Factors influencing organotin distribution in different marine environmental compartments, and their potential health risk

Tributyltin (TBT) and triphenyltin (TPT) in different marine environmental compartments such as seawater, sediments, and inshore fishes were investigated in 21 Taiwanese harbors between 2001 and 2004 in order to determine the major factors influencing their distribution. The existence of major input sources and the limited water exchange rate inside the harbors were indicated by higher TBT concentrations in seawater from inner harbor than from outer harbor areas. The levels of TBT in sediments were found to be mainly affected by their geographic distribution, water exchange rates and shipping activity. No significant correlations in TBT concentrations between water, sediment and fish suggested TBT accumulation by fish might not result from water and sediment, but from their food. TPT were detected in most fish samples, but found in few sediment samples and none in seawater, indicating fish could be as a target element for monitoring contaminated levels of TPT in the aquatic environment. Mean concentrations of TBT in fish muscle higher than tolerable average residue levels (TARLs), and mean hazard indices of TBT and TPT higher than 1 suggested consumption of fishes from Taiwanese harbor areas might have potential high risk to human health.     

1985 Directory of Governmental Air Pollution Control Agencies

Abstract

Clay that contains kaolinite has been used extensively as a raw material for manufacturing of bricks and china at 900–1100 °C. This study used clay to stabilize the contaminant chromium(VI) [Cr(VI)] through a heating process at 500–1100 °C. X-ray absorption spectroscopic results indicated that the 500–900 °C heating process transformed hazardous Cr(VI) to nontoxic Cr(III); Cr₂O₃ was the species detected as most abundant. The 1100 °C heating process caused the formation of Cr₂SiO₅, which was not detected in the samples heated at 500–900 °C. Fourier transformed extended X-ray absorption fine structure spectra were fitted by use of WinXAS software. Phase shifts and backscatter(ing) amplitudes for specific atom pairs, based on the crystallographic data for CrO₃ and Cr₂O₃, were theoretically calculated with the FEFF software. The processed XAS data show that the first shell coordination numbers were similar to each other as the temperature was increased from 500 to 900 °C and 1100 °C, implying that their Cr(III) crystallite size was relatively similar. The interatomic distance between the target center element and the first shell for the 500– 1100 °C samples was 1.98Å. The Debye-Waller factor for the 1100 °C sample was increased compared with the 500 and 900 °C samples and probably indicates the formation of Cr₂SiO₅.