This study was done in an artificial setting. The male participants were not tested with the laptops on their laps - semen samples were taken, placed under laptops for four hours, and then analyzed.
Previous studies had already shown that placing a laptop on a man's lap could potentially affect his fertility, especially if this occurs frequently and for long periods. The laptop can cause scrotal hyperthermia (elevated testicle temperature), which can considerably affect the quality of his sperm (Link to 2010 study).
In this new study, the authors explain that not only might the laptop-on-lap undermine semen quality, but also the Wi-Fi, if the laptop is near semen. They found that there was less damage when there was no Wi-Fi signal than when there was.
The double-whammy of the Wi-Fi signal and laptop temperature can cause:
- A decrease in human sperm motility
- Sperm DNA fragmentation - irreversible changes in the genetic code
Wi-Fi stands for "wireless fidelity". The term refers to a group of technical standards which enable the transmission of data over wireless networks. Put simply: Wi-Fi means wireless internet connection.
Conrado Avendaño and team carried out a study involving semen samples from 29 healthy and fertile males. They experimented on their semen samples in two environments:
- The Wi-Fi sample. A few drops of semen were place under a laptop with the Wi-Fi switched on. The laptop was downloading data from the internet non-stop.
- The non-Wi-Fi sample. Identical to the environment above, but with no Wi-Fi switched on.
- One quarter of the sperm had lost motility in the Wi-Fi samples
- 14% of the sperm had lost motility in the non-Wi-Fi samples
- 9% of the sperm showed DNA damage in the Wi-Fi samples
- 3% of the sperm showed DNA damage in the non-Wi-Fi sampes
"Our data suggest that the use of a laptop computer wirelessly connected to the internet and positioned near the male reproductive organs may decrease human sperm quality.
At present we do not know whether this effect is induced by all laptop computers connected by Wi-Fi to the internet or what use conditions heighten this effect."
The authors carried out a separate test to determine what the EM radiation levels might be near a Wi-Fi connected laptop and a non-Wi-Fi one. The difference was significant - when the computer was not Wi-Fi connected EM radiation readings were "negligible".
According to PC Mag, Electromagnetic Radiation, also known as EM Radiation, or EMR is:
"The energy that radiates from all things in nature and from man-made electronic systems. It includes cosmic rays, gamma rays, x-rays, ultraviolet light, visible light, infrared light, radar, microwaves, TV, radio, cellphones and all electronic transmission systems. Electromagnetic radiation is made up of electric and magnetic fields that move at right angles to each other at the speed of light."
The authors, as well as other experts who have commented on this study, stress that until a long-term study with a larger group of men and in natural environments is carried out, this one is only "interesting" and not really biologically relevant for humans.
Even though previous studies have looked at laptop usage and sperm quality, none have determined whether there is any impact on how many children men subsequently have or don't have.
In an Abstract in the journal, the authors concluded:
"To our knowledge, this is the first study to evaluate the direct impact of laptop use on human spermatozoa. Ex vivo exposure of human spermatozoa to a wireless internet-connected laptop decreased motility and induced DNA fragmentation by a nonthermal effect.
We speculate that keeping a laptop connected wirelessly to the internet on the lap near the testes may result in decreased male fertility. Further in vitro and in vivo studies are needed to prove this contention."