TOXMAP® (https://toxmap.nlm.nih.gov) is a Geographic Information System (GIS) from the Division of Specialized Information Services of the US National Library of Medicine® (NLM) that uses maps of the United States to help users visually explore environmental health data from the US Environmental Protection Agency (EPA)'s Toxics Release Inventory (TRI) and Superfund Program, as well as several non-EPA datasets.

The current version of TOXMAP, developed with the Esri® Web AppBuilder, replaces both previous versions of TOXMAP, including TOXMAP classic and the newer Flash-based version of TOXMAP. This version does not require any additional browser plug-ins and runs on tablet and mobile devices.

For more information, see the TOXMAP Fact Sheet.

The effect a chemical has on a living organism-- if any-- is called the organism's response. The response is related to the chemical dose and to the resulting concentration of the chemical in the organism. The dose of a chemical often determines the extent of the effect it produces. Understanding the dose-response relationship is necessary for understanding the cause and effect relationship between chemical exposure and illness.

The toxicity of a substance depends on many factors: the form and chemical activity; the dosage, especially the dose-time relationship; exposure route; species; age; sex; ability of the chemical to be absorbed; metabolism; distribution within the body; excretion; and the presence of other chemicals.

The variety of responses among organisms that get the same dose of chemical is due to individual susceptibility. Dose and individual susceptibility play roles in all situations involving chemical exposure. Toxicologists study responses of living organisms to doses of chemicals.

Always keep in mind that the co-occurrence of a substance and a particular health problem does not by itself imply an effect on human health by that substance; the association of two or more variables (correlation) does not, by itself, imply a cause and effect relationship.

You can learn more about chemicals and toxicity with this Toxicology Tutorial, which covers basic toxicology, organized by chapter and offering text, graphics, and quizzes/assessments.

It is difficult to answer this question simply because there is currently no standard approach to assess overall human health risk. People are exposed to chemicals in our environment via in the air we breathe, the water we drink, the houses we live in, and the food we eat. TRI releases and Superfund sites are just a few examples of sources of chemical exposure.

Some of these chemicals may affect our health. Understanding exposure and determining whether there is a health risk is a very complex process. There are many factors that affect health risk. A large release of one chemical might be less harmful to our health than a smaller release of another chemical; the impact of air releases can be affected by wind direction and other factors.

Learn more about chemicals and risk to human health with the links below:

At this time, TOXMAP uses reported on-site releases only. Some TRI chemicals have no reported releases, and so will not appear in the TRI release data or in TOXMAP.

Certain industries in the United States that manufacture, process, use, or transport significant amounts of specific toxic chemicals (approximately 650 chemicals and chemical categories covering about 23,000 industrial and federal facilities) are required by law to report annually on the releases of these chemicals to the EPA (through its Toxics Release Inventory Program). TOXMAP maps on-site releases of the listed chemicals covered by the EPA TRI program.

It should be noted that although facilities are required by federal law to use the best available data for their reporting, the accuracy of the reported data is unknown since it can be based on both actual measurements and on estimates. However, the Toxics Release Inventory is the best public information available on these chemicals.

The EPA Superfund Program is part of a federal government effort to decontaminate any land in the United States that has been contaminated by hazardous waste and that has been identified by the EPA as a candidate for cleanup because it poses a risk to human health and/or the environment. The program designates more than 800 substances as hazardous, and many more as potentially hazardous to human health or to the environment when improperly treated, stored, transported, disposed of, or otherwise managed.

The toxic chemicals reported in this way make up only a small portion of the total amount manufactured, handled and used in the United States.

Industries are not the only entities responsible for toxic chemicals. Since the current reporting requirements apply only to industrial sources, sources of toxic chemicals from transportation, farming and households are not included. In addition, thousands of new chemicals are studied each year and thousands are manufactured. It is not possible to test each chemical regarding possible toxic effects on people, plants or animals.

The data found in TOXMAP comes from several providers, including:
  • Toxics Release Inventory (TRI)

    A federal law called the Emergency Planning and Community Right to Know Act (EPCRA) requires facilities in certain industries which manufacture, process, or use significant amounts of toxic chemicals, to report annually on their releases of these chemicals. The reports contain information about the types and amounts of toxic chemicals that are released each year to the air, water, land and by underground injection, as well as information on the quantities of toxic chemicals sent to other facilities for further waste management.

    Facilities with ten or more full-time employees that process more than 25,000 pounds in aggregate, or use greater than 10,000 pounds of any one TRI chemical, are required to report releases annually. The US Environmental Protection Agency (EPA) maintains this information in a database called the Toxics Release Inventory (TRI). The toxics release files on the National Library of Medicine's® (NLM) Toxicology Data Network (TOXNET®) come from TRI.

    TOXMAP uses the TRI data from the 2016 National Analysis dataset. NLM TOXNET uses the most current TRI data. Data submission deadlines, data entry processes, and data quality control and review all influence the actual date of data release by both the EPA and by TOXNET. A complete list of TRI chemicals required to be reported to the EPA can be found at their TRI-Listed Chemicals page.

    NOTE: At this time, TOXMAP uses reported on-site releases only. Some TRI chemicals have no reported releases, and so will not appear in the TRI release data or in TOXMAP.

    For more information, see the TRI Fact Sheet.

  • EPA's CERCLIS

    CERCLIS contains information about Superfund sites, such as the current status of cleanup efforts, cleanup milestones reached, and amounts of liquid and solid media treated at sites on the National Priorities List (NPL) or under consideration for the NPL. The CERCLIS database can be searched online.

  • US Census

    TOXMAP Census data from 2000 and 2010 comes directly from the US Census. This includes selected county-level demographics (age, male/female ratio, population and race/ethnicity) and can be found in its original form on the US Census Bureau's website. TOXMAP's Native Lands layer is also comprised of data from the US Census.

  • National Cancer Institute SEER

    TOXMAP uses the NCI's SEER*Stat database for its cancer and disease mortality data. Underlying mortality data is provided by the NCHS, part of the US Department of Health and Human Services.

  • EPA's Air Markets Program Data (AMPD)

    AMPD is a publicly-available data system from the EPA Clean Air Markets program for searching and downloading data collected as part of EPA's emissions trading programs. TOXMAP displays all facilities in all programs covered in the AMPD in 2017 whose primary or secondary fuel type is coal-related (e.g., Coal, Coal Refuse, and Petroleum Coke).

  • Energy Information Administration (EIA)

    Coal plants in TOXMAP link to their associated record in the EIA Electricity Data Browser.

  • EPA's Facility Registry System (FRS)

    TOXMAP plots the location of TRI facilities using addresses and coordinates from the EPA's Facility Registry System (FRS). The FRS is a centrally managed database that identifies facilities, sites or places subject to environmental regulations or of environmental interest.

  • Hazardous Substances Databank® (HSDB)

    HSDB contains comprehensive toxicological information on more than 4,700 chemicals. Data in HSDB are peer-reviewed, and are derived and referenced from a core set of books, government documents, technical reports and selected primary journal literature. For more information, see the HSDB Fact Sheet.

  • The Bureau of Economic Analysis (BEA)

    The BEA, part of the US Department of Commerce, publishes the per capita personal income data used by TOXMAP.

  • National Atlas of the United States of America (USGS)

    TOXMAP used the USGS's National Atlas (now part of The National Map) for 1990 county-level demographics (age, male/female ratio, population and race/ethnicity) and can be found in its original form on the US Census Bureau's website.

  • Environment and Climate Change Canada

    Environment and Climate Change Canada publishes data from the NPRI, Canada's legislated, publicly accessible inventory of pollutant releases (to air, water and land), disposals and transfers for recycling.

  • Nuclear Regulatory Commission

    The Nuclear Regulatory Commission publishes the commercial nuclear power plant data found in TOXMAP.

  • Esri

    All basemaps (Streets, Topographic, Aerial) come from Esri, as do congressional district boundaries.

TOXMAP facility locations are calculated by an estimation process that relies on "geocoding." Geocoding is a method that assigns latitude and longitude to an address. Even the most accurate latitude/longitude coordinate calculations, including those used by TOXMAP, are estimates; this can account for minor inaccuracies in site locations on a map.

Addresses are geocoded using software that accesses location information from a variety of sources which contain street segments; address ranges are attached to each side of the segment. TOXMAP's geocoding program estimates the location of each facility address based on this address range. Although very accurate, these locations are estimates, and they should not be used to definitively locate a particular facility.

For more information about the accuracy of locations in TOXMAP, see "How accurate are TRI locations in TOXMAP?"

Although TOXMAP is not specifically designed for any one particular group, the TRI and Superfund Programs can be of interest to specific populations such as Native Americans by helping to find sources of chemical releases and contamination in locations of interest to them. For instance, in TOXMAP click "Enter location" search box, type in a place of interest like an Indian reservation, then click the magnifying glass to search. You can also save the location for later use by clicking the "Bookmark" icon in the toolbar, then use this named "bookmark" to zoom to that location for quick reference later in your session.

The TOXMAP Native Lands map layer shows geographic areas of certain native populations, including American Indian Reservations and Off-Reservation Trust Lands, Alaska Native Village Statistical Areas, and Hawaiian Home Lands, as defined by the US Census. This layer can be toggled on and off via the Map Contents side panel.

You can also overlay US Census data by race: "American Indian and Alaskan Native" (1990), "One Race: American Indian and Alaska Native" and "Two or more races including: American Indian" (2000), or "American Indian" (2010).

For more information, see the TOXMAP and Native American Populations page.

The Toxics Release Inventory (TRI) is a publicly available database that contains information on toxic chemical releases and other waste management activities reported annually by certain covered industry groups as well as federal facilities. This inventory was established under a federal law called the Emergency Planning and Community Right to Know Act of 1986 (EPCRA) and was expanded by the Pollution Prevention Act of 1990. It requires facilities in certain industries which manufacture, process, or use significant amounts of toxic chemicals, to report annually on their releases of these chemicals. The reports contain information about the types and amounts of toxic chemicals that are released each year to the air, water, land and by underground injection, as well as information on the quantities of toxic chemicals sent to other facilities for further waste management.

Facilities with ten or more full-time employees that process more than 25,000 pounds in aggregate, or use greater than 10,000 pounds of any one TRI chemical, are required to report releases annually. The US EPA maintains this information in the TRI. The toxics release files on the National Library of Medicine's® TOXNET® come from TRI.

TOXMAP uses the TRI data from the 2016 National Analysis dataset. NLM TOXNET uses the most current TRI data. Data submission deadlines, data entry processes, and data quality control and review all influence the actual date of data release by both the EPA and by TOXNET. A complete list of TRI chemicals required to be reported to the EPA can be found at their TRI-Listed Chemicals page.

NOTE: At this time, TOXMAP uses reported on-site releases only. Some TRI chemicals have no reported releases, and so will not appear in the TRI release data or in TOXMAP. All release amounts are reported in pounds except dioxin which is reported in grams.

For more information, see the TRI Fact Sheet.

TOXMAP maps the TRI chemicals reported to the EPA, as required by the Emergency Planning and Community Right to Know Act (EPCRA).

TOXMAP uses the TRI data from the 2016 National Analysis dataset. NLM TOXNET uses the most current TRI data.

Some TRI chemicals have no reported releases, and so will not appear in the TRI release data or in TOXMAP. A complete list of TRI chemicals required to be reported to the EPA can be found at their TRI-Listed Chemicals page.

The EPA's Toxics Release Inventory (TRI) program is a national database that identifies facilities, chemicals manufactured, processed and used at the identified facilities, annual amounts of chemicals released and otherwise managed (on and off site) in waste.

The following information is excerpted from the EPA's "Factors to Consider When Using Toxics Release Inventory Data":

TRI data do not include release information from all sources or from other waste management activities, and all industry sectors and all chemicals are not covered. TRI data report releases and waste management of the chemicals, but do not reflect exposure information of the public to the chemicals. Only facilities meeting specific criteria are required to report.

All data in TRI (chemicals released, release amounts, etc.) is required by law to be self-reported annually, and is not validated by the EPA. In addition, some of the reporting facilities submit estimated data to TRI. (Since different estimation practices are used, the EPA has published estimation guidance for the user.)

TRI release estimates are one resource that can be used to evaluate exposure or calculate potential risks to human health and the environment. However, it is essential to understand that they do not, by themselves, represent risk. The determination of potential risk depends on many factors, including toxicity, chemical fate after release, release location, and population concentrations.

Finally, TRI release values are specified for 17 digits after the decimal point, but TOXMAP rounds them to six digits. NLM's TOXNET TRI displays exact values.

TOXMAP uses the TRI data from the 2016 National Analysis dataset. NLM TOXNET uses the most current TRI data. 1987 is the first reporting year of the TRI program, but by industry convention, 1988 is the first year that TRI data is used for analysis. Data submission deadlines, data entry processes, and data quality control and review all influence the actual date of data release by both the EPA and by TOXNET.  You may download data from the 1987 TRI year directly from EPA.

Prior to the final release of a given TRI release year, EPA publishes a preliminary dataset of the upcoming release data. However, TOXNET does not update TRI data until it is final.

A complete list of TRI chemicals required to be reported to the EPA can be found at their TRI-Listed Chemicals page.

NOTE: At this time, TOXMAP uses reported on-site releases only. Some TRI chemicals have no reported releases, and so will not appear in the TRI release data or in TOXMAP.

For more information, see the TRI Fact Sheet.

TOXMAP plots the location of all TRI facilities and Superfund sites using addresses and coordinates from the EPA Facility Registry System (FRS). The location of some of these may appear to be slightly inaccurate, because they are calculated by a geocoding estimation process. For general information about the accuracy of locations in TOXMAP, see "Why are the locations of some TOXMAP facilities slightly inaccurate?"

The EPA recommends use of addresses and coordinates from the FRS.  TOXMAP only plots TRI facilities with defined FRS locations. Corrections to FRS are made year-round by EPA and are incorporated into TOXMAP annually with each year's publicly available data.

This approach avoids many errors in the TRI location data. However, there are also limitations to FRS data, such as in the case of a large facility (tens or hundreds of square miles in area) that reports to multiple EPA programs. Since FRS only uses the "best" of the reported coordinates, a more accurate location for a TRI release may be overlooked (e.g. the street address coordinate is used because it is easily identified as "best", but the TRI release actually takes place elsewhere).

EPA works continuously to ensure that TRI data are accurate and reliable.  For more information, see the EPA TRI Data Quality page.

Or to report a data error to EPA, please contact EPA.

(This list includes federal government sites only.)

  • US NLM TOXNET®

    TOXNET TRI allows users to search TRI chemical names, CAS Registry Numbers, TRI data years, and/or details about the releasing facility. The left menu of the "TRI Search Results" page provides a download option for the retrieved TRI data.

  • US EPA TRI Explorer

    EPA TRI Explorer offers custom reports on Releases, Waste Transfer, and Waste Quantity. Users can view and sort report data online or download it to a text file.

  • US EPA Envirofacts

    EPA Envirofacts provides simple and advanced queries and reports for TRI data. Find them on the right under "Advanced Capabilities".

  • US EPA's TRI data site

    EPA's TRI data site gives the user different ways to download TRI data:

    • "Annual TRI Public Data Release"-- includes a general overview of that year's TRI data and information on trends;
    • State Fact Sheets-- provide a brief summary of the TRI data by state and downloadable data files containing TRI reports submitted for the reporting year;
  • US EPA TRI Explorer Dynamic Maps

    TRI Explorer Dynamic Maps lets the user create reports and color-coded state and county maps of TRI data.

  • US EPA EnviroMapper for Envirofacts and MyEnvironment

    EnviroMapper for Envirofacts and MyEnvironment both display TRI facility locations along with other locations that report to the US EPA.

The Superfund program is part of a Federal government effort to clean up land in the United States that has been contaminated by hazardous waste and that has been identified by the US Environmental Protection Agency (EPA) as a candidate for cleanup because it poses a risk to human health and/or to the environment.

The program was created in 1980 when Congress enacted the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA). The EPA works with communities, "potentially responsible parties" (PRPs), scientists, researchers, contractors, and state, local, tribal, and Federal authorities to identify hazardous waste sites, test the conditions of the sites, formulate cleanup plans, and to decontaminate the sites.

Sites where releases or potential releases have been reported are listed in a searchable EPA database called CERCLIS. CERCLIS was retired in November 2013 and has been replaced by SEMS.

CERCLA was amended by the Superfund Amendments and Reauthorization Act (SARA) in 1986.

CERCLIS (Comprehensive Environmental Response, Compensation and Liability Information System) and SEMS (Superfund Enterprise Management System) are databases maintained by the US EPA as part of the Superfund program. The EPA retired CERCLIS in November 2013 and has been transitioning to SEMS, which contains the same content as CERCLIS. SEMS contains information such as the current status of cleanup efforts, cleanup milestones reached, and amounts of liquid and solid media treated at sites on the National Priorities List (NPL) or under consideration for the NPL.

Search Superfund site information at the EPA web site.

The substances found at Superfund sites have been designated by CERCLA as 1) causing or contributing to an increase in mortality or in irreversible or incapacitating illness, or 2) posing a substantial present or potential hazard to human health or to the environment when improperly treated, stored, transported, disposed of, or otherwise managed.

More than 800 substances are currently designated as hazardous, and many more as potentially hazardous. These substances do not include petroleum or natural gas.

The Superfund site cleanup process begins with the reporting of possible releases of hazardous substances by individual citizens, responsible parties or EPA regional offices. The EPA then registers the information in CERCLIS, an electronic record of sites affected by potentially hazardous substances.

The EPA examines possible release of hazardous substances from a site via several processes:

The development of Superfund site cleanup plans includes several cleanup options. The EPA regularly invites public comment on the cleanup process in their community. The EPA also encourages citizens to participate in community advisory groups.

Potentially Responsible Parties (PRPs) of Superfund sites are current or former owners or operators of a facility, transporters of a hazardous substance who chose the site for disposal, or agents who coordinate treatment or disposal of hazardous substances at the site. Identifying the PRPs for cleanup of a site is an EPA priority.

Sometimes the PRP is unwilling or unable to assume responsibility, or the PRP cannot be found. In these cases, the EPA, the state, or the tribe will clean the area with funding from the Superfund program. The EPA Enforcement pages provide further information on legal responsibility for cleaning dangerous waste sites.

The National Technical Information Service offers a list of PRPs at individual sites.

A Superfund site is any land in the United States that has been contaminated by hazardous waste and identified by the EPA as a candidate for cleanup because it poses a risk to human health and/or the environment. These sites are placed on the National Priorities List (NPL).

The NPL is the list of national priorities among the known releases or threatened releases of hazardous substances, pollutants, or contaminants throughout the United States and its territories. The NPL is intended primarily to guide the EPA in determining which sites warrant further investigation. The site's NPL "status" can provide more information about the site in relationship to the NPL:

  • Proposed: Site proposed (by the EPA, the state, or concerned citizens) for addition to the NPL due to contamination by hazardous waste and identified by the Environmental Protection Agency (EPA) as a candidate for cleanup because it poses a risk to human health and/or the environment.
  • Withdrawn: Site removed from the NPL because EPA has determined that it poses no real or potential threat to human health and the environment.
  • Final: Site determined to pose a real or potential threat to human health and the environment after completion of HRS screening and public solicitation of comments about the proposed site.
  • Deleted: Site deleted from the NPL by the EPA (with state concurrence) because site cleanup goals have been met and no further response is necessary at the site.

The National Priorities List (NPL) contains the most serious uncontrolled or abandoned hazardous waste sites throughout the United States and its territories. The NPL lists sites after 1) completing a Hazard Ranking System (HRS) screening and 2) soliciting and addressing public comments about the proposed site.

The NPL guides the federal government in determining which sites should be investigated. It is updated on a regular basis.

The EPA designates several NPL statuses for Superfund sites: Proposed, Final, Deleted, Withdrawn, and Removed. Not all Superfund sites are considered national priorities by EPA, and so do not appear on the NPL. TOXMAP contains data only on sites designated as Final (currently on the final NPL), Proposed (proposed for the NPL), and Deleted (deleted from the final NPL). These three statuses are collectively referred to by the EPA as the "NPL Dataset".

For details about the NPL site assessment process, see this EPA page.

The National Pollutant Release Inventory (NPRI) is Canada's legislated, publicly accessible inventory of pollutant releases (to air, water and land), disposals and transfers for recycling. According to its home page, it is a key resource for:

  • identifying pollution prevention priorities;
  • supporting the assessment and risk management of chemicals, and air quality modelling;
  • helping develop targeted regulations for reducing releases of toxic substances and air pollutants;
  • encouraging actions to reduce the release of pollutants into the environment; and
  • improving public understanding.

The best way to find out more about NPRI topics is to visit its website, including the Frequently Asked Questions.  Note that the FAQ is archived content and is not updated after the date of archiving.  You can also contact the NPRI program directly.

For broader topics about the Canadian environment, see the Environment and Climate Change Canada (ECCC) website.

The Clean Air Markets Program Division (CAMD), or simply "Clean Air Markets," answers scientific, general, policy, and regulatory questions about industry emissions. The program is designed to improve air quality and ecosystems by lowering outdoor concentrations of fine particles, mercury, ozone, and other significant air emissions. The most well-known of these programs are EPA's Acid Rain Program and the NOx Budget Trading Programs, which reduce emissions of sulfur dioxide (SO2) and nitrogen oxides (NOx)-- compounds produced by fossil fuel combustion.

TOXMAP's coal data includes all facilities in all programs covered in the AMPD's 2017 database whose primary or secondary fuel type is coal-related (e.g., Coal, Coal Refuse, and Petroleum Coke).

According to the US Energy Information Administration (EIA), in 2017, the United States generated about 4,015 billion kilowatt-hours of electricity at utility-scale facilities. About 62.7% of the electricity generated was from fossil fuel (coal, natural gas, and petroleum), with 30.1% attributed from coal.

See a complete breakdown of all energy sources from the US EIA.

According to the US Energy Information Administration (EIA), the total US energy-related emissions of carbon dioxide (CO2) by the electric power sector in 2016 were 1,821 million metric tons, or about 35% of total US energy-related CO2 emissions.

About 1,241 million metric tons of carbon dioxide emissions were attributable to electricity generated from coal.

For more information, see the latest analysis from the US EIA.

The US EPA and US EIA both have many online resources where you can learn more about coal, electricity generation, and related topics:

For a comprehensive source of data on the environmental characteristics of almost all electric power generated in the United States, see the EPA's eGRID.

For questions, suggestions or comments about TOXMAP or other resources from NLM's Division of Specialized Information Services contact:

National Library of Medicine
Division of Specialized Information Services
2 Democracy Plaza, Suite 510
6707 Democracy Blvd., MSC 5467
Bethesda, MD 20892-5467

Fax: (301) 480-3537
Telephone: 301-496-3147 or 301-496-1131 (local and international)
e-mail: tehip@teh.nlm.nih.gov
URL: https://sis.nlm.nih.gov/siscontact.html