Michael Arnold Glueck and Robert J. Cihak
Wednesday, Jan. 7, 2004

However, the Precautionary Principle is now an article of faith among environmental activists, whom, one wishes, would apply this reasoning to their own activities ... and stay in bed.

But the Precautionary Principle alone is not the source of all the environmental mischief, meddling and malaise that these people attempt to inflict upon the rest of us. Several decades or so ago, a bunch of academics with time on their hands came up with a notion called "The Social Construction of Reality."

At certain levels, reality is indeed socially constructed. Table manners, speed traps, the bills in your mailbox: These are indeed socially constructed realities.

Then the belief that reality is what we think it is got into science.

When feminists denounced the law of gravity as a male chauvinist construct, it was merely amusing. But when the Social Construction of Reality melds with the Precautionary Principle, it produces a curious phenomenon: people who do enormous harm while believing, in the face of overwhelming scientific evidence, that they're actually doing good.

Example du jour: a coalition that styles itself "Health Care without Harm" (HCWH) and whose crusade against the medical use of polyvinyl chloride (PVC) products could harm patients by the millions (yes, millions) without doing any ecological or human good whatsoever.

But when no level of perceived risk is acceptable, and when reality is what you say it is ... what does it matter? PVCs are plastics – sturdy, nonporous and cheap – used in many medical products, from blood bags to surgical instruments. Without PVCs, bacterial sterility would be harder to achieve, many medical instruments and tools would be too stiff to do their medical jobs well, and the shelf life of many products would be lessened.

These benefits notwithstanding, HCWH, a coalition of over 350 environmentalist, religious and other groups, wants a total ban on medical PVCs because they contain the additive DEHP, claimed to cause birth defects and to do reproductive damage. HCWH wants them banned both because of their alleged direct effects and because, they claim, incineration releases harmful carcinogens.

The problem with this argument is twofold. First, no scientific study has ever demonstrated that PVCs have actually harmed any patients. Logic suggests that patients should receive special consideration and not be used as an excuse to ban entire classes of useful products.

Also, there is no scientific consensus on the harmful effect of incinerating DEHP. In fact, the World Health Organization has downgraded DEHP from a "possible carcinogen" to one "not classifiable as to carcinogenicity in humans."

But this hasn't slowed down HCWH, because they cling to a wrongly interpreted theory of toxicity. As doctors have known for millennia, everything is toxic – and nothing is toxic. It all depends on how much, how concentrated and how quickly. Exposure is measured by time as well as by amount.

For example, 100 aspirin, taken all at once, would kill me. But I've been taking 1/4 tablet daily for years, to reduce the likelihood of blood clots, and others say I seem to still be alive.

However, groups such as HCWH hold to an absolutist "linear dose/response" gospel: Toxicity accumulates over time. In some rare cases, this may be true. But in the vast majority of instances, toxicity does not accumulate because human beings, and all living things, are dynamic systems, self-cleansing and regenerating.

Nor does HCWH deign to measure the direct harm that a PVC ban would do to patients, i.e., nearly all of us at some time or other. How many would die or suffer because of a ban that would produce only the most minuscule medical and environmental improvements, if any?

No one has an absolute answer to that question, but HCWH doesn't even ask it. Unlike many HCWH claims, decisions in reality always involve trade-offs – trade-offs which HCWH ignores.

Related Articles:

The Dirty Bomb: Precautionary Principle vs. Disaster Preparedness

Are Your Teeth Toxic?

At Thanksgiving Dinner IT'S STILL THE DOSE That Counts]

Editor's Note: Robert J. Cihak wrote this week's column.

Robert J. Cihak, M.D., is a Senior Fellow and Board Member of the Discovery Institute and a past president of the Association of American Physicians and Surgeons. Michael Arnold Glueck, M.D., is a multiple-award-winning writer who comments on medical-legal issues.

Contact Drs. Glueck and Cihak by e-mail.

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