Leukaemia is the most common childhood cancer in France, affecting 43 in every million children every year.
The findings are based on 280 children newly diagnosed with acute leukaemia and a further 288 children matched for sex and age, but free of the disease.
Detailed face to face interviews were carried out with each of their mothers. These included questions about the employment history of both parents, the use of insecticides in the home and garden, and the use of insecticidal shampoos to eradicate head lice.
The risk of developing acute leukaemia was almost twice as likely in children whose mothers said that they had used insecticides in the home while pregnant and long after the birth.
Exposure to garden insecticides and fungicides as a child was associated with a more than doubling of the risk of acute childhood leukaemia. And the use of insecticidal shampoos to eradicate head lice, based on what the mothers had said, was associated with almost double the risk.
The authors say that no one agent can be singled out and a causal relation between insecticides and the development of acute childhood leukaemia "remains questionable,"
They add: "However, the consistency of our results and the results from previous studies suggests that it may be opportune to consider preventive action."
Journal
Occupational and Environmental Medicine