Breathing in polluted air can reduce sperm production, study claims

A new study has found that exposure to tiny particles of air pollution could damage the fertility of men by reducing how much sperm they produce.

The research, which was released on Sunday, is expected to be presented on Monday during the ongoing Endocrine Society’s annual meeting in New Orleans.

The study focused on particulate matter (PM); the tiny particles that penetrate deep into the lungs and enter the blood stream.

The findings showed that the exposure to PM with diameters that are 2.5 micrometers or smaller (PM2.5) could lead to changes in the levels of genes related to testicular cell function.

Tests carried out on mice indicated that those exposed to toxic air had lower counts and worse quality sperm compared to those who had inhaled clean air since birth.

The researchers at Sao Paulo University, Brazil, examined the testes of four groups of mice and their production of sperm.

The first group of the mice was exposed to PM2.5 before and after birth until adulthood, while the second group was exposed only during their time in the womb.

The third group was exposed after birth from weaning until adulthood while the fourth group was exposed only to filtered air.

They discovered that the tubes in the testes producing sperm of all the mice exposed to pollution showed signs of deterioration, compared to the group that only breathed filtered air.

The study found that the mice that breathed only PM2.5 after birth appeared to have been the most affected. It is believed that the exposure to PM2.5 led to changes in the levels of genes related to testicular cell function.

Elaine Maria Frade Costa, the study’s lead researcher, said these changes are epigenetic, which means they are not caused by changes in the DNA sequence but by environmental factors.

Costa and her team also believed that the first time research has demonstrated that exposure to air pollution impairs production of sperm through epigenetics.

“These findings provide more evidence that governments need to implement public policies to control air pollution in big cities,” the study’s lead researcher said.

“Infertility rates are increasing around the world, and air pollution may be one of the main factors.”