Manufacturers released nearly 4 billion pounds of toxic chemicals into the environment in 2010, a 16 percent increase over the previous year, according to the EPA’s Toxics Release Inventory (TRI) National Analysis.

The agency’s annual report on toxic chemical releases, which was issued Jan. 5, found that 3.93 billion pounds of toxic chemicals were released into the air, water and land by U.S. facilities in 2010, a significant upswing from 2009’s total of 3.37 billion and a reversal of a general trend downward in releases since 2001.

The 2010 national analysis — which was drawn from TRI reports filed by 20,904 industrial facilities covering more than 650 toxic chemicals — attributed much of the increase to a 21 percent surge in releases from the metal mining industry, which accounted for 41 percent of all toxic chemical releases in 2010.

Other major contributors to toxic chemical releases also reported increases, including the chemical manufacturing industry (19 percent) and paper product manufacturers (1 percent), while others industries saw their total releases fall, including electric utilities (19 percent) and cement manufacturers (2 percent).

The report noted that all data are self-reported by industry and much of them are estimates. The agency has had most of the industry’s TRI reports since July 1 — the due date for annual filings — but needed the additional time to compile the information.

The overall increase in toxic chemical releases came despite a 2 percent decrease in the number of facilities reporting TRI data.

Of the 3.93 billion pounds of chemicals released into the environment in 2010, 2.2 billion (56 percent) of those releases were classified as Land Disposal/Other Releases. Aerial emissions accounted for 22 percent of the remaining volume of chemical releases, off-site disposal added another 10 percent to the total, while surface water discharges and underground injection of chemicals each contributed 6 percent to the total volume of releases in 2010.

For more information, see the February edition of the Emergency Planning and Community Right-to-Know Manual newsletter.