In Minnesota, officials are adjusting levels for chemicals found in drinking water in the Twin Cities metro area
Minnesota health officials are adjusting acceptable levels for two pollutants found in drinking water supplies in the Twin Cities metro area, based on new scientific data.
The Minnesota Department of Health lowered the health-based advisory values for perfluorooctane sulfonate, or PFOS, to 15 parts per trillion, down from the previous level of 27 parts per trillion set two years ago. According to MPR News, the levels are used to determine whether water from public systems and private wells is safe to drink.
State health officials use scientific research to set health-based advisory values for a variety of chemicals at levels that are likely to pose little or no risk to human health. According to MPR News, the state Pollution Control Agency uses the values to determine whether cities and other public water suppliers must treat their drinking water to reduce contaminants.
The impact of the change is minor, but will allow health officials to accurately evaluate the potential health risks of exposure to the chemicals, manager of environmental surveillance and assessment at the state health department Jim Kelly said.
"It's a tweak, it's a slight adjustment, in our minds," Kelly said. "That's really a very small difference when you're talking about low, low parts per trillion."
According to MPR News, the health department for the first time also set a value for perfluorohexane sulfonic acid, or PFHxS, at 47 parts per trillion. Until now, there has not been enough scientific data available to set a value for PFHxS, Kelly said, so the health department was using the PFOS value of 27 parts per trillion as a substitute.
About 20 years ago, studies found that PFAS were showing up around the globe; in water, soil, wildlife and in humans. According to MPR News, scientists are still studying the health effects of the chemicals, but research has linked prolonged exposure to PFAS to health problems including some cancers, thyroid disease and infertility.