Chapter 15 Persistent Organic Pollutants in Singapore's Marine Environment

Abstract

Abstract Singapore is one of the busiest ports in the world and has many shipyards, petroleum refineries and pharmaceutical manufacturing plants are located on its coastline. Data on the prevalence of persistent organic pollutants (POPs) in Singapore's coastal ecosystems are therefore important in order to support research on the potential threats to the local marine environment and human health. This chapter presents data on the prevalence of POPs in the seawater, sediments, biota and mangrove habitats of Singapore. Data are presented for a range of POPs including polycyclic aromatic hydrocarbons (PAHs), organochlorine compounds (OCPs), polychlorinated biphenyls and polybrominated diphenyl ethers (PBDEs). Local studies confirm the ubiquity of POPs in the marine environment of Singapore. The prevailing ocean currents in the region govern the fate and transport of POPs in coastal waters, where the presence of localized high levels of POPs is likely to be a function of local shipping and industrial discharges. Land reclamation activities may also be a factor in the prevalence of POPs in seawater, where compounds are released from sediments and transported to the water column by seabed dredging. The land area under agricultural use in Singapore is negligible, and there is no direct application of OCPs in the country. However, pesticides may be easily transported through the atmosphere following volatilization from soil, and the presence of OCPs in Singapore's marine waters is likely to be a function of their use in neighbouring countries, with subsequent atmospheric transport and deposition. A biomagnification phenomenon was observed amongst the species collected and analysed from mangrove sites, but levels of POPs were not found to exceed relevant food safety standards. However, PCB concentrations in mangrove fish muscles were found to be higher than mean levels of PCBs found in seafood commonly consumed in Singapore. Overall, available data on the prevalence, fate and transfer of POPs in Singapore's marine environment highlights the ubiquity of these pollutants, and supports the need for a greater awareness on their fate, transport and bioaccumulation in local ecosystems.