Concentrations of polychlorinated biphenyl congeners in cultivated oysters (Crassostrea gigas) in western Taiwan

Spatial and temporal variations of polychlorinated biphenyl (PCB) concentrations in cultivated oysters from five aquaculture areas along the western coast of Taiwan were investigated. Poor correlations between total PCB concentrations (ng/g dry weight [dw]) and physiologic parameters of oysters (shell length, width, thickness, and lipid content) were found. Total PCB concentrations ranged from 3.4 to 94 cng/g dw. The highest value was found in oysters from the Lu'ermen aquaculture area, which receives wastewater from a sodium hydroxide and pentachlorophenol factory. Furthermore, principal component analysis confirmed that the PCB congener pattern in this area was distinct from others and that two additional pollution sources might exist in the Tainan and Hsinchu areas. Oysters with PCB concentrations > 1 SD above the geometric mean were found mainly in Tainan (stations TN5 to TN9) with only one increased concentration in the Yunlin (station YL2) and Hsinchu (station HC4) aquaculture areas. Except for four confined stations, TN3 to TN6, where total PCB concentrations were higher (p = 0.028) in the warmer (May and July) than in the colder season (November and March), seasonal variation of total PCB concentrations in oysters was not significant. Geometric mean and geometric mean plus 1 SD of total PCB concentrations in this study are lower than those in South Korea and the United States (Mussel Watch).

Concentrations of chlorobenzenes, hexachlorobutadiene and heavy metals in surficial sediments of Kaohsiung coast, Taiwan

This work analyzes surface sediment samples collected from 40 stations along the Kaohsiung coast in southern Taiwan for chlorobenzenes (CBs), hexachlorobutadiene (HCBD) and heavy metals (Cu, Zn, Pb, Cd, Ni, Fe, Mn and Cr). The highest CBs concentrations are recorded in station T7-15 (about 10 km west off the outlet of Da-lin-pu ocean outfall pipe), with total di-, tri-, tetra-, penta- and hexa-chlorobenzenes concentrations of 290.5, 117.1, 64.5, 15.7 and 22.3 ng/g, respectively. The major pollution source of HCBD is most likely located in the Tso-yin ocean outfall field; while the Dah-lin-pu ocean outfall field and Kao-ping Chi estuary, located in the southern portion of Kaohsiung coast, are the major contributors of hexachlorobenzene. The concentration of CBs congeners correlate fairly well with each other, as do metals. However, concentrations of organics (CBs and HCBD) did not correlate with metals. This finding implies that the pollution characteristics of organics and heavy metals in this highly utilized coastal zone markedly differ from each other.