Accumulation of butyltin compounds and total tin in marine mammals

Concentrations of butyltin compounds (BTs), including tributyltin (TBT) and its metabolites, di-(DBT) and monobutyltin (MBT), and total tin (n=organic +inorganic tin) were determined in various tissues and organs of marine ma mmals collected from Japanese coastal waters. Some marine mammal species fr om Hong Kong, India, Philippines, Black Sea and North Pacific Ocean were an alyzed for comparison. Among the organs and tissues analyzed. concentration s of Sigma BTs (TBT+DBT+MBT) and Sigma Sn were the highest in the liver. Co ncentrations of Sigma BTs and Sigma Sn in most coastal species were higher than those in offshore species, indicating a greater input of tin compounds in coastal waters. Lower hepatic concentrations of Sigma BTs and ratio of Sigma BTs to Sigma Sn observed in pinnipeds may be attributed to higher met abolic capacity to degrade BTs and to their excretion through hair shedding . Age trends in accumulation of both Sigma BTs and Sigma Sn showed increasi ng concentrations in immature growth stage and stable levels in mature anim als. A significant correlation was observed between the hepatic concentrati ons of Sigma BTs and Sigma Sn in marine mammals. These findings suggest a s ignificant input and/or bioaccumulation of anthropogenic tin. A significant correlation was found between concentrations of Sigma BTs (as wen as Sigma Sn) in hair and liver of pinnipeds, suggesting that hair can be used as an indicator for monitoring butyltin contamination in the body of pinnipeds u nder non-killing condition.