Deborah Orr: The childless future facing men

'Loads of things we feel we need have been fingered in the fight to prove and explain the rise in male infertility'

Better safe than sorry. Prevention is better than cure. An ugly mend is better than a pretty hole. Such are the dear old homilies of caution, and erring on the side of it, quaintly concerned with what's for better rather than worse, in the best of all possible worlds. Like Pangloss, only without the blind optimism, if such an idea wasn't a crashing contradiction in terms.

There's a pre-war feel to the homespun wisdom in these words that seems to have lost any validity it might once have had. Instead we continue the headlong rush towards a contingent future that we long to embrace without too much worry about what it might actually consist of. Even it that future is quite possibly set to feature humans who cannot manage little things like natural reproduction.

Again plunging levels of male fertility are in the news, as they are sporadically, year after year. Again, one particular theory is expounded as offering a plausible explanation. This theory is not new and focuses on the human endocrine system, which governs and regulates our hormones.

There is every possibility that our endocrine systems are being tricked by oestrogen mimicking chemicals, used in industry, into sending the wrong messages round our bodies. Because these chemicals, known as endocrine modulators, or more commonly endocrine disruptors, attach themselves to our oestrogen receptors, they have the potential to interfere powerfully with our reproductive systems. They're in the food chain, in the water supply, and according to the New Yorker of some years ago, they've been creating vile, barren mutant fish in our oceans for a quite long time now. The mutant fish in the New Yorker, were of course, back then, linked to mutant sperm, cancerous testicles, malfunctioning prostates and mis-formed genitals. Now here we are again.

Big business, and particularly the manufacture of cosmetics, plastics, food cans and household furniture are cited this time as pollutants of this type, although plenty of other manufacturing culprits have been pointed out before. Some of these pollutants are now banned in various countries, but mainly just the super-toxic chemicals like DDT or notorious pesticides like aldrin or kepone. It seems more like common sense than grand science that these sorts of chemicals have the potential to cause reproductive abnormalities in boys. But even now, little is likely to come of it all, for a good while anyway.

According to a study made at the University of Copenhagen as long ago as 1992, figures of speech haven't been the only things in serious decline since 1938. This landmark investigation warned us almost a decade ago that the average sperm count was down 50 per cent in the last half-century, from 113 million to 66 million per millilitre worldwide. The study also pointed to an increase in testicular cancer, prostate cancer and genital defects at birth among male babies

One theory explaining the phenomenon was that the high level of the female hormone oestrogen, or chemicals mimicking its properties, might be a possible cause. The survey, never mind the theory, has been widely debunked ever since. It has been criticised for problems with its methodology, its ignoring of marked geographical and temporal variations, and its glossing over of substantial differences among different races.

Many scientists have stated that there was in fact no evidence at all of an overall fall in sperm counts, and certainly not a fall anyway as large as the Danish report suggested. Likewise, when a recent German study suggested that falling sperm counts might be due to the use of disposable nappies in young children, and the consequent disruption of the cooling of the scrotal sac, this too was rubbished.

Paradoxically, representatives of the nappy industry pointed to the Danish study, saying that it had pinpointed a decline in sperm counts since 1938, while disposable nappies had only been around for 25 years. It didn't deny sperm counts were falling, just that the phenomenon had been going on far too long for the finger of guilt to be pointed its way. Of course, it takes no responsibility either for the fact that its product is damaging to the environment and biodegradable only over many centuries, if at all.

Who cares what damage disposable nappies wreck? They're so useful that they're irresistible. In this fashion the consumer becomes a shareholder too. It's easy to blame business, not so easy to take on board that consuming is just a part of the business process. The nappy industry should be doing further research into the possible threat to their customers that disposable nappies may pose, just as the companies using endocrine modulators should have been hectored and legislated into investing in studies as soon as the issue came up.

Loads of things we feel we need – pharmaceuticals, consumer goods, fashion items, lifestyle developments – have been fingered in the fight to prove and to explain the rise in male infertility. Oestrogen in the water supply, widespread use of the contraceptive pill, hormone-mimicking chemicals in food packaging, growth hormones in beef, tight-fitting underwear, central heating, sedentary jobs, pesticides, plastics, detergent ingredients, computer chips, and various other food products.

Nevertheless, the debate over male fertility, in the face of overwhelming anecdotal evidence, and plausible scientific explanation, has been as gruesomely polarised as global warming. The polarisation has served the same purpose. As the arguments rage, nothing gets done and the interests of business are protected.

In this and in many other major scientific debates – from the increasing incidence of autism to the link between self-harm and SSRIs – "don't know for sure" means "plough on regardless".

To err may be human but to err on the side of caution has become not the sensible course but the whine of the crazy alarmist spoiling the planet's fun.

There must therefore be a modicum of satisfaction for Professor Niels Skakkebaek, who led the 1992 investigation, in the fact that he is now achieving some recognition for his efforts. Dr Richard Sharpe, of the Medical Research Council's human reproductive sciences unit in Edinburgh, has reviewed the latest evidence on male reproductive problems. He has concluded hormone disrupting chemicals do have an effect on male fertility and on the health of male reproductive organs. He suggests the effect is particularly damaging during the first three months in the womb. He also says that dietary changes may have a damaging effect, but is unequivocal in his condemnation of the presence of endocrine disruptors in the food chain. Actually, the dietary evidence and the endocrine modulator evidence may also converge.

These chemicals are stored in our fatty tissues, which may explain why it is that the symptoms of male reproductive failure are more prevalent in developed countries.

If only the information chain was as efficient as the food chain, then the results of this knowledge that academic rather than industrial science has brought to us would be coursing round our bodies in no time at all. Instead humans will continue with their erring. If we are forgiven for our usury and our short-termism, that will be indeed divine. In fact, if we humans get away with all we're risking at the moment, it will be a miracle.

d.orr@independent.co.uk