Concentrations of Organotin Compounds in Tissues and Organs of Dugongs from Thai Coastal Waters

Abstract

Concentrations of butyltin (BT) and phenyltin (PT) compounds were measured in organs and tissues of dugongs (Dugong dugon) from the coastal waters of Thailand. Concentrations of BTs and PTs were in the range of 14-14,468 and <1-30 microg kg(-1)(detection frequency: 79%), respectively. Although concentrations of BTs in dugongs were higher then reported concentrations in cetaceans and pinnipeds, PTs were lower in dugongs. In half of the dugongs in which measurements were made, the concentration of BTs in the liver was the highest among the all the tissues and organs tested. Dibutyltin (DBT) or monobutyltin (MBT) was found to be the dominant compounds among the BTs. The distribution in the body of PTs was not clear because of the lower levels of this compound. TPT was the dominant compound among PTs. The coastal area of Thailand is located off the Gulf of Thailand and the Andaman Sea. Concentrations of organotin (OT) compounds in dugongs collected from the Gulf of Thailand were compared to those from the Andaman Sea. No significant differences in BT or PT concentrations were observed between the two areas (p < 0.05). The concentrations of BTs and PTs in the livers of dugongs were decreased between 1998 and 2002, suggesting a decrease in OT concentrations in the surrounding environment.