Methyl- and butyltin compounds in water and sediments of the Rhine River

Concentrations of methyl- and butyltin compounds in water and sediment samples for the Rhine river were determined. Possible sources of these compounds were also examined with respect to tin species concentrations and their potential contributions to organotin levels in the Rhine. Water samples contained dimethyltin, monobutyltin and dibutyltin in the low ppt range. Sediments contained methyl- and butyltin compounds in the middle parts-per-billion range. High levels of tributyltin, the most toxic compound for aquatic organisms, occurred in harbours along the Rhine. Among other contributors to the total input of methyl- and butyltin compounds to the river, municipal sewage treatment effluents were potentially significant. Further work was necessary to elucidate origins and pathways for these compounds.