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Researchers have already uncovered worrying signs that exposure to traffic - and the vehicle emissions that come with it - can increase a child's risk of developing asthma and autism. Now comes evidence that it may make children more susceptible to certain kinds of cancers.

Researchers used the California Department of Transportation's computer model of traffic-related air pollution to estimate pollution exposure in communities across the state. They also used the California Cancer Registry to identify 3,590 children born between 1998 and 2007 who were diagnosed with some type of cancer. Then they compared the two to look for links between traffic and cancer incidence.

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