

•E

ach

risk

asse

ssm

ent i

s co

nstr

ain

ed b

y th

e av

aila

bilit

y of

val

idda

ta a

nd

scie

ntifi

c un

ders

tan

din

g, e

xper

tise,

tim

e, a

nd

finan

cial

res

ourc

es.

Que

stio

ns A

ddre

ssed

by

Ris

k M

anag

ers

and

Ris

k A

sses

sors

•Q

ues

tion

s p

rin

cip

ally

fo

r ri

sk m

anag

ers

to a

nsw

er:

•W

hat i

s th

e n

atu

re o

f th

e pr

oble

m a

nd

the

best

sca

le f

or th

e as

sess

men

t?•

Wha

t are

the

man

agem

ent

goal

s an

d de

cisi

ons

nee

ded,

an

d h

ow

will

ris

k as

sess

men

t hel

p?•

Wha

t are

the

ecol

ogic

al v

alu

es (

e.g.

, en

titie

s an

d ec

osys

tem

ch

arac

teris

tics

of c

once

rn)?

•W

hat a

re th

e po

licy

cons

ider

atio

ns (

law

, cor

pora

te s

tew

ards

hip,

so

ciet

al c

once

rns,

en

viro

nm

enta

l jus

tice,

inte

rgen

erat

ion

al e

quity

)?•

Wha

t pre

cede

nts

are

set

by

sim

ilar

risk

asse

ssm

ents

an

d pr

evio

us

deci

sion

s?•

Wha

t is

the

cont

ext

of th

e as

sess

men

t (e.

g.,

indu

stri

al s

ite, n

atio

nal

pa

rk)?

•W

hat r

esou

rces

(e.

g., p

erso

nnel

, tim

e, m

oney

) ar

e av

aila

ble?

•W

hat l

evel

of

unce

rtai

nty

is a

ccep

tabl

e?

3

Que

stio

ns A

ddre

ssed

by

Ris

k M

anag

ers

and

Ris

k A

sses

sors

•Q

uest

ion

s p

rin

cip

ally

fo

r ri

sk a

sses

sors

to

an

swer

:

•W

hat i

s th

e sc

ale

of th

e ri

sk a

sse

ssm

ent?

•W

hat a

re th

e cr

itica

l eco

logi

cal e

ndpo

ints

and

eco

syst

em

an

d re

cept

or c

hara

cter

istic

s?•

How

like

ly is

rec

ove

ry, a

nd h

ow

long

will

it ta

ke?

•W

hat i

s th

e na

ture

of t

he p

robl

em: p

ast,

pres

ent,

futu

re?

•W

hat i

s th

e st

ate

of k

now

ledg

e of

the

prob

lem

?•

Wha

t dat

a an

d da

ta a

naly

ses

are

ava

ilabl

e an

d ap

prop

riate

?•

Wha

t are

the

pote

ntia

l con

stra

ints

(e

.g.,

limits

on

exp

ertis

e, ti

me,

ava

ilab

ility

of m

etho

ds a

nd d

ata)

?

Pro

blem

For

mul

atio

n

•P

robl

em

form

ula

tion

:pro

cess

of g

ener

atin

g an

d

eva

luat

ing

prel

imin

ary

hyp

othe

ses

abou

t wh

y ef

fect

s ha

ve o

ccur

red,

or

may

occ

ur, f

rom

hum

an a

ctiv

itie

s.

•E

arly

in p

robl

em fo

rmul

atio

n, t

he o

bjec

tive

s ar

e r

efin

ed.

•T

hen

the

natu

re o

f th

e pr

oble

m is

eva

luat

ed a

nd a

pla

n fo

r an

alyz

ing

data

and

cha

ract

eriz

ing

ris

k is

de

velo

ped.

•T

hree

pro

duct

s: (

1) a

sse

ssm

ent e

ndpo

ints

tha

t ad

equa

tely

ref

lect

man

agem

ent g

oals

and

the

ec

osys

tem

the

y re

pres

ent,

(2)

conc

eptu

al m

odel

s th

at

desc

ribe

key

rela

tions

hip

s be

twee

n a

str

ess

or a

nd

asse

ssm

ent e

ndpo

int o

r be

twee

n se

vera

l str

ess

ors

and

asse

ssm

ent e

ndpo

ints

, an

d (3

) an

an

alys

is p

lan.

Pro

blem

For

mul

atio

n•

Inte

gra

tio

n o

f Ava

ilab

le In

form

atio

n•

Ade

quac

y de

term

ined

by

ho

w w

ell a

vaila

ble

info

rmat

ion

on

stre

ssor

so

urce

s an

d ch

arac

teris

tics,

exp

osur

e op

port

uniti

es, c

har

acte

ristic

s of

th

e h

um

ans

or e

cosy

stem

(s)

pote

ntia

lly a

t ris

k, a

nd

effe

cts

are

inte

grat

ed a

nd

used

.•

Initi

al e

valu

atio

ns �

gen

erat

ion

of p

relim

inar

y co

ncep

tual

mod

els

or

asse

ssm

ent e

ndp

oint

s �

lead

ass

esso

rs t

o se

ek o

ther

type

s of

av

aila

ble

info

rmat

ion

not

pre

viou

sly

reco

gniz

ed a

s n

eede

d.

•W

hen

data

is li

mite

d, th

e lim

itatio

ns o

f con

clus

ions

, or

unc

erta

inty

, fr

om th

e ris

k as

sess

men

t m

ust

be

clea

r in

the

risk

char

acte

rizat

ion

. •

Rea

son

beh

ind

risk

asse

ssm

ent i

nflu

ence

s w

hat

info

rmat

ion

is

avai

labl

e at

the

outs

et a

nd

wh

at in

form

atio

n sh

ould

be

colle

cted

. –

Exa

mpl

e, r

isk

asse

ssm

ent

can

be

initi

ated

bec

ause

a k

now

n or

pot

entia

l st

ress

or m

ay e

nter

the

en

viro

nmen

t. I

n th

at c

ase,

the

ris

k as

sess

ors

will

se

ek d

ata

on t

he

effe

cts

that

hav

e b

een

asso

ciat

ed in

th

e p

ast

with

tha

t ex

pos

ure.

4

Wha

t’s D

iffer

ent W

hen

Str

esso

rs, E

ffect

s,

or V

alue

s D

rive

the

Pro

cess

?

•W

hen

conc

ern

ed a

bou

t str

esso

rs,

info

rmat

ion

abo

ut s

tres

sor

and

sour

ce fo

cuse

s as

sess

men

t. –

Obj

ectiv

es b

ased

on

det

erm

inin

g ho

w t

he s

tres

sor

may

con

tact

and

affe

ct p

ossi

ble

rece

ptor

s.

–T

his

lead

s to

dev

elop

ing

conc

eptu

al m

odel

s an

d se

lect

ing

asse

ssm

ent

endp

oint

s.

•W

hen

resp

ondi

ng

to o

bser

ved

effe

ct,

endp

oin

ts a

re n

orm

ally

es

tabl

ish

ed fi

rst.

–F

requ

ently

, af

fect

ed e

colo

gica

l ent

ities

(hu

man

s, fi

sh,

and/

or b

enth

os)

and

thei

r re

spon

se d

efin

e as

sess

men

t en

dpoi

nts.

–

Pro

tect

ion

-bas

ed g

oals

are

th

en e

stab

lish

ed,

whi

ch s

upp

ort

deve

lopm

ent

of c

once

ptu

al m

odel

s to

iden

tify

likel

y st

ress

or(s

).

•F

or v

alu

e-in

itiat

ed r

isk

asse

ssm

ents

, goa

ls a

re e

colo

gica

l val

ues

of

conc

ern

(sp

ecie

s, c

omm

uniti

es, e

cosy

stem

s, o

r pl

aces

).

–A

sses

smen

t en

dpoi

nts

are

mea

sura

ble

inte

rpre

tatio

ns o

f th

e g

oals

. T

hey

sup

por

t id

entif

ying

str

esso

rs t

hat

may

be

influ

enci

ng t

he

asse

ssm

ent

endp

oint

s an

d d

escr

ibin

g th

e di

vers

ity o

f pot

entia

l eff

ects

. T

his

info

rmat

ion

is t

hen

cap

ture

d in

th

e co

ncep

tual

mod

el(s

).

Bac

k to

the

scen

ario

…

•V

alue

s-in

itiat

ed a

sse

ssm

ent.

–T

he v

alu

e is

str

eam

hea

lth a

nd

desi

re t

o en

sure

that

it c

urre

ntly

m

aint

ains

, an

d w

ill c

ontin

ue

to m

aint

ain

, th

e de

sign

ated

use

(dr

inki

ng

wat

er s

ourc

e, fi

shab

le/s

wim

mab

le,

or a

gric

ultu

ral/i

ndu

stri

al).

–

Ass

um

e th

at th

e st

ream

is d

esig

nat

ed a

s fis

hab

le/s

wim

ma

ble.

In th

e U

nite

d S

tate

s, th

e U

S E

PA

has

set

the

wat

er q

ual

ity c

riter

ia f

oraq

uat

ic li

fe. T

his

doc

um

ent c

an b

e re

fere

nced

at t

he

follo

win

g U

RL:

ht

tp://

ww

w.e

pa.g

ov/w

ater

scie

nce/

crite

ria/

nrw

qc-2

006

.pdf

. –

Ass

um

e fo

ur p

ollu

tan

ts w

ere

two

nutr

ien

ts (

phos

phat

e an

d n

itrat

e)

and

two

hea

vy m

etal

s (le

ad a

nd

zin

c) a

nd

the

wat

er ty

pe w

as

fres

hw

ater

. Aqu

atic

life

crit

eria

(*2

5th

perc

entil

e da

ta f

or r

egio

n):

120

120

Zin

c

7*

214

*P

hosp

hate

58

*5

8*

Nitr

ate

2.5

65

Le

ad

Cri

teri

on C

onti

nuou

s C

once

ntra

tion

[C

CC

] (µ µµµ

g/L

)C

rite

ria

Max

imum

C

once

ntra

tion

[C

MC

] (µ µµµ

g/L

)P

ollu

tant

Pro

blem

For

mul

atio

n: In

tegr

atio

n of

A

vaila

ble

Info

rmat

ion

•In

form

atio

n (a

ctua

l, in

ferr

ed, o

r es

timat

ed)

initi

ally

in

tegr

ated

as

a pr

elim

inar

y pr

oble

m s

cope

.–

Fou

nda

tion

for

pro

blem

for

mu

latio

n.

–K

now

led

ge g

ain

ed d

urin

g sc

opin

g us

ed to

iden

tify

mis

sin

g in

form

atio

n a

nd

pote

ntia

l ass

essm

ent

endp

oin

ts–

Kno

wle

dge

pro

vide

s th

e ba

sis

for

early

con

cept

ual

izat

ion

.

•P

red

ictin

g ri

sks

from

mul

tiple

che

mic

al, p

hys

ical

, and

bi

olog

ical

str

ess

ors

requ

ires

unde

rsta

nd

ing

the

ir in

tera

ctio

ns

as

best

as

is p

oss

ible

giv

en c

urre

nt

info

rmat

ion

and

mod

els.

•

Ris

k a

sse

ssm

ents

for

a re

gio

n or

wa

ters

hed

, whe

re

mul

tiple

str

ess

ors

are

the

rule

, req

uire

con

side

ratio

n of

ec

olog

ical

pro

cess

es o

pera

ting

at l

arge

r sp

atia

l sca

les.

Que

stio

ns to

Ask

Con

cern

ing

Sou

rce,

Str

esso

r an

d E

xpos

ure

Cha

ract

eris

tics,

Eco

syst

em

Cha

ract

eris

tics,

and

Effe

cts

(der

ived

in p

art f

rom

Bar

ntho

use

and

Bro

wn,

199

4)

•S

our

ce a

nd

Str

esso

r C

har

acte

rist

ics

•W

hat i

s th

e so

urce

? Is

it a

nth

ropo

gen

ic, n

atur

al, p

oin

t so

urce

, or

diff

use

non

poin

t?•

Wha

t typ

e of

str

ess

or is

it: c

hem

ical

, phy

sica

l, or

bi

olog

ical

?•

Inte

nsi

ty o

f th

e st

ress

(e.

g., t

he d

ose

/con

cent

ratio

n of

a

chem

ical

, the

mag

nitu

de o

r e

xten

t of p

hys

ical

dis

rupt

ion

, th

e de

nsi

ty o

r po

pula

tion

size

of a

bio

logi

cal s

tres

sor)

?•

Wha

t is

the

mod

e of

act

ion?

Ho

w d

oes

the

stre

ssor

act

on

org

anis

ms

or e

cosy

stem

func

tion

s?

5

Que

stio

ns to

Ask

Con

cern

ing

Sou

rce,

Str

esso

r an

d E

xpos

ure

Cha

ract

eris

tics,

Eco

syst

em

Cha

ract

eris

tics,

and

Effe

cts

(der

ived

in p

art f

rom

Bar

ntho

use

and

Bro

wn,

199

4)

•E

xpo

sure

Ch

arac

teri

stic

s•

How

oft

en d

oes

a st

ress

or e

vent

occ

ur

(e.g

., is

it is

olat

ed,

epis

odic

, or

co

ntin

uou

s; is

it s

ubj

ect t

o n

atu

ral d

aily

, sea

son

al, o

r an

nual

per

iodi

city

)?•

How

lon

g do

es th

e ev

ent l

ast?

How

lon

g do

es th

e st

ress

or p

ersi

stin

the

envi

ron

men

t (e.

g., f

or c

hem

ical

, wh

at is

its

hal

f-lif

e, d

oes

it bi

oacc

um

ulat

e; f

or p

hysi

cal,

is h

abita

t alte

ratio

n s

uffic

ient

topr

even

t re

cove

ry; f

or b

iolo

gica

l, w

ill it

rep

rodu

ce o

r pr

olife

rate

)?•

Tim

ing

of e

xpos

ure

? W

hen

doe

s it

occu

r in

rel

atio

n to

crit

ical

org

anis

m

life

cycl

es o

r ec

osys

tem

eve

nts

(e.g

., re

prod

uctio

n, la

ke o

vert

urn)

?•

Spa

tial s

cale

of

expo

sure

/influ

ence

(lo

cal,

regi

onal

, gl

obal

, hab

itat-

spec

ific,

or

ecos

yste

m-w

ide)

?•

Dis

trib

utio

n?

How

doe

s th

e st

ress

or m

ove

thro

ugh

the

envi

ron

men

t(e

.g.,

for

chem

ical

, fat

e an

d tr

ansp

ort,

for

phys

ical

mov

emen

t of

phys

ical

st

ruct

ure

s; fo

r bi

olog

ical

, life

-his

tory

dis

pers

al c

har

acte

ristic

s)?

Que

stio

ns to

Ask

Con

cern

ing

Sou

rce,

Str

esso

r an

d E

xpos

ure

Cha

ract

eris

tics,

Eco

syst

em

Cha

ract

eris

tics,

and

Effe

cts

(der

ived

in p

art f

rom

Bar

ntho

use

and

Bro

wn,

199

4)

•E

cosy

stem

s P

ote

ntia

lly a

t Ris

k•

Geo

grap

hic

bou

nda

ries

? H

ow d

o th

ey r

elat

e to

func

tion

al

char

acte

ristic

s of

the

ecos

yste

m?

•K

ey a

biot

ic f

acto

rs a

ffec

ting/

influ

enci

ng

the

ecos

yste

m (

e.g.

, clim

atic

fa

ctor

s, g

eolo

gy, h

ydro

logy

, soi

l typ

e, w

ater

qu

ality

)?•

Wha

t driv

es th

e ec

osys

tem

(e.

g., e

ner

gy s

ourc

e/pr

oces

sin

g, n

utr

ient

cy

clin

g)?

•S

truc

tura

l ch

arac

teris

tics

of th

e ec

osys

tem

(e.

g., s

peci

es

num

ber/

abun

danc

e, tr

oph

ic r

elat

ion

ship

s)?

•W

hat h

abita

t typ

es a

re p

rese

nt?

•H

ow d

o th

ese

char

acte

ristic

s in

fluen

ce th

e su

scep

tibili

ty (

sens

itivi

ty

and

likel

ihoo

d of

exp

osur

e) o

f th

e ec

osys

tem

to

the

stre

ssor

(s)?

•A

re th

ere

uniq

ue

feat

ure

s th

at a

re p

artic

ula

rly v

alu

ed (

e.g.

, th

e la

st

repr

esen

tativ

e of

an

ecos

yste

m ty

pe)?

•W

hat i

s th

e la

nds

cape

con

text

with

in w

hic

h th

e ec

osys

tem

occ

urs?

Que

stio

ns to

Ask

Con

cern

ing

Sou

rce,

Str

esso

r an

d E

xpos

ure

Cha

ract

eris

tics,

Eco

syst

em

Cha

ract

eris

tics,

and

Effe

cts

(der

ived

in p

art f

rom

Bar

ntho

use

and

Bro

wn,

199

4)

•E

colo

gic

al E

ffec

ts•

Wha

t inf

orm

atio

n is

ava

ilab

le a

bout

the

ecol

ogic

al e

ffect

s (e

.g.,

field

sur

veys

, lab

orat

ory

test

s, o

r st

ruct

ure-

activ

ity r

ela

tions

hips

)?

•G

iven

the

natu

re o

f the

str

esso

r (if

kno

wn)

, w

hic

h ef

fect

s ar

e e

xpec

ted

to b

e e

licite

d b

y th

e

stre

ssor

?•

Und

er w

hat c

ircum

stan

ces

will

effe

cts

occ

ur?

Ris

k A

sses

smen

t Ove

rvie

w

•Q

uest

ion

rais

ed d

urin

g a

rec

ent r

esea

rch

proj

ect:

‘wha

t as

pect

of u

rban

run

off

is c

ausi

ng th

e b

iolo

gic

al

degr

adat

ion

of u

rban

str

eam

s?’

•A

lite

ratu

re r

evi

ew

wa

s pe

rfor

med

and

the

resu

lts w

ere

sum

mar

ized

(C

lark

et a

l., 2

006)

. The

tabl

e in

clud

es a

co

lum

n is

incl

uded

on

data

gap

s si

nce

part

of

the

proj

ect

requ

irem

ents

wa

s to

sum

mar

ize

the

liter

atu

re a

nd

iden

tify

the

data

gap

s. A

s ca

n be

see

n fr

om th

e ta

ble,

th

e st

udie

s do

not

nar

row

do

wn

the

pote

ntia

l cau

ses

of

degr

adat

ion.

The

refo

re, a

ny fo

llow

-up

risk

asse

ssm

ents

w

ill n

eed

to in

clud

e ph

ysic

al, b

iolo

gic

al a

nd c

hem

ical

st

ress

ors

in th

e p

relim

inar

y lis

ts o

f deg

rada

tion

cau

ses.

6

Urb

an R

unof

f Stu

dies

–W

ater

Qua

lity

and

Hab

itat

Gar

iean

d M

cInt

osh,

19

86

Sto

rm fl

ow e

vent

s no

t con

clus

ive.

La

ck o

f dat

a on

flo

w v

arie

ty

antic

ipat

ed in

ye

arly

urb

an

runo

ff.

Wat

er q

ualit

y w

ithin

lim

its d

urin

g lo

w fl

ows.

W

ater

qua

lity

mea

sure

men

ts d

id n

ot

indi

cate

any

ser

ious

pr

oble

ms

limiti

ng

mac

roin

vert

ebra

tes.

Ass

esse

d im

pact

of u

rban

st

orm

wat

er

runo

ff on

str

eam

bi

ota.

Sha

baku

nkC

reek

, Tr

ento

n, N

J

Gra

y, 2

004

Onl

y on

e su

mm

er

test

ed.

Cha

nges

pro

port

iona

l to

incr

ease

in

disc

harg

e. R

etur

ned

to p

revi

ous

leve

ls

with

in 1

2 hr

. No

sign

ifica

nt e

ffect

s on

m

acro

inve

rteb

rate

s.

Det

erm

ine

chan

ges

in

wat

er q

ualit

y du

e to

urb

an

runo

ff du

ring

sum

mer

th

unde

rsto

rms

Pro

vo

Riv

er, U

T

Aut

hor

Dat

a G

apR

esul

tsS

tudy

Goa

lsS

tudy

Are

a

Str

esso

rs to

Con

side

r w

hen

Eva

luat

ing

Diff

eren

t Rec

eivi

ng W

ater

Use

s

XX

Hab

itat

des

tru

ctio

n

(ch

ann

el s

tab

ility

, se

dim

ent

scou

r an

d d

epos

ition

)

XD

ebris

an

d

obst

ruct

ion

s (c

han

nel

co

nve

yan

ce

cap

acity

)

She

llfis

h ha

rves

ting

and

othe

r co

nsum

ptiv

e fis

hing

use

s

Wat

er

supp

lyS

wim

min

g an

d ot

her

cont

act

recr

eatio

n

Non

-con

tact

re

crea

tion

Bio

logi

cal

life

and

inte

grity

Dra

inag

e

Pro

blem

For

mul

atio

n: S

ele

ctin

g A

sses

smen

t E

ndpo

ints

•E

xpre

ss e

xplic

itly

the

act

ual v

alue

tha

t is

to b

e p

rote

cte

d –

an e

colo

gica

l ent

ity (

orga

nis

m, p

opul

atio

n, c

omm

unity

, ec

osys

tem

) an

d its

attr

ibut

es.

–

Rel

evan

ce d

eter

min

ed b

y h

ow w

ell i

t/th

ey t

arge

t/ide

ntify

the

affe

cted

org

anis

ms/

ecos

yste

ms

of in

tere

st.

–U

sefu

lnes

s in

ris

k as

sess

men

t req

uir

es th

at it

be

mea

sura

ble

(at

leas

t be

able

to b

e ra

nke

d, if

it c

ann

ot b

e as

sign

ed a

nu

mer

ical

valu

e).

•C

riter

ia fo

r S

elec

tion

•T

hree

prin

cipa

l crit

eria

: (1)

eco

log

ical

rel

evan

ce, (

2)

susc

eptib

ility

to k

now

n or

po

tent

ial s

tre

ssor

s, a

nd (

3)

rele

vanc

e to

man

agem

ent g

oals

.

Pro

blem

For

mul

atio

n: S

ele

ctin

g A

sses

smen

t E

ndpo

ints

•E

colo

gic

al R

elev

ance

•E

colo

gica

lly r

elev

ant

endp

oin

ts: r

efle

ct/id

entif

y im

port

ant c

har

acte

rist

ics

of th

e sy

stem

, are

func

tion

ally

rel

ated

to

oth

er e

ndp

oint

s, a

nd

may

be

foun

d at

any

leve

l (e.

g.,

indi

vidu

al,

popu

latio

n, c

omm

un

ity, e

cosy

stem

, la

nds

cape

).

•M

ay h

elp

sust

ain

the

nat

ural

str

uctu

re, f

unct

ion

and

biod

iver

sity

of

an

ecos

yste

m o

r its

com

pon

ents

. •

Cha

nge

s qu

antif

ied

(e.g

., al

tera

tion

of c

omm

unity

str

uct

ure

from

the

loss

of

a ke

ysto

ne

spec

ies)

or

infe

rred

(e.

g., s

urvi

val o

f in

divi

dual

s is

ne

eded

to

mai

nta

in p

opu

latio

ns)

. –

Cas

cadi

ng e

ffect

s w

her

e th

e st

ress

ing

of o

ne

org

anis

m a

ffect

s th

e su

rviv

abili

ty o

r h

ealth

of

anot

her

sh

ould

be

cons

ider

ed,

esp

ecia

lly if

ch

ang

es a

ffect

on

e or

mor

e of

the

key

ston

e sp

ecie

s.

•A

spec

ts to

con

side

r:

–N

atur

e an

d in

ten

sity

of p

oten

tial e

ffec

ts,

–S

patia

l and

tem

por

al s

cale

s w

here

eff

ects

may

occ

ur,

and

–P

oten

tial f

or r

ecov

ery.

7

Pro

blem

For

mul

atio

n: S

ele

ctin

g A

sses

smen

t E

ndpo

ints

•S

usc

epti

bili

ty t

o K

no

wn

or

Po

ten

tial

Str

esso

rs•

‘Sus

cept

ible

’: w

hen

an o

rgan

ism

is s

ensi

tive

to a

str

esso

r to

whi

ch t

hey

are,

or m

ay b

e, e

xpos

ed.

•S

ensi

tivity

ref

ers

to h

ow r

eadi

ly a

n or

gan

ism

/pop

ulat

ion

is a

ffec

ted

by a

pa

rtic

ular

str

esso

r an

d is

dir

ectly

rel

ated

to

the

stre

ssor

’s m

ode

of a

ctio

n (e

.g.,

che

mic

al s

ensi

tivity

is in

fluen

ced

by

indi

vidu

al p

hys

iolo

gy a

nd

met

abol

ic p

athw

ays)

. –

Influ

ence

d by

indi

vidu

al a

nd c

omm

unity

life

-his

tory

cha

ract

eris

tics.

•

Sen

sitiv

ity m

easu

res:

mor

talit

y or

adv

erse

rep

rodu

ctiv

e ef

fect

s fr

om t

oxic

ant

exp

osur

e; b

ehav

iora

l abn

orm

aliti

es;

avoi

dan

ce o

f sig

nific

ant

food

sou

rces

an

d n

estin

g si

tes;

loss

of

offs

prin

g to

pre

dat

ion

bec

ause

of t

he

prox

imity

of

stre

ssor

s su

ch a

s n

oise

, ha

bita

t al

tera

tion,

or

loss

; co

mm

unity

str

uctu

ral

chan

ges

; or

oth

er f

acto

rs.

•E

xpos

ure

: co

-occ

urre

nce,

con

tact

, or

th

e ab

senc

e of

con

tact

, de

pen

din

g on

th

e st

ress

or a

nd a

sses

smen

t en

dp

oint

. –

Am

ount

and

con

ditio

ns o

f exp

osur

e di

rect

ly in

fluen

ce h

ow a

n or

gani

sm/p

opul

atio

n w

ill r

espo

nd to

a s

tres

sor.

–

Mus

t con

side

r st

ress

or p

roxi

mity

, exp

osur

e tim

ing

(bot

h in

term

sof

freq

uenc

y an

d du

ratio

n), a

nd e

xpos

ure

inte

nsity

dur

ing

sens

itive

per

iods

. Don

’t fo

rget

: D

elay

ed e

ffect

s an

d m

ultip

le-s

tres

sor

expo

sure

s.

•S

ee t

oxic

olog

y n

otes

!

Pro

blem

For

mul

atio

n: S

ele

ctin

g A

sses

smen

t E

ndpo

ints

•D

efin

ing

Ass

essm

ent

En

dp

oin

ts•

Onc

e po

tent

ial a

sses

smen

t en

dpoi

nts

sel

ecte

d, d

efin

e th

em

oper

atio

nal

ly.

–F

irst,

a v

alu

ed e

colo

gica

l ent

ity m

ust

be id

entif

ied

(sp

ecie

s [e

.g.,

eel

gras

s,

pipi

ng p

love

r],

a fu

nctio

nal

gro

up o

f sp

ecie

s [e

.g.,

pis

civo

res]

, a

com

mun

ity

[e.g

., b

enth

ic in

vert

ebra

tes]

, an

eco

syst

em [

e.g.

, la

ke],

a s

pec

ific

valu

ed

habi

tat

[e.g

., w

et m

ead

ows]

, a

uniq

ue

plac

e, o

r ot

her

ent

ity o

f con

cern

).

–S

econ

d, t

he c

har

acte

ristic

tha

t is

impo

rtan

t to

pro

tect

an

d p

oten

tially

at

risk

mus

t be

iden

tifie

d.•

Wha

t dis

tingu

ish

es a

sses

smen

t en

dpoi

nts

from

man

agem

ent g

oals

isth

eir

neu

tral

ity a

nd

spec

ifici

ty. A

sses

smen

t en

dpoi

nts

do n

ot r

epre

sen

t a

desi

red

ach

ieve

men

t (i.e

., go

al).

•

Ass

essm

ent e

ndp

oint

s m

ay b

e th

e sa

me

as m

easu

res,

dep

endi

ng

on

the

asse

ssm

ent e

ndp

oin

ts s

elec

ted

and

the

type

of

mea

sure

s. N

ote:

S

urro

gate

en

dpoi

nts

can

be

effe

ctiv

e.•

Sug

gest

ion

: Sel

ect

an e

ndp

oin

t th

at is

sen

sitiv

e to

man

y of

the

iden

tifie

d st

ress

ors,

yet

res

pon

ds in

diff

eren

t w

ays

to d

iffer

ent s

tres

sors

. Su

gge

st

sele

ctin

g so

that

all

the

effe

cts

can

be e

xpre

ssed

in th

e sa

me

units

.

Pro

blem

For

mul

atio

n: S

ele

ctin

g A

sses

smen

t E

ndpo

ints

•C

omm

on P

robl

ems

in S

elec

ting

Ass

essm

ent E

ndpo

ints

•E

ndpo

int i

s a

goal

(e.

g.,

mai

ntai

n a

nd

rest

ore

ende

mic

pop

ula

tions

)•

End

poin

t is

vagu

e (e

.g.,

estu

arin

e in

tegr

ity in

stea

d of

eel

gras

sab

un

danc

e an

d di

stri

butio

n)•

Eco

logi

cal e

ntit

y is

bet

ter

as a

mea

sure

(e.

g.,

emer

genc

e of

mid

ges

can

be

use

d to

eva

luat

e an

ass

essm

ent

endp

oin

t for

fish

fee

din

g be

hav

ior)

•E

colo

gica

l en

tity

may

not

be

as s

ensi

tive

to th

e st

ress

or (

e.g.

,cat

fish

vers

us s

alm

on f

or s

edim

enta

tion

)•

Eco

logi

cal e

ntit

y is

not

exp

osed

to th

e st

ress

or (

e.g.

, usi

ng

inse

ctiv

orou

s bi

rds

for

avia

n ris

k of

pes

ticid

e ap

plic

atio

n to

see

ds)

•E

colo

gica

l en

titie

s ar

e irr

elev

ant t

o th

e as

sess

men

t (e.

g.,

lake

fish

in

salm

on s

trea

m)

•Im

port

ance

of

a sp

ecie

s or

attr

ibu

tes

of a

n ec

osys

tem

are

not

fully

co

nsid

ered

. •

Attr

ibu

te is

not

suf

ficie

ntly

sen

sitiv

e fo

r de

tect

ing

impo

rtan

t ef

fect

s (e

.g.,

surv

ival

com

pare

d w

ith r

ecru

itmen

t for

en

dan

gere

d sp

ecie

s)

Pro

blem

For

mul

atio

n: C

once

ptua

l Mod

els

•C

on

cep

tual

Mo

del

s: w

ritte

n d

escr

iptio

n a

nd/

or v

isu

al

repr

esen

tatio

n of

pre

dict

ed r

elat

ions

hip

s be

twee

n ec

olog

ical

ent

ities

an

d th

e st

ress

ors

to w

hic

h th

ey m

ay b

e ex

pose

d.

–M

ay in

clud

e ec

osys

tem

pro

cess

es t

hat

influ

ence

rec

epto

r re

spon

ses

or

exp

osur

e sc

enar

ios

that

qu

alita

tivel

y lin

k la

nd-

use

act

iviti

es t

o st

ress

ors.

–

May

des

crib

e pr

imar

y, s

econ

dar

y, a

nd t

ertia

ry e

xpos

ure

pat

hway

s or

co

-occ

urre

nce

amon

g ex

pos

ure

pat

hway

s, e

colo

gica

l effe

cts,

and

ec

olog

ical

rec

epto

rs.

•D

evel

oped

from

info

rmat

ion

abou

t str

esso

rs, p

oten

tial e

xpos

ure

, an

d pr

edic

ted

effe

cts

on a

n ec

olog

ical

ent

ity (

the

asse

ssm

ent

endp

oint

).

•C

once

ptu

al m

odel

s co

nsis

t of

two

com

pon

ents

:–

A s

et o

f hyp

oth

eses

th

at d

escr

ibe

pred

icte

d re

latio

nsh

ips

amon

g st

ress

or,

exp

osu

re,

and

asse

ssm

ent

endp

oint

res

pon

se,

alon

g w

ithth

e ra

tion

ale

for

thei

r se

lect

ion

–A

dia

gram

tha

t ill

ustr

ates

th

e re

latio

nshi

ps p

rese

nted

in t

he r

isk

hyp

oth

eses

.

8

Pro

blem

For

mul

atio

n: C

once

ptua

l Mod

els

•R

isk

Hyp

othe

ses

:pr

opos

ed a

nsw

ers

(ass

um

ptio

ns)

to th

e qu

estio

ns o

f how

exp

osur

e w

ill o

ccu

r an

d w

hat

res

pons

es th

e en

dpoi

nts

will

sh

ow w

hen

they

are

exp

osed

to s

tres

sors

. •

Cla

rify

rela

tions

hips

that

are

pro

pose

d in

the

con

cept

ual

mod

el a

nd

from

oth

er s

ourc

es.

–N

ot e

quiv

alen

t to

sta

tistic

al t

estin

g of

nul

l and

alte

rnat

ive

hyp

oth

eses

. –

How

ever

, pr

edic

tions

gen

erat

ed f

rom

ris

k hy

pot

hes

es c

an b

e te

sted

in a

va

riet

y of

way

s, in

clud

ing

stan

dar

d st

atis

tical

app

roac

hes

.

•C

once

ptua

l Mod

el D

iagr

ams

:vis

ual

rep

rese

ntat

ion

of r

isk

hypo

thes

es.

•D

esig

n f

acto

rs: t

he

nu

mbe

r of

rel

atio

nsh

ips

depi

cted

, th

e co

mpr

ehen

sive

nes

s of

the

info

rmat

ion

, th

e ce

rtai

nty

surr

oun

din

g a

linka

ge, a

nd

the

pote

ntia

l for

mea

sure

men

t.

Exa

mpl

es o

f Ris

k H

ypot

hese

s•

Str

esso

r-in

itiat

ed: C

hem

ical

s w

ith a

hig

h K

owte

nd to

bio

accu

mul

ate.

Che

mic

al A

ha

s a

Kow

of 5

.5 a

nd m

olec

ular

str

uctu

re s

imila

r to

kno

wn

chem

ical

str

esso

r B

.•

Hyp

othe

ses

: Bas

ed o

n th

e K

owof

che

mic

al A

, the

mod

e of

act

ion

of c

hem

ical

B,

and

the

food

web

of t

he ta

rget

eco

syst

em, w

hen

chem

ical

A is

rel

ease

d at

a s

peci

fied

rate

, it w

ill b

ioac

cum

ulat

e su

ffici

ently

in 5

yea

rs to

cau

se d

evel

opm

enta

l pro

blem

s in

w

ildlif

e an

d fis

h.

•E

ffect

s-in

itiat

ed: B

ird k

ills

wer

e re

peat

edly

obs

erve

d on

gol

f cou

rses

follo

win

g th

e ap

plic

atio

n of

the

pest

icid

e ca

rbof

uran

, whi

ch is

hig

hly

toxi

c.

•H

ypot

hese

s: B

irds

die

whe

n th

ey c

onsu

me

rece

ntly

app

lied

gran

ulat

ed c

arbo

fura

n;

as th

e le

vel o

f app

licat

ion

incr

ease

s, th

e nu

mbe

r of

dea

d bi

rds

incr

ease

s. C

asca

ding

ex

posu

re a

nd e

ffect

s oc

cur

whe

n de

ad a

nd d

ying

bird

s ar

e co

nsum

ed b

y ot

her

anim

als.

Bird

s of

pre

y an

d sc

aven

ger

spec

ies

will

die

from

eat

ing

cont

amin

ated

bird

s.

•E

colo

gica

l val

ue-in

itiat

ed: W

aquo

itB

ay, M

assa

chus

etts

, sup

port

s re

crea

tiona

l bo

atin

g an

d co

mm

erci

al a

nd r

ecre

atio

nal s

hellf

ishi

ng a

nd is

a s

igni

fican

t nur

sery

for

finfis

h. L

arge

mat

s of

mac

roal

gae

clog

the

estu

ary,

mos

t of t

he e

elgr

ass

has

died

, an

d th

e sc

allo

ps a

re g

one.

•H

ypot

hese

s:

Nut

rient

load

ing

from

sep

tic s

yste

ms,

air

pollu

tion,

urb

an ru

noff

and

law

n fe

rtili

zers

cau

ses

eelg

rass

loss

by

shad

ing

from

alg

al g

row

th a

nd d

irect

toxi

city

fro

m n

itrog

en c

ompo

unds

. Fis

h an

d sh

ellfi

sh p

opul

atio

ns a

re d

ecre

asin

g be

caus

e of

lo

ss o

f eel

gras

s ha

bita

t and

per

iodi

c hy

poxi

a fr

om e

xces

s al

gal g

row

th a

nd lo

w

diss

olve

d ox

ygen

.

Pro

blem

For

mul

atio

n: C

once

ptua

l Mod

els

Unc

erta

inty

in C

once

ptua

l Mod

els

•O

ne

of th

e m

ost

impo

rtan

t sou

rces

of u

ncer

tain

ty.

–W

hy?

Unc

erta

inty

aris

es fr

om la

ck o

f kn

owle

dge

abou

t ho

w t

he

ecos

yste

m fu

nctio

ns,

fai

lure

to

iden

tify

and

inte

rrel

ate

tem

pora

l an

d sp

atia

l par

amet

ers,

om

issi

on o

f str

esso

rs,

and/

or o

verl

ooki

ng s

econ

dar

y ef

fect

s.

•U

ncer

tain

ty e

xplo

red

by c

onsi

derin

g al

tern

ativ

e re

latio

nsh

ips.

•T

o ad

dres

s un

cert

ain

ty, t

he

risk

asse

ssor

sh

ould

do

the

follo

win

g w

hen

dev

elop

ing

the

conc

eptu

al m

odel

:–

Be

expl

icit

in d

efin

ing

asse

ssm

ent

endp

oint

s; in

clud

e b

oth

an e

ntity

and

its

mea

sura

ble

attr

ibut

es.

–R

educ

e or

def

ine

vari

abili

ty b

y ca

refu

lly d

efin

ing

bou

ndar

ies

for

the

asse

ssm

ent.

–B

e op

en a

nd

expl

icit

abou

t th

e st

reng

ths

and

limita

tions

of p

athw

ays

and

rela

tions

hips

dep

icte

d in

the

con

cept

ual

mod

el.

–Id

entif

y an

d d

escr

ibe

ratio

nal

e fo

r ke

y as

sum

ptio

ns m

ade

bec

ause

of

lack

of k

now

ledg

e, m

odel

sim

plifi

catio

n, a

ppro

xim

atio

n, o

r ex

trap

olat

ion.

–D

escr

ibe

dat

a lim

itatio

ns.

Pro

blem

For

mul

atio

n: C

once

ptua

l Mod

els

Bac

k to

the

sce

nario

…•

The

dra

ft co

ncep

tual

mod

el c

ould

look

som

ethi

ng li

ke t

his.

•Z

inc,

pho

sph

ate,

lead

and

nitr

ate

are

know

n st

ress

ors

to o

rgan

ism

s in

fr

eshw

ater

str

eam

s in

thi

s ar

ea.

Th

e so

urce

s of

the

se p

ollu

tant

sar

e un

know

n; t

here

fore

, th

at w

ill n

eed

to b

e d

eter

min

ed.

Th

e fis

h in

the

com

mun

ity a

re e

xpos

ed t

o th

ese

pol

luta

nts

in t

wo

way

s –

one,

tho

ugh

in

ges

tion

of c

onta

min

ated

foo

d an

d w

ater

; an

d tw

o, t

hrou

gh

skin

ad

sorp

tion

or “

inh

alat

ion”

of t

hes

e p

ollu

tant

s as

par

t of

“b

reat

hing

.”•

Pho

sph

ate

and

nitr

ate

also

will

affe

ct t

he a

lgal

com

posi

tion

of t

he s

trea

m,

pote

ntia

lly e

ncou

ragi

ng

the

exce

ssiv

e gr

owth

of s

pec

ific

alg

ae

(eut

roph

icat

ion)

th

at d

eple

te t

he o

xyg

en s

uppl

y. T

he

chan

ge

in t

he a

lgal

co

mm

unity

str

uctu

re a

lso

may

cha

ng

e th

e m

icro

bial

com

mun

ity s

truc

ture

, en

cou

ragi

ng t

he

grow

th o

f sp

ecifi

c m

icro

org

anis

ms

that

hav

e a

toxi

c ef

fect

on

th

e fis

h.

•In

add

ition

, zi

nc a

nd

lead

will

sor

b to

the

str

eam

sed

imen

ts w

here

th

ey m

ay

have

an

effe

ct o

n th

e b

enth

os,

whi

ch is

nee

ded

for

th

e or

gan

ism

sth

at

supp

ort

the

food

web

in t

hat

str

eam

.•

The

refo

re,

the

final

ass

essm

ent

will

nee

d to

look

at

the

effe

cts

of t

he

pollu

tant

s th

emse

lves

on

the

fish

thro

ugh

the

vari

ous

rout

es o

f ex

pos

ure,

bu

t al

so w

ill n

eed

to lo

ok a

t th

e ef

fect

s on

dis

solv

ed o

xyg

en a

nd o

n th

e be

nth

os.

9

Pro

blem

For

mul

atio

n: A

naly

sis

Pla

n

•F

inal

sta

ge o

f pro

blem

form

ulat

ion.

•

Ris

k h

ypot

hese

s ar

e e

valu

ated

to d

eter

min

e ho

w th

ey

will

be

ass

ess

ed.

•In

clud

es th

e a

sse

ssm

ent d

esig

n, d

ata

nee

ds,

mea

sure

s,

and

met

hods

for

cond

uctin

g th

e a

naly

sis

pha

se o

f the

ris

k as

sess

men

t. •

Incl

udes

pat

hw

ays

and

rel

atio

nsh

ips

iden

tifie

d du

ring

prob

lem

form

ulat

ion

that

will

be

purs

ued

durin

g th

e a

naly

sis

phas

e.

–R

atio

nal

e in

corp

orat

ed.

–D

ata

gaps

ack

now

led

ged.

–U

ncer

tain

ties

ackn

owle

dged

.

Pro

blem

For

mul

atio

n: A

naly

sis

Pla

n

Sel

ectin

g M

easu

res

•S

elec

tion

of a

ppro

pria

te m

easu

res

com

plic

ated

wh

en a

cas

cade

of

ecol

ogic

al e

ffec

ts is

like

ly t

o oc

cur

from

a s

tres

sor.

•T

hree

cat

egor

ies

of m

easu

res:

–M

easu

res

of e

ffec

t: m

easu

rabl

e ch

ang

es in

an

attr

ibut

e of

an

asse

ssm

ent

endp

oint

or

its s

urro

gat

e in

res

pon

se t

o a

stre

ssor

to

whi

ch it

is e

xpos

ed.

–M

easu

res

of e

xpos

ure:

mea

sure

s of

str

esso

r ex

iste

nce

and

mov

emen

t in

the

envi

ronm

ent

and

thei

r co

ntac

t or

co-

occu

rren

ce w

ith t

he a

sses

smen

t en

dpoi

nt.

–M

easu

res

of e

cosy

stem

and

rec

epto

r ch

arac

teris

tics:

mea

sure

s of

ec

osys

tem

cha

ract

eris

tics

that

influ

ence

the

beh

avio

r an

d lo

catio

n of

ent

ities

se

lect

ed a

s th

e as

sess

men

t en

dpoi

nt,

the

dist

ribut

ion

of a

str

esso

r, a

nd li

fe-

hist

ory

char

acte

ristic

s of

th

e as

sess

men

t en

dpoi

nt o

r its

sur

rog

ate

that

may

af

fect

exp

osu

re o

r re

spon

se t

o th

e st

ress

or.

•W

hen

dire

ct m

easu

rem

ent

of a

sses

smen

t en

dpoi

nt r

espo

nses

is n

ot

poss

ible

, th

e se

lect

ion

of s

urro

gate

mea

sure

s is

nec

essa

ry.

Exa

mpl

es o

f a M

anag

emen

t Goa

l, A

sses

smen

t E

ndpo

int,

and

Mea

sure

s

Goa

l: V

iabl

e, s

elf-s

usta

inin

g co

ld w

ater

trou

t fis

hery

in a

nat

ural

str

eam

bel

ow a

nur

ban

stor

mw

ater

dis

char

ge o

utle

t dra

inin

g a

prim

arily

indu

stria

l are

a.

Ass

essm

ent E

ndpo

int:

Trou

t bre

edin

g su

cces

s, fr

y su

rviv

al, a

nd a

dult

popu

latio

n su

stai

nabi

lity.

Mea

sure

s of

Effe

cts

•E

gg a

nd fr

y re

spon

se to

low

dis

solv

ed o

xyge

n•

Adu

lt be

havi

or (

repr

oduc

tive

and

gene

tic)

in r

espo

nse

to d

isch

arge

d to

xins

•E

gg s

urvi

val w

ith c

hang

es in

sed

imen

tatio

nM

easu

res

of E

cosy

stem

and

Rec

epto

r Cha

ract

eris

tics

•W

ater

tem

pera

ture

, wat

er v

eloc

ity, a

nd p

hysi

cal o

bstru

ctio

ns•

Abu

ndan

ce a

nd d

istr

ibut

ion

of s

uita

ble

bree

ding

sub

stra

te•

Abu

ndan

ce a

nd d

istr

ibut

ion

of s

uita

ble

food

sou

rces

for

fry

•F

eedi

ng, r

estin

g, a

nd b

reed

ing

beha

vior

•N

atur

al r

epro

duct

ion,

gro

wth

, and

mor

talit

y ra

tes

Mea

sure

s of

Exp

osur

e•

Toxi

c ch

emic

al c

once

ntra

tions

in w

ater

, sed

imen

t, an

d fis

h tis

sue.

•N

utrie

nt a

nd d

isso

lved

oxy

gen

leve

ls in

am

bien

t wat

ers

•R

ipar

ian

cove

r, s

edim

ent l

oadi

ng, a

nd w

ater

tem

pera

ture

Pro

blem

For

mul

atio

n: A

naly

sis

Pla

n

•B

ack

to o

ur s

cena

rio…

•S

ince

the

hea

lth o

f th

e st

ream

an

d of

the

fish

is th

e co

ncer

n, w

e w

ill

likel

y w

ant t

o sa

mpl

e so

me

repr

esen

tativ

e fis

h [fi

sh ti

ssu

e an

d fis

h

gut c

onte

nt] (

espe

cial

ly if

we

are

con

cern

ed th

at th

ese

pollu

tan

ts w

ill

accu

mul

ate

[bio

accu

mul

ate

in a

n o

rgan

ism

or

biom

agn

ifyin

the

foo

d w

eb]

in th

e fis

h o

r in

the

prey

of

thes

e fis

h.

•O

bvio

usly

we

are

conc

ern

ed a

bout

the

wat

er c

once

ntr

atio

n.

•T

he s

edim

ent c

once

ntr

atio

n al

so w

ould

be

a co

ncer

n si

nce

the

ben

thos

will

feed

on

the

sedi

men

t an

d po

ssib

ly a

ccu

mu

late

thes

e po

lluta

nts

in th

eir

syst

em.

•A

n ad

ditio

nal

mea

sure

mig

ht b

e bi

och

emic

al o

xyge

n d

eman

d, s

ince

w

e h

ave

expr

esse

d a

con

cern

abo

ut d

isso

lved

oxy

gen

chan

ges

at

nigh

t if t

he

area

un

derg

oes

eutr

oph

icat

ion

. •

The

ch

emic

al m

easu

res

(wat

er a

nd

sedi

men

t col

um

n)

likel

y w

ill b

ere

peat

ed a

s po

ten

tial s

ourc

es a

re id

entif

ied.

10

How

Do

Wat

er Q

ualit

y C

riter

ia R

elat

e to

A

sses

smen

t End

poin

ts?

•R

egul

ator

y G

oal

•C

lean

Wat

er A

ct, §

101:

Pro

tect

the

chem

ical

, phy

sica

l, an

d bi

olog

ical

inte

grity

oft

he

Nat

ion’

s w

ater

s•

Pro

gram

Man

agem

ent D

ecis

ions

•P

rote

ct 9

9% o

f ind

ivid

uals

in 9

5% o

f the

spe

cies

in a

quat

ic c

omm

uniti

es fr

om a

cute

an

d ch

roni

c ef

fect

s re

sulti

ng fr

om e

xpos

ure

to a

che

mic

al s

tres

sor

•A

sses

smen

t End

poin

ts•

Sur

viva

l of f

ish,

aqu

atic

inve

rteb

rate

, and

alg

al s

peci

es u

nder

acu

te e

xpos

ure

•S

urvi

val,

grow

th, a

nd r

epro

duct

ion

of fi

sh, a

quat

ic in

vert

ebra

te, a

nd a

lgal

spe

cies

un

der

chro

nic

expo

sure

•M

easu

res

of E

ffect

•La

bora

tory

LC

50s

for

at le

ast e

ight

spe

cies

mee

ting

cert

ain

requ

irem

ents

•C

hron

ic n

o-ob

serv

ed-a

dver

se-e

ffect

leve

ls (

NO

AE

Ls)

for

at le

ast t

hree

spe

cies

m

eetin

g ce

rtai

n re

quire

men

ts•

Mea

sure

s of

Eco

syst

em a

nd R

ecep

tor C

hara

cter

istic

s•

Wat

er h

ardn

ess

(for

som

e m

etal

s)•

pH

•Th

e w

ater

qua

lity

crite

rion

is a

ben

chm

ark

leve

l der

ived

from

sin

gle-

spec

ies

toxi

city

da

ta. I

t is

assu

med

that

the

spec

ies

test

ed a

dequ

atel

y re

pres

entt

he c

ompo

sitio

n an

d se

nsiti

vitie

s of

spe

cies

in a

nat

ural

com

mun

ity.

Ana

lysi

s P

hase

•“A

naly

sis”

exa

min

es th

e tw

o pr

imar

y co

mpo

nent

s of

ris

k –

exp

osu

re a

nd e

ffec

ts –

and

the

ir re

latio

nsh

ips

betw

een

each

oth

er a

nd e

cosy

stem

cha

ract

eris

tics.

•

Pro

duct

s: s

umm

ary

prof

iles

that

des

crib

e e

xpo

sure

and

th

e re

latio

nsh

ip b

etw

een

the

stre

ssor

(s)

and

resp

onse

. •

Dur

ing

the

anal

ysis

pha

se, t

he r

isk

asse

ssor

:–

Sel

ects

the

data

that

will

be

used

on

the

basi

s of

thei

r u

tility

for

eval

uat

ing

the

risk

hypo

thes

es

–A

naly

zes

expo

sure

by

exa

min

ing

the

sour

ces

of s

tres

sors

, th

e di

stri

butio

n of

str

esso

rs in

the

envi

ron

men

t, an

d th

e ex

tent

of c

o-oc

curr

ence

or

con

tact

–A

naly

zes

effe

cts

by e

xam

inin

g st

ress

or-r

espo

nse

rel

atio

nsh

ips,

th

e ev

iden

ce fo

r ca

usal

ity, a

nd

the

rela

tions

hip

bet

wee

n

mea

sure

s of

eff

ect a

nd

asse

ssm

ent e

ndp

oint

s–

Su

mm

ariz

es th

e co

nclu

sion

s ab

out e

xpos

ure

an

d ef

fect

s.

Ana

lysi

s P

hase

: Eva

luat

ing

Dat

a an

d M

odel

s fo

r A

naly

sis

•S

tren

gths

and

Lim

itatio

ns o

f Diff

eren

t Typ

es o

f Dat

a•

Ma

ny

type

s of

dat

a c

an b

e u

sed

for

risk

ass

ess

men

t. –

Labo

rato

ry s

tudi

es–

Fie

ld s

tudi

es–

Pro

cess

mod

el r

esu

lts•

Eco

logi

sts

and

ep

idem

iolo

gist

s ob

serv

e pa

ttern

s an

d pr

oces

ses

in th

e fi

eld

and

ofte

n u

se s

tatis

tical

tech

niq

ues

(e.g

., co

rrel

atio

n, c

lust

erin

g, fa

ctor

ana

lysi

s) to

de

scrib

e a

n as

soci

atio

n b

etw

een

a d

istu

rban

ce a

nd a

n ec

olog

ical

effe

ct.

•M

uch

of t

he d

ata

on

hum

an e

xpo

sure

com

es e

ither

from

e

xtra

pola

tion

of la

bora

tory

dat

a o

r fr

om e

pide

mio

logi

c d

ata

on h

uman

pop

ulat

ions

(of

ten

as

a re

sult

of o

ccup

atio

nal

exp

osur

e).

•S

ee e

pid

emio

log

y no

tes!

11

Ana

lysi

s P

hase

: Eva

luat

ing

Dat

a an

d M

ode

ls fo

r A

naly

sis

•M

ay b

e si

ngle

var

iabl

e da

ta o

r in

dex

valu

es (

e.g.

, RB

P r

esul

ts, I

BI d

ata)

. •

Inde

x da

ta a

dvan

tage

s:–

Ove

rall

ind

icat

ion

of b

iolo

gic

al c

ond

ition

by

inco

rpor

atin

g m

any

attr

ibut

es f

rom

ind

ivid

ual

to

ecos

yste

m le

vels

–E

valu

ate

resp

onse

s fr

om a

bro

ad r

ang

e of

an

thro

pog

enic

str

esso

rs–

Min

imiz

e th

e lim

itatio

ns

of in

div

idu

al m

etric

s fo

r d

etec

ting

sp

ecifi

c ty

pes

of

resp

onse

s.•

Inde

x da

ta d

isad

vant

ages

: –

Com

bin

ing

het

erog

eneo

us

vari

able

s.–

Diff

eren

tial s

ensi

tivity

or

oth

er f

acto

rs m

ay m

ake

it d

iffic

ult t

o at

trib

ute

cau

salit

y.

–In

terp

reta

tion

diff

icul

t w

hen

an

ind

ex c

omb

ines

mea

sure

s of

exp

osu

re a

nd

eff

ects

bec

ause

d

oub

le c

oun

ting

may

occ

ur

or c

han

ges

in o

ne

vari

able

can

mas

k ch

ang

es in

an

oth

er.

•P

roce

ss m

odel

s ca

n be

use

d to

pre

dict

effe

cts.

–

Par

ticu

larl

y u

sefu

l wh

en m

easu

rem

ents

can

not

be

take

n.

–P

rovi

de

estim

ates

for

tim

es o

r lo

catio

ns

that

are

imp

ract

ical

to

mea

sure

.–

Pro

vid

e b

asis

for

ext

rap

olat

ing

bey

ond

the

ran

ge

of o

bse

rvat

ion

.•

Eva

luat

ing

Mea

sure

men

t or M

odel

ing

Stu

dies

•S

tudy

sho

uld

incl

ude

a de

scrip

tion

of th

e pu

rpos

e, m

etho

ds u

sed

to c

olle

ct d

ata,

and

re

sults

of t

he w

ork.

•

Com

pare

stu

dy o

bjec

tives

with

thos

e of

the

risk

asse

ssm

ent f

or c

onsi

sten

cy (

see

ques

tions

in te

xt b

ox b

elow

).

•E

valu

ate

whe

ther

the

inte

nded

obj

ectiv

es w

ere

met

and

whe

ther

the

data

are

of

suffi

cien

t qua

lity

Que

stio

ns fo

r E

valu

atin

g a

Stu

dy’s

Util

ity fo

r R

isk

Ass

essm

ent

•A

re th

e st

udy

obje

ctiv

es r

ele

vant

to th

e ris

k as

sess

men

t?•

Are

the

varia

ble

s an

d co

nditi

ons

the

stud

y re

pres

ents

com

para

ble

with

thos

e im

port

ant t

o th

e ris

k as

sess

men

t?•

Is th

e st

udy

desi

gn a

dequ

ate

to m

eet i

ts

obje

ctiv

es?

•W

as th

e st

udy

cond

ucte

d pr

oper

ly?

•H

ow

are

var

iab

ility

and

unc

erta

inty

trea

ted

and

repo

rted

?

Ana

lysi

s P

hase

: Eva

luat

ing

Unc

erta

inty

•O

bjec

tive

: de

scrib

e an

d q

uant

ify w

hat

is k

now

n an

d n

ot

know

n ab

out e

xpos

ure

and

effe

cts

in th

e s

yste

m o

f in

tere

st.

–U

ncer

tain

ty a

nal

yses

incr

ease

the

cred

ibili

ty o

f as

sess

men

ts b

y ex

plic

itly

desc

ribi

ng

the

mag

nitu

de a

nd

dire

ctio

n o

f unc

erta

intie

s,

and

they

pro

vide

the

basi

s fo

r ef

ficie

nt d

ata

colle

ctio

n or

ap

plic

atio

n of

ref

ined

met

hod

s.

–U

ncer

tain

ties

char

acte

rize

d du

ring

the

anal

ysis

ph

ase

are

used

du

ring

risk

char

acte

rizat

ion

, wh

en r

isks

are

est

imat

ed a

nd

the

conf

iden

ce in

diff

eren

t lin

es o

f ev

iden

ce is

des

crib

ed.

•T

his

sect

ion

dis

cuss

es

sour

ces

of u

ncer

tain

ty r

ele

vant

to

the

anal

ysis

of e

colo

gica

l exp

osu

re a

nd e

ffec

ts. R

eade

rs

are

also

ref

erre

d to

the

dis

cuss

ion

of u

ncer

tain

ties

in th

e e

xpos

ure

ass

ess

men

t gu

idel

ines

(U

.S. E

PA

, 199

2b).

Unc

erta

inty

Eva

luat

ion

in th

e A

nal

ysis

Ph

ase

Sou

rce

of U

nce

rtai

nty

Exa

mp

le A

nal

ysis

Pha

se S

trat

egie

s Sp

ecif

ic E

xam

ple

Co

nta

ct p

rin

cip

al i

nve

stig

ato

r o

r o

the

r st

ud

y p

art

icip

an

ts if

ob

ject

ive

s o

r m

eth

od

s o

f lit

era

ture

stu

die

s a

re u

ncl

ea

r. C

lari

fy w

he

the

r th

e s

tud

y w

as

de

sig

ne

d t

o

cha

ract

eri

ze lo

cal p

op

ula

tion

s o

r re

gio

na

l p

op

ula

tio

ns.

Un

cle

ar

com

mu

nic

ati

on

Do

cum

en

t d

eci

sio

ns

ma

de

du

rin

g t

he

co

urs

e o

f th

e a

sse

ssm

en

t.

Dis

cuss

ra

tio

na

le f

or

sele

ctin

g t

he

cri

tica

l to

xici

ty s

tud

y.

De

scri

pti

ve e

rro

rs

Ve

rify

th

at

da

ta s

ou

rce

s fo

llow

ed

a

pp

rop

ria

te Q

A/Q

C p

roce

du

res.

D

ou

ble

-ch

eck

ca

lcu

lati

on

s a

nd

da

ta e

ntr

y.

De

scri

be

he

tero

ge

ne

ity

usi

ng

po

int

est

ima

tes

(e.g

., c

en

tra

l te

nd

en

cy a

nd

hig

h

en

d)

or

by

con

stru

ctin

g p

rob

ab

ility

or

fre

qu

en

cy d

istr

ibu

tion

s.

Va

ria

bili

ty

Dif

fere

nti

ate

fro

m u

nc

ert

ain

ty d

ue

to

lack

o

f kn

ow

led

ge

.

Dis

pla

y d

iffe

ren

ces

in s

pe

cie

s se

nsi

tivi

ty

usi

ng

a c

um

ula

tive

dis

trib

utio

n f

un

ctio

n.

Co

llect

ne

ed

ed

da

ta.

De

scri

be

ap

pro

ach

es

use

d f

or

bri

dg

ing

g

ap

s a

nd

th

eir

ra

tio

na

les.

Dis

cuss

ra

tio

na

le f

or

usi

ng

a f

act

or

of

10

to

ext

rap

ola

te b

etw

ee

n a

low

est

-ob

serv

ed

-a

dve

rse

-eff

ect

leve

l (L

OA

EL

) a

nd

a

NO

EA

L.

Da

ta G

ap

s

Dif

fere

nti

ate

sci

en

ce-b

ase

d ju

dg

me

nts

fr

om

po

licy-

ba

sed

jud

gm

en

ts.

Use

sta

nd

ard

sta

tistic

al m

eth

od

s to

co

nst

ruct

pro

ba

bili

ty d

istr

ibu

tio

ns

or

po

int e

stim

ate

s (e

.g.,

co

nfi

de

nce

lim

its)

Eva

lua

te p

ow

er

of

de

sig

ne

d e

xpe

rim

en

ts

to d

ete

ct d

iffe

ren

ces.

Pre

sen

t th

e u

pp

er

con

fide

nce

lim

it o

n t

he

a

rith

me

tic m

ea

n s

oil

con

cen

tra

tion

, in

a

dd

itio

n t

o t

he

be

st e

stim

ate

of

the

a

rith

me

tic m

ea

n.

Co

llect

ad

dit

ion

al d

ata

.

Un

ce

rta

inty

ab

ou

t a

q

ua

nti

ty’s

tru

e v

alu

e

Ve

rify

loca

tion

of

sam

ple

s o

r o

the

r sp

ati

al

fea

ture

s.

Gro

un

d-t

ruth

re

mo

te s

en

sin

g d

ata

.

Dis

cuss

ke

y a

gg

reg

atio

ns

an

d m

od

el

sim

plif

ica

tio

ns.

M

od

el s

tru

ctu

re

un

cert

ain

ty (

pro

cess

m

od

els

) C

om

pa

re m

od

el p

red

icti

on

s w

ith d

ata

co

llect

ed

in t

he

sys

tem

of

inte

rest

.

Dis

cuss

co

mb

inin

g d

iffe

ren

t sp

eci

es

into

a

gro

up

ba

sed

on

sim

ilar

fee

din

g h

ab

its.

Eva

lua

te w

he

the

r a

lte

rna

tive

mo

de

ls

sho

uld

be

co

mb

ine

d f

orm

ally

or

tre

ate

d

sep

ara

tely

.

Pre

sen

t re

sult

s o

bta

ine

d u

sin

g a

lte

rna

tive

m

od

els

. U

nc

ert

ain

ty a

bo

ut

a

mo

de

l’s f

orm

. (e

mp

iric

al

mo

de

ls)

Co

mp

are

mo

de

l pre

dic

tio

ns

with

da

ta

colle

cte

d in

th

e s

yste

m o

f in

tere

st.

Co

mp

are

re

sults

of

a p

lan

t u

pta

ke m

od

el

wit

h d

ata

co

llect

ed

in t

he

fie

ld.

12

Ana

lysi

s P

hase

: Sou

rces

of U

ncer

tain

ty

•V

aria

bilit

y/h

eter

ogen

eity

.•

Unc

erta

inty

abo

ut a

qu

antit

y’s

tru

e va

lue.

•

Dat

a ga

ps.

•A

ddre

ssin

g so

urc

es o

f un

cert

aint

y:–

Var

iabi

lity

–pr

esen

t a

dist

ribut

ion

or s

pec

ific

per

cent

iles

from

it (

e.g.

, m

ean

and

95th

per

cent

ile).

–

Unc

erta

inty

(ab

out

its m

agni

tud

e, lo

catio

n, o

r tim

e of

occ

urre

nce)

–ta

ke

addi

tion

al m

easu

rem

ents

. D

escr

ibed

by

sam

plin

g er

ror

(or

varia

nce

in

exp

erim

ents

) or

mea

sure

men

t er

ror.

Kn

ow s

tudy

’s s

igni

fican

ce a

nd

pow

er.

–D

ata

gap

s –

usu

ally

brid

ged

with

a c

ombi

natio

n of

sci

entif

ic a

nal

yses

, sc

ient

ific

judg

men

t, a

nd p

erh

aps

pol

icy

dec

isio

ns.

Dat

a g

aps

mus

t be

no

ted.

•R

esul

ts c

an b

e pr

esen

ted

as a

ser

ies

of p

oint

est

imat

es w

ith

diff

eren

t as

pect

s of

unc

erta

inty

ref

lect

ed in

eac

h. C

lass

ical

sta

tistic

al

met

hod

s (e

.g.,

conf

iden

ce li

mits

, pe

rcen

tiles

) ca

n re

adily

des

crib

e pa

ram

eter

unc

erta

inty

.

Ana

lysi

s P

hase

•B

ack

to th

e sc

enar

io…

•N

ow to

go

in s

earc

h of

his

toric

al d

ata

that

cou

ld b

e in

corp

orat

ed in

to th

e r

isk

ass

essm

ent.

Firs

t, w

e w

ant t

o se

arch

for

info

rmat

ion

on z

inc

toxi

city

to th

e sp

ecifi

c fis

h

of in

tere

st. F

or e

xam

ple,

a s

earc

h on

zin

c pr

ovi

des

info

rmat

ion

on th

e to

xici

ty o

f a fo

rm o

f zin

c, z

inc

phos

phid

e. A

sea

rch

on G

oogl

e fo

und

EX

TO

XN

ET

(E

xten

sion

To

xici

ty N

etw

ork)

, wh

ich

pro

vide

s in

form

atio

n on

pes

ticid

es.

Zin

c ph

osp

hid

e (w

hic

h m

ay o

r m

ay

not b

e th

e fo

rm o

f zin

c in

the

stre

am)

is a

pe

stic

ide

with

a li

st o

f kn

own

toxi

citie

s. H

ere

is a

n e

xcer

pt fr

om th

at w

ebsi

te:

EX

TO

XN

ET

Res

ults

for

Zin

c P

hosp

hide

Toxi

colo

gica

l Effe

cts:

•A

cute

toxi

city

:Z

inc

phos

phid

e in

gest

ed o

rally

rea

cts

with

wat

er a

nd a

cid

in th

e st

omac

h an

d pr

oduc

es p

hosp

hine

gas

. Sym

ptom

s of

acu

te z

inc

phos

phid

e po

ison

ing

by in

gest

ion

incl

ude

naus

ea, a

bdom

inal

pai

n, ti

ghtn

ess

in c

hest

, exc

item

ent,

agita

tion,

and

chi

lls. O

ther

sy

mpt

oms

incl

ude

vom

iting

, dia

rrhe

a, c

yano

sis,

ral

es, r

estle

ssne

ss, a

nd fe

ver.

The

in

hala

tion

of z

inc

phos

phid

e or

its

brea

kdow

n pr

oduc

t pho

sphi

ne g

as m

ay r

esul

t in

vom

iting

, dia

rrhe

a, c

yano

sis,

rap

id p

ulse

, fev

er, a

nd s

hock

. In

rats

, the

LD

50 fo

r th

e te

chni

cal p

rodu

ct (8

0 to

90%

pur

e) is

40

mg/

kg, w

hile

the

LD50

val

ues

for

low

er

conc

entr

atio

n fo

rmul

atio

ns a

re s

light

ly h

ighe

r, in

dica

ting

low

erac

ute

toxi

city

. In

shee

p th

e LD

50 r

ange

s fro

m 6

0 to

70

mg/

kg. T

he c

ompo

und

is n

onirr

itatin

g to

the

skin

and

eye

s.

•C

hron

ic to

xici

ty:

Rat

s fe

d zi

nc p

hosp

hide

ove

r a

wid

e ra

nge

of d

oses

exp

erie

nced

toxi

c ef

fect

s. In

crea

sed

liver

, bra

in, a

nd k

idne

y w

eigh

ts, a

nd le

sion

son

thes

e or

gans

, wer

e no

ted

in r

ats

expo

sed

to a

roun

d 14

mg/

kg/d

ay. B

ody

hair

loss

, red

uctio

n in

bod

y w

eigh

t, an

d re

duct

ion

of fo

od in

take

wer

e al

l not

ed a

t 3.5

mg/

kg/d

ay. T

here

hav

e be

en n

o ob

serv

ed s

ympt

oms

of c

hron

ic p

oiso

ning

due

to z

inc

phos

phid

e ex

posu

re in

hum

ans.

•

Rep

rodu

ctiv

e ef

fect

s:

No

data

are

cur

rent

ly a

vaila

ble.

•

Ter

atog

enic

effe

cts:

N

o da

ta a

re c

urre

ntly

ava

ilabl

e.

•M

utag

enic

effe

cts:

No

data

are

cur

rent

ly a

vaila

ble

rega

rdin

g th

e m

utag

enic

ity o

f zin

c ph

osph

ide.

How

ever

, its

met

abol

ite, p

hosp

hine

, has

sho

wn

a co

ncen

trat

ion-

depe

nden

t in

crea

se in

chr

omos

omal

abe

rrat

ions

in s

tudi

es u

sing

hum

an ly

mph

ocyt

e cu

lture

s. T

hus,

its

mut

agen

icity

is u

ncle

ar.

EX

TO

XN

ET

Res

ults

for

Zin

c P

hosp

hide

Toxi

colo

gica

l Effe

cts:

•C

arci

noge

nic

effe

cts:

No

data

are

cur

rent

ly a

vaila

ble.

•

Org

an to

xici

ty:

Dam

age

to th

e ki

dney

s, th

e liv

er, a

nd th

e st

omac

h no

ted

in h

uman

s,

but o

nly

at h

igh

acut

e do

ses.

Zin

c ph

osph

ide

reac

ts w

ith w

ater

and

sto

mac

h ju

ices

to

rele

ase

phos

phin

e ga

s, w

hich

can

ent

er th

e bl

ood

stre

am a

nd a

dver

sely

affe

ct th

e lu

ngs,

live

r, k

idne

ys, h

eart

, and

cen

tral

ner

vous

sys

tem

. •

Fat

e in

hum

ans

and

anim

als:

Sm

all a

mou

nts

of th

e ro

dent

icid

e fe

d to

exp

erim

enta

l an

imal

s m

ay h

ave

prod

uced

an

80%

abs

orpt

ion

of z

inc

as w

ell.

Zin

c in

suf

ficie

nt

conc

entr

atio

ns m

ay h

ave

an e

met

ic e

ffect

[8].

Hyp

opho

sphi

te m

ay b

e ex

cret

ed in

the

urin

e as

a m

etab

olite

of z

inc

phos

phid

e. T

here

is li

ttle

tend

ency

for

the

com

poun

d to

co

ncen

trat

e in

livi

ng ti

ssue

, as

it is

rea

dily

con

vert

ed to

pho

sphi

ne.

Eco

logi

cal E

ffect

s:•

Effe

cts

on b

irds:

high

ly to

xic

to w

ild b

irds

The

mos

t sen

sitiv

e bi

rds

are

gees

e (L

D50

of

7.5

mg/

kg fo

r th

e w

hite

-fron

ted

goos

e), p

heas

ants

, mou

rnin

g do

ves,

qua

il, m

alla

rd

duck

s, a

nd th

e ho

rned

lark

are

als

o ve

ry s

usce

ptib

le to

this

com

poun

d. B

lack

bird

s ar

e le

ss s

ensi

tive.

•

Effe

cts

on a

quat

ic o

rgan

ism

s:hi

ghly

toxi

c to

fres

hwat

er fi

sh. T

he fi

sh s

peci

es

whi

ch h

ave

been

eva

luat

ed in

clud

e bl

uegi

ll su

nfis

h (L

C50

of 0

.8 m

g/L)

and

rai

nbow

tr

out (

LC50

of 0

.5 m

g/L)

. Car

p w

ere

also

foun

d to

be

susc

eptib

leto

zin

c ph

osph

ide,

es

peci

ally

in w

eakl

y ac

idic

wat

er.

•E

ffect

s on

oth

er o

rgan

ism

s:to

xic

to n

on-t

arge

t mam

mal

s w

hen

inge

sted

dire

ctly

. S

ome

of th

e to

xic

effe

cts

to p

reda

tors

hav

e be

en d

ue to

the

inge

stio

n of

zin

c ph

osph

ide

that

was

in th

e di

gest

ive

trac

t of t

he ta

rget

org

anis

m. S

tudi

es o

n se

cond

ary

orga

nism

s ha

ve fo

cuse

d on

coy

otes

, fox

, min

k, w

ease

ls,a

nd b

irds

of p

rey.

13

Ana

lysi

s P

hase

: Cha

ract

eriz

atio

n of

Exp

osur

e

•D

escr

ibes

pot

entia

l or

actu

al c

onta

ct o

r co

-occ

urre

nce

of s

tres

sors

with

re

cept

ors.

•

Bas

ed o

n m

easu

res

of e

xpos

ure

and

ecos

yste

m a

nd

rece

ptor

ch

arac

teris

tics

that

are

use

d to

an

alyz

e st

ress

or s

ourc

es, t

hei

rdi

stri

butio

n in

the

envi

ron

men

t, an

d th

e ex

tent

an

d pa

tter

n o

f con

tact

or

co-o

ccur

renc

e.

•P

rodu

ce a

su

mm

ary

expo

sure

pro

file

that

iden

tifie

s th

e re

cept

or (

i.e.,

the

expo

sed

ecol

ogic

al e

ntity

), d

escr

ibes

the

cour

se a

str

esso

r ta

kes

from

th

e so

urce

to

the

rece

ptor

(i.e

., th

e ex

posu

re p

ath

way

), a

nd

desc

ribe

s th

e in

tens

ity a

nd

spat

ial a

nd

tem

pora

l ext

ent

of c

o-oc

curr

ence

or

cont

act.

Incl

ude

s va

riab

ility

. •

Com

bin

ed w

ith a

n ef

fect

s pr

ofile

to

estim

ate

risks

.

Sou

rce(

s)•

Def

initi

on: t

he

plac

e w

her

e th

e st

ress

or o

rigi

nat

es o

r is

rel

ease

d (e

.g.,

a sm

okes

tack

, his

toric

ally

con

tam

inat

ed s

edim

ents

) or

the

man

agem

ent

prac

tice

or a

ctio

n (e

.g.,

dred

gin

g) th

at p

rodu

ces

stre

ssor

s.

•Lo

catio

n o

f a

sour

ce a

nd

the

envi

ron

men

tal m

edia

that

firs

t rec

eive

st

ress

ors

are

two

attr

ibut

es th

at d

eser

ve p

artic

ula

r at

ten

tion.

Que

stio

ns fo

r S

ourc

e D

escr

iptio

n

•W

here

doe

s th

e st

ress

or o

rigin

ate?

•W

hat

envi

ronm

enta

l med

ia fi

rst

rece

ive

stre

ssor

s?•

Doe

s th

e so

urce

gen

erat

e ot

her

con

stitu

ents

tha

t w

ill in

fluen

ce a

str

esso

r’s

even

tual

dis

trib

utio

n in

the

env

iron

men

t?•

Are

th

ere

oth

er s

ourc

es o

f th

e sa

me

stre

ssor

?•

Are

th

ere

bac

kgro

und

sou

rces

?•

Is t

he s

ourc

e st

ill a

ctiv

e?•

Doe

s th

e so

urce

pro

duce

a d

istin

ctiv

e si

gnat

ure

that

can

be

seen

in t

he

envi

ronm

ent,

org

anis

ms,

or

com

mun

ities

?

•A

dditi

onal

que

stio

ns fo

r in

trod

uctio

n of

bio

logi

cal

str

esso

rs:

•Is

the

re a

n op

por

tuni

ty f

or r

epea

ted

intr

oduc

tion

or e

scap

e in

toth

e n

ew

envi

ronm

ent?

•W

ill th

e or

gan

ism

be

pres

ent

on a

tra

nsp

orta

ble

item

?•

Are

th

ere

miti

gatio

n re

quir

emen

ts o

r co

nditi

ons

that

wou

ld k

ill o

r im

pair

the

org

anis

m b

efor

e en

try,

dur

ing

tran

spor

t, o

r at

the

por

t of

ent

ry?

Ana

lysi

s P

hase

: Cha

ract

eriz

atio

n of

Exp

osur

e

•B

ack

to t

he s

cena

rio…

•P

oten

tial s

ourc

es o

f th

ese

pol

luta

nts

mus

t be

iden

tifie

d. S

upp

osin

g th

at t

he

wat

ersh

ed o

f int

eres

t dr

aini

ng t

o th

e st

ream

was

sh

own

in t

he f

ollo

win

g ae

rial

ph

otog

raph

, se

vera

l pot

entia

l sou

rces

cou

ld b

e id

entif

ied.

For

th

e zi

nc

and

lead

, ro

ofin

g m

ater

ials

wou

ld b

e su

spec

t –

part

icul

arly

in t

he

area

w

here

gal

vani

zed

and

pai

nted

roo

fs w

ere

used

(su

ch a

s th

e in

dust

rial

are

a).

For

th

e nu

trie

nts,

pot

entia

l sou

rces

wou

ld in

clud

e le

akin

g se

wer

s (s

eptic

sy

stem

s, if

ap

plic

able

) an

d fe

rtili

zer

appl

icat

ions

. A

t th

at p

oint

, hi

stor

ical

da

ta o

n th

ese

sou

rces

wou

ld b

e co

llect

ed if

it e

xist

s.•

Foc

usin

g on

zin

c, f

ortu

nat

ely,

ear

lier

stud

ies

hav

e in

vest

igat

edth

e p

oten

tial

cont

ribut

ion

of z

inc

to s

torm

wat

er r

unof

f fr

om g

alva

nize

d ro

ofs,

such

as

the

one

that

tes

ted

sim

ulat

ed r

un

off f

rom

60+

-yea

r-ol

d g

alva

nize

d p

aint

ed

roof

ing

pan

els.

A r

evie

w o

f thi

s st

udy

show

ed t

hat

the

“sp

raye

d”ca

teg

ory

was

a s

imul

ated

rai

nfa

ll w

here

th

e p

anel

s w

ere

“rai

ned

on

”fo

r th

ree

day

s in

term

itten

tly.

Thi

s w

ould

be

usef

ul d

ata,

esp

ecia

lly if

sto

rmw

ater

is a

po

tent

ial s

ourc

e.•

Oth

er s

ourc

es o

f dat

a m

ay in

clud

e ru

nof

f dat

a co

llect

ed in

th

at w

ater

shed

or

in s

imila

r w

ater

shed

s. I

n th

e U

nite

d S

tate

s, a

rel

ativ

ely-

new

too

l cal

led

the

Nat

ion

al S

torm

wat

er Q

ual

ity D

atab

ase

(NS

QD

) h

as b

een

dev

elop

ed.

Thi

s da

tab

ase

pre

sent

s su

mm

arie

s of

mon

itori

ng d

ata

colle

cted

by

mun

icip

aliti

es

as p

art

of t

hei

r re

qui

rem

ents

for

th

eir

Ph

ase

I N

PD

ES

per

mit.

The

dat

abas

e ca

n b

e fo

und

at:

http

://rp

itt.e

ng.u

a.ed

u/R

esea

rch/

ms4

/mai

nms4

.sht

ml.

Ana

lysi

s P

hase

: Cha

ract

eriz

atio

n of

Exp

osur

e

•D

istr

ibut

ion

of th

e S

tres

sors

or

Dis

turb

ed

Env

ironm

ent

•D

escr

ibe

the

spa

tial a

nd te

mpo

ral d

istr

ibu

tion

of

stre

ssor

s in

the

en

viro

nmen

t. –

For

ph

ysic

al s

tres

sors

that

dire

ctly

alte

r or

elim

inat

e po

rtio

nsof

th

e en

viro

nm

ent,

the

asse

ssor

des

crib

es th

e te

mpo

ral a

nd

spat

ial d

istr

ibu

tion

of th

e di

stu

rbed

env

iron

men

t. –

Bec

ause

exp

osur

e oc

curs

wh

en r

ecep

tors

co-

occu

r w

ith o

r co

ntac

t str

esso

rs, t

his

ch

arac

teri

zatio

n is

a p

rere

quis

ite f

or

estim

atin

g ex

posu

re.

–S

tres

sor

dist

ribut

ion

in th

e en

viro

nm

ent i

s ex

amin

ed b

y ev

alu

atin

g pa

thw

ays

from

the

sour

ce a

s w

ell a

s th

e fo

rmat

ion

an

d su

bseq

uen

t dis

trib

utio

n o

f sec

onda

ry s

tres

sors

.

•S

tres

sors

can

be

tran

spor

ted

via

man

y pa

thw

ays

.

14

Que

stio

ns to

Ask

in E

valu

atin

g S

tres

sor

Dis

trib

utio

n

•W

hat a

re th

e im

port

ant t

rans

port

pat

hw

ays

?

•W

hat c

hara

cter

istic

s of

the

stre

ssor

influ

ence

tr

ansp

ort?

•W

hat c

hara

cter

istic

s of

the

ecos

yste

m w

ill

influ

ence

tran

spor

t?

•W

hat s

econ

dary

str

esso

rs w

ill b

e fo

rmed

?•

Whe

re w

ill th

ey b

e tr

ansp

orte

d?

Gen

eral

Mec

hani

sms

of T

rans

port

and

Dis

pers

al

Ph

ysic

al, c

hem

ical

, an

d b

iolo

gic

al s

tres

sors

:•

By

air

curr

ent

•In

sur

face

wat

er (

rive

rs, l

akes

, str

eam

s)•

Ove

r an

d/or

thro

ugh

the

soil

surf

ace

•T

hrou

gh g

roun

d w

ater

Pri

mar

ily c

hem

ical

str

esso

rs:

•T

hrou

gh th

e fo

od w

ebP

rim

arily

bio

log

ical

str

esso

rs:

•S

plas

hin

g or

ra

indr

ops

•H

uman

act

ivity

(b

oats

, cam

pers

)•

Pas

sive

tran

smitt

al b

y ot

her

orga

nis

ms

•B

iolo

gica

l vec

tors

Ana

lysi

s P

hase

: Cha

ract

eriz

atio

n of

Exp

osur

e

•F

or a

che

mic

al s

tres

sor,

the

eva

luat

ion

usu

ally

beg

ins

by

dete

rmin

ing

into

wh

ich

med

ia it

can

par

titio

n. K

ey

cons

ider

atio

ns

incl

ude

phys

icoc

hem

ical

pro

pert

ies

such

as

sol

ubili

ty a

nd v

apor

pre

ssur

e. B

ioac

cum

ulat

ion

and

biom

agni

ficat

ion

also

mus

t be

con

side

red.

•

The

attr

ibut

es

of p

hys

ical

str

ess

ors

also

influ

ence

whe

re

the

y w

ill g

o.•

The

dis

pers

ion

of b

iolo

gic

al s

tre

ssor

s ca

n be

des

crib

ed

in tw

o w

ays

: diff

usio

n an

d ju

mp-

disp

ersa

l. D

iffus

ion

invo

lve

s a

grad

ual s

prea

d fr

om th

e es

tabl

ishm

ent s

ite

and

is p

rimar

ily a

func

tion

of r

epro

duct

ive

rat

es a

nd

mot

ility

. Jum

p-di

sper

sal i

nvo

lves

err

atic

spr

eads

ove

r pe

riod

s of

tim

e, u

sual

ly b

y m

eans

of a

vec

tor.

•

Eco

syst

em c

hara

cter

istic

s in

fluen

ce th

e tr

ansp

ort o

f all

type

s of

str

ess

ors.

Ana

lysi

s P

hase

: Cha

ract

eriz

atio

n of

Exp

osur

e

Bac

k to

the

scen

ario

…•

For

zin

c ph

osph

ide

(fro

m E

XT

OX

NE

T)…

. Th

ese

data

may

be

used

to

pre

dict

fat

e an

d tr

ansp

ort

of z

inc

phos

phid

e in

the

envi

ron

men

t•

Phy

sica

l Pro

pert

ies:

•

App

eara

nce:

Zin

c ph

osph

ide

is a

n a

mor

phou

s bl

ack-

grey

pow

der

with

a g

arlic

-lik

e od

or [1

]. It

is s

tabl

e w

hen

dry

an

d de

com

pose

s in

m

oist

air.

•

Che

mic

al N

ame:

triz

inc

diph

osph

ide

•C

AS

Num

ber:

13

14-8

4-7

•M

olec

ular

Wei

ght:

258

.09

•W

ater

Sol

ubili

ty:

Pra

ctic

ally

inso

lubl

e in

wat

er (

deco

mpo

ses

slow

ly)

•S

olub

ility

in O

ther

Sol

vent

s:P

ract

ical

ly in

solu

ble

in a

lcoh

ol;

slig

htly

sol

ubl

e in

ben

zen

e an

d ca

rbon

dis

ulfi

de

•M

eltin

g P

oint

: >

420

C

•V

apor

Pre

ssur

e:N

eglig

ible

in th

e dr

y st

ate

(as

solid

)

•P

artit

ion

Coe

ffici

ent:

Not

Ava

ilabl

e •

Ads

orpt

ion

Coe

ffici

ent:

Not

Ava

ilabl

e

15

Ana

lysi

s P

hase

: Cha

ract

eriz

atio

n of

Exp

osur

e

•E

valu

atin

g S

eco

nd

ary

Str

esso

rs.

•F

or c

hem

ical

s, u

sual

ly f

ocus

on

met

abol

ites,

bio

degr

adat

ion

prod

ucts

, or

ch

emic

als

form

ed th

rou

gh a

biot

ic p

roce

sses

. •

Can

als

o be

for

med

thro

ugh

eco

syst

em p

roce

sses

. –

Fie

ld r

ates

may

diff

er g

reat

ly fr

om la

bor

ator

y ra

tes!

Als

o m

ay n

ot b

e ab

le t

o ef

fect

ivel

y re

plic

ate

field

pro

cess

in a

lab

orat

ory!

•

Phy

sica

l dis

turb

ance

s ca

n a

lso

gen

erat

e se

con

dary

str

esso

rs. T

ask

is t

o id

entif

y th

e sp

ecifi

c co

nse

quen

ces

that

will

aff

ect t

he

asse

ssm

ent e

ndp

oint

. –

The

rem

oval

of r

ipar

ian

veg

etat

ion,

for

exa

mpl

e, c

an g

ener

ate

man

y se

cond

ary

stre

ssor

s, in

clud

ing

incr

ease

d nu

trie

nts,

str

eam

tem

pera

ture

, se

dim

enta

tion,

and

alte

red

stre

am fl

ow.

How

ever

, it

may

be

the

tem

pera

ture

ch

ang

e th

at is

mos

t re

spon

sibl

e fo

r ad

ult

salm

on m

orta

lity

in a

par

ticul

ar s

trea

m.

•B

ack

to th

e sc

ena

rio…

•H

ere

is w

her

e w

e w

ould

mea

sure

BO

D5

. Th

e de

pres

sion

of

the

stre

am’s

dis

solv

ed o

xyge

n is

a s

econ

dary

str

esso

r on

our

fis

h o

f in

tere

st.

Ana

lysi

s P

hase

: Cha

ract

eriz

atio

n of

Exp

osur

e

•D

escr

ibe

Con

tact

or

Co-

Occ

urre

nce

•E

xten

t and

pa

ttern

of c

o-oc

curr

ence

or

cont

act b

etw

een

st

ress

ors

and

rec

epto

rs (

i.e.,

exp

osu

re).

•

Thi

s is

crit

ical

—if

ther

e is

no

exp

osu

re, t

here

can

be

no

risk.

•

Incl

ude

situ

atio

ns

whe

re e

xpo

sure

may

occ

ur in

the

fu

ture

, wh

ere

exp

osur

e ha

s oc

curr

ed in

the

pas

t bu

t is

not c

urre

ntly

evi

dent

(e.

g.,

in s

ome

retr

ospe

ctiv

e

asse

ssm

ents

), a

nd w

here

eco

syst

em c

ompo

nent

s im

port

ant f

or fo

od o

r ha

bita

t are

or

may

be

exp

osed

, re

sulti

ng

in im

pact

s to

the

valu

ed e

ntity

. •

Exp

osu

re c

an b

e d

esc

ribed

in te

rms

of s

tre

ssor

and

re

cept

or c

o-oc

curr

ence

, act

ual s

tre

ssor

con

tact

with

re

cept

ors,

or

stre

ssor

upt

ake

by

a re

cept

or.

Que

stio

ns T

o A

sk in

Des

crib

ing

Con

tact

or

Co-

Occ

urre

nce

•M

ust t

he r

ecep

tor

actu

ally

con

tact

the

stre

ssor

fo

r ad

vers

e ef

fect

s to

occ

ur?

•M

ust t

he s

tres

sor

be ta

ken

up in

to a

rec

epto

r fo

r ad

vers

e ef

fect

s to

occ

ur?

•W

hat c

hara

cter

istic

s of

the

rece

ptor

s w

ill

influ

ence

the

exte

nt o

f con

tact

or

co-o

ccur

renc

e?

•W

ill a

bio

tic c

hara

cter

istic

s of

the

envi

ronm

ent

influ

ence

the

exte

nt o

f con

tact

or

co-o

ccur

renc

e?

•W

ill e

cosy

stem

pro

cess

es o

r co

mm

unity

-leve

l in

tera

ctio

ns in

fluen

ce th

e ex

tent

of c

onta

ct o

r co

-oc

curr

ence

?

Ana

lysi

s P

hase

: Cha

ract

eriz

atio

n of

Exp

osur

e

•M

ost

stre

ssor

s m

ust

cont

act

rece

ptor

s to

cau

se a

n ef

fect

. F

unct

ion

of a

mou

nt o

r ex

tent

of s

tres

sor

in e

nvi

ronm

enta

l and

act

ivity

or

beh

avio

r of

th

e re

cept

ors.

–

For

bio

logi

cal s

tres

sors

, con

tact

ass

umed

to o

ccur

in a

reas

and

dur

ing

times

whe

re

the

stre

ssor

and

rec

epto

r ar

e bo

th p

rese

nt. M

ode

of tr

ansm

issi

onim

port

ant!

–F

or c

hem

ical

s, c

onta

ct is

qua

ntifi

ed a

s th

e am

ount

of a

che

mic

alin

gest

ed, i

nhal

ed, o

r in

mat

eria

l app

lied

to th

e sk

in (

pote

ntia

l dos

e).

–F

or in

gest

ed m

edia

(fo

od, s

oil),

mod

eled

or m

easu

red

conc

entr

atio

ns c

ombi

ned

with

as

sum

ptio

ns o

r pa

ram

eter

s de

scrib

ing

the

cont

act r

ate

(U.S

. EP

A,1

993b

).•

Som

e st

ress

ors

mus

t no

t on

ly b

e co

ntac

ted

but

also

mus

t be

inte

rnal

ly

abso

rbed

. U

ptak

e is

usu

ally

ass

esse

d by

mod

ifyin

g an

est

imat

e of

cont

act

with

a

fact

or in

dica

ting

the

prop

ortio

n of

th

e st

ress

or t

hat

is a

vaila

ble

for

upta

ke (

the

bioa

vaila

ble

frac

tion)

or

actu

ally

ab

sorb

ed.

•A

biot

ic a

ttrib

utes

may

incr

ease

or

dec

reas

e th

e am

ount

of

a st

ress

or c

onta

cted

by

rec

epto

rs.

Bio

tic in

tera

ctio

ns

can

also

influ

ence

exp

osur

e.

•T

hree

dim

ensi

ons

shou

ld b

e co

nsid

ered

wh

en e

stim

atin

g ex

pos

ure

: in

ten

sity

, tim

e, a

nd s

pac

e.–

Inte

nsity

may

be

expr

esse

d as

the

amou

nt o

f che

mic

al c

onta

cted

per

day

or

the

num

ber

of p

atho

geni

c or

gani

sms

per

unit

area

. –

The

tem

pora

l dim

ensi

on o

f exp

osur

e ha

s as

pect

s of

dur

atio

n, fr

eque

ncy,

and

tim

ing.

D

urat

ion

can

be e

xpre

ssed

as

the

time

over

whi

ch e

xpos

ure

occu

rs, s

ome

thre

shol

d in

tens

ity is

exc

eede

d, o

r in

tens

ity is

inte

grat

ed.

–S

patia

l ext

ent m

ost c

omm

only

exp

ress

ed in

term

s of

are

a (e

.g.,

hect

ares

of p

aved

ha

bita

t, sq

uare

met

ers

that

exc

eed

a pa

rtic

ular

che

mic

al th

resh

old)

.

16

Ana

lysi

s P

hase

: Cha

ract

eriz

atio

n of

Exp

osur

e

•B

ack

to th

e sc

enar

io…

•C

onta

ct is

a c

ritic

al v

aria

ble

in th

is r

isk

ass

essm

ent.

Bec

ause

sto

rmw

ater

run

off i

s a

conc

ern,

sam

plin

g ne

eds

to e

ncom

pass

bot

h d

ry-

and

wet

-wea

ther

flow

s. In

ad

ditio

n, t

o m

inim

ize

the

cost

of m

anag

emen

t act

ion

s,

the

sour

ces

of c

once

rn in

the

wa

ters

hed

nee

d to

be

id

entif

ied.

For

exa

mpl

e, fo

r th

e zi

nc a

nd le

ad, t

he

indu

stri

al a

rea

of th

e si

te is

of m

ost c

once

rn. S

ampl

ing

for

thes

e pa

ram

eter

s m

ay b

e ta

rge

ted

for

tha

t loc

atio

n.

•In

ord

er to

app

ropr

iate

ly q

uant

ify th

e c

ontr

ibut

ions

from

th

e va

rious

so

urce

s in

the

wat

ersh

ed, a

sta

tistic

ally

-so

und

sam

plin

g pl

an w

ill n

eed

to b

e de

velo

ped.

Ana

lysi

s P

hase

: Cha

ract

eriz

atio

n of

Exp

osur

e

•E

xpos

ure

Pro

file

•E

xpos

ure

desc

ribe

d in

ter

ms

of in

ten

sity

, spa

ce,

and

time

in u

nits

th

at c

an b

e co

mbi

ned

with

the

effe

cts

asse

ssm

ent.

•S

um

mar

ize

path

s of

str

esso

rs fr

om th

e so

urc

e to

the

rece

ptor

s,

com

plet

ing

the

expo

sure

pat

hw

ay.

•A

sses

sor

expl

ain

s h

ow e

ach

of th

e th

ree

gen

eral

dim

ensi

ons

of

expo

sure

(in

tens

ity, t

ime,

an

d sp

ace)

was

trea

ted.

Th

e pr

ofile

sh

ould

al

so d

escr

ibe

how

exp

osu

re c

an v

ary

depe

ndi

ng

on r

ecep

tor

attr

ibut

es o

r st

ress

or le

vels

.

•T

he

expo

sure

pro

file

shou

ld s

um

mar

ize

impo

rtan

t unc

erta

intie

s (e

.g.,

lack

of

know

ledg

e). I

n p

artic

ula

r, th

e as

sess

or s

hou

ld:

–Id

entif

y ke

y as

sum

ptio

ns a

nd

des

crib

e h

ow t

hey

wer

e h

andl

ed–

Dis

cuss

(an

d qu

antif

y, if

pos

sibl

e) t

he m

agni

tud

e of

sam

plin

g an

d/or

m

easu

rem

ent

erro

r–

Iden

tify

the

mos

t se

nsiti

ve v

aria

bles

influ

enci

ng e

xpos

ure

–Id

entif

y w

hich

unc

erta

intie

s ca

n b

e re

duce

d th

rou

gh t

he c

olle

ctio

n of

m

ore

dat

a.

Que

stio

ns A

ddre

ssed

by

the

Exp

osur

e P

rofil

e

•H

ow

doe

s ex

posu

re o

ccur

?

•W

hat i

s ex

pose

d?•

Ho

w m

uch

exp

osur

e oc

curs

? W

hen

and

whe

re

does

it o

ccur

?

•H

ow

doe

s ex

posu

re v

ary?

•H

ow

unc

erta

in a

re th

e ex

posu

re e

stim

ates

?

•W

hat i

s th

e lik

elih

ood

that

exp

osur

e w

ill o

ccur

?

Ana

lysi

s P

hase

: Cha

ract

eriz

atio

n of

Effe

cts

•Li

nk s

tres

sor

effe

cts

to a

sses

smen

t en

dpoi

nts

. •

Eva

luat

e h

ow e

ffec

ts c

han

ge w

ith v

aryi

ng

stre

ssor

leve

ls.

Res

pons

e A

naly

sis

•E

xam

ines

thre

e pr

imar

y el

emen

ts: t

he

rela

tions

hip

bet

we

en s

tres

sor

leve

ls a

nd

ecol

ogic

al e

ffec

ts, t

he

plau

sibi

lity

that

eff

ects

may

occu

r or

are

occ

urrin

g as

a r

esu

lt of

exp

osur

e to

str

esso

rs, a

nd

linka

ges

betw

een

mea

sura

ble

effe

cts

and

asse

ssm

ent

endp

oint

s w

hen

the

latt

er c

ann

ot b

e di

rect

ly m

easu

red.

Str

esso

r-R

esp

on

se A

nal

ysis

•A

.k.a

. in

hu

man

ris

k as

sess

men

t, do

se-r

espo

nse

rel

atio

nsh

ips

in

hum

an r

isk

asse

ssm

ent

•D

epen

d on

the

scop

e an

d n

atur

e of

the

risk

asse

ssm

ent a

s de

fined

in p

robl

em f

orm

ula

tion

and

refle

cted

in th

e an

alys

is p

lan

. •

Cur

ve s

hap

e m

ay b

e n

eede

d to

det

erm

ine

the

pres

ence

or

abse

nce

of

an

eff

ects

thre

shol

d or

for

eval

uat

ing

incr

emen

tal r

isks

.

17

A s

impl

e e

xam

ple

of a

str

esso

r-re

spon

se

rela

tions

hip

. ht

tp://

ww

w.s

afet

ylin

e.w

a.g

ov.a

u/in

stitu

te/le

vel2

/cou

rse1

6/le

ctur

e127

/l127

_02

.asp

Que

stio

ns fo

r S

tres

sor-

Res

pons

e A

naly

sis

•D

oes

the

asse

ssm

ent r

equi

re p

oint

es

timat

es o

r st

ress

or-r

espo

nse

curv

es?

•D

oes

the

asse

ssm

ent r

equi

re th

e es

tabl

ishm

ent o

f a “

no-e

ffect

”le

vel?

•W

ould

cum

ulat

ive

effe

cts

dist

ribut

ions

be

usef

ul?

•W

ill a

naly

ses

be u

sed

as in

put t

o a

proc

ess

mod

el?

Ana

lysi

s P

hase

: Cha

ract

eriz

atio

n of

Effe

cts

•M

edia

n E

ffect

Lev

els

•M

edia

n ef

fect

s ar

e th

ose

effe

cts

elic

ited

in 5

0%

of

the

test

or

gan

ism

s ex

pose

d to

a s

tres

sor,

typi

cally

ch

emic

al s

tres

sors

. M

edia

n ef

fect

con

cent

ratio

ns c

an b

e ex

pres

sed

in te

rms

of le

thal

ity

or m

orta

lity

and

are

know

n a

s LC

50 o

r LD

50, d

epen

din

g on

wh

eth

erco

ncen

trat

ions

(in

the

diet

or

in w

ater

) or

dos

es (

mg/

kg)

wer

e us

ed.

Med

ian

effe

cts

oth

er th

an le

thal

ity (

e.g.

, eff

ects

on

gro

wth

) ar

e ex

pres

sed

as E

C5

0 or

ED

50. T

he

med

ian

eff

ect l

evel

is a

lway

s as

soci

ated

with

a ti

me

para

met

er (

e.g.

, 24

or

48 h

ours

). B

ecau

seth

ese

test

s se

ldom

exc

eed

96 h

ours

, th

eir

mai

n va

lue

lies

in

eval

uat

ing

shor

t-te

rm e

ffec

ts o

f ch

emic

als.

Ste

phan

(19

77)

disc

usse

s se

vera

l sta

tistic

al m

eth

ods

to e

stim

ate

the

med

ian

effe

ct

leve

l.•

In a

dditi

on,

dose

-res

pons

e re

latio

nsh

ips

can

be u

sed

to c

ompa

re

resp

onse

s am

ong

orga

nis

ms

to d

eter

min

e w

hic

h o

rgan

ism

s h

ave

a gr

eate

r to

lera

nce

for

a pa

rtic

ula

r st

ress

or.

Exa

mpl

e do

se-r

espo

nse

curv

es.

A: H

uman

res

pons

e to

et

hano

l as

a fu

nctio

n of

dos

e; B

: per

cent

age

of m

ouse

pup

s w

ith

clef

t pal

ate

as a

re

sult

of th

e m

ater

ial d

ose

of 2

,3,7

,8-T

CD

D (

tetr

achl

oro

dibe

nzo-

p-di

oxin

) –

a ve

ry to

xic

diox

in a

nd th

e co

ntam

inan

t of c

once

rn in

Age

nt O

rang

e

18

Var

iatio

ns in

str

esso

r-re

spon

se r

elat

ions

hips

. The

se

curv

es

illus

trat

e a

rang

e of

res

pons

es to

pes

ticid

e ex

posu

re o

n pl

ant

surv

ival

, whe

re 2

/98R

and

10/

99S

are

var

iant

s of

the

sam

e w

ild o

at

spec

ies.

ags

psrv

34.a

gric

.wa.

gov.

au/..

./Has

hem

_Dh

amm

u.h

tm

Upt

ake

of m

ercu

ry a

nd th

e r

espo

nse

for

diff

eren

t le

vels

of

mer

cury

in th

e d

iet.

Ana

lysi

s P

hase

: Cha

ract

eriz

atio

n of

Effe

cts

•D

ata

from

ind

ivid

ual e

xper

imen

ts c

an b

e u

sed

to d

eve

lop

curv

es

and

po

int e

stim

ates

bo

th w

ith a

nd w

ithou

t as

soci

ate

d un

cert

ain

ty e

stim

ates

. •

Ad

van

tage

s of

cur

ve-f

ittin

g ap

proa

ches

: use

all

ava

ilabl

e e

xper

imen

tal d

ata;

ab

ility

to in

terp

olat

e to

val

ues

othe

r th

an th

e d

ata

po

ints

mea

sure

d.

•If

ext

rapo

latio

n is

req

uire

d, a

sse

ssor

s sh

ould

just

ify th

at

the

obse

rved

exp

erim

enta

l rel

atio

nsh

ips

rem

ain

valid

. A

disa

dva

ntag

e o

f cur

ve f

ittin

g is

tha

t the

req

uire

d am

ount

of

dat

a to

com

plet

e an

ana

lysi

s m

ay

not a

lwa

ys b

e a

vaila

ble.

•O

ther

mea

sure

s th

at a

re d

eriv

ed fr

om th

ese

curv

es

incl

ude

the

der

iva

tion

of n

o-ef

fect

leve

ls .

Ana

lysi

s P

hase

: Cha

ract

eriz

atio

n of

Effe

cts

•N

o-E

ffect

Lev

els

Der

ived

Fro

m S

tatis

tical

Hyp

othe

sis

Tes

ting

•S

tatis

tical

hyp

oth

esis

tes

ts h

ave

typi

cally

bee

n u

sed

with

chr

onic

ch

emic

al to

xici

ty t

ests

to

eval

uat

e m

ulti

ple

endp

oin

ts.

•F

or e

ach

endp

oint

, th

e ob

ject

ive

is to

det

erm

ine

the

high

est t

est

leve

l for

wh

ich

eff

ects

are

not

sta

tistic

ally

diff

eren

t fro

m th

eco

ntro

ls

(th

e n

o-ob

serv

ed-a

dver

se-e

ffec

t le

vel,

NO

AE

L) a

nd

the

low

est l

evel

at

wh

ich

eff

ects

wer

e st

atis

tical

ly s

ign

ifica

nt fr

om th

e co

ntr

ol(t

he

low

est-

obse

rved

-adv

erse

-eff

ect l

evel

, LO

AE

L).

•R

ange

bet

wee

n th

e N

OA

EL

and

the

LOA

EL

is s

omet

imes

cal

led

the

max

imu

m a

ccep

tabl

e to

xica

nt c

once

ntra

tion,

or

MA

TC

. Th

e M

AT

C,

wh

ich

can

als

o be

rep

orte

d as

the

geom

etric

mea

n of

the

NO

AE

L

and

the

LO

AE

L (

i.e.,

GM

AT

C),

pro

vide

s a

refe

renc

e w

ith w

hic

h to

co

mpa

re t

oxic

ities

of v

ario

us c

hem

ical

str

esso

rs.

•R

epor

ting

the

resu

lts o

f ch

ron

ic te

sts

in t

erm

s of

the

MA

TC

or

GM

AT

C h

as b

een

wid

ely

used

with

in th

e A

genc

y fo

r ev

alu

atin

g pe

stic

ides

an

d in

dust

rial

ch

emic

als

(e.g

., U

rban

an

d C

ook,

198

6;N

abh

olz,

199

1).

19

Ana

lysi

s P

hase

: Cha

ract

eriz

atio

n of

Effe

cts

Est

ablis

hin

g C

ause

-an

d-E

ffec

t Rel

atio

nsh

ips

(Cau

salit

y)•

Rel

atio

nsh

ip b

etw

een

cau

se (

one

or m

ore

stre

ssor

s) a

nd

effe

ct

(res

pons

e to

the

stre

ssor

[s])

.

Gen

eral

Crit

eria

for

Cau

salit

y (A

dapt

ed F

rom

Fox

, 199

1)

•C

riter

ia s

tron

gly

affir

min

g ca

usal

ity:

–S

tren

gth

of a

ssoc

iatio

n–

Pre

dict

ive

per

form

ance

–D

emon

stra

tion

of a

str

esso

r-re

spon

se r

elat

ions

hip

–C

onsi

sten

cy o

f as

soci

atio

n•

Crit

eria

pro

vidi

ng a

bas

is fo

r re

ject

ing

caus

ality

:–

Inco

nsis

tenc

y in

ass

ocia

tion

–T

empo

ral i

ncom

pat

ibili

ty–

Fac

tual

impl

ausi

bilit

y•

Oth

er r

elev

ant c

riter

ia:

–S

peci

ficity

of

asso

ciat

ion

–T

heor

etic

al a

nd

biol

ogic

al p

lau

sibi

lity

Ana

lysi

s P

hase

: Cha

ract

eriz

atio

n of

Effe

cts

•K

och’

s P

ostu

late

s (P

elc

zar

and

Rei

d, 1

972)

–A

pat

hog

en m

ust b

e co

nsi

sten

tly fo

und

in a

ssoc

iatio

n w

ith a

giv

en

dis

ease

.–

The

pat

hoge

n m

ust b

e is

olat

ed fr

om th

e ho

st a

nd

grow

n in

pur

e cu

lture

.–

Whe

n in

ocul

ated

into

test

an

imal

s, th

e sa

me

dise

ase

sym

ptom

s m

ust b

e e

xpre

ssed

.–

The

pat

hoge

n m

ust a

gain

be

isol

ated

from

the

test

or

gani

sm.

–O

ften

it is

nec

essa

ry to

ext

rapo

late

/est

imat

e ef

fect

s in

th

e fie

ld fr

om la

bora

tory

dat

a. T

he fo

llow

ing

text

bo

x pr

ovi

des

guid

ance

on

the

que

stio

ns

to c

onsi

der.

Que

stio

ns to

Con

side

r w

hen

Ext

rapo

latin

g F

rom

E

ffect

s O

bser

ved

in th

e La

bora

tory

to F

ield

Effe

cts

of

Che

mic

als

Exp

osur

e F

acto

rs

•H

ow w

ill e

nviro

nm

enta

l fat

e an

d tr

ansf

orm

atio

n of

the

chem

ical

af

fect

exp

osur

e in

the

field

?•

How

com

para

ble

are

expo

sure

con

ditio

ns

and

the

timin

g of

ex

posu

re?

•H

ow c

ompa

rabl

e ar

e th

e ro

ute

s of

exp

osur

e?•

How

do

abio

tic fa

ctor

s in

fluen

ce b

ioav

aila

bilit

y an

d ex

posu

re?

•H

ow li

kely

are

pre

fere

nce

or a

void

ance

beh

avio

rs?

•E

ffect

s fa

ctor

s:•

Wha

t is

know

n ab

out t

he

biot

ic a

nd

abio

tic f

acto

rs c

ontr

ollin

g po

pula

tions

of t

he

orga

nis

ms

of c

once

rn?

•T

o w

hat

deg

ree

are

criti

cal l

ife-s

tage

dat

a av

aila

ble?

•H

ow m

ay e

xpos

ure

to

the

sam

e or

oth

er s

tres

sors

in th

e fie

ld h

ave

alte

red

orga

nis

m s

ensi

tivity

?

Ana

lysi

s P

hase

: Cha

ract

eriz

atio

n of

Exp

osur

e

•S

tres

sor-

Res

pons

e P

rofil

e•

Obj

ectiv

e: e

nsu

re th

at th

e in

form

atio

n n

eede

d fo

r ris

k ch

arac

teri

zatio

n h

as b

een

col

lect

ed a

nd

eval

uat

ed.

Que

stio

ns A

ddre

ssed

by

the

Str

esso

r-R

espo

nse

Pro

file

•W

hat e

colo

gica

l en

titie

s ar

e af

fect

ed?

•W

hat i

s th

e n

atu

re o

f th

e ef

fect

(s)?

•W

hat i

s th

e in

tens

ity o

f th

e ef

fect

(s)?

•W

here

app

ropr

iate

, w

hat

is th

e tim

e sc

ale

for

reco

very

?•

Wha

t cau

sal i

nfor

mat

ion

lin

ks th

e st

ress

or w

ith a

ny

obse

rved

ef

fect

s?•

How

do

chan

ges

in m

easu

res

of e

ffec

ts r

elat

e to

ch

ange

s in

as

sess

men

t en

dpoi

nts?

•W

hat i

s th

e un

cert

ain

ty a

ssoc

iate

d w

ith th

e an

alys

is?

20

Ris

k C

hara

cter

izat

ion

•F

inal

ph

ase!

•A

sses

sors

can

now

cla

rify

the

rela

tions

hip

s be

twee

n s

tres

sors

, eff

ects

, an

d ec

olog

ical

en

titie

s an

d to

rea

ch c

oncl

usio

ns r

egar

din

g th

e oc

curr

ence

of

expo

sure

an

d th

e ad

vers

ity o

f ex

istin

g or

an

ticip

ated

ef

fect

s.

Ris

k E

stim

atio

n•

Inte

grat

e ex

posu

re a

nd

effe

cts

data

an

d ev

alu

ates

an

y as

soci

ated

unce

rtai

ntie

s.

•R

isk

estim

ates

can

be

deve

lope

d us

ing

one

or m

ore

of th

e fo

llow

ing

tech

niq

ues

: (1

) fie

ld o

bser

vatio

nal

stu

dies

, (2)

cat

egor

ical

ran

kin

gs, (

3)

com

pari

sons

of s

ingl

e-po

int

expo

sure

an

d ef

fect

s es

timat

es, (

4)

com

pari

sons

inco

rpor

atin

g th

e en

tire

stre

ssor

-res

pons

e re

latio

nsh

ip,

(5)

inco

rpor

atio

n of

var

iabi

lity

in e

xpos

ure

and/

or e

ffec

ts e

stim

ates

, an

d (6

) pr

oces

s m

odel

s th

at r

ely

part

ially

or

entir

ely

on th

eore

tical

ap

prox

imat

ion

s of

exp

osu

re a

nd

effe

cts.

Ris

k C

hara

cter

izat

ion

Fie

ld O

bser

vatio

nal S

tudi

es•

Fie

ld o

bse

rvat

ion

al s

tudi

es (

surv

eys)

can

ser

ve a

s ris

k es

timat

ion

tech

niq

ues

be

cau

se t

hey

pro

vid

e em

piric

al e

vid

ence

link

ing

expo

sure

to

effe

cts.

•

The

y m

easu

re b

iolo

gica

l cha

nges

in n

atur

al s

ettin

gs t

hrou

gh

colle

ctio

n of

ex

pos

ure

and

effe

cts

dat

a fo

r ec

olog

ical

ent

ities

iden

tifie

d in

pro

blem

fo

rmul

atio

n.

•A

dvan

tag

e of

fiel

d su

rvey

s is

th

at t

hey

can

be

use

d to

eva

luat

e m

ultip

le

stre

ssor

s an

d co

mpl

ex e

cosy

stem

rel

atio

nshi

ps t

hat

can

not

be

repl

icat

ed in

the

la

bor

ator

y.

•D

isad

vant

ages

: (1

) a

lack

of r

eplic

atio

n, (

2) b

ias

in o

btai

ning

rep

rese

ntat

ive

sam

ples

, or

(3

) fa

ilure

to

mea

sure

crit

ical

com

pon

ents

of t

he s

yste

m o

r ra

ndo

m

vari

atio

ns.

Fur

ther

, a

lack

of

obse

rved

effe

cts

in a

fiel

d su

rvey

may

occ

ur

beca

use

th

e m

easu

rem

ents

lack

th

e se

nsi

tivity

to

det

ect

ecol

ogic

al e

ffec

ts.

•S

ever

al a

ssum

ptio

ns

or q

ual

ifica

tions

nee

d to

be

clea

rly

artic

ulat

ed w

hen

de

scrib

ing

the

resu

lts o

f fie

ld s

urve

ys.

A p

rimar

y qu

alifi

catio

nis

wh

eth

er a

ca

usal

rel

atio

nshi

p b

etw

een

stre

ssor

s an

d ef

fect

s is

sup

por

ted.

C

ateg

orie

s an

d R

anki

ngs

•T

his

appr

oach

is m

ost

freq

uen

tly u

sed

whe

n ex

pos

ure

and

effe

cts

data

are

lim

ited

or a

re n

ot e

asily

exp

ress

ed in

qu

antit

ativ

e te

rms.

Ran

king

tec

hniq

ues

ca

n b

e us

ed t

o tr

ansl

ate

qual

itativ

e ju

dgm

ent

into

a m

ath

emat

ical

com

par

ison

.

Ris

k C

hara

cter

izat

ion:

Sin

gle-

Po

int E

xpos

ure

and

Effe

cts

Com

paris

ons

•Q

uot

ient

: ra

tio (

or q

uot

ient

) is

exp

ress

ed a

s an

exp

osur

e co

ncen

trat

ion

divi

ded

by a

n ef

fect

s co

ncen

trat

ion.

Qu

otie

nts

are

com

mon

ly u

sed

for

chem

ical

st

ress

ors,

whe

re r

efer

ence

or

ben

chm

ark

toxi

city

val

ues

are

wid

ely

avai

lab

le.

•A

dvan

tag

es:

sim

ple

and

quic

k to

use

and

ris

k as

sess

ors

and

man

ager

s ar

e fa

mili

ar w

ith it

. It

is a

n ef

ficie

nt,

inex

pen

sive

mea

ns o

f id

entif

yin

g hi

gh-

or lo

w-r

isk

situ

atio

ns

that

can

dir

ect

risk

man

agem

ent

deci

sion

s w

ithou

t th

en

eed

for

furt

her

in

form

atio

n.

•Li

mita

tions

: m

ay n

ot h

elp

in m

akin

g a

dec

isio

n re

qui

ring

an in

crem

enta

l qu

antif

icat

ion

of r

isks

. O

ther

lim

itatio

ns m

ay b

e ca

use

d by

def

icie

ncie

s in

the

pr

oble

m fo

rmul

atio

n an

d an

alys

is p

has

es.

•In

tera

ctio

ns a

nd e

ffect

s m

ay b

e cr

itica

l to

char

acte

rizi

ng t

he

full

exte

nt o

f im

pact

s fr

om e

xpos

ure

to

the

stre

ssor

s (e

.g.,

bio

accu

mul

atio

n, e

utro

phic

atio

n, lo

ss o

f pr

ey s

pec

ies,

opp

ortu

nitie

s fo

r in

vasi

ve s

pec

ies)

.•

Fin

ally

, in

mos

t ca

ses,

the

qu

otie

nt m

etho

d d

oes

not

exp

licitl

y co

nsid

er

unce

rtai

nty.

•

In h

uman

epi

dem

iolo

gy,

unce

rtai

nty

is in

her

ently

rep

orte

d in

a s

tudy

’s r

esu

lts.

The

res

ults

of

an e

pid

emio

logi

c st

udy

are

rep

orte

d as

a r

ate

ratio

, ei

ther

a

rela

tive

risk

or a

n od

ds

ratio

.

21

Ris

k C

hara

cter

izat

ion

Co

mp

aris

on

s In

corp

ora

tin

g t

he

En

tire

Str

esso

r-R

esp

on

se

Rel

atio

nsh

ip•

If do

se-r

espo

nse

curv

e av

aila

ble,

then

exa

min

e ris

ks a

ssoc

iate

d w

ith

vary

ing

leve

ls o

f ex

posu

re.

–A

pplic

able

mos

tly w

hen

out

com

e is

not

bas

ed o

n ex

ceed

ing

regu

lato

ry

leve

l/sta

ndar

d.

•A

dvan

tage

s of

com

paris

on o

f do

se-r

espo

nse

& c

um

. ex

posu

re:

–S

lop

e of

eff

ects

sh

ows:

•M

agni

tude

of c

hang

e in

effe

cts

due

to in

crem

enta

l cha

nges

in e

xpos

ure

•C

apab

ility

to p

redi

ct c

hang

es in

mag

nitu

de a

nd li

kelih

ood

of e

ffect

s fo

r di

ffere

nt

expo

sure

s.

•U

ncer

tain

ty s

how

n us

ing

erro

r bo

unds

on

stre

ssor

-res

pons

e or

exp

osur

e es

timat

es.

•Li

mita

tion

s:–

Lim

itatio

ns f

rom

the

pro

blem

form

ulat

ion

and

anal

ysis

ph

ases

may

limit

usef

uln

ess

of t

he r

esul

ts.

Exa

mpl

es:

–N

ot fu

lly c

onsi

der

ing

seco

ndar

y ef

fect

s–

Ass

umin

g ex

pos

ure

pat

tern

beh

ind

stre

ssor

-res

pon

se c

urve

is c

ompa

rabl

e to

the

env

iron

men

tal e

xpos

ure

pat

tern

–F

ailu

re t

o co

nsid

er u

ncer

tain

ties,

suc

h as

ext

rap

olat

ion

s fr

om t

este

d sp

ecie

s to

the

sp

ecie

s or

com

mun

ity o

f con

cern

.

Ris

k C

hara

cter

izat

ion

Co

mp

aris

on

s In

corp

ora

tin

g V

aria

bili

ty in

Exp

osu

re

and

/or

Eff

ects

•If

expo

sure

or

stre

ssor

-res

pons

e cu

rves

des

crib

e va

riab

ility

in

expo

sure

or

effe

cts,

then

man

y di

ffer

ent r

isk

estim

ates

can

be

calc

ulat

ed.

•E

xpos

ure

vari

abili

ty in

exp

osur

e us

ed to

est

imat

e ris

ks to

mod

erat

ely

or h

igh

ly e

xpos

ed o

rgan

ism

s.•

Eff

ects

var

iabi

lity

used

to e

stim

ate

risks

to a

vera

ge o

r se

nsi

tive

popu

latio

n m

embe

rs.

–A

dvan

tag

e: a

bilit

y to

pre

dict

cha

nges

in t

he

mag

nitu

de

and

likel

ihoo

d of

ef

fect

s fo

r di

ffer

ent

exp

osur

e sc

enar

ios �

com

parin

g di

ffer

ent

risk

man

agem

ent

optio

ns.

–Li

mita

tions

: in

crea

sed

dat

a re

quir

emen

ts;

impl

icit

assu

mpt

ion

that

full

rang

e of

var

iabi

lity

in t

he e

xpos

ure

and

effe

cts

dat

a is

rep

rese

nted

. –

Can

be

used

to

ran

k su

scep

tibili

ty if

mul

tiple

org

anis

ms

are

bei

ng

eval

uat

ed,

or it

will

allo

w a

rel

ativ

e ra

nkin

g of

th

e st

ress

ors/

haz

ard

s.

Ris

k C

hara

cter

izat

ion

Ap

plic

atio

n o

f P

roce

ss M

od

els

•U

sefu

l too

ls a

lso

in r

isk

char

acte

riza

tion.

•

Adv

anta

ge: C

onsi

der

“wh

at if

”sc

enar

ios;

for

ecas

t bey

ond

limits

of

obse

rved

dat

a.

•A

dvan

tage

: Pro

cess

mod

el c

an a

lso

cons

ider

sec

onda

ry e

ffec

ts.

•A

dvan

tage

: Som

e pr

oces

s m

odel

s ca

n fo

reca

st th

e co

mbi

ned

ef

fect

s of

mul

tiple

str

esso

rs.

•O

utpu

ts: p

oint

est

imat

es,

dist

ribut

ions

, or

corr

elat

ion

s.•

Cau

tion:

Inte

rpre

t with

car

e. M

ay im

ply

a h

igh

er le

vel o

f cer

tain

ty

than

is a

ppro

pria

te a

nd

are

all t

oo o

ften

vie

wed

with

out s

uffic

ient

at

ten

tion

to u

nde

rlyin

g as

sum

ptio

ns.

22

Ris

k C

hara

cter

izat

ion

Bac

k to

the

scen

ario

…•

Tw

o ty

pes

of p

roce

ss m

odel

s m

ay b

e of

inte

rest

her

e.

•O

ne

type

will

cou

ld p

redi

ct th

e fa

te a

nd

tran

spor

t of

thes

e po

lluta

nts

from

sou

rce

to u

ltim

ate

“dis

posa

l”in

the

urba

n st

ream

. •

Mod

els

also

can

be

run

a se

con

d tim

e to

det

erm

ine

wh

eth

er s

peci

fic

man

agem

ent o

ptio

ns w

ill b

e ef

fect

ive.

•

The

sec

ond

type

of

mod

el w

ill u

se th

e to

xici

ty a

nd

fate

-an

d-tr

ansp

ort

data

to

pred

ict w

het

her

tox

ic e

ffec

ts m

ay b

e se

en in

the

orga

nis

ms

in th

e st

ream

. Tox

icity

mod

els

will

allo

w f

or a

pre

dict

ion

to b

em

ade

as

to th

e ov

eral

l hea

lth o

f th

e st

ream

bot

h a

t th

e cu

rren

t co

ncen

trat

ions

an

d af

ter

sour

ce m

anag

emen

t has

bee

n

impl

emen

ted.

Ris

k C

hara

cter

izat

ion

Ris

k D

escr

ipti

on

•A

fter

gen

erat

ing

risk

estim

ate,

no

w in

terp

ret t

he

data

an

d di

scus

s it!

•

Ris

k de

scri

ptio

n: e

valu

atio

n o

f th

e lin

es o

f ev

iden

ce s

upp

ortin

gor

re

futin

g th

e ris

k es

timat

e(s)

an

d an

inte

rpre

tatio

n of

the

sign

ifica

nce

of

the

adve

rse

effe

cts

on th

e as

sess

men

t en

dpoi

nts.

•

Line

s of

Evi

denc

e•

Lin

es o

f ev

iden

ce s

how

how

con

clus

ions

wer

e re

ach

ed (

as w

ell a

s ad

dres

sin

g un

cert

aint

y)

•N

ot th

e ki

nd

of p

roof

dem

ande

d by

exp

erim

enta

lists

, nor

is it

a r

igor

ous

exam

inat

ion

of w

eigh

ts o

f ev

iden

ce.

•In

crea

sed

conf

iden

ce r

esul

ts fr

om m

ulti

ple

lines

of

evid

ence

. •

Thr

ee a

reas

to

cons

ider

wh

en e

valu

atin

g lin

es o

f ev

iden

ce: (

1) d

ata

adeq

uac

y an

d qu

ality

, (2)

deg

ree

and

type

of u

nce

rtai

nty,

an

d (3

) re

latio

n of

evi

denc

e to

orig

inal

qu

estio

ns.

•D

ata

qual

ity d

irec

tly in

fluen

ces

how

con

fiden

t ris

k as

sess

ors

can

be in

th

e re

sults

of

a st

udy

an

d co

nclu

sion

s th

ey m

ay d

raw

from

it. O

ne

maj

or

sour

ce o

f unc

erta

inty

com

es fr

om e

xtra

pola

tions

.

Ris

k C

hara

cter

izat

ion

•B

ack

to th

e sc

ena

rio…

•H

isto

rical

dat

a h

as s

how

n th

at th

e w

ater

shed

is li

kely

a s

ourc

e of

th

ese

pollu

tan

ts.

•T

he p

ollu

tant

s h

ave

been

mea

sure

d in

the

wat

er a

nd

sedi

men

t at

conc

entr

atio

ns o

f co

ncer

n ba

sed

on b

oth

his

toric

al to

xici

ty d

ata

and

on th

e ad

ditio

nal

tes

ts th

at w

ere

run

as p

art

of th

is r

isk

asse

ssm

ent.

•T

here

fore

, th

e so

urce

dat

a an

d ou

tfal

l dat

a, w

hen

com

bin

ed w

ith th

e to

xici

ty a

nd

stre

am c

once

ntr

atio

n da

ta, h

as li

kely

sh

own

that

on

e or

m

ore

of th

e po

lluta

nts

iden

tifie

d as

pos

sibl

e st

ress

ors

are

actu

al

stre

ssor

s to

the

syst

em.

•T

he m

anag

emen

t opt

ions

ava

ilabl

e to

con

trol

the

stre

ssor

s is

ou

tsid

e of

the

scop

e of

the

risk

asse

ssm

ent

but i

t is

inco

rpor

ated

into

th

e ris

k m

anag

emen

t de

cisi

on-m

akin

g fr

ame

wor

k.

Ris

k C

hara

cter

izat

ion

Det

erm

inin

g E

colo

gica

l Adv

ersi

ty•

Nex

t ste

p: in

terp

ret

wh

eth

er th

ese

chan

ges

are

cons

ider

ed a

dver

se.

•A

dver

se e

colo

gica

l eff

ects

: un

desi

rabl

e ch

ange

s be

caus

e th

ey a

lter

valu

ed s

tru

ctu

ral o

r fu

nctio

nal

attr

ibut

es o

f th

e ec

olog

ical

ent

ities

.•

Ris

k as

sess

men

t ev

alu

ates

the

degr

ee o

f ad

vers

ity u

sin

g fo

llow

ing

crite

ria:

–

Nat

ure

of e

ffect

s an

d in

ten

sity

of

effe

cts

–S

patia

l and

tem

por

al s

cale

–P

oten

tial f

or r

ecov

ery.

•It

is im

port

ant f

or r

isk

asse

ssor

s to

con

side

r bo

th th

e ec

olog

ical

an

d st

atis

tical

con

text

s of

an

eff

ect w

hen

eva

luat

ing

inte

nsity

. •

Rec

over

y ca

n be

eva

luat

ed in

spi

te o

f th

e di

ffic

ulty

in p

redi

ctin

g ev

ents

in e

colo

gica

l sys

tem

s.

•F

or e

xam

ple,

it is

pos

sibl

e to

dis

tingu

ish

chan

ges

that

are

usu

ally

re

vers

ible

(e.

g., s

trea

m r

ecov

ery

from

urb

an d

isch

arge

), fr

equ

ently

irr

ever

sibl

e (e

.g.,

esta

blis

hm

ent

of n

ew e

ner

gy g

radi

ents

in a

str

eam

du

e to

incr

ease

d di

sch

arge

en

ergy

pos

t-u

rban

izat

ion)

, an

d al

way

s irr

ever

sibl

e (e

.g.,

extin

ctio

n).

23

Ris

k C

hara

cter

izat

ion

Rep

ort

ing

Ris

ks•

At e

nd,

sh

ould

be

able

to e

stim

ate

ecol

ogic

al r

isks

, in

dica

te th

e ov

eral

l de

gree

of c

onfid

ence

in th

e ris

k es

timat

es, c

ite li

nes

of

evid

ence

su

ppor

ting

the

risk

estim

ates

, an

d in

terp

ret t

he

adve

rsity

of

ecol

ogic

al

effe

cts.

P

ossi

ble

Ris

k A

sses

smen

t Rep

ort E

lem

ents

•D

escr

ibe

risk

asse

ssor

/ris

k m

anag

er p

lan

nin

g re

sults

.•

Rev

iew

the

conc

eptu

al m

odel

an

d th

e as

sess

men

t en

dpoi

nts

.•

Dis

cuss

the

maj

or d

ata

sour

ces

and

anal

ytic

al p

roce

dure

s us

ed.

•R

evie

w th

e st

ress

or-r

espo

nse

and

expo

sure

pro

files

.•

Des

crib

e ris

ks to

en

dpoi

nts,

incl

udi

ng

risk

estim

ates

an

d ad

vers

ity

eval

uat

ions

.•

Rev

iew

unc

erta

inty

an

d ap

proa

ches

use

d to

add

ress

them

.–

Dis

cuss

sci

entif

ic c

onse

nsu

s (if

exi

sts)

in k

ey a

reas

of u

ncer

tain

ty.

–Id

entif

y m

ajor

dat

a ga

ps a

nd

indi

cate

if m

ore

data

wou

ld a

dd

sign

ifica

ntly

to th

e ov

eral

l con

fiden

ce in

the

asse

ssm

ent r

esu

lts.

–D

iscu

ss s

cien

ce p

olic

y ju

dgm

ents

/ass

um

ptio

ns u

sed

to b

ridg

e in

form

atio

n g

aps

and

the

basi

s fo

r th

ese

assu

mpt

ion

s.–

Dis

cuss

ho

w q

uan

titat

ive

unce

rtai

nty

an

alys

is a

re e

mbe

dded

.

Ris

k C

hara

cter

izat

ion

Rep

ort

Cle

ar, T

rans

pare

nt, R

easo

nabl

e, C

onsi

sten

t Ris

k C

hara

cter

izat

ions

•F

or c

larit

y:•

Be

brie

f; a

void

jarg

on.

•M

ake

lan

guag

e an

d or

gan

izat

ion

unde

rsta

nda

ble.

•

Ful

ly d

iscu

ss/e

xpla

in u

nusu

al is

sues

spe

cific

to th

is r

isk

asse

ssm

ent

.

•F

or tr

ansp

aren

cy:

•Id

entif

y th

e sc

ien

tific

con

clus

ions

sep

arat

ely

from

pol

icy

judg

men

ts.

•C

lear

ly a

rtic

ula

te m

ajor

diff

erin

g vi

ewpo

ints

of s

cien

tific

judg

men

ts.

•D

efin

e an

d ex

plai

n th

e ris

k as

sess

men

t pur

pose

.•

Ful

ly e

xpla

in a

ssu

mpt

ion

s an

d bi

ases

(sc

ien

tific

an

d po

licy)

.

Ris

k C

hara

cter

izat

ion

Rep

ort

Cle

ar, T

rans

pare

nt, R

easo

nabl

e, C

onsi

sten

t Ris

k C

hara

cter

izat

ions

•F

or r

easo

nabl

enes

s:•

Inte

grat

e al

l com

pon

ents

into

an

over

all c

oncl

usio

n o

f ris

k.•

Ack

now

ledg

e un

cert

ain

ties

and

assu

mpt

ion

s.•

Des

crib

e ke

y da

ta a

s ex

peri

men

tal,

stat

e-of

-th

e-ar

t, or

gen

eral

ly

acce

pted

sci

entif

ic k

now

led

ge.

•Id

entif

y re

ason

able

alte

rnat

ives

an

d co

ncl

usio

ns s

upp

orte

d by

dat

a.•

Def

ine

the

leve

l of

effo

rt (

e.g.

, qui

ck s

cree

n, e

xten

sive

ch

arac

teri

zatio

n)

and

reas

on(s

) fo

r se

lect

ing

leve

l of

effo

rt.

•F

or c

onsi

sten

cy w

ith o

ther

ris

k ch

arac

teriz

atio

ns:

•D

escr

ibe

how

the

risks

pos

ed b

y on

e se

t of

stre

ssor

s co

mpa

re w

ith th

e ris

ks p

osed

by

a si

mila

r st

ress

or(s

) or

sim

ilar

envi

ron

men

tal c

ondi

tion

s.•

Exa

mpl

e ec

olog

ical

ris

k as

sess

men

t pe

rfor

med

by

the

US

Arm

y C

orps

of

Eng

inee

rs c

an b

e fo

und

at: h

ttp:

//ww

w2

.mvr

.usa

ce.a

rmy.

mil/

um

r-iw

wsn

s/do

cum

ents

/env

16_s

um

mar

y.pd

f. T

his

sum

mar

y lin

ks th

e va

rious

pi

eces

into

a b

rief

nar

rativ

e th

at h

ighl

igh

ts th

e pe

rtin

ent f

indi

ngs

of

the

risk

asse

ssm

ent.