2011-09-29 / News

Potters Cove among Narragansett Bay’s contaminated waters


A researcher at the University of Rhode Island has found low levels of hazardous compounds in the waters of Narragansett Bay. Associate Professor of Chemical Oceanography Rainer Lohmann said that while these compounds do not pose an immediate threat to human or marine life, there is cause for concern should these chemicals continue to build up in the bay.

“We got funded in 2008 to develop, in conjunction with the [Environmental Protection Agency], a simplified sampling project looking for contaminants in the water,” Lohmann said. “That was basically what we did. What we used was a very basic polyethylene sheet that we put in the water for a few weeks and let it enrich with the contaminants that we were interested in. We took it back to the lab, analyzed the results, and came up with some conclusions.”

Lohmann said that the EPA had an interest in several compounds and he didn’t know if they were prevalent and if we should worry about them.

“So we called them emerging contaminants,” Lohmann said.

The study was conducted by former graduate student Victoria Sacks and a team of 40 volunteers at 27 sites around the bay. One of those sites was Potters Cove, right here in Jamestown.

Tests were conducted to determine the presence of three chemical compounds that are not generally tested for by the Environmental Protection Agency. Triclosans are antibacterial agents normally found in personal care items like soaps and toothpaste. The concern about triclosans is that they can lead to bacterial resistance.

Triclosans were found only in a few smaller bays and coves, which might indicate that the water treatment plants are doing a good job in filtering them out. Levels were higher near Providence, and lower to the south.

Polybrominated diphenyl ethers (PBDE) are industrial products used in flame-retardants for mattresses and a wide variety of consumer products. They are banned in some countries, and although they have been phased out in the United States, there are still many products in existence that were manufactured using the chemicals. As might be expected, PBDEs were also found in higher levels in the industrial areas near Providence.

“What we expect to see now that the production [of PBDEs] is banned, or momentarily reduced, is that we’ll see the continuing release of these compounds for several decades because as the things age and as they are used there will be a slow release of these flame-retardants over time,” Lohmann said.

Alkylphenols are often found in detergents and are known to disrupt reproductive systems. Alkylphenols were found in a more uniform picture across the bay and concentrations didn’t vary much.

“Overall, concentrations were always low, so by itself none of this would justify a safety warning,” Lohmann said.

Lohmann added that it is not the individual compounds that are something to worry about but the fact that people are continuously exposed to, and continually discharge a range of compounds.

“Some of those will end up in the water, and some of those will end up in the fish that somebody eats,” Lohmann said.

Lohmann reports that levels of alkylphenol were on the high side in Potters Cove, which possibly indicates a discharge. Triclosans were detected also, but PBDEs were not.

According to Lohmann, the present levels of the three chemical compounds in the bay should not cause any concern about swim- ming in the bay or eating seafood from the bay, but adds that his study only tested for three compounds and that there are likely to be many more out there.

“What I should point out is that we looked at three kinds of compounds, but you could probably look at a hundred more and find those in the bay too,” Lohmann said.

According to Lohmann, there is presently no funding to test for more compounds, although he believes that the EPA is trying to develop guidelines for what compounds to monitor. He is not sure when those guidelines might go into effect.

“If you’re not worried about the fact that we found trace compounds everywhere we looked then there is nothing unusual about my results,” Lohmann said. “If you concerned about the fact that due to the products that we use and the way that we live we are inadvertently releasing compounds into the environment that have a life after the intended use, that’s the part that worries me. It’s the continual low release that is frustrating for people like me.”

As an example, Lohmann cited the use of pharmaceuticals that may have the desired effect on your health, but then go through your body and into the water supply. He also suggested that products could be developed to replace the hazardous flame-retardants by using intelligent design.

Lohmann is presently looking at estrogen compounds in the bay and their effect on fish. In places where there is little rain, fish can change sexes as a result of living in water that contains estrogen, which comes from human and animal waste. Lohmann feels that this may not be a problem in Narragansett Bay because of the significant rainfall in the area, but thinks it should be tested.

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