CDC report warns of sludge danger
Scientists and medical researchers are raising concerns that municipal sludge spread on farm fields across the U.S. may be responsible for illnesses and even deaths.
Officially known as “Class B biosolids,” the sludge is made from human sewage and hospital waste. The U.S. Environmental Protection Agency, which authorized the field-spreading of sludge in its 1993 “Sludge 503" rule, steadfastly defends the sludge as harmless to humans.
But in a recently released report, the Centers for Disease Control found Class B sludge to be the likely cause of a rash of illnesses among sludge handlers in LeSourdsville, Ohio. According to the report, the workers contracted gastro-intestinal diseases through either ingestion or inhalation of pathogens contained in the material.
The CDC report recommends certain safety precautions be taken by workers handling Class B sludge--including the wearing of “protective clothing, boots, goggles, and face shields.” It further says sludge-handlers should immediately use on-site showers after completing their work, and gear should be cleaned or discarded after use. Such precautions are not mentioned in EPA’s sludge-handling regulations.
A scientist close to the CDC study expressed concern not only for sludge-handlers’ safety, but for the general public’s safety as well. Speaking on condition of anonymity, the scientist said Class B sludge could even, in some cases, contain “super bugs,” bacteria resistant to modern antibiotics.
EPA microbiologist David L. Lewis Ph.D., who has been raising concerns about EPA’s sludge policy since 1996, agrees. “The CDC study shows what a serious oversight it was for EPA to approve Class B sludge without a comprehensive risk assessment for pathogens,” he said.
CDC’s Dr. Greg Wagner, who is drafting the agency’s new policy on Class B sludge, said he considers the report to be the best work done on the subject to date.
A second investigation is underway involving illnesses contracted by United Mine Workers members working with Class B sludge in Pennsylvania. The material is also suspected in the deaths several years ago of a boy in Pennsylvania and a New Hampshire man.
A spokesperson for Northfield, Illinois-based Kraft Foods, Inc. said the company refuses to accept food products grown on sludge-covered farm fields.
In Kern County, California, county supervisors voted to phase out the dumping of all but “exceptional-quality” sludge--one grade above Class A. Neither “exceptional quality” nor Class A sludge has been linked to pathogen hazards. “It frightens me . . . what we don’t know about biosolids and what scientists may learn tomorrow,” Supervisor Pete Parra told The Bakersfield Californian.
Chicago investigation exposes sludge
Over 20,000 tons of potentially disease-causing sludge is produced every year by the Metropolitan Water Reclamation District of Greater Chicago. Over 60 farm fields used for the disposal of sludge were identified in a recent Chicago Sun-Times investigation.
Officials at EPA, the Water Reclamation District, and Wheelabrator Technologies Inc.--whose BioGro division is a prime sludge contractor for the district--strenuously deny the material poses a threat to human health. All dismissed the CDC report as irrelevant to their operations.
In a wide-ranging meeting with the Sun-Times, top Water Reclamation District officials insisted Class B sludge represented no health risk. They defended EPA’s “Sludge 503" rule at length. Tom O’Connor, chief of maintenance and operations for the Water Reclamation District, said he has confidence in the sludge rule but “would be open-minded” to any new data.
John Colletti, representing EPA region 5 in Chicago, said the CDC report showed only that workers should use common sense when handling sludge. He indicated the report would not cause EPA to re-evaluate its sludge regulations.
Wheelabrator’s public relations consultant, Bill Plunkett said only that “the LeSourdsville study appears to be inconclusive and adds nothing to the body of knowledge about biosolids.”
A history of controversy
EPA’s Class B sludge 503 Rule was developed in 1993 as an alternative to ocean dumping of sludge from municipal waste treatment plants. But the rule’s author, EPA’s Dr. Alan Rubin, testified before the New Hampshire legislature that “[sludge] wasn’t too toxic for the ocean [where much of it had been dumped previously]. The reason we got it out of the ocean was basically an image-political deal.”
Rubin was testifying, in part, to refute questions raised about the safety of Class B sludge and Lewis’s concern that sludge exposure may have resulted in the death of a New Hampshire man, Shayne Connor.
Lewis is well known in the scientific community for his research into the ability of viral, bacterial, and fungal human pathogens to survive in the environment. His work led to extensive changes in the way dental instruments are sterilized. While his peer-reviewed work on sludge was published in a recent issue of British science journal Nature, he began raising concerns about the dangers of Class B sludge as early as 1996.
At the time of Rubin’s testimony, Lewis was investigating the death of Connor, who was exposed to Class B sludge near his home in Greenland, New Hampshire and became ill, along with other residents of the town, with flu-like symptoms.
“Medical records of Shayne Connor [who died in 1995] and Tony Behun [an 11-year-old Pennsylvania boy who died within days of riding his motorcycle on a sludge-covered field in 1994] are consistent with exposure to a combination of chemical and biological hazards associated with sludge,” Lewis said. “In both cases, workers handling the sludge experienced similar symptoms, including nausea, vomiting, severe headaches, sore throats, skin irritation, respiratory problems, and flu-like symptoms.
“In Shayne’s case, the plant that produced the sludge responded to worker complaints by building enclosures to protect them from noxious gases emitted by the material. In Tony’s case, workers who were getting ill requested a Centers for Disease Control investigation [which is now being carried out].”
For his trouble, Lewis has been subjected to harassment and other job-related discrimination by EPA officials. He has already won two lawsuits against the agency, and a third suit is pending. EPA has since ordered him to cease even his private research on sludge.
This report is based on a Chicago Sun-Times investigation by Frank Main and Tom Randall.