Environmental ▼News Staphylococcus not found in sludge, but controversy continues taphylococcus aureus, a bacteriraw and undigested sewage sludge sludge application (www.biomed um that can cause serious insamples. No S. aureus (at a deteccentral.com/1471-2458/2/11). For fections, is uncommon in tion limit of less than 30 colonies in several years, Lewis and David treated sewage sludge, according to 100 grams) were found from any of Gattie have argued that exposure to research published in the September the biosolids tested. They also treated sludges delivers a one-two 15 issue of ES&T (pp 4027–4030). failed to find S. aureus in aerosols punch to neighbors. Chemicals The findings undermine controverusing a technique that has been used to treat the sludge irritate skin sial allegations that some people demonstrated as effective in control and breathing pathways, which who live close to sludged makes people more vulland have become sick. nerable to pathogens in “This paper is important the sludge or elsewhere because it knocks down the (Environ. Sci. Technol. idea that S. aureus is aero2002, 36, 286A–293A). solized and results in expoLewis’s long-standing clash sure,” says Charles Haas, a with EPA over sludge risks microbiologist at Drexel led to his termination in University, Philadelphia, Pa. May. He is still embroiled “It is good work—they samin legal actions against EPA pled a large number of loand Synagro, a major cations; conducted careful, biosolids company. thorough analysis; and docS. aureus bacteria are umented their limitations.” not rare. They are comBut former U.S. EPA monly found on the skin microbiologist David Lewis, and in the noses of healthy who has been investigating people. Most S. aureus inResearchers specifically looking for infectious S. aureus did not find these bacteria in treated sewage sludge. links between sludge expofections are minor erupsure and illness and whose tions like pimples and work prompted Patricia Rusin’s inexperiments, according to WQC diboils; however, these bacteria can vestigation, vehemently objects. rector and coauthor Ian Pepper. cause serious and sometimes fatal “This paper completely misrepre“This is evidence that biosolids are ailments, such as bloodstream and sents our work,” he says. “We never an unlikely source of S. aureus insurgical wound infections and claimed that residents were solely fection,” says first author Rusin. pneumonia, according to the vulnerable to direct infection by S. This is the first time that reCenters for Disease Control (CDC). aureus in biosolids. We argue that searchers have specifically set out S. aureus tends to enter the body chemicals in the sludge make resito look for S. aureus in treated through cuts or irritated mucus dents more vulnerable to infection.” sludge, according to Pepper. The membranes and skin abrasions. The ES&T paper comes from miWQC, which receives about 25% of The widening range of antibiotic recrobiologists with the National its funding from industry, is now sistance genes found in the bacteria Science Foundation Water Quality conducting a much larger investimakes treatment formidable, acCenter (WQC) at the University of gation into the fate and transport of cording to Joseph John, Jr., profesArizona, Tucson, who sampled raw pathogens associated with treated sor of medicine at the Medical and treated sludge from 15 sites in sludge, he adds. University of South Carolina and the Southwest and in eastern parts Lewis and colleagues raised conchief of the medical service at the of the United States. They analyzed cerns about S. aureus in June 2002 Veterans Administration Medical biosolids from all of the sites as well when they investigated problem Center in Charleston, S.C. as biological aerosol samples taken sites and reported a higher than exMany activists and some scienwithin 2–30 meters of fields where pected incidence of such infections tists contend that exposure to treatbiosolids had been applied. among people who claimed to have ed sludge is making people sick. They only found S. aureus in the gotten sick from living close to a The Cornell Waste Management PHOTODISC
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Such attention to problem sites is long past due, according to Cornell Waste Management Institute Director Ellen Harrison, who notes that Rusin and colleagues fail to address what could be happening at problem sites. Only some sites where treated sludge is applied to land appear to be associated with illness, she says. It might be more productive to specifically examine these locations. “This paper, while interesting, doesn’t appear to address the questions about what’s happening at sites where people are becoming ill,” she says. —REBECCA RENNER
Endocrine disrupter found in aircraft deicer
STEVE CORSI, U.S. GEOLOGICAL SURVEY
With a little bit of detective work and some “reverse engineering”, scientists have discovered what may be contributing to the toxicity of aircraft deicing fluids. In the September 15 issue of ES&T (pp 4031–4037), Steven Corsi of the U.S. Geological Survey (USGS) in Middleton, Wis., and colleagues report finding alkylphenol ethoxylate surfactants in various aircraft deicers and one of their breakdown products, nonylphenol, a known endocrine disrupter, in streams receiving airport runoff. Although the main ingredient in aircraft deicers is either propylene glycol or ethylene glycol, numerous studies have shown toxicological effects of deicer solutions that can-
Nonylphenols have been found in streams that receive airport deicer runoff.
not be attributed to these two chemicals. Manufacturers are reluctant to disclose what kinds of additives are in their deicer formulations, which often include surfactants, corrosion inhibitors, flame retardants, dyes, and foam suppressors. “All of the additives are proprietary, which makes it real difficult for us to determine what is causing the true toxicity,” Corsi says. Using a technique called fast atom bombardment mass spectrometry, coauthor Jennifer Field of Oregon State University screened nine different aircraft deicers for numerous surfactants. Nonylphenol ethoxylates showed up in three of them, and octylphenol ethoxylates showed up in two. Alkylphenol ethoxylates are non-ionic surfactants widely used to reduce surface tension in numerous products, including detergents, paints, pesticides, and now aircraft deicers. The chemicals have been shown to break down during wastewater treatment processes into more toxic alkylphenols, which have estrogenic properties. Even though octylphenol is 10–20 times more estrogenic than nonylphenol,
News Briefs Farmed salmon highin PCBs Seven out of 10 U.S. farm-raised salmon have polychlorinated biphenyl (PCB) levels that exceed U.S. EPA health standards for PCBs in wild fish, according to an independent analysis commissioned by the nonprofit Environmental Working Group (EWG). The tests, which were the first ever conducted on farmed salmon from U.S. grocery stores, suggest that the fish contains more PCBs than any other protein source in the U.S. food supply. Compared with wild salmon, farmed salmon contains an average of 16 times more dioxin-like PCBs, according to the analysis. The U.S. Food and Drug Administration’s store-bought fish standards are 500 times less safe than EPA’s for wild fish, according to EWG. PCBs in Farmed Salmon: Factory Methods, Unnatural Results is available at www.ewg.org/reports/ farmedPCBs.
Extracting commitments Energy and mining companies that do not make clear their commitments to the environment may be risking their businesses, according to Insight Investment, one of the United Kingdom’s largest investment managers. “Growing resource scarcity, increasing development pressures on biodiversity, and escalating public concern mean this issue will present a greater business risk for extractive and utility companies in the future,” says Kerry ten Kate, Insight’s director of investor responsibility. Insight’s research shows that 45% of extractive companies make little or no mention of biodiversity or environmental conservation in their public documents. For more information, go to www. insightinvestment.com.
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NOAA
Institute in Ithaca, N.Y., has compiled a database of about 40 incidents in 15 states that affected more than 300 people, as of February 10, 2003. However, a recent National Research Council committee found no documented evidence that exposure to treated sludge is causing illness. But the committee also found that no government agency has investigated or tracked health complaints (Environ. Sci. Technol. 2001, 35, 338A). EPA has promised to work with the CDC and other public health agencies to remedy this deficiency (Environ. Sci. Technol. 2003, 37, 212A).
