Federal agency responds to PFC investigation

by Kule Bagenstose and Jenny Wagner, originally posted on January 5, 2017


It’s a question on the minds of many residents in Bucks and Montgomery counties: After decades of drinking water containing PFOA and PFOS, just how much of the mysterious chemicals does their blood contain?

The Agency for Toxic Substances and Disease Registry, an arm of the U.S. Centers for Disease Control and Prevention, revealed Wednesday that it knows the answer for at least some residents who had independent blood tests and then consulted with the agency about the results.

“At the request of a few individuals and their health professionals, ATSDR has reviewed some individual (blood data) from Bucks and Montgomery Counties,” ATSDR health communication specialist Taka Allende wrote in an email.

But the ATSDR won’t be sharing its knowledge of some local blood levels due to privacy concerns, even though this news organization told the agency it was not requesting personally identifiable information, such as names or addresses of those tested.

“With the small numbers (of residents) involved, sharing any … results, even in a summarized form, would violate our policy for protecting individual identities,” Allende wrote.

The information was provided in response to a series of questions sent by this news organization as part of its investigation of the actions being taken by the ATSDR and the Environmental Protection Agency regarding PFOA and PFOS drinking water contamination in the area.

Our early November investigative report specifically questioned the accuracy of statements made by ATSDR officials that blood tests for area residents wouldn’t be valuable.

The following were among our findings:

  • A basic blood testing program can show how much of the chemicals accumulated in the bodies of area residents.
  • Multiple rounds of testing can ensure exposures to the chemicals have stopped.
  • Residents can share their blood level information with their doctors and make decisions regarding screenings for possible health effects.
  • Blood level information, along with other data, can be used in lawsuits, and in health studies to determine whether contaminated water made people sick.

In its responses, the agency acknowledged blood levels, water consumption habits, and medical histories of residents would be useful for health studies.

“Yes, those types of variables would be important to consider in any potential future (health studies) in Bucks and Montgomery Counties,” Allende wrote.

The agency also stated it is developing a guide to help state and local health departments conduct their own health studies, through testing the blood of a “subset” of residents and administering a questionnaire. This information also could be used to compare blood levels across different communities around the country, and track how those levels change over time, the agency wrote.

Whether or not such a program would be implemented in the area remains to be seen. Previously, Pennsylvania Gov. Tom Wolf estimated the cost for a local blood testing program could run as high as $7 million, which he said the state cannot afford.

The ATSDR did not say how much it expects its recommended program would cost. No amount of funding for blood testing has been set aside at the state or federal level.

In other responses to this news organization’s questions, the ATSDR appeared to place itself at odds with some of the science behind the EPA’s 70 part per trillion advised limit for PFOA and PFOS in drinking water, another subject of an investigative report by this news organization.

The EPA is steadfast in saying it is safe to consume 70 ppt or less of the chemicals in drinking water, even over a lifetime. It made the determination in May, after spending years studying what it said is the best available research on the chemicals.

However, some health experts and researchers disagree with the EPA, as does the Drinking Water Quality Institute, an advisory group to the New Jersey Department of Environmental Protection. That group has recommended a 14 ppt drinking water limit for PFOA alone, which is five times lower than the EPA’s advised limit for both chemicals.

Consuming more than that amount, the institute said, could result in health effects that include testicular cancer, liver toxicity, and impaired immune systems and childhood development.

Before they were taken offline in recent years, some public drinking water wells were found to contain the chemicals in excess of 1,500 ppt — more than 20 times the EPA’s advised limit. But because this highly contaminated water was mixed with water from other sources before reaching taps, it’s unclear how much of the chemicals to which area residents were exposed.

Drinking water at the Horsham Air Guard Station also previously tested at more than 15,000 ppt before its use was discontinued. That water was not diluted by other sources.

One of the main points on which the New Jersey institute and EPA disagree is how much of the chemicals accumulate in blood from drinking water.

Citing a series of studies, the New Jersey institute believes that for every 1 ppt of PFOA in someone’s drinking water, over time, 100 ppt will build up in their blood. That’s in addition to the thousands of parts per trillion of the chemicals that already may be in their blood, since historically PFOA and PFOS also have been found in foods, dust and other products.

The New Jersey institute is concerned that the “baseline” levels of PFOA in average Americans already may be causing health effects in the general population. Any unusually high amounts in drinking water would just present an additional risk, according to the institute.

Asked whether it agreed with the 1 to 100 ratio, the EPA wrote that it could not because “too many other variables” exist, including ingestion of the chemicals through food and dust.

Instead, the EPA took a different approach to figure out the significance of drinking water contamination. It used a standard formula that assumes 20 percent of the chemicals in an individual’s body stemmed from drinking water, and 80 percent came from other sources.

While the ATSDR said it agreed with the EPA that “many factors” contribute to chemical levels in blood, it also agreed with this news organization’s assessment that the EPA’s 20 percent assumption — a standard ratio applied to a range of chemicals — may not be accurate for people exposed to highly contaminated drinking water.

“ATSDR agrees drinking water may contribute more than 20 percent to the exposure in (the Bucks and Montgomery) area,” Allende wrote, adding that the agency’s own documentation concluded that “when drinking water is contaminated with (the chemicals), it is often the primary source of exposure.”

The ATSDR also appeared to diverge from the EPA on a related point: whether the 70 ppt advisory is safe for people who already have high levels of the chemicals in their blood. Because the human body struggles to eliminate PFOA and PFOS, it can take anywhere from two to nine years to flush out just half of the chemicals, assuming all other exposures stop.

This news organization has twice questioned the EPA on whether or not highly exposed populations, such as area residents, would be at risk of health effects until the level of chemicals in their blood dropped. Further, we asked if avoiding drinking water containing any amount of the chemicals, even in amounts deemed safe for most people, would help the chemical levels in their blood drop more quickly.

In its responses, the EPA failed to answer the questions directly, and instead reiterated that its 70 ppt advisory is safe and that blood levels of highly exposed people will “slowly decrease” once their drinking water is brought below it.

Asked a similar question, the ATSDR referred comment back to the EPA, but did note that the EPA’s advised limit “does not specifically include” a variable for individuals whose blood levels already are elevated.

Another area of concern is the chemicals’ effect on reproduction. Some research has shown that the chemicals easily pass from mother to child during pregnancy and through breastfeeding, and that the chemicals may be to blame for tens of thousands of low-weight births across the country each year.

The ATSDR says it is reviewing studies on the effects of PFOA and PFOS on birth weight and that such research will be “considered for possible inclusion in the final toxicological profile.”

The agency also wrote that “breastfeeding is linked with numerous health benefits for both infants and mothers. Based on our current scientific understanding, it is recommended that nursing mothers continue to breastfeed.”

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