US Finds Toxic Substances in Fish in Some Lakes and Reservoirs
US Finds Toxic Substances in Fish in Some Lakes and Reservoirs
The research results released by the US Environmental Protection Agency on the 10th show that fish in nearly half of the lakes and reservoirs in the United States contain levels of metallic mercury exceeding the standards set by the federal government, which may affect human health.
The Environmental Protection Agency conducted a survey of 500 lakes and reservoirs in the United States between 2000 and 2003, and the fish samples taken were all found to contain metallic mercury and the organic compound polychlorinated biphenyls. Researchers found that fish in 49% of the surveyed lakes and reservoirs contained metallic mercury levels exceeding the safe human intake standards set by the EPA.
The survey results also showed that fish in 17% of the lakes and reservoirs contained polychlorinated biphenyls at levels exceeding the standard.
According to the researchers, excessive intake of metallic mercury can damage the nervous system and endanger human health. Polychlorinated biphenyls are carcinogenic substances that readily accumulate in human fatty tissue and affect the nervous, reproductive and immune systems.
The researchers believe that coal-fired power stations are the main source of mercury pollution in lakes and reservoirs.
The EPA said the research results show the importance of further reducing mercury pollution. The US government said earlier this year that it would begin drafting new rules to control mercury emissions from power stations.
The Environmental Protection Agency conducted a survey of 500 lakes and reservoirs in the United States between 2000 and 2003, and the fish samples taken were all found to contain metallic mercury and the organic compound polychlorinated biphenyls. Researchers found that fish in 49% of the surveyed lakes and reservoirs contained metallic mercury levels exceeding the safe human intake standards set by the EPA.
The survey results also showed that fish in 17% of the lakes and reservoirs contained polychlorinated biphenyls at levels exceeding the standard.
According to the researchers, excessive intake of metallic mercury can damage the nervous system and endanger human health. Polychlorinated biphenyls are carcinogenic substances that readily accumulate in human fatty tissue and affect the nervous, reproductive and immune systems.
The researchers believe that coal-fired power stations are the main source of mercury pollution in lakes and reservoirs.
The EPA said the research results show the importance of further reducing mercury pollution. The US government said earlier this year that it would begin drafting new rules to control mercury emissions from power stations.