Could excessive use of mobile phones affect male fertility? A new study reveals a worrying link between mobile usage and semen quality.

The World Health Organization estimates that one in six couples has infertility issues and approximately half of them is due to male infertility. Semen quality, a measure of male fertility, is decided by factors such as sperm concentration, total sperm count, sperm motility and sperm morphology.

Men who use their phones more than 20 times a day are at 21% higher risk of having a low sperm count and a 30% higher risk for a low sperm concentration, the study revealed. However, higher use does not impact sperm motility and morphology. The findings were published in the journal Fertility and Sterility.

Studies show that semen quality has decreased over the years due to a combination of environmental factors, such as endocrine disruptors, pesticides, radiation, and lifestyle habits that include diet, alcohol, stress and smoking. In the last 50 years, the average sperm count has dropped from 99 million sperm per milliliter to 47 million per milliliter.

"Previous studies evaluating the relationship between the use of mobile phones and semen quality were performed on a relatively small number of individuals, rarely considering lifestyle information, and have been subject to selection bias, as they were recruited in fertility clinics. This has led to inconclusive results," study first author Rita Rahban said in a news release.

The research team from the University of Geneva (UNIGE), in collaboration with the Swiss Tropical and Public Health Institute (Swiss TPH), examined the semen quality of 2,886 men between 18 and 22 years. They were recruited between 2005 and 2018 at six military conscription centers.

The participants were asked to fill in a questionnaire to measure the number of hours they spent on mobile phones and to understand where they placed the phones when not in use.

"These data revealed an association between frequent use and lower sperm concentration. The median sperm concentration was significantly higher in the group of men who did not use their phone more than once a week (56.5 million/mL) compared with men who used their phone more than 20 times a day (44.5 million/mL). This difference corresponds to a 21% decrease in sperm concentration for frequent users (>20 times/day) compared to rare users (<1 time>)," the news release said.

There were no consistent links between mobile phone usage and sperm motility or sperm morphology. Keeping a mobile phone in the pants pocket also did not affect the semen quality.

The study has certain limitations as it is based on self-reported data, which may not be an accurate measure of exposure to electromagnetic radiation.

To address the gap, another study was launched by the Swiss Federal Office for the Environment (FOEN) this year. It aims to accurately measure the exposure to electromagnetic waves and evaluate their impact on male productivity based on the type of mobile phone usage.