For people who eat fish out of Silverwood Lake

The state today, Aug. 7, issued a more stringent fish consumption advisory for Silverwood Lake in the San Bernardino Mountains because of high levels of mercury and toxic PCBs.

The guidelines from the Office of Environmental Health Hazard Assessment recommend that everyone avoid eating striped bass, blackfish and tui chub from the reservoir.
Fish in Silverwood Lake in San Bernardino County contains high levels of mercury and PCBs.

Fish in Silverwood Lake in San Bernardino County contains high levels of mercury and PCBs.
FILE PHOTO/THE PRESS-ENTERPRISE

The advisory, which will be posted in kiosks in the state park, is available here.

The amped-up warning follows a widespread advisory last week for bass, carp and larger brown trout at all lakes and reservoirs in the state. The advisory was based on test data from 272 lakes and reservoirs, including 19 in Riverside and San Bernardino counties, and more than 2,600 individual fish samples from popular angling spots, including Big Bear Lake, Lake Arrowhead and the eastern Sierra Nevada.

The state went a step further for Silverwood Lake. Women of child-bearing age and children should also avoid eating any largemouth bass, bluegill or channel catfish caught there. Men over 17 and women older than 45 can eat one serving per week of those species.

Rainbow trout from the lake have much lower levels of contaminants and can be safely eaten up to seven times per week by all groups, state health officials said. Tule perch consumption should be limited to one serving per week.

The advisory is based on sampling of more than 100 fish. Some species were also tested for pesticides, including chlordanes, DDTs, and dieldrin, but none was detected at levels high enough to cause health concerns, state officials said.

Fish tissue samples did contain methylmercury, a form of mercury created when it reacts with bacteria in the water.

Mercury in the environmental comes from historic gold-mining operations and is carried in air emissions from coal burning and possibly cement plants, even from distant locations. It can harm the brain and nervous system, particularly in fetuses and children.

PCBs, or polychlorinated biphenyls, are heat-tolerant chemicals used in electronics. They are linked to cancer and other health problems, according to the state Water Resources Control Board.

Contaminants that fall or flow into a lake move up the food chain, concentrating in larger species of fish.

Silverwood Lake is a man-made reservoir that stores drinking water for San Bernardino and Metropolitan Water District, the wholesaler for Southern California. It is overseen by the state Department of Water Resources.

“Water delivered from Silverwood Lake is still considered safe to drink after processing in a water treatment plant. Water quality continues to be tested on a monthly basis,” said Jeffrey Janik, program manager for the water quality section at the Department of Water Resources.

sources: http://blog.pe.com/2013/08/07/pollut...lverwood-lake/