The U.S. Toxic Release Inventory (TRI) is a public EPA database tracking over 650 toxic chemicals released by industrial facilities across America. This interactive map plots 21,022 TRI-reporting facilities across all 50 states, representing 3.09 billion pounds of releases in the most recent reporting year. Use the filters to explore by release pathway—air, water, or land—and click any facility circle to see its chemical breakdown and total release volume.

Toxic Releases by State

Total toxic releases vary dramatically across states, driven largely by the presence of metal mining operations. Alaska alone accounts for 20% of all U.S. releases from just 41 facilities, while Vermont, New Hampshire, and Rhode Island each report under 600,000 pounds combined from their small industrial base. Select any state below to explore its facilities in detail.

Which Industries Release the Most Toxic Chemicals?

Metal mining dominates U.S. toxic releases, accounting for 44% of all pounds reported despite representing a small fraction of total TRI facilities. The chemicals involved are largely naturally occurring minerals—zinc, lead, arsenic, and mercury—disturbed during ore extraction and deposited on-site. Chemical manufacturing and primary metals together contribute nearly a quarter of all releases, while electric utilities add another 8% primarily through coal ash and cooling water discharges.

Top 15 Facilities by Total Releases

The single largest TRI reporter—Red Dog Operations in Kotzebue, Alaska—releases more toxic material than the combined total of 46 individual U.S. states. The facility is a zinc and lead mine operated by Teck Alaska; its releases consist almost entirely of zinc compounds and lead deposited on land at the mine tailings facility. Nine of the top 15 national facilities are gold or base-metal mines operating in remote western and Alaskan landscapes.

What Is the Toxic Release Inventory?

The Toxic Release Inventory was established by the Emergency Planning and Community Right-to-Know Act (EPCRA) of 1986, following heightened public concern about industrial chemical hazards after the Bhopal disaster. Facilities in covered industry sectors that manufacture, process, or otherwise use listed chemicals above threshold quantities must report annually to the EPA. Reports are submitted by July 1 for the prior calendar year and are freely accessible through the EPA’s TRI Explorer database.

TRI covers over 650 chemicals and chemical categories, including heavy metals such as lead, mercury, and arsenic; volatile organic compounds; persistent bioaccumulative toxics (PBTs); and known carcinogens. Not all releases carry equal health risk—a pound of mercury discharged to a river poses very different hazards than a pound of zinc compounds deposited on a mine tailings pile. The TRI tracks quantity but does not directly measure human health exposure or risk.

Why Do Releases Vary So Much by State?

The extreme variation between states reflects industrial mix rather than environmental compliance. States with large hard-rock mining sectors—Alaska, Nevada, Utah, Montana, and Idaho—report high totals because mining operations disturb large volumes of mineral-bearing earth, and naturally occurring metals in that material count as toxic releases even when deposited back on-site as part of permitted operations. A single large mine can easily dwarf the combined output of thousands of manufacturing plants in another state.

California’s 1,160 TRI facilities release only 32.8 million pounds—less than 6% of Alaska’s total from 41 facilities—because California’s economy leans toward technology, services, and light manufacturing. Similarly, states with heavy chemical and steel industries like Indiana, Ohio, and Louisiana rank high not from mining but from conventional industrial discharges to air and water, which carry more direct community health significance per pound than mine tailings.

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