What Is A 'Safe' Amount Of PFOA?

Polyfluoroalkyl and perfluoroalkyl substances like PFOA and PFOS have emerged as the contaminants of greatest concern for many consumers. While the U.S. EPA has issued a health advisory with limits on the chemicals, some affected communities wonder if their restrictions go far enough. So, what is an acceptable amount of PFOA in your drinking water?

Perfluorooctanoic acid and perfluorooctanesulfonic acid (PFOA and PFOS) have become the most feared and discussed drinking water contaminants among consumers.

Contamination can be traced back to manufacturers of numerous consumer products, including Teflon™, though many companies agreed to phase out their production of PFOA and PFOS by 2006. The substances were also found to have entered water sources via firefighting foam from military operations, though these too have pledged to put an end to use of the chemicals.

Despite the recent vows to change, communities across the country have found the substances in their water, indicating years of undisclosed consumption. Polyfluoroalkyl and perfluoroalkyl substances (PFASs), a family to which PFOA and PFOS belong, have been known to cause cancer, development effects to fetuses, liver effects, immune effects, thyroid effects, and other complications, according to the U.S. EPA. Town hall meetings have been organized and regulators have been grilled over health concerns.

Where Things Stand
The EPA has not established a national primary drinking water regulation for PFOA and PFOS, though water systems are required to monitor them under the third Unregulated Contaminant Monitoring Rule (UCMR 3) established in 2012, which could be a path to regulation.

“In accordance with the Safe Drinking Water Act (SDWA), EPA will consider the occurrence data from UCMR 3, along with the peer-reviewed health effects assessments supporting the PFOA and PFOS health advisories, to make a regulatory determination on whether to initiate the process to develop a national primary drinking water regulation,” the agency said.

For the EPA to regulate PFOA and PFOS, they must be found to have adverse health effects and occur frequently at levels of public health concern, and there must be a meaningful opportunity for health risk reduction by public water systems, per the SDWA. The agency said that it will continue to evaluate scientific evidence on the need for stricter PFOA and PFOS regulation.

In the meantime, the EPA has established a lifetime health advisory level of 70 parts per trillion (ppt), claiming this would offer a margin of protection for all Americans throughout their life from adverse health effects resulting from exposure to PFOA and PFOS in drinking water.

“EPA has established health advisories for PFOA and PFOS based on the agency’s assessment of the latest peer-reviewed science to provide drinking water system operators and state, tribal, and local officials who have the primary responsibility for overseeing these systems, with information on the health risks of these chemicals,” the agency said. “To provide Americans, including the most sensitive populations, with a margin of protection from a lifetime of exposure to PFOA and PFOS from drinking water, EPA has established the health advisory levels of 70 parts per trillion.”

The agency reached its advisory levels by examining the effects observed in available animal studies.

“EPA modeled data from multiple studies of various duration which observed adverse health effects including development, body and kidney weight, liver, and immune endpoints,” the EPA said. “For both PFOA and PFOS, the reference doses (RfDs) based on multiple adverse effects resulting from shortterm and longer-term exposures, fall within a narrow dose range… EPA selected the RfDs for PFOA and PFOS based on the most sensitive effects so that they are protective for the general population and sensitive life stages.”

However, this advisory is strictly voluntary and water utilities have no obligation to meet it. Furthermore, questions have been raised over the effectiveness of its 70 ppt limit.

A Different Take
The New Jersey Department of Environmental Protection’s Drinking Water Quality Institute (NJDWQI) serves a state with a greater frequency of PFASs in its drinking water than any other besides California, according to a Harvard University analysis. It is responsible for determining maximum contaminant level (MCL) standards for hazardous pollutants in drinking water and, in that capacity, its commissioner asked it to examine PFAS compounds.

“Each compound is examined independently for its health effects, treatability, and detection methods,” said Dr. Keith Cooper, academic governor for NJDWQI and professor of toxicology at Rutgers University. “NJDWQI potential health-based MCL were based on sensitive and well-established animal toxicology endpoints that are considered relevant to humans based on mode of action data.”

NJDWQI shared its findings from that analysis in a September presentation. In regards to the EPA’s 70 ppt advisory for PFOA, the publicly available PowerPoint from that presentation reads, “It cannot be concluded that exposure to these drinking water concentrations is protective of the most sensitive populations with a margin of exposure.”

Among the conclusions shared in NJDWQI’s public report on PFOA were that continued exposure to even relatively low levels of PFOA in drinking water is known to cause substantial increases in PFOA in blood serum and that the considerable evidence for increased risk of health effects from low-level PFOA exposure suggests a need for caution. Ultimately, the NJDWQI concluded that a 14 ppt MCL would be more appropriate.

Cooper did not want to speculate as to how the EPA should determine its health advisories. He did, however, laud the NJDWQI’s approach to determining its own MCL.

“In many instances, it is not the approach as much as it is the specific studies and endpoints used and the risk assumptions applied that you have differences between groups,” he said. “The NJDWQI gains its strength by having a diverse group of experts working on a single compound. The evaluation is based on the science and does not become influenced by the policy issues.”

How To Respond
When asked how it responds to those calling for stricter limits on PFOA and PFOS, the EPA reiterated its criteria for regulating contaminants under the SDWA — its potential for adverse health effects, frequency at levels of public health concern, and whether or not there is a meaningful opportunity for health risk reduction at public water systems — and indicating its evaluation of the chemicals is ongoing.

For those concerned about their exposure to PFASs in drinking water, it may not be wise to wait for federal regulations to tighten. For the time being, individual water systems and institutes like the NJDWQI stand the best chance of protecting consumers from undue exposure. Local options include closing contaminated wells and changing blending rates or treatment with activated carbon or high-pressure membrane systems. In any case, it is worth finding out for yourself.