ARE sperm counts plummeting in western countries? This long-debated issue was raised again by a report on Monday showing that sperm counts have plunged by 29 per cent in just 14 years in men attending an infertility clinic in Aberdeen, UK.
The analysis, by Siladitya Bhattacharya of the University of Aberdeen, included 16,000 semen samples from 7500 men taken from 1989 to 2002. Over that period, sperm concentrations in men considered to have normal counts had fallen from 87 million to 62 million per millilitre.
Though this was the largest study ever in the UK, it raises more questions than it answers. It looked at potentially infertile men, so it may not reflect what is happening in the general population. And it throws no light on the cause of the decline, if there really is one. Water-borne pollutants that have 鈥済ender-bending鈥� effects on animals are one obvious suspect. But tight underpants or working in a warm environment may also be to blame.
Advertisement
To find out whether there is a genuine decline in sperm counts, and to pinpoint possible causes, a large group of men needs to monitored over many years, says Allan Pacey, a hormone expert at the University of Sheffield, UK. By monitoring exposure to pollutants or other factors as the study proceeds, it might be possible to explain why sperm counts decline in some men but not others.