Butyltin compounds in sediments from the commercial harbor of Alexandria City, Egypt

Tributyltin (TBT), dibutyltin (DBT), and monobutyltin (MBT) compounds were quantitatively determined in surface-sediment samples collected from 23 sit es in the commercial harbor of Alexandria City, Egypt. Butyltin concentrati ons in sediments varied widely depending on the sample location, ranging fr om less than 0.1 to 186 ng g(-1) of Sn for MBT, less than 0.1 to 379 ng g(- 1) of Sn for DBT, and 1 to 2,067 ng g(-1) of Sn for TBT. Elevated TBT conce ntrations, ranging from 727 to 2,067 ng g(-1) of Sn were observed in harbor s. marinas, and near ship-repair facilities, indicating that the butyltin-c ontaining, antifouling paints of boats and vessels are the major source of butyltin contamination. The TBT concentration decreased rapidly away from p otential source areas of boat docking and repair facilities. The high relat ive concentrations of TBT in the sediments indicated that degradation proce sses in the sediments are minor, probably due to the anoxic sedimentary con ditions at the sampling sites and/or relatively fresh input of TBT to these sites.