April 2005: Scientists call for a new risk assessment of bisphenol A and report dramatic biases in industry research

What's the issue? Fred vom Saal and his colleagues at the University of Missouri, Columbia, have published a series of papers documenting endocrine disrupting effects by bisphenol A at very low levels. For example (graph to right), male mice have dramatically enlarged and hypersensitized prostates in adulthood when exposed during in utero when their mother is fed bisphenol A at 2 parts per billion (2 micrograms per kg/day) .

Nagel et al. 1997

In another experiment in vom Saal's lab, Howdeshell et al. discovered that females exposed in the womb to comparable levels of BPA reach puberty early.

These are extraordinarily low levels of contamination which under traditional concepts of toxicology would have been unlikely even to have been tested. Because of vom Saal's long history of work with low level effects of natural hormones in the womb (see OSF, Chapter 4), however, he began to run experiments at these new levels. And he discovered troubling effects.

Industry PR flacks and lawyers like Jim Lamb, and even industry scientists like John Ashby (from Zeneca) have been unremitting in their criticisms of vom Saal's research. They point to several industry attempts to replicate vom Saal's experiments which failed, and claim that this failure means that vom Saal's work is unreliable. A review of the most highly publicized industry study, however, reveals that it is their incompetence which led to the failures. Moreover, two independent laboratories have now found results similar to vom Saal's, one in Japan, one in the US.

UPDATE: In May 2000 at a scientific meeting in Copenhagen, Denmark, Ashby reversed his long-standing position on vom Saal's work and stated: "I would like to place on record that I am in no doubt about the results that Fred vom Saal had found." [pS 300, Andersson et al. 2001.]

Further update: In March 2003, Welshons et al. published an analysis suggesting that the two main industry attempts to replicate vom Saal's work failed because their control animals were inadvertently estrogenized by a contaminant, and thus unable to respond normally to bisphenol A.

vom Saal's work ups the ante dramatically: his research focuses on the effects at very low doses of compounds that currently are big sources of income for a number of companies.

The acceptable daily intake dose for bisphenol A--which generates revenues on the order of $1 million per day worldwide--had been set by data reported by the Society of Plastics Industry based on a no-effect level of 50 milligrams/kg, or 50 parts per million. vom Saal's data indicates the acceptable daily dose for this compound should be at least 25,000 times lower than the current standard.

These were levels thought completely irrelevant by traditional toxicology. Unfortunately, they were also background levels... experienced by many people living normal lives in the real world, not just (just) individuals whose circumstances had them growing up beside a toxic waste dump or exposed because by excesses of occupation.

That is why vom Saal's research, and an increasing volume of data from other laboratories asking questions about low level impacts, is so important and challenging to current regulatory standards, and via regulatory standards, to common practices in the chemical industy. vom Saal's work shows that every day levels matter.

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