Your editorial "Deeper look into Hudson," March 19, misguidedly advocates expanding Hudson River PCB dredging based upon a recent report by the Hudson River Natural Resources Trustees, stating that PCB contamination extends "all the way to New York City."
Our published investigations have revealed primitive "clamshell" dredging mobilizes safely buried PCBs, which is nearly all of the PCBs that were disposed by GE and buried naturally decades ago. Invisible to Environmental Protection Agency performance standards, mobilization increases downstream sediment transport and returns previously buried PCBs to ecosystems, where they concentrate in food chains.
The trustees also reported that "surface waters, sediments, floodplain soils, fish, birds, wildlife and other biota are all contaminated with PCBs." Dredges mainly target PCBs in sediments which, as shown, is not where the action is. PCBs threaten sensitive endangered species such as sturgeon in the lower Hudson River. They also have been linked, in animal studies, with processes that are thought to underlie autism causation in people, but the EPA has refused to address autism risks that river communities may face.
Clamshell dredging has spread PCB sediments to new areas of the riverbed, as is evident to anyone watching GE dredges spreading billowing clouds of non-barged black, brown and gray sediments across the river.
Clamshell dredging may seem "politically correct," but it is part of the problem, not the solution, which we join you in seeking. We recommend renewed consideration of hydraulic dredging, which mobilizes far less sediment, to complete remediation of the Hudson River PCB Superfund Site.
Robert A. Michaels, Ph.D,
Schenectady
and Uriel M. Oko, Ph.D,
Glenmont