Mystery mail
Does anyone know who sent out the unsigned letter ‘‘Waimea community dam – A public deception’’? I got one with my mail yesterday. Surely if you have something so important to say you need to give it credibility with the author’s name?
Among the many varieties of end-of-the-world stories we like to tell ourselves, the infertility apocalypse is the least violent, and therefore (in good hands) the most interesting in human terms. But the sperm crisis really isn’t here yet, or even looming on the horizon.
What the scientists did in the meta-regression analysis was very useful from a general public health point of view. There have been many estimates of what is happening to sperm counts, but they are conducted under different circumstances, usually with fairly small groups of people, and often in clinics that are treating couples with infertility problems.
This big review of the existing research did no new work, but it did extract rather more reliable data from the many studies that have been conducted by other groups, and there definitely is something going on. Compared to 1970s, sperm counts now in the predominantly white developed countries (North America, Europe, Australia and New Zealand) are between 50 per cent and 60 per cent down now.
It has been a fairly steady decline in those places, and and it is continuing in the present, but no such fall has been found in the sperm counts in South America, Africa and Asia. So maybe it’s just whites going extinct.
Probably not, though. Most people in South America are white, but there has been no fall in sperm counts there. And there’s no separate data in the survey about what’s happening in the heavily industrialised Asian consumer societies like Japan, Korea, China and Taiwan, but one suspects that there have been declines in sperm counts there. It’s almost certainly an environmental, dietary or lifestyle effect, and therefore probably reversible.
As to which of these possible causes it might be, the jury is still out, but a 2012 study by researchers at the Universities of Sheffield and Manchester concluded that smoking, drinking alcohol, recreational drug use and obesity had little or no effect on sperm counts. Other reports, however, have suggested that eating saturated fats, riding bicycles, watching too much television and wearing tight underpants do adversely effect sperm counts.
In any case, there’s no immediate cause for panic, because all of the studies showed that sperm counts, though lower than in the 1970s in some parts of the world, are not ‘‘sub-fertile’’ anywhere. They are still well within the normal range, just lower on average than they used to be. There’s no shortage of human beings at present, and there’s lots of time to sort this out.
It will almost certainly turn out, when more research has been done, that the main cause of reduced sperm counts is the presence of various man-made chemicals in the environment. Not just one or two chemicals, but more likely a cocktail of different ones that collectively impose a burden on the normal functioning of human metabolism.
We are breathing and ingesting a lot of toxins, and have been since shortly after the rise of civilisation (lead-lined water pipes, etc.). The sheer volume of visible pollutants (particulate matter, etc.) has probably peaked and begun to decline in the most developed countries, but the variety of new chemicals in the environment continues to rise. Further nasty surprises probably lie in wait for us.
Unfortunately, that’s the way human beings work: ignore the problem or put up with it until it becomes unbearable, and only then do something about it. It’s a strategy that has served us well enough in the past, but will do us increasing damage as the problems become more complex. It’s very unlikely, however, that falling sperm counts will be the one that finally gets us.