Many pesticides used in the European Union may damage brain growth in foetuses and young children, according to a study published Friday.

The study urged the European Union to tighten restrictions.

"Toxicity to the brain is not routinely included in testing pesticides," Philippe Grandjean of the Havard School of Public Health and the University of Southern Denmark told Reuters.

"Because many of them are by design toxic to the brain of insects, it is very likely that they are also toxic to human brains," he said of a review of almost 200 scientific reports worldwide about the brain and pesticides.

"Laboratory experimental studies using model compounds suggest that many pesticides currently used in Europe...can cause neuro-developmental toxicity," Grandjean and two colleagues in Denmark wrote in the journal Environmental Health.

The developing brain of the foetus and young child is far more sensitive than the adult brain to disruptions from chemicals, they said.

The study focussed on the use of pesticides in the 27-nation EU, which is currently reviewing pesticide laws. It urged greater testing and caution in approving chemicals because of uncertainties about their effects.

Manufacturers say their pesticides are safe for humans.

"Many other countries are watching what the EU is doing...It should take these matters much more seriously than in the past," Grandjean said. Many pesticides used in the EU are also used in other nations.

Pesticides used on food crops in the EU exceed 140,000 tonnes a year, corresponding to 280 grams (10 ounces) per EU citizen, the study said.

More than 25 percent of fruits, vegetables, and cereals contain detectable residues of at least two pesticides.

The study said that pesticide chemicals that could be damaging included organophosphates, carbamates, pyrethroids, ethylenebisdithiocarbamates and chlorophenoxy herbicides.