Air pollution can increase the risk of death from kidney, bladder and colorectal cancer besides causing lung cancer, a study has showed.According to researchers, air pollution represents a complex mixture of a broad range of carcinogenic and mutagenic substances that may play a role in chronic systemic inflammation, oxidative stress and DNA damage in tissues that could ultimately prove fatal."This research suggests that air pollution was not associated with death from most non-lung cancers, but the associations with kidney, bladder and colorectal cancer deserve further investigation," said lead author Michelle Turner, researcher at the Barcelona Institute of Global Health (ISGlobal) in Spain. For the study, published in the journal Environmental Health Perspectives, the team included more than 600,000 adults in the US and examined associations of mortality from cancer at 29 sites with long-term residential exposure to three ambient pollutants: PM2.5, nitrogen dioxide (NO2) and ozone (O3).Over 43,000 non-lung cancer deaths were registered among the participants. PM2.5 was associated with mortality from kidney and bladder cancer, with a 14 and 13 per cent increase respectively, for each 4.4 µg/m3 (microgram) increase in exposure. In turn, exposure to NO2 was associated with colorectal cancer death, with a 6 per cent increase per each 6.5 ppb (parts per billion) increment. No significant associations were observed with cancer at other sites.