Air Toxics: Current Status, New Directions

Kenneth L. Mitchell, Ph.D.; ChiefAir Toxics Assessment & Implementation U.S. Environmental Protection AgencyAtlanta, Georgia

Good Afternoon!

• What are Air Toxics?

• Program Overview

• Current Status

• Future Directions

What do we mean by “Air Toxics?”

The Federal Clean Air Act

Six“Criteria” Pollutants

O3, NO2, SO2, PbCO, PM

Mobile Source Pollutants

21 Chemicals & Mixtures

HazardousAir Pollutants(Air Toxics)

187 Chemicals &Compounds

Why are air toxics a problem?

Millions of Sources

Sources/Populations Colocated

Some Persist & Bioaccumulate

Many are Highly Toxic

CancerKidney,Liver

Damage

Skin Rashes

Birth Defects,Miscarriages

Nervous System Damage

Developmental Problems in

Children

Cough,Throat

Irritation

Asthma,Chronic

Bronchitis

WIND DIRECTION

TRANSFORMATION

DRY DEPOSITIONEVAPORATION/

REENTRAINMENT

IN AIR

INGESTION

WET DEPOSITION

DISPERSION

B A

INTAKE/UPTAKEEXCRETION

OTHER NON-CANCER ENDPOINTS

CANCERTARGET

ORGAN/TISSUE

WIND DIRECTION

BIOACCUMULATIONIN FOOD

INHALATIONDERMAL

There Are Sources Everywhere!

Courtesy of Sustaining the Environment and Resources for Canadians

Types of SourcesTypes of Sources

Major Sources

10 TPY or more of one HAPOr

25 TPY or more of a combination of HAPS

Area Sources

Less than 10 TPY of one HAPOr

Less than 25 TPY of a combination of HAPS

Types of SourcesTypes of Sources

Indoor Sources

Not regulated but pose(on average) 3-5 times the concentrations of

outdoor air

Mobile Sources

On- and Off-road;Engines, fuels, and operation

all contribute to pollution;21 MSATs

Outdoor Air

THE NATIONAL AIR TOXICS PROGRAM(Stationary, Mobile, and Indoor Air Sources)

Risk Assessment Methods for

Facility Specific &Community-Scale

Risk Decision Criteria for

Facilities and Communities

Education and

Outreach

VoluntaryReduction

Options

SLT Program

Structure Design

RegulatoryApproaches

Achieve Meaningful ReductionsAt The Local Level

Residual Risk – Mandate from Congress

• Assess risks from stationary sources that emit air toxics after technology-based (MACT) standards are in place

• Set additional standards if MACT does not protect public health with an “ample margin of safety”

• Set additional standards if necessary to prevent adverse environmental effects

Residual Risk – Status

• Coke ovens – April 2005

• March 2006 – Industrial cooling towers– Magnetic tape– Ethylene oxide sterilizers– Gasoline distribution

• Dry cleaning – July 2006

• HON – December 2006

• Halogenated Solvents – December 2006

Residual Risk – New Directions

• Develop “total facility low-risk demonstration (TFLRD)” rule

• Develop comprehensive or generic residual risk rule (GRRR)

Area Sources – Current Status

• The Integrated Urban Strategy was published July 19, 1999– Identified chemicals of concern– Identified initial list of area source categories

• 70 source categories have been listed– Listing completed in November 2002– Source categories required to be “subject to

regulation”– 16 rules completed– 4 under court order

20 of the 70 Standards

Area Sources – Recent Additional Court Ordered Schedule

• Dec. 15, 2006 4 categories

• June 15, 2007 6 categories

• Dec. 15 2007* 10 categories

• June 15, 2008 10 categories

• Dec. 15, 2008 10 categories

• June 15, 2009 10 categories 50 Categories

*3 area source standards subject to CAA 112(c)(6) (related to PBT chemicals) must be promulgated by this date.

Area Sources – Future Directions

• National Rulemaking Approach– Establish national standards for

source categories that have a national level of concern

• Flexible Rulemaking Approach– Enact a rule, covering a set of

categories, that will regulate how categories are controlled at the local level based on local needs

– EPA will provide guidance on control approaches

Mobile Source Air Toxics (MSATs) – Current Status

• In March 2001, EPA published first MSAT rule

• Toxics emissions performance standard for gasoline– Refinery-specific baselines to ensure no

backsliding from 1998-2000 performance

• No additional standards for fuels or vehicles

• Identified data gaps and committed to additional research

• Committed to additional rulemaking to evaluate the need for and feasibility of additional controls

Mobile Source Air Toxics – Future Directions

• Proposed Rule signed on February 28, 2006

• Public hearing on April 12

• 60-day comment period (through May 30th)

• Final rule by February 9, 2007

Mobile Source Air Toxics – Future Directions

• Benzene content standard for gasoline

• Vehicle standards– Exhaust emissions– Evaporative emissions

• Gas can standards

Diesel Exhaust – Current and Future Directions

• Building on the successes of EPA’s regulatory and voluntary efforts to reduce emissions from diesel engines, EPA has created the National Clean Diesel Campaign (NCDC) – Successful implementation of the 2007 Highway Engine Rule and the

Clean Air Nonroad Diesel Rule

– Develop new emissions standards for locomotive and marine diesel engines

– Promote reduction of emissions for existing diesel engines through cost-effective and innovative strategies, including use of cleaner fuels, retrofitting and repairing existing fleets, idling reduction among others

Dr. Ken MitchellU.S. Environmental Protection Agency (404) 562-9065mitchell.ken@epa.gov

http://www.epa.gov/region4/air/airtoxic/index.htm

Thanks for your attention!