Jan. 6 — A total of 3.93 billion pounds of toxic chemicals was released into the environment nationwide in 2010, a 16% increase over 2009, the U.S. EPA said.The agency released its annual analysis of the Toxics Release Inventory, which includes information on toxic chemical disposals and other releases into the air, land and water. The data is submitted annually to the EPA by multiple industry sectors, including manufacturing, mining, electric utilities and commercial hazardous waste facilities.

The increase is largely a result from changes in the metal mining sector, the EPA said. In this sector, even a small change in the chemical composition of the ore being mined — which EPA understands is one of the reasons for the increase in total reported releases — may lead to big changes in the amount of toxic chemicals reported nationally.

Toxic chemical releases into surface water increased 9% and releases onto land increased 28% over 2009, while total air releases dropped 6%, the EPA said.