Yet another study suggests sperm numbers are falling in rich countries.
AS HEALTH scares go, the idea that sperm counts are plummeting across the industrialised world, probably as a result of chemical pollution that has an adverse hormonal effect, takes some beating. In 1992 a meta-analysis of 61 papers, published in the British Medical Journal, suggested they had fallen by half in the preceding half-century, from 113m per millilitre of semen to 66m. Since then, the decline has apparently continued. The most recent paper, just published in Human Reproduction, by Joëlle le Moal, Matthieu Rolland and their colleagues at France’s Institute for Public Health Surveillance, is also one of the most comprehensive yet.
Its conclusions are stark. The sperm count of the average Frenchman, say the researchers, fell by 32.2% between 1989 and 2005. At the same time, the proportion of properly formed sperm also fell, from 60.9% to 52.8%.
This paper is an important contribution to a lively debate. For although the idea of falling sperm counts has entered the public mind as an established fact, fertility experts remain divided about just how big the effect really is. Not all studies have found drops. Though one of Parisians in 1995 suggested that counts were indeed falling, by about 2.1% a year, another, carried out in Toulouse, suggested that they weren’t. Read full article.
