1. Persistence is a measure of

A. the concentration of a toxinB. the time it takes for a toxin

to degrade.C. how chemically reactive a

toxin is.D. how harmful a toxin is to an

organism.

the co

ncentra

tion of a to

xin

the time it

take

s for a

tox..

how chemica

lly re

active ...

how harmfu

l a to

xin is

to...

10%0%

15%

75%

2. The endocrine system is the system that

A. fights infectious disease.B. breaks down toxins in the

body.C. sends chemical messages

throughout the body.D. sends sensory input to the

brain.

fights infecti

ous dise

ase.

breaks down to

xins in t..

sends c

hemical m

essage

s...

sends s

ensory in

put to ...

0% 0%

76%

24%

3. Which type of toxin were used widely as insulators, fire retardants and lubricants between 1929 and 1977?A. BPAB. VOC’s such as

benzeneC. DDTD. PhthalatesE. PCB’s

BPA

VOC’s su

ch as b

enzene

DDT

Phthalate

sPCB’s

5% 5%

86%

5%0%

4. PCB’s A. are water solubleB. biomagnify C. biodegrade quicklyD. have been linked to liver

cancer and learning disabilities

E. A and BF. B and CG. B and D

are w

ater s

oluble

biomagnify

biodegrade quick

ly

have been lin

ked to liv

er...

A and B

B and C

B and D

5% 5%0%

65%

10%5%

10%

PCB’s are one of the POP’s (Persistent Organic Compounds). They do not degrade easily so PCB’s used decades ago are still in the environment.PCB’s are fat soluble so they bioaccumulate (remain in body tissue) and can therefore be biomagnified throughout the food chain.

5. A toxin that can damage brain, spinal cord and peripheral nerves is called

A. a neurotoxinB. a mutagenC. a teratogenD. an immunosuppressantE. an endocrine disruptor

77%

9% 9%0%

5%

6. Examples of neurotoxins include

A. LeadB. ArsenicC. Methyl mercuryD. All of the above

Lead

Arsenic

Meth

yl mercu

ry

All of t

he above

10%

75%

5%10%

7. What fraction of mercury comes from anthropogenic (human-caused) sources and what is the main source?

A. 2/3; pesticidesB. 1/10; pesticidesC. 2/3; coal-burningD. 1/10; coal-burning

2/3; p

esticid

es

1/10; p

esticid

es

2/3; c

oal-burn

ing

1/10; c

oal-burn

ing

15%5%

75%

5%

8. Humans can be exposed to mercury through

A. Consuming fish, esp. top-consumer fish like tuna.

B. Inhaling mercury vapors.

C. Eating beef and other red meat

D. Both A and B

Consuming fish

, esp

. top...

Inhaling m

ercury

vapors.

Eating beef a

nd other r

e...

Both A and B

20%

80%

0%0%

9. A chemical used to soften polyvinyl chloride (PVC) plastic and as a solvent in many consumer products like hair spray, body lotion and shampoo is

A. BPAB. DDTC. POPD. PhthalatesE. Cadmium

BPADDT

POP

Phthalate

s

Cadmium

50%

0%

10%

30%

10%

10. What chemical is used in water bottles, microwave dishes, and food and beverage can liners?

A. BPAB. DDTC. CadmiumD. Lead

BPADDT

CadmiumLe

ad

75%

5%5%

15%

Both phthalates and BPA are endocrine disruptors.

Both have recently been banned from products for infants.- Phthalates were banned as of 2010 for baby toys and BPA was banned from use in baby bottles and cans of baby formula. But both chemicals are in use in many other products.

11. Effects produced from a long-term, low-level exposure is called

A. acuteB. chronicC. pathologicalD. symptomaticE. synergistic

acute

chro

nic

pathologic

al

sympto

matic

synergisti

c

11%

68%

5%5%11%

12. Chemicals that cause changes in DNA are known as

A. teratogensB. mutagensC. antigensD. carcinogensE. gametogens

terato

gens

mutagens

antigens

carci

nogens

gameto

gens

0%

100%

0%0%0%

Mutagens may increase the risk of cancer because mutations But not all carcinogens cause mutations in genes- may promote the growth of cancer cells. So mutagen is the correct term for a substance that increases the rate of mutations.

13. The LD50 dose

A. shows a response in 50% of the population.

B. kills half of the population.C. has a threshold of 50%.D. is administered to 50% of

the population.

shows a

resp

onse in

50%...

kills half o

f the population.

has a th

resh

old of 50%.

is administ

ered to

50% of...

28%

0%

22%

50%

14. 50 parts per million (ppm) is equivalent to

A. 5 x 10-3 ppbB. 5 x 10-2 ppbC. 5000 ppbD. 50,000 ppbE. 500,000 ppb

5 x 10-3 ppb

5 x 10-2 ppb

5000 ppb

50,000 ppb

500,000 ppb

21%

16% 16%

42%

5%

15. Which of the following is equivalent to ppm?

A. mg/gB. g/mgC. kg/gD. g/kgE. mg/kgF. kg/mg

mg/gg/m

gkg/

gg/k

g

mg/kg

kg/mg

19% 19%

0%

38%

10%

14%

16. If the graph is a dose-response curve, what might be the labels of the x and y axes, respectively

A. Time; number of organismsB. Number of organisms; timeC. Dose concentration;

percent mortalityD. Percent mortality; Dose

concentrationTim

e; number o

f orga

nisms

Number of o

rganism

s; time

Dose co

ncentra

tion; per..

.

Percent m

ortality

; Dose

...

17%11%

67%

6%

17. Using the graph below, determine the LD50.

A. 7.5 mgB. 20 mgC. 25 mgD. 30 mg

7.5 mg

20 mg

25 mg

30 mg

5%11%

5%

79%

18. What is the threshold level for this toxin?

A. 30 mgB. 25 mgC. 20 mgD. 7.5 mgE. 0

30 mg

25 mg

20 mg

7.5 mg 0

29%

12%

0%

59%

0%

19. What is the TC50 for the toxin shown in the graph?

A. 0.1 µg/mLB. 9 µg/mLC. 15 µg/mLD. 80 µg/mL

0.1 µg/mL

9 µg/mL

15 µg/mL

80 µg/mL

6%0%

76%

18%

20. If a chemical with a concentration of 8 g/L is diluted in a serial dilution that is a 10 fold dilution for each step, what is the concentration after the fourth dilution?

A. 0.008 mg/LB. 0.08 mg/LC. 0.8 mg/LD. 8 mg/LE. 80 mg/L

0.008 mg/L

0.08 mg/L

0.8 mg/L

8 mg/

L

80 mg/

L

26%

21%

11%

5%

37%

Starting Concentration: 8 g/L or 8000 mg/L

1st dilution 0.8 g/L or 800 mg/L

2nd dilution 0.08 g/L or 80 mg/L

3rd dilution 0.008 g/L or 8 mg/L

4th dilution 0.0008 g/L or 0.8 mg/L

21. Which toxin is more toxic?

A. AB. B

A B

32%

68%

A

B

1. B2. C3. D4. G5. A6. D7. C8. D9. D10. A

11.B12.B13.B14.D15.E16.C17.B18.D19.C20.C