Could Wi-Fi be more dangerous than we know? When mobiles first became popular, stories about the dangers of them cropped up all over. Now it seems it's Wi-Fi’s turn. A test by schoolchildren has found that Wi-Fi does affect plant life negatively.

After finding it difficult to concentrate in class, following a night sleeping next to their mobiles, a group of schoolgirls in Denmark carried out an experiment. They placed six trays of planted garden cress seeds next to two Wi-Fi routers and did the same in a radiation-free room for 12 days.

The results showed that seeds placed near routers either didn’t grow or turned brown and died. While those placed away from the radiation blossomed into healthy plants. This fits with results from Holland who found trees exposed to wireless radio signals suffered from damaged bark and dying leaves.

To avoid sounding like a certain fear-monger newspaper we’re going to take the results of these schoolchildren with a pinch of salt. Presumably every factor that affects growth wasn’t taken into account so there’s every chance, for example, one room was more moist than the other, or had more light. Others have pointed out that the heat given off by the routers could have been the cause.

Kim Horsevad, the students’ biology teacher at Hjallerup School, said: "This has sparked quite a lively debate in Denmark regarding the potential adverse health effects from mobile phones and wifi equipment."

While the results may still be in question, it is an interesting point. Ms Horsevad, a professor of neuroscience at the Karolinska Institute in Sweden, was so impressed with the experiment that she is interested in repeating it in a controlled scientific environment.

While there is no evidence to support claims Wi-Fi affects humans, they are radio waves which measure 100,000 times more powerful than a microwave. But standing in a spot by Wi-Fi for a year would expose you to the same amount of radio waves as making a 20-minute mobile call. If you are worried, then sitting more than three feet away from the router diminishes the signals considerably.

It’s all interesting stuff. Let us know what you think in the comments below.