Doctors from the All India Institute of Medical Sciences (AIIMS) found that while the sperm count of a normal Indian adult male used to be 60 million per ml around three decades ago, it now stands at around 20 million per ml.
The study found that majority of men who were exposed to high temperature at their workplace — welders, dyers, blast furnace workers and those employed in cement and steel factories — were more prone to infertility.
Over 12-18 million couples in India are diagnosed with infertility every year.
AIIMS doctors say a one degree elevation in testicular temperature leads to 14% depression of spermatogenesis.
Experts say the normal temperature of the testes is three degrees lesser than the core body temperature (37 degrees Celsius or 98.6 degrees Fahrenheit).
“Not only has quantity of sperm production declined in males across the world, there has been a decrease in motility (Sperm movement) and morphology (shape and structure) of the sperms. There has been a 2% decrease in quality of male sperm annually. Also, 40% men in reproductive age group are presently recording a quantitative and qualitative decline in sperm quality. Stress also decreases the hormones that stimulate spermatogenesis,” said Dr Rima Dada from AIIMS.
IVF expert Dr Sonia Malik recently conducted a 10-year comparison study on sperm quality and quantity (2000-2001 to 2010-2011) in Southend Fertility and IVF Centre.
According to her study, the percentage of semen ejaculation, which is considered less than normal (below 4 ml), increased from 34% to 65% and most suitable ejaculation volume (more than 4ml) went down from 15% to 3%.
As far as morphology of sperm was concerned, in 2000-2001, 26% of the sperms showed above 60% normality, whereas in 2000-2011 this was reduced to 7%.
Malik said, “Over the past 50 years, expansion of the chemicals has resulted in the release of a plethora of xenobiotics (molecules foreign to biological systems) into the environment leading to male infertility.”
The 10-year-long AIIMS study had surveyed 1,000 men from north India and found that lifestyle factors like tight clothing, hot tub dips and long visits to the sauna, intensive gardening and farming resulting in pesticide exposure and increased obesity rates were major causes for the ever decreasing sperm count.