December 5, 2013
Traces of 18 unregulated chemicals were found in drinking water from more than one-third of U.S. water utilities in a nationwide sampling, according to a new unpublished research (Abstract Book - SETAC North America 34th Annual Meeting) by federal scientists.
Included are 11 perfluorinated compounds, an herbicide, two solvents, caffeine, an antibacterial compound, a metal and an antidepressant, reports Environmental Health News.
While studies increasingly report newly emerging contaminants in wastewater, there has been little data on which ones are in drinking water.
Researchers from the U.S. Geological Survey (USGS) and the U.S. Environmental Protection Agency (EPA) analyzed single samples of untreated and treated water from 25 U.S. utilities that voluntarily participated in the project.
Twenty-one contaminants were detected - mostly in low concentrations of parts per trillion - in treated drinking water from at least nine of the utilities.
Eighteen of the chemicals are not regulated under the federal Safe Drinking Water Act so utilities do not have to meet any limit or even monitor for them.
For many of the contaminants, little is known about potential human health effects of low doses.
But one of the perfluorinated compounds, known as PFOA, has been linked to a variety of health problems, including cancer, among people in communities where water is contaminated by a chemical plant in West Virginia.
Of 251 chemicals, bacteria, viruses and microbes the scientists measured,
Four of the chemicals found in the samples,
...are on the EPA’s list of chemicals under consideration for drinking water standards.
The EPA plans to make decisions regarding at least five of the contaminants on its list next year.
Perfluorinated chemicals, which were found most frequently, are widely used in a variety of industrial processes, including manufacture of some nonstick and stain-resistant food packaging, fabrics and cookware.
The two most common perfluorinated compounds, PFOS and PFOA, in the utilities’ water have been detected in the blood of nearly all people in the U.S.
A panel of scientists has concluded there is a "probable link" between PFOA in drinking water and,
The findings were based on people in Mid-Ohio Valley communities whose water was polluted with PFOA from a DuPont plant.
The EPA has classified metolachlor as a possible human carcinogen based on studies of highly exposed rats. Strontium can affect bone growth, according to some animal studies that used doses much higher than those found in drinking water.
The perfluorinated compounds were at similar concentrations in the untreated and treated drinking water, suggesting that treatment techniques are largely unsuccessful.
Only one plant was successful at removing them and it used activated carbon treatment.
...are generally better at removal than traditional chlorine treatment, but such techniques are often prohibitively expensive, said EPA research chemist Susan Glassmeyer, who led the project.
Treatment also can sometimes transform compounds into new ones, said Laurel Schaider, a research associate at the Harvard School of Public Health.
Glassmeyer said the utilities, which remain anonymous, represented a mix of large and small and used different water treatment technologies.
Preliminary findings of the study, which is expected to be published next year, were presented by the scientists at a toxicology conference in Nashville last month.