Inventory, Toxicity

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Inventory, Toxicity Benchmarking Subcommittees
Report to The Air Toxics Advisory Committee

• Maine Air Toxics Initiative
• November 18, 2005

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For More Information

• David Wright
• Air Toxics Emissions Inventory Prog, BAQ
• Maine DEP
• 207-287-6104 (phone)
• David.W.Wright_at_maine.gov
• http//www.maine.gov/dep/air/toxics/mati.htm

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Air Toxics Advisory Committees Phase I Goals

• Develop a final Air Toxics Priority List
• Use the lessons learned from developing the
  Strawman Air Toxics Priority list
• Gather available information to help determine
  whether or not Maine has an Air Toxics Problem

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Options for developing an ATPL

• Pounds emissions
• Toxicity-weighted emissions
• Emissions modeling

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NATA Modeling
AT Priority List
ASPEN
Characterizing Health Risks
HAPEM4
Emissions Inventory
RSEI Toxicity factor
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ATAC forms 3 Subcommittees

• Inventory Subcommittee determine emissions of
  Air Toxics from all significant source categories
• Toxicity Subcommittee establish toxicity rating
  scale for each Air Toxic
• Benchmarking Subcommittee- formulate a way to
  benchmark the toxicity-weighted emissions
  against some known risk standard

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Developing the AT Priority List
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Inventory Development

• Reviewed available AT inventories
• Selected 1999 National Emissions Inventory (1999
  NEI) - update to 2005
• Corrected and updated emissions
• Point Sources
• Forest Fires
• Foam Production
• Electroplating
• Tipping Floors
• Etc.

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Inventory Development (cont)

• Reviewed
• Activity Data
• Emission Factors
• Methodology
• Checked for double entries between different
  sectors (ie point area)

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Inventory Development (cont)

• back-filled emission factors

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Inventory Development (cont)

• back-filled emission factors
• Uncertainty e.g. toxicity-weighted emissions for
  acrolein for large wood combustion could be 400
  greater or 90 lower, if different emission
  factors were used.

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Toxicity Factor Development

• EPA Risk Screening Environmental Indicators
  (RSEI) model - Estimates impacts of TRI chemical
  releases, considering
• toxicity
• exposure
• population
• To develop Maine AT Priority List, Used only RSEI
  Toxicity Factor from the model

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Toxicity Factor Development

• Selected toxicity factors - EPAs Risk Screening
  Environmental Indicators Model (RSEI)
• Reviewed updated with latest Toxicology
  information
• Developed factors for missing Pollutants
• Polycyclic Organic Matter (POM) -CARB
• Diesel Particulate Matter (DPM)-CARB
• Dioxins/Furans-WHO TEFs

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Toxicity-Weighted Inventory

• HAP inventory - update to 2005
• Toxicity Factors - from Risk Screening
  Environmental Indicators (RSEI) model
• For Each Pollutant
• Lbs X Toxicity Factor Toxicity-Weighted
  Emissions
• Able to sum emissions of multiple pollutants by
  sector as well

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Toxicity-Weighted Emissions

• PTWE PV PT
• Where P one of n Air Toxic Pollutants
• PTWE Risk Weighted Emission of Air Toxic P
  (risk pounds-pollutant P / year)
• PV Volumetric Release of Air Toxic P
  (pounds-pollutant P/ year)
• PT Toxicity Factor of Air Toxic P from RSEI
  (unitless)

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Developing the AT Priority List
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Issue - Relative Risk VS Actual Risk

• Once relative risks are determined, how do we
  know which compounds pose an actual risk?
• Tried a couple of approaches

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Update 1996 NATA to Current Emissions

• Roughly update NATA using simplistic ratio
• 2005 risk / 2005 emissions 1996 Risk / 1996
  emissions
• 2005 risk (1996 Risk / 1996 emissions) / 2005
  emissions

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Use updated NATA to Benchmark relative risk to
actual risk
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Use updated NATA to Benchmark relative risk to
actual risk

• Screening-level approach - rough estimate of
  current risk
• Reasonable first step to help focus further
  action
• Does not provide definitive estimates of actual
  risk
• County-wide estimates does not consider
  hot-spots

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Alternative Approach

• Use updated NATA to approximate ambient air
  concentrations
• Compare pollutant concentrations to Maine Ambient
  Air Guidelines

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Developing the AT Priority List
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Reality Check - Air Monitoring

• Benzene Hotspots near roadways (mobile)

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Reality Check - Air Monitoring

• Low Ambient Concentrations of Metals in
  background locations

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Reality Check - Air Monitoring

• Insufficient Data on Acrolein
• High detection limit relative to guideline
• Difficult to sample Analyze due to short
  half-life

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Reality Check - Air Monitoring

• Background Pollutants from Historic Emissions
• carbon tetrachloride
• chloroform
• ethylene dibromide
• ethylene dichloride

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Transport of Air Toxics into Maine

• Mercury (Deposition)

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Transport of Air Toxics into Maine

• Reviewed AT monitoring data from 4 Ozone
  monitoring stations along New Eng. coast
• Benzene Concentrations V. Latitude Wind
  Direction
• Diurnal Benzene Tends
• Relative ranking of HAPs and VOCs
• Long-Lived AT concentrations due to local
  emissions and Regional Transport

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Qualitatively Assess other Factors-Persistence

• Manganese
• Lead
• Cadmium
• Chromium
• Arsenic
• Cyanide Compounds

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Qualitatively Assess other Factors-Bioaccumulatio
n

• Mercury
• Dioxin/Furans
• Brominated Flame Retardants

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Qualitatively Assess other Factors-Other

• PM from Nano-Technology
• Unknown ATs

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Developing the AT Priority List
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Recommended Air Toxics Priority List

• Based on the best information that is currently
  available
• Uncertainties - rough estimate of rank
• Pollutants may be added and deleted as new
  information comes to light and emission
  reductions are implemented
• Also able to rank source categories based on
  Tox-weighted emissions

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Conclusions

• Further evaluation of potential hot spots needed
  in vicinity of
• major roadways
• point sources
• concentrations of area sources.
• Most current air toxic emissions from combustion
  rather than manufacturing processes

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Conclusions (cont)

• As developing solutions, consider
• AT reductions from pending regulations
• Uncertainty in EFs and Tox Factors
• Risks are lower in Maine than in Southern New
  England
• MATI inventory more complete use caution when
  comparing to other inventories
• Further analysis need on effects of cumulative
  exposure to multiple Air Toxics

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Subcommittee Recommendations

• Adopt proposed Air Toxics Priority List and Basis
  Statement, as amended by the majority opinion and
  discussions at this meeting
• MATI to move to solutions exploration phase,
  while continuously improving the emission
  estimates with new information
• Appoint subcommittees to develop
• early actions
• long-term targeted strategy
• clear implementation goals and timeframes
• reduce Air Toxics to acceptable levels.

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Subcommittee Recommendations

• Strategies could include economic incentives,
  targeted pollution prevention programs, voluntary
  programs, enhancement of existing regulatory
  programs, new legislation at the state level,
  partnering with regional agencies to resolve
  interstate issues, or no action
• Subcommittees develop consensus recommendation or
  options
• ATAC to review subcommittee work make
  recommendations to the Commissioner
• Commissioner develops AT Action Plan

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Subcommittee Recommendations

• Subcommittee Communications
• refinement in ATPL concurrent with reduction
  strategy development
• Chairs of subcommittees must ensure timely
  communication of this information
• ATACs directive for each subcommittee must be
  clear so that the committees stay on track and
  focus on their objectives
• Full ATAC to make decisions affecting important
  issues

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Subcommittee Recommendations on Subcommittee
Formation

• Form Science Advisory Subcommittee
• Combination of existing Inventory, Toxicity and
  Benchmarking Subcommittees
• Undertake the 15 items recommended in
  Subcommittees Majority Report
• Form Stationary Sources Subcommittee
• Undertake the items recommended in Subcommittees
  Majority Report
• Form Mobile Sources Subcommittee
• Undertake the items recommended in Subcommittees
  Majority Report

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Discussion
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For More Information

• David Wright
• Bureau of Air Quality, DEP
• 17 SHS, Augusta, ME 04333-0017
• 207-287-6104
• David.W.Wright_at_Maine.Gov
• http//www.maine.gov/dep/air/toxics/mati.htm