PAHs/NPAHs

Abstract

The environmental atmosphere contains numerous kinds of organic pollutants. Among them are the polycyclic aromatic hydrocarbons (PAHs) and nitropolycyclic aromatic hydrocarbons (NPAHs), which are carcinogenic and/or mutagenic. PAHs and NPAHs mainly originate from the imperfect combustion of organic matter such as coal, petroleum, and biomass. Both PAHs (having four rings or more) and NPAHs were detected in particulates from diesel- and gasoline-engine vehicles, and PAHs having lower molecular weights (three rings or less) were detected in the gaseous phase and unburned diesel fuel. PAHs and NPAHs were also detected in smoke from steel and iron industries, as well as in wastewater and sediment. In addition to the NPAHs such as 1,3-, 1,6-, 1,8-dinitropyrenes, and 1-nitropyrene (1-NP) that are emitted directly from the above sources, other important sources of NPAHs such as 2-NP and 2-nitrofluoranthene (2-NFR) are formed from the heterogeneous or homogeneous reactions of parent PAHs with nitrogen oxides and radicals in the atmosphere. PAHs and NPAHs need to be monitored because they are a health risk for humans and they are present throughout the environment. In this section, we review some reports on the analytical methods used in monitoring PAHs and NPAHs in the atmosphere.