Factories, power plants and other facilities released into Virginia's environment in 2006 more than 1 million pounds of highly toxic pollutants that can cause cancer and sickness in humans, according to federal and state experts.

These pollutants, called persistent bioaccumulative toxic chemicals, include lead, mercury, dioxins and other chemicals. They tend to build up in the environment and in the tissues of living organisms, including humans.

"Our main concern is with PBT chemicals," said Nichelle McDaniel, a spokesperson for the Environmental Protection Agency. "They can cause cancer, and have (negative) health and environmental effects."

The PBT chemicals are only eight of the 160 chemicals that the EPA monitors as part of their Toxic Release Inventory program. In the end, state industries released more than 70 million pounds of pollutants into Virginia's rivers, soil and air in 2006, the most recent year for which data are available.

Mercury and lead were released in the largest quantity, according to a compute analysis of TRI data. The two metals are byproducts of the coal burning process, which has become a key step in producing energy. Lead and mercury pollution can build up in the bodies of animals, specifically fish, and cause sickness in people who eat them. Direct exposure, as well as exposure from contaminated water, soil or air, causes severe and debilitating sickness in humans.

Other PBT chemicals include polycyclic aromatic compounds. These are released during agricultural processes or when fossil fuels or garbage is burned. These compounds can alter the basic hormonal systems in fish. According to Kyle Newman, an environmental scientist at Virginia Commonwealth University, this can occur even when only low levels of PCPs are present.

While the harmful effects of industry are acknowledged, they are typically overshadowed by the economic needs of the state. The electricity sector is a good example of how the expanding needs of the state are causing industries to produce more of their product, and subsequently, more harmful pollution. Coal use has increased over the past decade as Virginia's customer base has expanded, and the use of energy-sapping devices, such as flat-screen TVs, has become common.

"We gain 50,000 customers per year," said Jim Norvelle, Dominion's director of media relations. "(As a result) we are using more coal today than we ever did previously."

A scientist who works for the company said Dominion deals with pollution in responsible ways. The Chesterfield Power Station, the largest fossil fueled power plant in Virginia, employs a team of scientists, engineers, biologists and environmental compliance workers who "make sure that the right decisions are being made to protect the environment," said Cathy Taylor, director of environmental support for Dominion.

While responsibility and transparency among big industries can be beneficial for citizens, and for monitoring agencies such as the EPA, Virginia's history of illegal dumping has created a skeptical public.

"I'm not sure that there is any place where (some of these pollutants) are in not the water," said Ralph White, manager of the James River Park System.