EPA plans to take a bite out of mercury

Here's some good news for fish from the U.S. Environmental Protection Agency:

Sept. 27, 2010

EPA will propose rule to reduce mercury from dental offices

WASHINGTON — The U.S. Environmental Protection Agency today announced it intends to propose a rule to reduce mercury waste from dental offices.

Dental amalgams, or fillings containing mercury, account for 3.7 tons of mercury discharged from dental offices each year. The mercury waste results when old mercury fillings are replaced with new ones.

The mercury in dental fillings is flushed into chairside drains and enters the wastewater systems, making its way into the environment through discharges to rivers and lakes, incineration or land application of sewage sludge.

Mercury released through amalgam discharges can be easily managed and prevented.

EPA expects to propose a rule next year and finalize it in 2012. Dental offices will be able to use existing technology to meet the proposed requirements. Amalgam separators can separate out 95 percent of the mercury normally discharged to the local waste treatment plant. The separator captures the mercury, which is then recycled and reused.

Until the rule is final, EPA encourages dental offices to voluntarily install amalgam separators. Twelve states and several municipalities already require the installation of amalgam separators in dental offices.

Approximately 50 percent of mercury entering local waste treatment plants comes from dental amalgam waste. Once deposited, certain microorganisms can change elemental mercury into methylmercury, a highly toxic form that builds up in fish, shellfish and animals that eat fish.

Fish and shellfish are the main sources of methylmercury exposure to humans. Methylmercury can damage children's developing brains and nervous systems even before they are born.

Federal study finds mercury in all fish

Here's an AP story summarizing the findings of "the most comprehensive look to date at mercury in the nation's streams."

The bottom line: All tested fish had some mercury contamination, but only about a quarter showed levels above safe limits for average consumers.

The story has a couple of Alaska references.

USGS announces breakthrough mercury study

Here's word of a new study on how mercury, which can contaminate fish, travels across the North Pacific Ocean from Asia. The release contains a Kodiak reference.