Just because a fish came from a lake — rather than the ocean — doesn't make it safe to eat. On Nov. 10, EPA published the results of a four-year study sampling the tissue of fish caught in freshwater lakes throughout the US — revealing widespread contamination by pollutants such as mercury and PCBs.

"Mercury and PCBs were detected in all of the fish samples collected from the nationally representative sample of 500 lakes and reservoirs in the study. Because these findings apply to fish caught in lakes and reservoirs, it is particularly important for recreational and subsistence fishers to follow their state and local fish advisories."

• EPA release. [2] Press: Enesta Jones, [3] 202-564-7873.

• EPA: Leanne Stahl, [4] Office of Science and Technology, Office of Water, 202-566-0404.

• National Lake Fish Study data and analysis. [5]

In EPA's biennial national listing of fish advisories, [6] published Sept. 2009, mercury, PCBs, dioxins and furans, DDT, and chlordane were responsible for 97% of the advisories in effect at the end of 2008.

• Search for advisories by state. [7]

It's not all bad news, though. Of the 268 target chemicals tested for in the study, 43 were not detected in any fish samples. This includes nine organophosphate pesticides (such as chlorpyriphos and diazinon).

Find out where fish samples were gathered in your state: map [8] and list of sampling locations. [9]

On Nov. 5-9, the National Forum on Contaminants in Fish was held in Portland, OR. The agenda [10] for this event includes a list of current experts in fish contamination.