Environmentalists have been pursuing a campaign to demonize the chemical bisphenol-A (BPA)which is used in some plastics claiming that it has deleterious effects on human health. However, even the highly chemophobic World Health Organization doesn't think that BPA is hazardous.

NPR's Morning Edition program ran a good segment on the issue today which pointed out:

...recent studies done government researchers at the request of regulatory agencies suggest it's very unlikely that BPA poses a health risk to people. And in the past the FDA has relied heavily on this sort of in-house research for its decisions.

In its effort to review the safety of BPA, the FDA called on a high-powered team of government scientists to help answer several key questions.

One is: how much of the BPA a person eats actually makes it into their bloodstream in a dangerous form?

That's an important question because the human body often inactivates potentially dangerous chemicals like BPA as they pass through the intestine and liver.

Once that happens, the chemical is no longer a health risk because it's no longer "bioactive", says Justin Teeguarden, a toxicologist and senior research scientist at the Pacific Northwest National Lab in Richland, Washington.

So with BPA, he says, "you may be exposed to relatively large amounts in the diet. But what matters most is how much of the bioactive form actually reaches your blood and your tissues."

Teeguarden studied 20 men and women who spent a day on a diet loaded with BPA from canned foods and juice in plastic containers. He wanted to know how much bioactive BPA would end up in their blood.

The answer: not enough to measure. "If it is present it is below our limit of detection," Teeguarden says.

Some studies that have found quite high levels of BPA in the blood, Teeguarden says. But he questions whether those results are reliable.

The reason is that to get blood levels that high,a person would have to ingest hundreds or thousands of times more BPA than people typically get in their diet.

"The question is, where did that bioactive BPA come from?" Teeguarden says. And he says one likely answer is that the chemical got into blood samples accidentally sometime after they were drawn from a person's body.

"Contamination is a common problem," Teeguarden says. "We observed it in our own study. But because we were monitoring for it we were able to overcome that particular problem."

The studies that found high levels of bioactive BPA in blood used samples collected in hospitals or doctors' offices, not research settings, Teeguarden says. And those studies did not include a common test to detect contamination.

In addition, new studies find that the chemical is unlikely to be a danger to newborns. Let's hope that the FDA will follow the science in this case instead of bowing to the environmentalist lobby.