The US Environmental Protection Agency claims that its proposal to dredge sections of the Hudson river as part of a programme to remove polychlorinated biphenyls (PCBs) from the environment has been vindicated by a National Academy of Sciences report.

The report, which was commissioned by the EPA and will not be finalised for months, does not specifically address the controversial dredging plan though it does confirm the probable toxicity of PCBs and offers an overview for managing the associated risks. The EPA proposal is being contested by GE which will have to foot the bill for the dredging programme.

The EPA has identified former GE factories along the Hudson River near the New York State capital, Albany, as sources of PCB contamination.