By Peter Montague
For most of history, humans were so puny, compared to the rest of nature, that the speed of technological change didn't matter. But since 1945, humans have become a major force that nature must reckon with.
Human activities now pull from the deep earth and redistribute into surface soils and water much larger quantities of many minerals than all the rest of nature put together. Humans dwarf the rest of nature when it comes to moving nitrogen, phosphorus, sulfur, arsenic, mercury, lead, and a dozen other metals.
In addition, we have invented and dumped into the environment enormous quantities of synthetic chemicals that nature does not ordinarily create. As a result, we are changing the chemical balance of the soils and waters of the entire planet. We are now waiting (without paying close attention) to learn what effects these changes will have on wildlife and on human health.
We are flying blind. When we deploy new chemical technologies (and genetic engineering technologies), we have little or no idea what the consequences will be. We learn by trial and error, exposing wildlife and humans and then waiting until harm becomes evident.
Usually, we do not even study the exposed individuals in any systematic way. Wildlife may or may not be studied. In the case of humans, we almost invariably wait until they notice symptoms in themselves. Then we generally ignore them until they become desperately angry and organise themselves into a political force.
Then we may begin to look for harm, using crude techniques like epidemiology, which can only discover problems that affect a large proportion of the study population. Such studies take years to complete; meanwhile exposure to the chemical continues. This is the "prove harm" philosophy of public health protection, and it forms the basis of the public health system in the civilised world today. Victims have to prove harm before controls can be initiated.
Although corporate polluters complain bitterly that they are being strangled by environmental regulations, in truth, all of the USA's environmental laws, taken together, impose controls on only about 350 individual chemicals. There are 71,000 chemicals in commercial use, so 99.5% of chemicals are entirely unregulated.
Under the "prove harm" system, the way we learn about chemical problems is by unpleasant surprises. We learn after the fact that we have begun to heat up the planet by our emission of greenhouse gases. We learn after the fact that our refrigerators and air conditioners have eaten holes as big as the United States in the ozone over the north and south poles. We watch cancer rates steadily rise, and after about three decades of this, we begin to scratch our heads.
The most recent bad news has to do with hormones. A new book, Our Stolen Future, describes how scientists during this decade have pieced together the latest threat to the well-being of wildlife and humans: many industrial chemicals we have been dumping into the ecosystem in huge quantities for years are now thought to interfere with hormones.
Hormones are natural chemical messengers that flow through the bloodstream, providing instructions that control growth, development and behaviour in birds, fish, amphibians, reptiles and mammals, including humans. No-one knows how many of the 71,000 chemicals now in use can actually interfere with hormones; so far, 51 chemicals have been shown to have such an effect.
The range of problems that may be caused by hormone disruption is large: cancer, birth defects, confusion in sexual preference, poor parenting, stunted growth, reproductive failure, diminished sperm count, endometriosis, ectopic (tubal) pregnancies, damage to the immune system, impaired short-term memory, decreased ability to pay attention, diminished intelligence, violent behaviour — the list is long and unpleasant.
There is no doubt that hormone-related damage is occurring in some wildlife populations. The case for damage to humans is less firm; however, it seems certain that this is a serious problem that the public health system must now gear up to define and then begin to solve.
The main question raised is this: given that we are flying blind, what public policies could we adopt that might reduce the number of unpleasant surprises we leave to our children?
The problem breaks down into two parts: (1) what should we do about existing chemicals? (2) what should we do about newly created chemicals?
For existing chemicals, Our Stolen Future offers some useful suggestions:
- Greatly reduce the number of chemicals on the market. Our Stolen Future describes an effort to find environmentally benign chemicals for use in the textile business. A group of researchers examined 7500 chemicals used to dye or process fabrics. They eliminated chemicals that were toxic, persistent, mutagenic, carcinogenic or known to interfere with hormones. Of the 7500 chemicals, only 34 passed all the tests. As a result, an environmentally benign fabric is now being marketed.
- Reduce the number of chemicals in products. Make products simpler.
- Make and market only chemicals that can be readily detected at relevant levels in the real world with current technology.
- Restrict production to products that have a completely defined chemical make-up and disallow products containing unpredictable mixtures of chemicals. Such mixtures — for example the 209 PCBs (polychlorinated biphenyls) — are difficult to test for safety and to track after they are released into the environment.
These are useful suggestions for altering our approach to existing chemicals. But the issues involved are very complicated. A campaign to achieve these changes would quickly bog down in debates between "duelling experts". Existing chemicals, therefore, offer limited opportunities for initiating needed changes.
On the other hand, new chemicals offer much greater opportunities.
- Our Stolen Future points out that we need to reverse the burden of proof for safety. Presently new chemicals are considered innocent until proven guilty. This should be reversed: new chemicals should be assumed harmful until they have been thoroughly tested for all the kinds of harm we presently know about.
Requiring that new chemicals be thoroughly tested, then banning the bad ones, is the essence of pollution prevention. Despite this, most corporate polluters — even those claiming to be green as grass — would almost certainly oppose it. A campaign to make this one fundamental change — to reverse the burden of proof for chemical safety — might quickly reveal the amorality and the raw power of corporate polluters.
True, shifting the burden of proof for chemical safety would slow the speed of chemical innovation — but that's part of the point. Evidence accumulated during the past 25 years strongly suggests that, when you are flying blind, you should fly more slowly than we are presently doing. That way, even if you hit a mountain, there still might be a chance for survival.
[From Rachel's Environment & Health Weekly.]