London, Nov 1 (IANS): Frequent use of mobile phones, which emit electromagnetic radiation, can lower sperm concentration and total sperm count, finds a study.

However, no association was found between mobile phone use and low sperm motility and morphology, revealed the study published in the journal Fertility & Sterility.

While various environmental and lifestyle factors have been proposed to explain the decline in semen quality observed over the last fifty years, the role of mobile phones has yet to be demonstrated.

To understand, a team from the University of Geneva (UNIGE) in Switzerland led a cross-sectional study based on data from 2,886 Swiss men aged 18 to 22, recruited between 2005 and 2018.

The 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 per cent decrease in sperm concentration for frequent users (>20 times/day) compared to rare users (<1 time>), the researchers said.

Semen quality is determined by the assessment of parameters such as sperm concentration, total sperm count, sperm motility and sperm morphology.

According to the values established by the World Health Organization (WHO), a man will most probably take more than one year to conceive a child if his sperm concentration is below 15 million per millilitre. In addition, the percentage chance of pregnancy will decrease if the sperm concentration is below 40 million per millilitre.

Many studies have shown that semen quality has decreased over the last fifty years.

Sperm count is reported to have dropped from an average of 99 million sperm per millilitre to 47 million per millilitre. This phenomenon is thought to be the result of a combination of environmental factors (endocrine disruptors, pesticides, radiation) and lifestyle habits (diet, alcohol, stress, smoking).

Data analysis also seems to show that the position of the phone -- for example, in a trouser pocket -- was not associated with lower semen parameters.

‘‘However, the number of people in this cohort indicating that they did not carry their phone close to their body was too small to draw a really robust conclusion on this specific point,’’ added Rita Rahban from the varsity.