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EPA doing too little on biosolids, new report says

(July 2, 2002 -- CropChoice news) -- Not only are U.S. Environmental Protection Agency standards governing the use of treated sewage sludge on soil based on outdated science, but the Agency has failed to rigorously enforce them, according to a new report from the National Research Council, the principal operating arm of the National Academy of Sciences.

"There is a serious lack of health-related information about populations exposed to treated sewage sludge," said Thomas A. Burke, a professor of health policy and management at the Johns Hopkins University in Baltimore. He was chairman of the committee that wrote the report. "To ensure public health protection, EPA should investigate allegations of adverse health effects and update the science behind its chemical and pathogen standards."

In 1993, the EPA established the regulation governing application of sewage sludge to land. It required that sludge be sufficiently treated to limit concentrations of certain chemicals and pathogens. Sewage sludge meeting those standards is referred to as biosolids.

Depending on the extent of treatment, biosolids may be applied as a fertilizer where there is limited public exposure to it, such as farms and forests, or on sites with more public contact such as parks, golf courses, lawns, and home gardens.

Since 1992, when a ban on ocean dumping was instituted, applying biosolids to land has reduced the amount of sewage sludge that would otherwise need to be buried in landfills or incinerated. About 5.6 million tons of sewage sludge are used or disposed of each year in the United States, and 60 percent of that is used for land application.

The report urges the EPA to increase its efforts to ensure that companies producing biosolids meet the regulatory requirements to remove or neutralize chemicals and pathogens. EPA also needs to ensure that biosolids are applied in accordance with special management practices. In certain cases, biosolids can be applied with the understanding that the land cannot be used for a specified period to allow pathogens to fall below detectable levels. However, EPA has not been verifying if pathogens are dying off, whether the land is being used for agriculture or grazing, or whether public access is adequately restricted. Field data could help to answer those questions.

"We applaud these efforts to put public health at the forefront and to get a better handle on all the health risks associated with biosolids," says Teri Olle, coordinator of the toxics program for the California Public Interest Research Group (CalPIRG). To see the organization's 1999 report on the issue, go to http://www.calpirg.org/reports/fertilizer.pdf

The National Research Council report also urged the EPA to conduct studies of the potential health risks, or lack thereof, to workers and residential populations exposed to biosolids. Anecdotal reports linking biosolids to adverse health effects, ranging from mild allergic reactions to more severe chronic conditions, along with public concern about those reports, should be investigated. Studies on workers exposed to raw sewage are not an adequate substitute for studies of farmers, gardeners and others exposed to biosolids, the committee concluded.

The report, "Biosolids Applied to Land: Advancing Standards and Practices," is available on the Internet at http://www.nap.edu/catalog/10426.html?onpi_topnews_070202