Department of Our Declining National Health

Crap like this tale of industry-friendly government agencies rekindles my disgust with John Kerry for running such a poor presidential campaign. Not that Kerry isn't a corporate Democrat who sucks from the same teat as Bush, but I don't think he is quite as dismissive of science as the dauphin. Mind you, this particular article doesn't particularly dwell on regulatory issues, but they bubble, right below the surface, as evidenced in the sentence: Some scientists, many of them in industry, dismiss such concerns. Yes, yes, pollution is just fine, we wouldn't want to lower any chemical company's profits by one iota to make everyone's planet better.... - Common Industrial Chemicals In Tiny Doses Raise Health Issue:
For years, scientists have struggled to explain rising rates of some cancers and childhood brain disorders. Something about modern living has driven a steady rise of certain maladies, from breast and prostate cancer to autism and learning disabilities.

One suspect now is drawing intense scrutiny: the prevalence in the environment of certain industrial chemicals at extremely low levels. A growing body of animal research suggests to some scientists that even minute traces of some chemicals, always assumed to be biologically insignificant, can affect such processes as gene activation and the brain development of newborns.
An especially striking finding: It appears that some substances may have effects at the very lowest exposures that are absent at higher levels.

Some scientists, many of them in industry, dismiss such concerns. But the new science of low-dose exposure is challenging centuries of accepted wisdom about toxic substances and rattling the foundation of environmental law.
Modern pollution restrictions aim to limit exposures to levels past studies have found safe. For example, it's known mercury can cause learning problems in children if it's above 58 parts per billion in the bloodstream. Dividing 58 by 10 to provide a margin of safety, U.S. regulators advise that children and young women not accumulate more than 5.8 parts per billion of mercury, by limiting consumption of certain fish such as tuna. But what if it turned out some common substances have essentially no safe exposure levels at all? That was ultimately what the U.S. Environmental Protection Agency concluded about lead after studying its effects on children for decades. Indications some other chemicals may have no safe limits have led regulators in Europe and Japan to bar the use of certain compounds in toys and in objects used to serve food. In the U.S., federal scientists are devising new tests that could be used to screen thousands of common chemicals to make sure they're safe at extremely low exposures. Using advanced lab techniques, scientists have found that with some chemicals, traces as minute as mere parts per trillion have biological effects. That's one-millionth of the smallest traces even measurable three decades ago, when many of today's environmental laws were written. With some of these chemicals, such trace levels exist in the blood and urine of the general population.

a few more excerpts, the whole article is worth reading if you can....

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For their part, companies and industry groups have attacked low-dose research as alarmist and are challenging the findings with scientific studies of their own. Some industry studies have contradicted the low-dose findings of university and government labs. One reason, says Rochelle Tyl, a toxicologist who does rodent studies on contract for industry groups, is that academics seek “to find out if a chemical has an intrinsic capacity to do harm,” while industry scientists try to measure actual dangers to people. The result is that low-dose research has sparked a number of heated scientific and regulatory controversies: • Tiny doses of bisphenol A, which is used in polycarbonate plastic baby bottles and in resins that line food cans, have been found to alter brain structure, neurochemistry, behavior, reproduction and immune response in animals. Makers and users of the chemical maintain, citing a Harvard review of 19 studies, that the chemical is harmless to humans at such levels. (See illustration)   • Minute levels of phthalates, which are used in toys, building materials, drug capsules, cosmetics and perfumes, have been statistically linked to sperm damage in men and genital changes, asthma and allergies in children. The U.S. Centers for Disease Control and Prevention has detected comparable levels in Americans' urine. Manufacturers say there is no reliable evidence that phthalates cause any health problems.   • A chemical used in munitions, called perchlorate, is known to inhibit production of thyroid hormone, which children need for brain development. The chemical has been detected in drinking-water supplies in 35 states, as well as in fruits, vegetables and breast milk. The EPA has spent years mulling what is a safe level in drinking water. The Defense Department and weapons makers maintain it is harmless at much higher doses than those that Americans ingest.   • The weed killer atrazine has been linked to sexual malformations in frogs that were exposed to water containing just 1/30th as much atrazine as the EPA regards as safe in human drinking water. The herbicide's main manufacturer, Syngenta AG, says other studies prove atrazine is safe. The EPA favors more study. ... Environmental chemicals don't exist in isolation. People are exposed to many different ones in trace amounts. So scientists at the University of London checked a mixture. They tested the hormonal strength of a blend of 11 common chemicals that can mimic estrogen.

Alone, each was very weak. But when scientists mixed low doses of all 11 in a solution with natural estrogen -- thus simulating the chemical cocktail that's inside the human body today -- they found the hormonal strength of natural estrogen was doubled. Such an effect inside the body could disrupt hormonal action.
“In isolation, the contribution of individual [estrogen-like chemicals] at the concentrations found in wildlife and human tissues will always be small,” wrote the scientists, led by Andreas Kortenkamp, who directs research on endocrine disruptors for the EU. But because such compounds are so widespread in the environment, the researchers concluded, the cumulative effect on the human endocrine system is “likely to be very large.”
To test chemicals, toxicologists traditionally dose animals with a single substance and then dissect them. But this method can't spot the subtle effects associated with today's multiple exposures to low-dose chemicals, says John Bucher, of the National Institute of Environmental Health Sciences.

Now he and his boss, Christopher Portier, are revamping the federal government's National Toxicology Program, which sets standards for how chemicals are tested. Over about seven years, they hope to develop a series of lab tests that will ultimately screen some 100,000 industrial compounds, individually and in mixtures, for biochemical “markers” such as effects on specific genes.
The chemicals then will be ranked by mechanism of action and suspected toxicity, and assigned priorities for further study. “It's taken us 25 years and $2 billion to study 900 chemicals,” Dr. Portier says. “If this works, we can study 15,000 in a year.”

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This page contains a single entry by Seth A. published on July 25, 2005 10:55 AM.

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