A small study by researchers in Japan has indicated that exposure to WiFi may have detrimental effects on sperm function.
The study assessed the effect of electromagnetic (EM) waves from WiFi devices on human sperm. It found that longer periods of direct exposure to a portable WiFi router decreased the motility rate and increased the death rate of sperm from human samples.
The researchers also found that using a small WiFi shield to block EM waves improved the outcome for the sperm. The work was presented at the Asia Pacific Initiative on Reproduction (ASPIRE) conference in Hong Kong.
'Recently, the decrease in fecundity in developed countries has been a matter of great concern,' said Kumiko Nakata at the Yamashita Shonan Yume Research Centre in Fujisawa, Japan, who led the study. 'EM waves are said to be safe, but the shower of them caused by WiFi devices may be a contributing factor to the declining fertility trend.'
She added: 'Our study has shown that over a relatively short time, a WiFi shield can offer some protection from the harmful effects of the EM waves.'
The sperm samples analysed were taken from 51 men seeking fertility treatment, such as IVF or artificial insemination, at the clinic.
Samples were tested under different conditions; no exposure to EM, shield-protected, and full exposure.
The exposed samples were placed near a pocket WiFi router – similar to the way a mobile phone might be carried in a man's trouser pocket. After two hours, sperm from all groups had decreased health and motility, but the most substantial effect was seen in the sperm with full exposure to EM waves. The difference in sperm health between groups was seen even more clearly after 24 hours of exposure.
'Judging by the results of the current study, it is fair to assume that the longer the exposure is, there is a higher risk for potential negative effects,' Nakata told newsGP. 'And what I mean by longer exposure is not only a few days, weeks or months – we are talking about years. So looking at billions of people over the next few decades, the impact could be huge when it comes to fertility rates.'
The rise in WiFi-based technology in recent years has prompted concerns over its effects on human health. The possible links between exposure to WiFi connections and sperm quality has been previously investigated with laptops (see BioNews 636), and mobile phones in trouser pockets (see BioNews 758).