Scholars who study the decline of great civilisations sometimes find an environmental factor behind their fall. The river-valley cultures of the Middle East may have destroyed their habitats by over-irrigation, depleting their soil and making them vulnerable to unfavourable climate. There is a theory that the Romans poisoned themselves with pewter. This is the alloy of lead and tin that they used for their drinking vessels, happily unaware that the alcohol in their wine dissolved out the lead and subjected them all to chronic lead poisoning, generation after generation.
Ever since the publication of Rachel Carson's Silent Spring in 1962, we have been aware of the possibility of such a fate for ourselves. If a pesticide like DDT could eliminate the songbirds, what could it do to us? Fortunately, the songbirds generally returned once pesticide use was regulated. And the long-term effects of DDT on us have, so far, been negligible. Well, as far as we know.
But other toxins are available to do the job - radiation, PCBs, dieldrin . . . Until recently we could take comfort in the evidence that in small doses their effects are not disastrous. Radiation was an early subject of suspicion. But thanks to public debate, first over nuclear weapons and then over nuclear power, we are well aware of the dangers of radiation. The use of Agent Orange by America in its dirty war in Vietnam also generated a highly politicised debate and the long-term dangers of dioxin were seriously studied. The new evidence of third-generation victims of dioxin in Vietnam is truly shocking. But horrific as this may be, it is not yet a bell that tolls for us all, as the initial dosage of dioxin was massive by any standards.
But recently we have discovered a new culprit. We are being constantly exposed to "feminising" chemicals that are having a serious effect on our manhood. The decline in human male sperm count - a 50 per cent drop - over the past half-century, controversial at first, is now confirmed. The size of our organs is also decreasing, not to mention the increase in malformed penises, undescended testes and other reproductive disorders. The cause of all this, some sort of "xeno-oestrogens" that mimic female hormones, is being identified with greater precision. The most recent suspect is a family of chemicals called parabens which are widely used in such necessities of modern life as deodorants and skin creams.
Parabens have been considered "safe" because their oestrogenic properties are very weak. So they have been approved by regulators for use in a wide variety of consumer products. The American Food and Drug Administration has registered over 13,000 products that use parabens. When absorbed through the skin of pregnant women, parabens are believed to act as xeno-oestrogens in the wombs affecting the normal development of male foetuses. A recent survey of 215 cosmetics found that 99 per cent of those designed to be left on the skin contained parabens. The cosmetic industry has been shoving this stuff at us for several decades - a few more decades and the cumulative effect could be devastating.
The "feminising chemicals" provide us with a good example of the price we are paying for our scientific civilisation. The high degree of safety, comfort and convenience that we enjoy also has a downside. Nature is not a free lunch. The term "Faustian bargain" was once used in connection with the civil nuclear power industry. It described our willingness to derive the present benefits of nuclear power, while bequeathing the problems of its wastes to our descendants. In that case the terms of the bargain were clear: we get the goods, and they will get the radioactive bads.
But the idea of a Faustian bargain can be extended to our whole material science and technology. New chemicals are created, produced and eventually released into the environment at the rate of thousands per year. To test these properly, even against known hazards, would absorb a significant fraction of our productive effort, and would also slow down innovation. The United States Environmental Protection Agency recently published plans to examine some 87,000 chemicals that are out there in the environment and have the potential ability to mimic the female hormone oestrogen. That is a massive undertaking. So the regulators in the US and elsewhere are doing their best and focusing on the most obviously risky chemicals. For the others, the ruling principle is that they are deemed safe until proved dangerous. There is a "precautionary principle" at work here, but with the precaution almost always applied to the benefit of business and profit.
So in some way our scientific and technological system is living on its luck. Up to now, we have been lucky. We have detected the effect of parabens in time to do something about it. Just as we discovered the ozone layer in the nick of time, found the side effects of DDT before they became serious, and, and . . . The laws of statistics say we can't be lucky for ever. If not xeno-oestrogens, then another possible manmade environmental health catastrophe may be lurking around the corner.
These sorts of reflections which raise the deep contradictions within our scientific enterprise are not popular. Still, the thought that we may follow the Romans, minus our penises, focuses the mind wonderfully.
