Chemicals likely cause for falling sperm counts
“I tried counting mine once, but I went blind with exhaustion,” tweeted one reader of the BBC website after it reported that sperm counts were down by half in the past 40 years all over the developed world. And it’s true: They are hard to count. The little buggers just won’t stay still.
The report, published by Human Reproduction Update on Tuesday, reviewed almost 200 studies done in different places and times and on various scales. It’s called “Temporal trends in sperm count: A systematic review and meta-regression analysis,” and the authors are working very hard to get the world’s attention.
Dr. Hagai Levine, the lead researcher, told the BBC: “If we will not change the ways that we are living and the environment and the chemicals that we are exposed to … eventually we may have a problem with reproduction in general, and it may be the extinction of the human species.”
I think I’ve seen this movie a few times already. There was Children of Men, and then The Handmaid’s Tale, and I was even in a sperm-count movie myself thirty years ago. It was a would-be comedy called The Last Straw, but happily it isn’t available online.
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.
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.
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 for heavily industrialised Asian consumer societies like Japan, South 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.
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.
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.
The sheer volume of visible pollutants 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 very unlikely, however, that falling sperm counts will be the problem that finally gets us. — Gwynne Dyer is an independent journalist based in London, England.