Half of All Fish In U.S. Lakes Are Toxic

03/18/2010 05:12 am ET | Updated Nov 17, 2011

A new EPA study, the most comprehensive to date, found 268 persistent, bio-accumulative, and toxic (PBT) chemicals--most notably mercury, polychlorinated biphenyls (PCBs), and dioxins and furans--in fish from a nationally representative sampling of 500 lakes and reservoirs. Mercury and PCBs were detected in every fish sample in the study, with mercury concentrations exceeding EPA's recommended tissue-based water quality criterion (of 0.3 ppm) in 49% of the sampled populations.

Exposure to mercury
, even at low levels, can cause neurological damage, memory and learning problems, and delays in speech and reading ability in children. PCBs are probable human carcinogens and can also cause non-cancer health effects, such as reduced ability to fight infections, low birth weights and learning problems.

These findings put in bold relief the actions that must be taken:

1. All of us--but in particular women of child-bearing age and children--must be very careful about the fish we consume. Refer to NRDC Simple Steps' Guide to Mercury in Fish to determine the portion size one should eat of different fish. The guide sorts the fish according to their mercury levels.

2. Before consuming any fish you have caught yourself, check with and follow the local fish advisories maintained by your state or tribal environmental agencies.

3. State and Federal governments must crack down on pollution of our waterways and put the nation's health and protection of the environment first. This means redoubling efforts to enforce the Clean Water Act and putting in place new initiatives that will cut mercury emissions from coal-fired power plants, the primary source of mercury air emissions and a significant contributor to mercury in water bodies.

As reported here just a month ago, EPA has pledged to set standards to limit mercury emissions from coal-and oil-burning power plants by late 2011. We must hold them to it. It is an outrage and an affront to us all that 40 years after the EPA was created, 50 percent of our fishable water bodies contain levels of mercury exceeding those EPA considers safe. Whose water is it anyway, whose air? It is ours, the American people, not the utilities'. Their pollution must be stopped.