Presence and origin of polycyclic aromatic hydrocarbon in sediments of nine coastal lagoons in central Vietnam

Several natural and anthropogenic processes can lead to the formation of polycyclic aromatic hydrocarbons (PAHs), a well known class of compounds, many of which with mutagenic and carcinogenic properties (Nielsen et al., 1995), that are regarded as priority pollutants by the US Environmental Protection Agency (US EPA, 1993). Anthropogenic sources include combustion of fossil fuels, coal gasification and liquification processes, petroleum cracking, waste incineration and production of: coke, carbon black, coal tar pitch and asphalt, (McCready et al., 2000). Another common anthropogenic source of PAHs is spillage of fossil fuels, both unrefined and refined products. PAHs also stem from natural combustion sources such as forest fires, and certain compounds (perylene and retene) are thought to be diagenetically produced (Wakeham et al., 1980).