Perfluorinated Chemicals: An Emerging Contaminant
An emerging contaminant of significant interest to regulators and the public is a class of chemicals known as perfluorinated chemicals (PFCs), human-made chemicals that do not naturally occur in the environment. PFCs are persistent in the environment (i.e., there is no natural degradation process) and have been linked to a number of adverse health effects. Although several specific types of chemicals are under the broad category of PFCs, the two of greatest interest are perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS), which typically are found in the environment at higher concentrations than other PFCs.
Uses of PFCs and Sources in the Environment
Because PFCs repel water and oil and are resistant to heat and chemical reactions, they were used in the historical manufacture of several materials, including waterproof and stainproof fabrics, carpets, some non-stick cookware, leak-proof coating on packaging materials, and aqueous film-forming foam, a type of fire-fighting foam. PFCs also are used as an additive in enhanced petroleum recovery.
Contamination from PFCs can be found at commercial and military airports, fire-fighting training facilities, oil refineries, landfills, and agricultural land receiving applications of PFC-contaminated wastewater and biosolids.
Manufacturing plants are some of the biggest contributors of PFCs to the environment through improper disposal of solid and liquid waste containing PFCs. In West Virginia, the DuPont manufacturing plant was found to be responsible for a significant PFC release that resulted in several class action lawsuits and a settlement for $16.5 million with the U.S. Environmental Protection Agency (EPA). In Minnesota and Alabama, 3M Company was found to be responsible for significant amounts of PFC contamination. While 3M has largely avoided serious financial and legal consequences, the company is being pursued through several lawsuits.
PFCs have been found in air, water, and soil throughout the United States. Because PFOA and PFOS are stable in the environment and do not naturally degrade over time, concentrations accumulate in these media, most significantly in groundwater. PFOA and PFOS in groundwater are a unique concern because they do not sorb onto aquifer materials, and can travel long distances from the source of contamination. Groundwater used as drinking water is a direct source for human exposure.
Health Effects Caused by Exposure to PFCs
Potential pathways for human exposure include ingestion of contaminated food and water, inhalation of contaminated air, and use of commercial products containing PFCs. Studies have shown that PFOA and PFOS have been detected in human blood samples collected from the general United States population, suggesting that exposure to PFCs is widespread.
Exposure to PFCs has been shown to have several adverse effects on human health, including delayed fetal and neurological development; and reduced liver, kidney, and immune function. Additionally, exposure to PFCs has been linked to kidney, liver, testicular, thyroid, and pancreatic cancers.
Regulations on PFCs through EPA
EPA has taken several regulatory steps to limit and terminate the use of PFCs in the U.S. over the past few decades. EPA also establishes nonregulatory Health Advisories that provide information regarding contaminant concentration levels for which adverse effects are not anticipated. The table below shows how EPA Health Advisory concentration levels for PFOA and PFOS in groundwater have decreased over time, suggesting that the acceptable level for protection of human health is still unknown.
Treatment Options for PFC Contamination
While the technology to remove PFC contamination from soil is limited, several technologies to remove PFCs from drinking water are available, with varying degrees of success. In most cases, the procedure for sites with known contamination is to extract contaminated groundwater, treat it, and discharge the treated water to the sanitary sewer or a surface water body.
Standard municipal and home treatment technologies do not employ the methods that remove PFCs in drinking water. Some of these technologies can be used in-home, but are expensive and require in-home installation, monitoring, and maintenance. Many counties that have detected PFCs in drinking water either are not pumping water from contaminated wells, or are blending contaminated water with uncontaminated water to reduce concentrations of PFCs.
The Future of PFC Contamination in Groundwater
As government and private research facilities continue to study the effects of exposure to PFCs on human health, it can be expected that acceptable concentration levels will continue to decrease and will include enforceable regulatory limits. Testing of both public and private drinking water for PFCs likely will increase.
It is highly unlikely that public water agencies and private well owners will have the funds to treat contaminated water, or an ample water supply available to dilute it. It is more likely that these stakeholders will attempt to identify the sources of contamination by testing groundwater at existing and new wells, and will pursue responsible parties for the cost of remediation.
Depending on the extent of contamination, the remediation process could be very costly for responsible parties, and likely will include significant additional costs from class-action lawsuits filed by third parties.
PFCs are not the only emerging contaminants under EPA scrutiny. Staying abreast of information regarding emerging contaminants such as PFCs is an important way for companies to determine the best possible environmental management practices to employ, and to minimize possible future liability.
For more information please contact Cliff Schmitt or Mark Havighorst.
