The Minnesota Department of Health (MDH) is taking steps to protect the health of residents in south Washington County from long-term exposure to perfluorochemicals (PFCs) in groundwater.
PFCs are a group of compounds manufactured by 3M Co. and other chemical manufacturers for use in stain repellents, lubricants, fire retardants and other products.
Based on the latest scientific information, MDH has lowered its Health Based Values (HBVs) for perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS), two members of PFC group of chemicals that have been found at low levels in groundwater in southern Washington County. The new HBVs are 0.5 parts per billion (ppb) for PFOA and 0.3 ppb for PFOS. The guidelines previously used were 1 ppb and 0.6 ppb respectively.
“We have been reviewing the available data over the last few months and concluded that there is sufficient scientific basis at this time to justify revising the health based values for PFOA and PFOS,” said Minnesota Health Commissioner Dianne Mandernach.
While research to date has shown no direct evidence that PFCs cause health problems in humans, studies in laboratory animals indicate that at higher doses, PFCs may interfere with liver and thyroid function and may cause developmental effects.
The updated HBVs for PFOA and PFOS take into consideration the potential for health impacts during fetal and other developmental life stages. A clearer understanding of how long these chemicals stay in the human body is also reflecteded in the revised HBVs.
The MDH is working with Oakdale and Lake Elmo to address public and private wells that may be affected by the lowering of the HBVs for PFOA and PFOS. Most residents in the Lake Elmo and Oakdale area will not be affected by the change because they are connected to municipal water systems that don’t contain PFCs or treat the groundwater before distribution.
Intake of contaminated drinking water can be reduced by drinking bottled water or by filtering tap water used for drinking or cooking through a point-of-use (POU) activated carbon filter, which removes or greatly reduces PFBA.
Point-of-use (POU) filters can be an effective way to reduce exposure, according to MDH staff. A faucet-mounted filter containing activated carbon worked well during tests, showing full removal of PFBA through about half of its manufacturer’s predicted filter lifetime, and good removal at up to 80 percent of its lifetime.
Additional information on activated carbon filters can be found by clicking here.