A new study has found even low level exposure to traffic fumes can increase the risk of cancer. 313,000 people were measured with their local pollution levels and cancer rates over 9 European countries. Over a 13 year follow up period, 2095 of these developed lung cancer. The chances of cancer increased with higher exposure to pollution - especially ultra fine sooty particles generated by deisel exhaust as these can be inhaled and lodge in the lungs. In fact, there was no level without risk but the more pollution, the higher the risk.