ACS - Researchers Find Little-Known PCB 11 "Pretty Much Everywhere"

[hatrack]

After a half-century of use in products ranging from electrical transformers to caulk to paint, PCBs were banned in the late 1970s as one of the “dirty dozen” persistent organic pollutants. But a little-known PCB is turning up in water and air in cities and watersheds in Illinois, Nova Scotia, and New Jersey. Researchers suspect the chemical is even more widespread, but do not know how—or whether—it affects human health or ecosystems.

In this issue of ES&T, Dingfei Hu and Keri Hornbuckle of the University of Iowa’s department of civil and environmental engineering report that they found PCB 11 (3,3′-dichlorobiphenyl) “in air all over Chicago,” says Hornbuckle (Environ. Sci. Technol. DOI 10.1021/es902413k). PCB 11 is one of 209 compounds, called congeners, in the PCB family. As a group, PCBs accumulate in fatty tissue, and concentrations increase in animals higher up the food chain. However, it is not known whether PCB 11 bioaccumulates.

PCB mixtures known by the trade name Aroclor were manufactured from 1929 to 1979 for commercial use in products, such as electrical transformers, lubricants, and carbonless copy paper. The U.S. banned them after they were linked to cancer and other health problems, but industries were still allowed to produce small amounts of “inadvertent” PCBs as byproducts of other manufacturing processes. In environmental monitoring, however, regulators mainly looked for Aroclor compounds, not inadvertent byproducts, so PCB 11 remained “under the radar” until the late 1990s, Hornbuckle says. In 1998, Simon Litten, a research scientist with the New York State Department of Environmental Conservation, used a method that could detect all 209 congeners. With this technique, he found high levels of PCB 11 in wastewater in New York Harbor and traced it to effluent from a pigment manufacturing plant.

Hornbuckle, who knew of Litten’s work, wondered if the PCB 11 in Chicago’s air could be coming from paint. She and Hu found >50 PCBs in the pigments used in three common paint brands, but PCB 11 was detected most often. “There are many questions,” Hornbuckle says. “Is it toxic? What is its major route into the environment? Can pigments be reformulated so they don’t produce those PCBs as byproduct? We don’t know, because we have not studied that didn’t come from Aroclors.” Hornbuckle suspects that PCB 11 is released when paint vaporizes, and wonders if the chemical could be deposited in nearby waterways, including the Great Lakes.

EDIT

http://pubs.acs.org/doi/full/10.1021/es100692h?cookieSet=1

[FredStembottom]

1. Dingfei Hu and Keri Hornbuckle......

....building on the pioneering research of Stickney Flop and Harllequin Gruntbunny III .

(hit return:dilemma: don't hit return.....)