Environmental studies on lead alkyl release in sea water by the Cavtat wreck

Abstract

Research into the problems that arose as a result of the Cavtat ship wreck in the Otranto Channel, Adriatic Sea, and the successive recovery of its alkyl-lead load have been conducted along two distinct lines, namely, protection of divers during recovery operations, and, environmental surveillance before, during and after recovery of the load. Field and laboratory procedures for lead and lead-alkyl analysis in sea water were established: for safety purposes, a rapid field test based on the extraction of tetra-methyl-lead (TML) and tetra-ethyl-lead (TEL) into chloroform, followed by titration with dithizone; for environmental studies a complete analytical procedure based on the electrothermal-atomic absorption analysis of lead, starting with the heavy metal dithizonates extracted in the field was used. Surveys were carried out in the area of the wreckage (Otranto Channel, Adriatic Sea) from February 1977 until October 1978. The analytical results indicate a low pollution level only in the immediate vicinity of the wreck, and negligible environmental effects a few hundred meters downstream from the wreck.