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Poisonous Chemicals or Poisoned Media Coverage?
July 22, 2005
Trevor Butterworth
CDC report on environmental chemical exposure triggers wildly different response in media.

The Centers for Disease Control had some good news for the American public yesterday, when it announced the results of its Third National Report on Human Exposure to Environmental Chemicals – an attempt to monitor track chemical compounds or elements in the air, water, dust, soil and food.
In referring to the reductions,, CDC Director Julie Geberding described the reduction in levels of lead in young children as “astonishing public health achievement.” When it came to other chemicals, Geberding stressed that ``It is important to reassure people that for the vast majority of chemicals, there is no evidence of health effects.''

Many news organizations reported the news in a positive light:

“CDC: Toxin levels dropping” – Newsday
“In Americans, Lower Levels of Chemicals” – Washington Post
“Drop reported in levels of some harmful chemicals” – San Jose Mercury News
“Americans freer from lead, secondhand smoke” – Fort Worth Star Telegram
“Amount of hazardous chemicals in Americans’ bodies on the decline” – Baltimore Sun
“U.S. bodies storing fewer bad chemicals” – Salt Lake Tribune

But some chose to go the scaremongering route:

“Dozens of Chemicals Found in Most American’s Bodies” – Los Angeles Times
“Presence of Harmful Chemicals In Humans Is Broad, Common” – Wall Street Journal

Here’s how the LAT opened its news account:

“In the largest study of chemical exposure ever conducted on human beings, the U.S. Centers for Disease Control and Prevention reported Thursday that most American children and adults were carrying in their bodies dozens of pesticides and toxic compounds used in consumer products, many of them linked to potential health threats.”

. It wasn’t until the fifth paragraph that the LAT let readers in on the unambiguously positive news on children’s exposure to lead and secondhand exposure.

Why is this problematic? Surely the newspaper would have been remiss not to note that the report brought ill tidings for public health? Who wants to be larded (literally) with pesticide residues, PCBs and phthalates?

First of all, this is the third report, so it’s not as if the presence of many of these chemicals is something of a newsflash (although the CDC did expand the number of chemicals monitored). But the real problem is that fact was displaced by speculation in terms of prioritizing what was news. The actual health benefits of a reduction in lead took second place to the “potential health threats” claimed by the LAT.

Simply put, many of these health threats are highly speculative, relying on inferences from research where animals are exposed to amounts of the chemical compounds at levels far beyond any possible human exposure.

Take PCBs for example – an obvious chemical bogeyman for the public given their widespread dumping in the nation’s rivers and lakes for many years. PCBs are considered carcinogenic based on animal studies; yet they have never been shown to cause cancer in humans, even in occupational situations where workers were exposed to high concentrations in workplace environments. Saccharine was considered carcinogenic for many years based on the fact that huge quantities administered to male rats caused bladder tumors (the equivalent of a human drinking hundreds of cans of soda per day). But the mechanism causing the tumors didn’t apply to humans – it didn’t even apply to female rats.

Or take the case of phthalates, which activist groups are trying to have banned in the U.S., and which the CDC study found were well below the already stringent safety levels for human exposure. To reach the level where there was no observable health effect in laboratory animal studies, you would have to absorb every phthalate molecule from a half gallon of perfume per day.

The LAT, however, mixed a lack of nuance with outright misinformation when it came to discussing phthalates:

”Eleven of 12 phthalates tested were higher in children than adults. All of the phthalates but one are used in fragrances. In animal tests, and in one recent study of human babies, some of the compounds have been shown to alter male reproductive organs or to feminize hormones.”

The Wall Street Journal also claimed that phthalates were “recently associated with genital abnormalities in boys.” But as STATS has noted, the study on male babies found no such effect.

In fact, the (Swann) study did not examine the impact of phthalates on genitals (and none of the boys in the study had defective or malformed genitalia). The authors of the study found a correlation between what they termed the anogenital index of a baby boy, and the level of residual chemicals from phthalates (also called metabolites) in the mother’s urine before his birth. The anogenital index is a measurement of the distance from the anus to the base of the penis, divided by the weight at the time of measurement. The researchers inferred that because a low anogenital index in rats is associated with both fertility problems in rats fed huge doses of phthalates, much lower exposures to phthalates in pregnant women could have a similar problematic effects.

But you can’t simply infer similar effects from huge dosages to miniscule dosages across species. Not all risks are linear, meaning that the risks decrease relative to decreases in the dosage but do not entirely disappear. Not all risks apply equally across species. To suggest otherwise, which is the upshot of playing up the presence of so many “dangerous” chemicals, and "potential" health risks, is to abandon science for political activism.


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