Then the EPA compiled data from a host of public, private, and academic scientists. The EPA identified nine metals-- arsenic, cadmium, copper, lead, mercury, molybdenum, nickel, selenium, and zinc-- that typically lace batches of sludge. Through a process called "risk assessment,' they evaluated the various ways those contaminants could make their way from sludge to the human body. A child could eat the sludge, for example, or the contaminants may absorb into the tomatoes in your garden. Finally, they evaluated how much of each metal it takes to give a person cancer.
Based on these calculations, the EPA wrote its "Part 503" regulations, which require waste treatment plants to test the sludge and make sure contaminants do not exceed acceptable levels. But recent research sponsored by Cornell University suggests the Part 503 rules that Desiree Lopasic uses to justify land application in Culpeper may be based on shaky science.
"A Case for Caution,' published by Cornell in February 1999 says sludge contains a host of potentially toxic chemicals, but when the EPA wrote its rules, the Agency ignored contaminants that appear in less than 10 percent of sludge or chemicals whose behavior they don't know much about. Furthermore, the EPA experiments assume people will be exposed to only one contaminant at a time and by only one pathway. The 503 rules don't take into account that a family may eat crops grown in sludge and drink milk from a cow grazing in sludged pastures, or that people may be exposed to a combination of arsenic and lead-- and possibly face greater risk.
The concept of "risk" is also debatable. There's no such thing as safety in public health , the Cornell paper reminds us, there's only "acceptable risk." The EPA's 503 rules assume that one case of sludge-related cancer in 10,000 is an acceptable-risk. The Cornell researchers say it should be raised to one in a million, and they say the EPA ignored other risks, such as IQ deficiency or hormonal damage sludge contaminants can cause
If the questions raised by "A Case for Caution" were troubling, the EPA's response was chilling. Ellen Harrison, head of Cornell's Waste Management Institute, testified before the House Committee on Science that the EPA tried to discredit the paper by making false claims about the scientists methods. 'They claimed we used metal salts and not sludges in the study," Harrison said. "That is simply untrue."
Later in the hearings, which were called "EPA Sludge Policy: Closed Minds or Open Debate?" Harrison criticized the EPA for funnelling most of its research money through the WEF, telling Congress that "while the Water Environment Research Fund and related groups provide valuable contributions, they also represent the generators of sludge who have a pro-land application point of view. While that viewpoint is consistent with EPA's position....it is inconsistent with maintaining scientific objectivity.
Although the EPA's own inspector general has written a report saying it's impossible to say sludge is without risk, scientists within the agency are confident in their knowledge.
Dr. Walker at the EPA says they have more information on biosolids than any other compound. As Bonnie Smith from the EPA's public relations department monitored Walker's comments, he explained the EPA is always open-minded about new biosolids research. "We just have no evidence of people getting sick," he says.- 'Oh, that's a good quote,' Smith chimes in.
The public relations machine was in equally high gear at the Water Environment Federation. "Have you been reading Toxic Sludge is Good For You?, asked Nancy Blatt, head of WEF public relations, with an exasperated sigh. "That book is so full of misinformation." For truly reliable information about the WEF, Blatt suggests visiting the group's website, which describes WEF as "the leading technical organization for the water quality industry since 1928.'
She says some members of the WEF represent the waste management industry, but that the federation is not a special interest group. She insists they are not a lobby group, but members of the WEF do "work
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