Butyltins in sediments and bivalves from U.S. coastal areas

Butyltin concentrations in sediment samples from U.S. coastal areas ranged from less than 5 to 282 ng Sn/g. Butyltins were detected in 75% of the sediment samples analyzed. The predominant butyltin was TBT, which is also the most toxic. DBT and MBT were detected in 30% of the sediment samples analyzed. These TBT degradation products were only found when TBT was present, usually at high concentrations. Mean bivalve butyltin concentrations were 18 times higher than mean sediment concentrations. Based on bivalve analyses, bioavailable butyltins were present at all the sites where butyltins were detected in the sediment.