Butyltin in ballast water of merchant ships

The time series of analyzed values indicated that concentration of butyltin (BT) compounds in ballast water varied widely depending on the tanks, depths, and dates of sampling, ranging 4-93 ng l−1 during 7-day voyage. Variations in concentrations of BT in the two ballast tanks corresponded well with the level of BT contamination in different pumping sites of ballast waters. Concentrations of BT species detected in ballast water were rather consistent with those found in port waters and sediment of Taiwan and Japan. This study suggested that the problems concerning BT contamination were neither static nor localized.