In the past 20 years, four new discoveries have completely changed our understanding of chemical hazards.
1. Many chemicals can interfere with the hormone system
Beginning roughly 80 years ago, scientific studies started showing that some chemicals can interfere with growth, development, and behavior of animals, including humans. For 50 years these studies were generally ignored. Then during the 1980s, dozens of new studies — often done in the Great Lakes region — showed that male fish were being feminized, that female gulls were pairing up to sit on nests together… and so on. There were other effects as well, but the sex- related changes caught people’s attention first.
In 1991 Theo Colborn pulled together a meeting at the Wingspread Conference Center in Racine, Wisconsin, which issued a consensus statement, “Chemically Induced Alterations in Sexual Development: The Wildlife/Human Connection.” Subsequently Colborn and others published the popular book, Our Stolen Future. Since that time, a flood of new studies have confirmed and reconfirmed that many industrial chemicals can interfere with the chemical signaling systems that coordinate all the biological activities that a living thing requires — beginning at conception and ceasing only with death. (See Rachel’s #263, #264, and #365.) And the changes are not just sex-related — the central nervous system is strongly affected, as is the immune system. “Endocrine disrupting” chemicals are all-purpose poisons.
With this new understanding of endocrine-disrupting chemicals, we have also learned that…
(a) the timing of exposure combines with the amount of exposure to produce a chemical’s effect;
(b) in some cases low doses can be more effective (more damaging) than higher doses.
Thus this new understanding of toxicity has falsified Paracelsus’s 450-year-old maxim, “The dose makes the poison.” Today we know that often the timing makes the poison and that sometimes less is worse. (See Rachel’s #754.) As you might imagine, this new understanding has greatly complicated the task of toxicity testing.
2. Chemical exposures in the womb can “program” a fetus for life
Scientists studying cell-signal-disrupting chemicals discovered “fetal programming” — that the lifelong development of a human can sometimes be permanently determined by chemical exposures in the womb, including chronic diseases that may only become apparent in middle age (cancer, adult-onset asthma, diabetes, etc.) (See Rachel’s #343, #447, and #909, among others. Of course this applies to non-human mammals as well.) This, too, has greatly complicated the task of toxicity testing.
3. “You are what your grandmother ate.”
In recent years, an entirely new theory of genetic inheritance — called epigenetics — has become widely (if not yet universally) accepted. Epigenetics tells us that environmental influences on cells can be inherited even though the structure of the cell’s DNA has not been fundamentally altered. A generation ago, such a concept was considered heresy, unthinkable really. This new knowledge means that environmental influences are far more important than anyone understood previously. (One popular expression of this understanding is, “You are what your grandmother ate.”) (See Rachel’s #876.) Many scientists believe that epigenetic changes contribute importantly to fetal programming and to the initiation of cancers and other chronic diseases that only become apparent years or decades later. Ask yourself, how can you rapidly test a chemical to see if it will cause a chronic disease years in the future?
4. The “cocktail” effect
Many studies now show that exposure to “insignificant” doses of several chemicals can combine to produce significant effects. In other words, simultaneous exposure to very “low” doses of several chemicals can cause biological effects that none of the chemicals alone could cause. British toxicologist Andreas Kortenkamp calls this the “something from nothing” effect. And U.S. Environmental Protection Agency (EPA) scientist Earl Gray calls this phenomenon “the new math — zero plus zero equals something.”
Initially scientists assumed that only chemicals acting by a particular biological mechanism could combine to produce an effect. But more recently, experiments have shown that chemicals acting by a variety of biological mechanisms can combine to produce a single effect. When we are exposed to a mixture of chemicals, “Every mixture component contributes to the effect, no matter how small,” says Andreas Kortenkamp.
These four new understandings of chemicals make chemical regulation a daunting task, to put it mildly.
First you need to know the potency of each single chemical, which biological tissues it affects in what ways, and whether a population will be exposed to other chemicals that affect the same tissues. Then you must test groups of chemicals in combinations at low doses and high doses, and several doses in between. Then you need to determine whether the creature being studied (rat, bird, human, or whatever) is affected by this combination of chemicals at one particular stage of life and not at other stages. For example in the case of humans we know that, during gestation in the womb, exposure during one particular week may produces effects not seen when exposure occurs during a different week.
Now consider the actual environment in which exposures to humans are presently occurring. Here is the opening paragraph from an article in New Scientist magazine in late 2007:
“Today, and every day, you can expect to be exposed to some 75,000 artificial chemicals. All day long you will be breathing them in, absorbing them through your skin and swallowing them in your food. Throughout the night they will seep out of carpets, pillows and curtains, and drift into your lungs. Living in this chemical soup is an inescapable side effect of 21st-century living. The question is: is it doing us any harm?
“There are good reasons to think that it might be. Not because of the action of any one chemical but because of the way the effects of different components combine once they are inside the body.”
Taken together, these new understandings of toxicity make thorough premarket chemical testing not merely difficult, but impossible. The steps required are far too cumbersome, complex, and — most importantly — expensive. Thorough testing is not going to happen. Scientists (or advocates) who says it is are kidding us (or themselves).
Not convinced? Suppose we wanted to test just 1000 chemicals in unique combinations of 5 chemicals. Then we’d have to test 8,250,291,250,200 (yes, 8 trillion) unique groups of chemicals. If we assume we could test a million combinations each year (a wildly optimistic assumption), then it would take us 8,000 years to complete the task. And we are presently putting 700 new chemicals into commercial channels each year.
No, chemicals are not going to be thoroughly tested before being marketed, especially not in combination with other chemicals already on the market.
These new understandings of chemical toxicity will eventually drive almost everyone to the conclusion that broad screening principles must be applied before individual chemical tests — thus requiring us to far go beyond even the European Union’s new chemicals policies. The Swedish Natural Step principles would seem to be the place to start in designing a truly adequate and protective chemicals policy, but few in the U.S. are there yet. (See Rachel’s #667-668.)
I don’t want to be too gloomy, but I notice that most chemical policy activists are not mentioning the real problem with chemical regulation: the regulators are routinely captured by the corporations they regulate. This is at least as true under Democrats as it is under Republicans.
To their credit, chemicals policy activists have petitioned the Obama administration for a well-though-out list of regulatory reforms. However in their “Letter of Principles for Toxic Chemical Regulatory Reform” (which I signed) to the Obama transition team, there is no mention — zero — of how to make regulations actually work. The letter spells out a vast array of requirements that could protect the public a little better from industrial poisons. But ideas for creating human regulatory agencies or departments that are independent of big money? Complete silence.
Former 30-year EPA employee William Sanjour in 1992 told us why regulatory agencies fail. We could probably all gain by carefully re- reading his essay, “Why EPA is Like It Is, and What Can Be Done About It.” (5 Mbytes PDF).
Chemical regulation is not a primarily a technical problem. It is primarily a human problem of money and political power. Many of us like to pretend that it’s not, but pretending — and hoping — won’t change what we’re up against.
PETER MONTAGUE is editor of Rachel’s Democracy and Health News.