Contamination of the Coastal Waters of Gijón (North West Spain) by Butyltin Compounds

An innovative method for the determination of butyltin compounds in seawater samples based on the use of isotope dilution analysis has been applied to study the contamination of butyltin compounds in the Bay of Gijon (Spain) where no previous data existed. The sampling in this bay allowed the evaluation of mono-, di-and tributyltin (MBT, DBT and TBT, respectively) contamination in very different environmental compartments (harbour, marina, shipyards and enclosed and open beaches). The results showed clearly a strong influence of the type of location, the water renewal and the proximity to contaminated areas on the levels of butyltin compounds. It was found that in more than 75% of the samples the TBT values were found to be higher than the US-EPA water quality criteria of 7.4 ng L−1 and that in 95% of the samples the concentration of TBT exceeded 1 ng L−1 which has been reported to be a toxic level for many marine species.