Month: December 2006

Chemical & Engineering News: Latest News – Bisphenol A May Trigger Human Breast Cancer

Soto and her colleagues exposed pregnant rats to bisphenol A at doses ranging from 2.5 to 1,000 µg per kg of body weight per day. By the time the pups exposed at the lowest dose reached the equivalent of puberty (50 days old), about 25% of their mammary ducts had precancerous lesions, a proportion three to four times higher than among the nonexposed controls. Mammary ducts from all other exposure groups showed elevated levels of lesions. Cancerous lesions were found in the mammary glands of one-third of the rats exposed to 250 µg/kg/day.

Bisphenol A is used in the manufacture of polycarbonate plastics and epoxy resins. It is found in many food and beverage containers, including baby bottles. It is also found in canned food linings and dental composites, and it leaches from all of these products. In one study, Soto notes, urine samples from 95% of the human subjects contained the chemical.

The Environmental Protection Agency has set a safe human intake dose of 50 µg/kg/day for bisphenol A. “On the basis of the effects observed in recent studies, this seems to be an unsafe level,” Soto says.

Bisphenol A is old news, BTW, people have known for a while about this chemical’s propensity to carcinogenicity. Of course, there’s that whole argument about pregnant mice being more susceptible to chemicals than humans, etc. So, the jury is still out. but Soto is right, 50 µg/kg/day seems to not provide enough of a safety factor. The EU uses 10 µg/kg/day, though they do say that

realistic worst-case estimates of consumer exposure via foodstuffs, range from 0.00048 mg/kg bw/day for adults to 0.0016 mg/kg bw/day for infants, which is well below the maximum exposure level

Of course, who knows what additive effects this chemical may have with the multitude of other chemicals floating around. Doing tests of single chemicals and trying to link that to epidemiological data is a perilous undertaking, the connections are tenuous most of the time and the plastics companies routinely fund studies that prove otherwise, because as you know, if you know what you’re going to find before you study it, you will find it!

Read the wikipedia stub on polycarbonates. Us yuppies who drink religiously from Nalgene bottles to avoid phthalates and nasty tastes would do good to take note! I guess glass is the best, though it does have that annoying tendency to shatter when dropped… Water from glass bottles do have the best taste, though.

Now if I were a journalist, that is the tag line I would use, not the lame byline used in this article. Greater is always good, right!

Greater Role for Nonscientists in E.P.A. Pollution Decisions – New York Times

The Environmental Protection Agency has changed the way it sets standards to control dangerous air pollutants like lead, ozone and tiny particles of soot, enhancing the role of the agency’s political appointees in scientific assessments and postponing the required review by independent scientific experts.

Now let’s see which famous “Industry advocacy group” may be behind this one…

The change, which largely tracks the suggestions of the American Petroleum Institute but also adopts some recommendations of the agency’s independent scientific advisers, was announced yesterday afternoon by the agency’s deputy administrator, Marcus Peacock. Mr. Peacock said it would streamline a cumbersome process and bring it “into the 21st century.”

Ah, the 21st century, where scientists know nothing and it is best for groups that will gain most from a weakening of legislation actually write the rules. This way, there’s no pesky “scientist” using “knowledge” to shape policy, only rules written for the short term gain of a few.

It gets worse

For one thing, agency scientists will no longer produce their own independent review of the latest science to start the process of deciding whether a pollution standard — for lead, say, or ozone — is tough enough to protect public health. Instead, initial reviews will now involve both agency scientists and their political bosses and will produce a synopsis of “policy-relevant” science, agency officials said.

“They are using this idea of streamlined and expedited decision-making as a Trojan horse to infect the most important decisions the administrator makes with politics,” Ms. Patton said.

In addition, she said, the role of the independent panel of scientific advisers — who act as auditors, reviewing the document produced by agency scientists and advising top management — has been diminished. The panel, the Clean Air Scientific Advisory Committee, will now comment on the agency’s proposed actions after the public has been notified of them, giving the scientists essentially the same kind of participation as industry lobbyists and environmental groups.

(Emphasis mine). And they wonder why morale at the EPA is low. There are hordes of good (not great, but good!) scientists at the EPA who spend all their lives working on each of their scientific niches, and to take away any decision making or policy input from them is dehumanizing their work. Wonder why the EPA has a lot of trouble attracting talent.