(Denver ) – The Colorado Department of Public Health and the Environment (CPDHE) recently determined from fish tissue samples that Denver Parks and Recreation's Rocky Mountain Lake located at Hooker Street and W. 46 th Avenue and Berkeley Lake located at Tennyson Street and W. 46 th Avenue show elevated levels of mercury in largemouth bass.   Due to these elevated levels, the CPDHE will be posting fish consumption advisories at both lakes to manage public consumption of largemouth bass for all age segments. 

To date, CDPHE has tested three lakes in Denver : Berkeley , Rocky Mountain , and Sloan ' s.  Sampling of additional lakes in Denver is planned for 2006 and/or 2007.

While research shows that most people's fish consumption does not cause a health concern, high levels of mercury in the bloodstream of unborn babies and young children may affect their neurological system. The Food and Drug Administration and the Environmental Protection Agency released a general fish consumption advisory in 2004 that provides guidance that if followed should keep an individual's mercury consumption below levels that have been shown to cause harm.  The advisory for Berkeley Lake applies only to consumption of largemouth bass (a large predator) and includes the following restrictions:

Berkeley Lake and Rocky Mountain Lake

 Fish Consumption Advisory

(largemouth bass)

Fish size	Pregnant, nursing, or women planning on being pregnant	Six years old or younger	General population
Greater than 14 inches	1 meal*/month	Do not consume	1 meal/month
Less than 14 inches	2 meals/month	1 meal/month	3 meals/month
*Meal size for adults weighing 150 lbs = 8 ounces  Meal size for children = 4 ounces

Nancy Severson , Manager of the Denver Department of Environmental Health said, “If people follow the fish consumption advisory recommendations, there is little concern for health effects.” 

Mercury air pollution comes from local, regional, and global sources.   Mercury is a naturally occurring element in the environment and is also released into the air through industrial pollution.  In the United States , coal-fired power plants are the largest industrial source of mercury emissions .  Additional industrial sources include waste incineration, and metal processing (e.g. smelting).  Natural sources include volcanoes, natural mercury deposits, and volatilization from the ocean. 

Mercury that is deposited from the atmosphere accumulates in water bodies. Bacteria in the water cause chemical changes that transform mercury into methylmercury.  Fish and shellfish are the main sources of methylmercury exposure to humans.  Fish absorb the methylmercury as they feed in these waters. Methylmercury builds up more in some fish than others depending on what they eat, how long they live, and how high up the food chain they are.  Largemouth bass are high on the food chain in Denver lakes.    

“Previous modeling studies by EPA showed that approximately 42 percent of the mercury emitted in Colorado is deposited within Colorado.” continued Severson .  “Obviously a large fraction originates outside Colorado , but all emissions eventually impact someone downwind.  At least 33 other states have issued mercury-based fish consumption advisories similar to those issued in Colorado .” 

Human risk from mercury exposure is primarily through consuming fish and shellfish, not through water contact.  The longer lived predatory fish such as bass are more likely to have elevated mercury concentrations than short-lived fish that feed on items other than fish.  Bluegill and carp from Berkeley Lake were also tested and were found to have mercury concentrations below advisory levels.  

In an effort to inform and educate the community about the fish advisories, Councilman Rick Garcia along with Denver Environmental Health, Denver Parks and Recreation and the CDPHE, is hosting a public meeting on Tuesday, July 18, 2006 from 7:00 p.m. – 8:00 p.m. at Scheitler Recreation Center located at 5031 W. 46 th Avenue .  This meeting intended on addressing any questions or concerns brought forward was suggested by Councilman Garcia who represents Northwest Denver to ensure that concerned citizens are well informed.

 “We highly encourage anyone who has questions or concerns about the fish consumption advisories to attend our upcoming public meeting,” commented Denver Parks and Recreation manager Kim Bailey .  “Experts will be on hand to educate and inform citizens regarding this issue.”

For more information, please contact the Colorado Department of Public Health and Environment (303-692-8273) or the Denver Department of Environmental Health (720-865-5452).

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