Air toxics in Minnesota
The United States Environmental Protection Agency (EPA) defines air toxics as those pollutants that cause or may cause cancer or other serious health effects (such as reproductive or birth defects), or adverse environmental and ecological effects. Air toxics include, but are not limited to, the 188 Hazardous Air Pollutants (HAPs) specified in the 1990 Clean Air Act Amendments. The Clean Air Act does not require the U.S. EPA to establish enforceable regulatory standards for air toxic concentrations in the environment. Instead, the Clean Air Act requires the U.S. EPA to develop National Emission Standards for Hazardous Pollutants to reduce overall air toxic emissions.
To assess the health risks associated with air toxics concentrations in the environment, the MPCA uses guidelines called health benchmarks. These benchmarks come from a variety of sources including the Minnesota Department of Health’s Health Risk Values (HRVs), the EPA’s Integrated Risk Information System (IRIS), and California’s Office of Health Hazard Assessment.
To meet the MPCA Strategic Plan goal that Minnesota’s outdoor air is healthy for all to breathe, the MPCA works to ensure that concentrations of all air toxic pollutants in Minnesota are below health benchmarks. The MPCA uses air emissions inventory, monitoring, and air dispersion modeling data to quantify air toxics concentrations in the environment. MPCA programs such as air permitting, environmental review, and other agency air emission reduction programs use this information to prioritize air toxic emission reductions in Minnesota.
Air toxics sources
Sources of air pollutants are generally described in three basic categories:
Air toxics data
Air emissions are a quantity of air pollutants that are released from an air pollution source. Estimates of the amount of air toxics pollutants released by sources throughout Minnesota can be found at:
- Minnesota Air Toxics Emission Inventory – The statewide inventory of annual air toxics emissions from point, nonpoint, and mobile air emission sources, reported every 3-years.
- U.S. EPA National Emissions Inventory – The national inventory of annual air toxics emissions is calculated every 3-years from air emissions data submitted by State, Local, and Tribal air agencies.
- U.S. EPA Toxics Release Inventory – The national database that contains information on toxic chemical releases to air, land, and water from facilities that manufacture, process, or otherwise use toxic chemicals across the country.
- For more information about the Minnesota Air Toxics Emissions inventory please contact Chun Yi Wu or Nate Edel.
Air monitoring provides direct measurements of pollution concentrations in the air at fixed locations. The MPCA monitors air toxic pollutants at over 20 sites across Minnesota. Air toxics monitoring results are compared to state and federal health benchmarks.
2013 Minnesota air toxics monitoring sites
Information about air toxics monitoring and results can be found at:
- Annual Minnesota Air Monitoring Network Plan
- U.S. EPA Air Data website
- Please contact Kellie Gavin with requests for ambient air monitoring data.
Minnesota air toxics studies and reports
- Air Quality in Minnesota: Biennial report to the Legislature; Available years: 2013, 2011, 2009, 2007
- Update on Air Monitoring near the Minneapolis St. Paul International Airport , May 2006.
- Air Toxics Monitoring in the Twin Cities Area , January 2003
- Minnesota Statewide Air Toxics Monitoring Study (1996-2001)
Air modeling provides computer-modeled estimates of pollutant concentrations and risks across Minnesota. Air modeling incorporates air pollution emissions data, facility characteristics, and meteorological data to predict air pollutant concentrations. The MPCA utilizes air modeling to support air permitting, to assess health risks associated with air toxics emissions in Minnesota, and to prioritize emission reduction activities.
Information about air toxics modeling programs and results can be found at:
- U.S. EPA National Air Toxics Assessment; Available years: 2005, 2002, 1999, 1996
- Minnesota Air Quality Dispersion Modeling (AQDM)
- Minnesota Air Emissions Risk Analysis (AERA)
- Contact information for Minnesota Air Dispersion Modeling staff is available on the AQDM website.
Regulatory and voluntary air toxics emissions reductions programs at MPCA
The MPCA is responsible for implementing and enforcing federal rules that control toxic releases from industries and certain business activities.
- EPA Air Toxics Rules and Implementation - Federal regulations establish air toxic controls for different industries and various business activities.
- Minnesota Air Emissions Risk Analysis (AERA) - The MPCA requires an analysis of potential risks from air toxic releases when building or expanding certain types of facilities in Minnesota.
The MPCA has programs that work towards reducing air pollutant emissions with other stakeholders, or through more voluntary and educational approaches.
- Clean Diesel Grants – An MPCA administered program providing grants or financial assistance to reduce diesel emissions from public or private on-road, non-road, or marine diesel fleets.
- Project Green Fleet – A community partnership coordinated by Clean Air Minnesota which works with school districts and school bus fleet operators to retrofit buses with diesel emissions control technology.
- Beyond Regulations – MPCA provides support for businesses who want to reduce emissions and wastes beyond state and federal requirements.
- Residential Wood Smoke –MPCA provides information, advice, and external links on limiting to air toxics from exposure through residential wood combustion.
MPCA/MDH inhalation health benchmark hierarchy
Air toxics do not have standards. Instead, the MPCA uses a set of risk guidelines called health benchmarks to inform regulatory and environmental decision making. See the Toxicity Values Used by MPCA for Air Toxics Comparisons . These benchmarks come from the following hierarchy of sources:
- MDH Health-Based Values and Risk Assessment Advice for Air
- MDH Health Risk Values
- EPA Integrated Risk Information System (IRIS)
- California Environmental Protection Agency Reference Exposure Levels and Cancer Potency Values
- Provisional Peer Reviewed Toxicity Values (PPRTVs) derived by EPA's Superfund Health Risk Technical Support Center (STSC) for the EPA Superfund program