Traffic fumes increase leukaemia risk

Exhaust fumes from cars and trucks increase the risk of childhood cancer. Leukaemia is the most common type cancer in children, but the cause is unknown in most cases. Several studies have detected an association between exposure to traffic exhaust and childhood and adult leukaemia, but other studies have not found a link. The researchers note that benzene, which is found in car exhaust, is an established cause of leukaemia. In a 20-year study of childhood leukaemia cases in an Italian province, children living near busy roads had an increased risk of developing the disease. Researchers from the National Cancer Institute in Milan, tracked cases of childhood cancer in the Varese province in northern Italy from 1978 to 1997. For each of the 120 children with leukaemia, researchers identified four children of the same age and gender who did not have cancer. To measure exposure to traffic fumes, researchers sampled the air outside each child's home for benzene. They took into account traffic density and weather patterns, which can affect levels of benzene in the air. It was found that children exposed to the highest levels of benzene were almost four times more likely to develop leukaemia than unexposed children. Exposure to intermediate levels of the chemical was associated with about a 50 percent increased risk. The increased risk associated with benzene exposure was similar in boys and girls.

The results suggest that living near busy roads is associated with an increased risk of leukaemia in childhood. Although the study is not the final word on the possible link between traffic and cancer, but it provides further evidence of a relationship between exposure to traffic exhausts and childhood leukaemia.

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