Persistent organic pollutants in Singapore's coastal marine environment: Part I, seawater

Persistent organic pollutants (POPs) continue to receive widespread attention as harmful contaminants in the global environment. Increasingly, there have been concerns regarding adverse effects on marine wildlife due to the potential of POPs to induce adverse health effects, including the disruption of endocrine systems. Marine water samples within one kilometer of the coastline of Singapore were analysed to determine prevalent concentrations of a range of persistent organic pollutants (POPs). Samples were collected from 0.5 m and mid-depth (approximately 14 m depth) at twenty-two locations. POPs analysed are classed as USEPA priority pollutants, and included: sixteen polycyclic aromatic hydrocarbons (PAHs); eight polychlorinated biphenyls (PCBs); and twelve organochlorine pesticides (OCPs). Total PAH concentrations varied from 88.44 to 1419.57 ng 1^-1 at the surface, and 129.78 to 940.41 ng 1^-1 at mid-depth. Total OCP concentrations varied between 4.90 ng 1^-1 to 22.04 ng 1^-1 at surface, and 4.09 to 18.05 ng 1^-1 at mid-depth. Total PCB concentrations varied from 0.22 ng 1^-1 to 20.41 ng 1^-1 at surface and 0.4 to 10.79 ng 1^-1 at mid-depth. In general, the distribution profile shows that the surface concentrations of POPs are higher than at mid depth. Concentrations of PAHs were considered higher than reported levels for several other countries, whereas levels of OCPs and PCBs are generally lower than reported levels for other Asian countries.