Living near highway may up leukaemia risk in kids

Living close to heavily-used roads may increase the risk of a type of leukaemia in children, according to a new study that found exposure to benzene related to car traffic might be partly to blame.
Researchers considered all 2,760 cases of leukaemia diagnosed in children under 15 years of age in metropolitan France over the 2002-2007 period.
The results show that the incidence of new cases of myeloblastic leukaemia (418 of 2,760 cases of leukaemia) was 30 per cent higher in children in the population whose residence was located within 150 metres of heavily used roads, and had a combined length of over 260 metres within this radius.

In contrast, this association was not observed for the more common, lymphoblastic type of leukaemia (2,275 cases).
The researchers particularly studied the case of the Ile-de-France region of Paris, the most urbanised region, for which the mean annual concentration of benzene, mainly from road traffic, was estimated in the vicinity of each residence in the study in a particularly precise manner with the help of data modelled by Airparif, which is responsible for the monitoring of air quality.
"Myeloblastic" or "myeloid" leukaemia is a type of leukaemia that affects myeloid stem cells, which give rise to the red blood cells.

The increased risk of myeloblastic leukaemia for adults with a history of occupational exposure to benzene has long been known, researchers said.

The EPICEA (Epidemiology of Childhood and Adolescent Cancers) team reported the results of a study on the incidence of leukaemias in children living close to heavily used roads.
It is a case-control study that allowed the assessment of exposure level to one or more risk factors.
"The frequency of myeloblastic type leukaemias was 30 per cent higher in children living within a 150 metres radius of heavily used roads, and where the combined length of road sections within this radius exceeded 260 metres," said Jacqueline Clavel from French Institute of Health and Medical Research (INSERM).

In keeping with the hypotheses on which the study is based, exposure to benzene related to car traffic might be one of the explanations for this association, researchers said.
The study was published in the American Journal of Epidemiology.