German researchers have reported that pollen from GM corns containing pest-killing properties is capable of travelling up to 4.45km by wind, according to a Daily Mail article.

The revelation was made following a decade-long investigation to determine the spread of such pollen over several areas in Germany, Switzerland and Belgium.

In addition, the researchers debunked the fact that corn pollen, being heavy, is not able to travel long-distance from cultivation sites. They found out that concentration ranged from 23.3million grains of pollen per square metre close to fields to 2,857 grains at longer distances. Some studies had, in fact, showed that the pollen could travel up to an astounding distance of more than 40 miles, with strong winds, the researchers said.

If the researchers' claim was found true, an urgent change of rules is required to control the spread of GM corn pollen over farms and the countryside, critics said. Pollen spread could threaten the population of butterflies and moths in affected areas.

To reduce the risk, the researchers suggested that GM corn sites should be more than half a mile away from vulnerable areas in the countryside.

Meanwhile, the study, which was published by the Environmental Sciences Europe journal, had reportedly prompted the European Food Safety Authority to review the approval process for the corn, known as Bt maize.

Presently, it is assumed by EU regulators that the actual travelling distance of corn pollen is 20-40m.