The decline of sperm quality is inseparable from the air pollution particles in the environment

2022-06-21 0 By

Sperm quality plays an important role in male reproductive health.In recent years, however, numerous studies have pointed to damage to male reproductive health, and western and industrialized countries have reported significant declines in sperm concentrations.Declining semen quality in humans may be becoming a regional and even global problem.In 2017, HagaiLevine of The Hebrew University of Hadessa conducted a big data analysis. Her team analyzed sperm counts of more than 40,000 men from 185 studies from 1973 to 2011, including men from more than 50 countries in North America and Europe.The results were surprising, with sperm counts in Men from North America, Europe, Australia and New Zealand falling by 53 per cent over the past 40 years.In the early 1970s, the average number of sperm per milliliter of semen was 99 million.By 2011, that number had fallen to 47 million.The same is true in China, where semen concentration and total sperm count have declined significantly over time in the 14 years since 1995.The World Health Organization has twice lowered its standards for acceptable semen. According to the Manual of Laboratories for The Processing and Testing of Human Semen, the number of male sperm per milliliter has fallen from an average of 100 million in 1970 to 15 million today.The plunge in sperm quality is not the result of a single factor, but of a combination of individual and environmental factors.Now, an analysis of sperm from more than 30,000 men in China has found that air pollution can affect semen quality, particularly sperm motility (the ability of sperm to swim in the right direction).The study was published in the Journal JAMA Network.Researchers from The Medical School of Tongji University in Shanghai looked at data records from a total of 33,876 men from 340 Chinese cities, with an average age of 34 and varying levels of exposure to air pollution, whose wives became pregnant with their sperm through assisted reproductive technology between January 2013 and December 2019.They then looked for patterns in semen quality related to whether participants had been exposed to particles smaller than 2.5 microns, 2.5 to 10 microns, and 10 microns in diameter at various points in the 90 days before they arrived at the hospital for semen injection.To determine semen quality, the researchers focused on factors such as sperm count, concentration and sperm motility.Although the researchers could not find a significant link between air pollution and sperm quality in terms of sperm count or concentration, they did find that the more participants were exposed to smaller particles, the lower both progressive and total sperm motility.Progressive sperm motility refers to the ability of sperm to swim forward, while total sperm motility refers only to the overall swimming ability of sperm.Specifically, sperm motility was estimated to drop 3.6 percent when exposed to particulate matter less than 2.5 microns in diameter, and 2.44 percent when exposed to particulate matter 10 microns in diameter.This means that particulate matter fractions of different sizes may have different effects on semen quality, and the smaller the size of pollution particles in the air, the greater the association with poor semen quality.The decline in the quality of male sperm is not only a clinical medical problem, but also a reproductive health education problem, but also a food safety and environmental protection problem, which is a problem of modern and modern life.