NTP Review of Selected* Nitropolycyclic Aromatic Hydrocarbon Compounds (NPAHs)

• NPAHs are ubiquitous air pollutants produced as a result of incomplete combustion, e.g.:
  • Diesel and gasoline combustion
  • Coal-fired power plants
  • Kerosene stoves
  • Cigarette smoke
• NPAHs can also form in polluted air from polycyclic aromatic hydrocarbons.
• NPAHs are primarily found in air, but also have been identified in soil, some bodies of water, food (e.g., teas, smoked food) and plants.
• People can be exposed to NPAHs by inhalation, ingestion, or dermal exposure.
• People working in occupations with high levels of gasoline and diesel fuel combustion products, such as trucking industry workers, bus drivers, taxi drivers and coal miners are more at risk for NPAH exposure than the general population.

* NPAHs to be evaluated are composed of rings containing only carbon and hydrogen atoms (but no side chains), contain at least two fused aromatic rings and have at least one nitro (-NO2) group bound to a carbon atom.