London: Wi-fi networks that enable our burgeoning online communications are a threat to trees, say Dutch scientists.
According to the study in Holland, trees planted close to a wireless router had bleeding bark and dying leaves, reports the Daily Mail.
The revelation has raised fears that wi-fi radiation may also be having an effect on the human body.
The city of Alphen aan den Rijn, in the Netherlands, ordered the study after officials found unexplained abnormalities on trees.
Researchers took 20 ash trees and for three months exposed them to six sources of radiation.
Trees placed closest to the wi-fi source developed a ``lead-like shine`` on their leaves that was caused by the upper and lower epidermis - the leaf’s skin - dying.
Researchers also discovered that wi-fi radiation could slow the growth of corn cobs.
In the Netherlands, 70 per cent of all trees in urban areas show the same symptoms, compared with 10 per cent five years ago, the study found.
The Wageningen University scientists, who conducted the study, said that further studies were needed to confirm their findings.
The Dutch health agency issued a statement, stressing that "these are initial results and that they have not been confirmed in a repeat survey".
It added: "There are no far-reaching conclusions from its results. Based on the information now available it cannot be concluded that the wi-fi radio signals leads to damage to trees or other plants."