Interesting news out today from Inside EPA (subscription required), which is reporting that DuPont Co. is leading a new push by industry to weaken a water pollution limit on the toxic chemical PFOA and other perfluorinated chemicals.

Officials from DuPont, 3M and other PFC companies met behind closed doors last month with the U.S. Environmental Protection Agency to make their pitch. According to the story, by reporter Maria Hegstad, the industry proposal could weaken drinking water limits on PFOA — taking them from the 0.4 parts per billion contained in an EPA health advisory to 1.3 parts per billion in a formal drinking water standard.

The story says:

Industry scientists are urging EPA’s water office to alter its method for assessing the risks posed by perfluorinated chemicals (PFCs) when the office sets drinking water cleanup standards for widespread persistent pollutants — a move that would result in weaker limits than provisional EPA standards and even stricter New Jersey standards set when EPA Administrator Lisa Jackson was the state’s environmental commissioner.

PFOA is another name for ammonium perfluorooctanoate, also known as C8. DuPont Co. has used the chemical since the 1950s at its Washington Works plant south of Parkersburg. C8 is a processing agent used to make Teflon and other nonstick products, oil-resistant paper packaging and stain-resistant textiles.

Around the world, researchers are finding that people have PFOA and other PFCs, in their blood at low levels. Evidence is mounting about the chemical’s dangerous effects, but regulators have yet to set a binding federal limit for emissions or human exposure.

In September, the Obama administration EPA listed PFOA and another PFC, PFOS, among the chemicals it might set new water quality limits on. And that same month, PFCs were among the chemicals EPA said it would “Existing Chemical Action Plans” for under a project to reform regulation of toxic chemicals in the U.S.

According to the Inside EPA report:

Scientists from DuPont and 3M as well as representatives of Japanese manufacturers Asahi Glass and Daikin Industries met with the [EPA] Office of Water staff Oct. 15-16 where they urged the agency to use serum blood levels to set risk-based drinking water standards rather than the traditional approach of using external dose animal testing when setting safe exposure limits.

It goes on:

In one presentation to the office, 3M scientists John Butenhoff and Larry Zobel, DuPont toxicologist Robert Rickard and consultant Harvey Clewell argued that exposure to the chemicals does not result in harm — “No causal associations have been observed” between human exposure and adverse health effects, according to one presentation — and urged EPA to base its risk assessment on blood serum concentrations.

The industry scientists’ slides also argue that occupational exposure data shows there are no harmful effects below 5,000 ppb in human blood.

The story adds:

But a critic of the approach says that very few people have levels of PFOA or PFOS in their blood above 5,000 ppb, making it unlikely that a drinking water standard based on this risk level would be protective. And an Environmental Working Group (EWG) source calls the 5,000 ppb number “really high,” especially considering that population levels of PFOA are at 3-4 ppb, and that’s where health effects are already reported — this is [a] pretty amazing claim.”

The Inside EPA story noted the recent release by the C8 Science Panel of data showing increased cholesterol levels in Parkersburg, W.Va.-area children with an average PFOA level of 69 ppb in their blood.

But, the story didn’t mention a more recent major scientific paper that connected increased cholesterol to PFOA in the blood at levels — an average of 3.8 parts per billion — similar to those found in the general U.S. population.