The general population can be exposed to benzo[a]pyrene through tobacco smoke, air, water, soil, food, and pharmaceutical products. Other major sources of benzo[a]pyrene are wood and coal heating. Much smaller amounts of benzo[a]pyrene are produced by oil and gas heating, cooking, exhaust gases from motor vehicles (especially diesel engines), industrial emissions, and forest fires. However, very high concentrations have been recorded in road tunnels and large cities that heavily use coal or other biomass as heating fuel. Estimates of dietary intake of benzo[a]pyrene are a maximum of several micrograms per person per day. Dietary sources of PAHs include roasted, grilled, and smoked meats, as well as fruits and vegetables grown on contaminated soil (usually areas with surface contamination of atmospheric benzo[a]pyrene). Exposure to benzo[a]pyrene is associated with cancers of the lung, bladder, skin, esophagus, hematolymphatic system, lips, oral cavity, and pharynx. Its urinary metabolites are benzo[a]pyrene-r-7, t-8, t-9, c-10-tetrahydrotetrol, BPT I-1, and benzo[a]pyrene-r-7, t-8, c-9, c-10-tetrahydrotetrol, BPT II-1.