On December 18, 2018, the Michigan PFAS Action Response Team (MPART) published the findings of its independent PFAS Science Advisory Committee regarding the presence, human health risks, and management recommendations for per- and polyfluoroalkyl substances (PFAS) contamination in Michigan. The report, titled “Scientific Evidence and Recommendations for Managing PFAS Contamination in Michigan” was prepared by a panel of diverse, nationally recognized experts from across the country and represents the first such effort conducted on behalf of a state.
Manufactured for more than 50 years, PFAS compounds have been used in thousands of applications throughout industrial, food, and textile industries. They have been used in many industrial applications and consumer products such as carpeting, waterproof clothing, upholstery, food paper wrappings, personal care products, fire-fighting foam, metal plating, and yes, environmental sampling equipment. Many of the properties for which the compounds are considered desirable become problematic in the environment. PFAS compounds are highly soluble, persistent (not readily breaking down in the environment), and bioaccumulative. Their solubility allows PFAS to readily migrate from soil to groundwater and other environmental media. They are found in groundwater, surface water, soil, sediment, food, indoor dust, and the atmosphere.
Most of the currently available toxicity and environmental pathways knowledge is for the long chain PFAS, including the perfluorooctanoic acid (PFOA) and perfluoroctane sulfonate (PFOS) compounds. According to EPA, these chemicals are toxic to laboratory animals and wildlife, producing reproductive, developmental, and systemic effects in laboratory tests. According to the Advisory Committee Report, based on blood testing conducted by the Center for Disease Control Prevention (CDC), four PFAS compounds are likely found in nearly all U.S. residents. The good news, if there is any, is that PFOS blood levels declined (see graph) in U.S. populations from 2000 to 2014 coinciding with declining PFOs use, although they are still used today. In January 2018, based in part on a Federal Lifetime Health Advisory, Michigan set a clean-up standard for PFAS in groundwater used for drinking of 70 parts per trillion (ppt) for combined concentrations of perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS).
Since at least 2017, Michigan has worked to identify locations across the state where PFAS may be present as a contaminant and to share the information with the public. The Michigan Department of Environmental Quality (MDEQ) has conducted testing of drinking water, groundwater, lakes and streams, soils, sediments, wastewater, and the foam that can accumulate on lakes and rivers. MDEQ is partnering with the Michigan Department of Health and Human Services and the Michigan Department of Natural Resources to test fish and wildlife, including deer. The MPART maintains a website, which includes a map of sites where MDEQ has confirmed detections of PFOA and PFOS in groundwater (see figure). The current map (dated January 14, 2019) includes 40 sites, 10 of which are on or impacted by active or former military facilities.
The 99-page Science Advisory Committee report outlines 17 recommendations related to investigation and monitoring, migration and exposure pathways, testing, health advisory levels, and mitigation. More than a few of the panel’s recommendations had been started or completed prior to publication of the report. While the report does not include specific recommendations on acceptable exposure levels, it does weigh in on the U.S. EPA’s lifetime health advisory of 70 ppt for PFOA and PFOS combined in drinking water that Michigan currently uses as its groundwater clean-up criteria, stating the following:
“If one accepts the probable links between PFOA exposure and adverse health effects detected in the epidemiological literature as critical effects for health risk assessment, then 70 ppt in drinking water might not be sufficiently protective for PFOA, and possibly by extrapolation to PFOS.” Based on the available evidence for PFOA, in particular, the combined evidence from toxicology and epidemiology the Panel concludes that the research supports the potential for health effects resulting from long-term exposure to drinking water with concentrations below 70 ppt.”
In deference to the incomplete, but quickly evolving understanding on health effects of specific forms of PFAS, the Panel
“… recommends that all judgments regarding acceptable levels in drinking water should be subject to periodic re-evaluation, with the potential for adopting more or less stringent criteria based on new insights.”
While many states are taking more of a wait and see position, relying in part on federal leadership, Michigan, being no stranger to drinking water health crises, has instead opted to be a leader in understanding and addressing the widespread presence of PFAS and related compounds in the environment. As Governor Risk Snyder states in the introduction to the Science Advisory Panel’s report,
“… their work will serve to inform the people of Michigan and others across the nation as the United States comes to grip with a growing contaminant for which the science continues to emerge.”
Due to the widespread use of PFAS and its physical and chemical properties, PFAS is likely to be present to some degree in one or more environmental media samples at most industrial facilities. In many cases, the contamination will be due to offsite sources, ambient conditions, or cross contamination by field equipment, clothing, or the laboratory. Thoughtful planning and precautions are, therefore, critical in the collection, analysis and evaluation of PFAS data. Please feel free to contact Cox-Colvin & Associates, Inc. for additional information or to assist in PFAS sampling.
Published in Cox-Colvin’s February 2019 Focus on the Environment newsletter.
George H. Colvin is a hydrogeologist with over 30 years of consulting experience. Much of his experience has focused on RCRA Corrective Action, RCRA closure, and groundwater investigation, monitoring, and cleanup. He holds a BS in Geology from Ohio University and MS in geology and hydrology from Vanderbilt University. He is a Certified Professional Geologist with the American Institute of Professional Geologists, a registered geologist in Kentucky, Pennsylvania, and Tennessee, and a Certified Hazardous Materials Manager.