Tons of chemicals in antibacterial soaps used in the bathrooms and kitchens of virtually every home are being released into the environment, yet no government agency is monitoring or regulating them in water supplies or food.
About 75% of a potent bacteria-killing chemical that people flush down their drains survives treatment at sewage plants, and most of that ends up in sludge spread on farm fields, according to Johns Hopkins University research. Every year, it says, an estimated 200 tons of two compounds -- triclocarban and triclosan -- are applied to agricultural lands nationwide.
The findings, in a study published last week in Environmental Science & Technology, add to the growing concerns of many scientists that the Environmental Protection Agency needs to address thousands of pharmaceuticals and consumer product chemicals that wind up in the environment when they are flushed into sewers.
Antibacterial soaps: An article in Wednesday's Section A about two chemicals in antibacterial soaps said triclocarban is an ingredient in toothpaste, some kitchen supplies and baby toys. It is triclosan that is used in those products. The article also said the chemicals could be accumulating in water. It is more accurate to say they are contaminating some water resources but not building up in them. The article also referred to microbes that might have reduced resistance to antibiotics. It should have said increased resistance.
From dishwashing soaps to cutting boards, about 1,500 new antibacterial consumer products containing the two chemicals have been introduced into the marketplace since 2000. Some experts worry that widespread use of such products may be helping turn some dangerous germs into "superbugs" resistant to antibiotics.
Triclocarban, an ingredient of antibacterial bar soaps and toothpaste, is "potentially problematic" because it breaks down slowly, which means it is accumulating in soil and perhaps water, said Rolf Halden, an assistant professor at Johns Hopkins' Department of Environmental Health Sciences, who led the study.
"What we are finding is this chemical is building up in the environment," Halden said. "This is an example of an emerging contaminant. It has been in the environment for almost five decades, and we manufacture large volumes of it, but we don't know what happens to it."
The scientists calculated that a large, modern East Coast sewage treatment plant spreads sludge containing more than 1 ton of triclocarban onto farm fields every year. The plant was not identified by the researchers, but data in the study indicated that it was in Baltimore.
Southern California's sludge has not been analyzed for antibacterial chemicals. But households in the Los Angeles region are likely to be a major source, because sewage plants in the area produce hundreds of thousands of tons of sludge every year.
- L. A. Sludge Sought for Use at 2 Landfills Jan 07, 1988
- New U.S. Sludge Rules May Affect Disposal in L.A. Area Jan 25, 1989
- Despite the Stigma, the Future of Sewage May Be to Renew Land Mar 18, 1990
