Cigarette butts: An overlooked source of PAHs in the environment?

Cigarette butts (CBs) are the most common littered objects in the environment and may contain high amounts of polycylic aromatic hydrocarbons (PAHs) from incomplete tobacco leave burning. But to date there is no comprehensive study on environmental emissions of PAHs by CBs. So the main aim of this study was to compare the concentration levels of 16 PAHs in freshly smoked CBs and CBs from the environment (collected from urban streets and river areas) with different exposure times to the environment. The results showed that the mean concentration levels of 4 PAHs including naphthalene, acenaphthylene, acenaphthene, and fluorene were significantly higher in the freshly smoked CB samples compared to the street samples and were the lowest in the river samples. Considering the number of CBs annually littered, considerable amounts of these 4 PAHs may be released to the environment, which may be a threat to the quality of water resources.