A study carried out by an international team and published in the Human Reproduction Update journal on 25 July shows that sperm levels in men in western countries (America, Europe, Australia and New Zealand) have fallen by 50% in less than 40 years. According to the scientists, this decrease is continuing and no end is apparently in sight.
The team focused on 185 studies carried out between 1973 and 2011, and involving almost 43,000 men. The data were sorted according to the origin of the men (whether or not of western origin). Since 1973, sperm concentrations have fallen by 52.4% and the overall quantity of sperm by 59.3%. Conversely, no significant decrease has been highlighted in South America, Asia and Africa.
As far as Hagai Levine, epidemiologist and principal author, is concerned, “this study is an urgent wake-up call for scientists and health authorities around the world to investigate the reasons for this substantial, persistent drop in sperm count“, thereby preventing masculine infertility. The phenomenon could be associated with several factors including contact with certain chemical products such as pesticides and cigarettes or even stress and obesity. Daniel Brison, embryology and stem cell biology specialist at Manchester University in Great Britain, believes that these results have “major implications not only for fertility but also for male health and public health in general”. He wonders what impact this will have on future generations.
The Guardian, Nicola Davis (25/07/2017), Reuters, Kate Kelland (25/07/2017)