TRI figures for 2003 show that metal mining operations released into the environment or sent for disposal 1.2 billion lb of toxic substances. Utilities released nearly 1.1 billion lb, and chemical companies reported almost 545 million lb. Together, these three sectors accounted for 64% of all releases and disposal of toxics.

Overall, U.S. industries that must file TRI reports curbed their releases and disposals of covered chemicals by 6% between 2002 and 2003, EPA says. The chemical industry saw a drop of 3% in the same period.

With nearly 169 million lb emitted from stacks or vents in 2003, chemical firms ranked second in TRI pollutants, behind utilities, which emitted 721 million lb. Chemical manufacturing, however, was ranked top in toxic releases to air via equipment leaks or ventilation systems with 62 million lb, followed by the paper industry with 27 million lb.

Chemical producers' 45 million lb of TRI chemical discharges to rivers, lakes, and streams was second to the food sector's 83 million lb, according to the data.

In 2003, the lumber industry took over the number one spot from chemical producers in releases and disposal of dioxins and dioxinlike compounds. This was due to a single lumber facility transferring waste-- including telephone poles--to landfills, according to EPA.

Without this one lumber facility, EPA says overall disposal and other releases of dioxins and dioxinlike substances fell 4% from 2002 to 2003, to 269,037 g. Chemical companies released or disposed of 118,652 g in 2003, down from 124,590 g in 2002.

Chemical makers cut their releases while increasing output by 29% in 2003, says Chris VandenHeuvel, spokesman for the American Chemistry Council.