What are the biggest sources of mercury air emissions in the U.S.?

According to EPA's 2008 National Emissions Inventory, version 2,  http://www.epa.gov/ttn/chief/net/2008inventory.html#inventorydoc, coal-fired electric power plants are the largest source of human-caused mercury air emissions in the U.S. These power plants account for about 48% of total U.S. man-made mercury emissions. Other large sources are:

• Industrial boilers (about 7% of U.S. mercury emissions),
• Burning waste from the manufacture of Portland cement (about 7%),
• Electric arc furnaces used in steelmaking (about 8%), and
• Gold mining (about 3%).

Burning municipal waste and medical waste was once a larger source of emissions. Today, in response to EPA and state regulations and reductions in mercury use, emissions from these sources have declined over 95 percent.

• Learn more about what the National Emissions Inventory tells us about mercury by reading pages 23-28 in the 2008 NEI Technical Support Document: http://www.epa.gov/ttn/chief/net/2008neiv2/2008_neiv2_tsd_draft.pdf
• For information about worldwide mercury emissions see: Mercury Emissions: The Global context: http://www.epa.gov/international/toxics/mercury/mercury_context.html

.

• Where can I locate information about Methyl Tertiary Butyl Ether (MTBE)?
• Where can I find out about tax credits for buying a new hybrid car?
• How can I find out if the replacement of a part of my vehicle is covered under an emissions warranty?