Nitrated polycyclic aromatic hydrocarbons in the environment: Formation, occurrences and analysis

Nitrated polycyclic hydrocarbons (NPAHs) are nowadays worldwide spread and can be found in traces in most of environmental compartments. Few studies has been carried out about NPAHs because of their low atmospheric concentration (generally one order of magnitude lower than their parent PAHs) often reaching the detection limit of most analytical instruments. Atmospheric NPAHs are often detected in particulate matter since most of them, formed in the gas phase, are then adsorbed in the suspended particulate matter. The scientific interest on these compounds is growing up since the discovery of their carcinogenic effects. In fact various tests conducted on Salmonella sp. have shown how some NPAHs are strong mutagens. (1)While it has been proved that PAHs are indirect mutagens, NPAHs are direct-acting mutagens such as 1,3-, 1,6-, 1,8-dinitropyrenes found in diesel particulate matter.(2),(3) The international Agency for research on cancer (IARC) considered several NPAH to be probable human carcinogens.(4) Follows an overview of NPAHs occurrence in the environment, their toxicity and recent methods of extraction and analysis.