Diesel exhaust from sources such as buses, trucks, and farm equipment is a major component of air pollution around the world and has been linked with lung cancer and other illnesses. Both the Environmental Protection Agency and the National Toxicology Program, the interagency program charged with assessing the impact of different chemicals on human health, have classified diesel exhaust as a probable human carcinogen. Now, researchers have found a way to measure people’s exposures to this pollutant by tracking a specific chemical in their urine.
Found almost exclusively in diesel exhaust is a chemical called 1-nitropyrene, or 1-NP. The body breaks down inhaled 1-NP into several smaller molecules, called metabolites, that show up in urine.