Organolead compounds in mussels (Mytilus galloprovincialis) from the eastern Adriatic coast

Mussels (Mytilus galloprovincialis) and surrounding seawater were collected from various sites on the eastern Adriatic coast and examined for the presence of alkyllead compounds and the total lead content. Organoleads were quantified by gas chromatography-atomic absorption spectrometry, and total lead was quantified by differential pulse anodic stripping voltammetry. The presence of all alkyllead species in mussel tissues was established (in nanograms/gram gram of wet weight): tetraalkyl (<0.2-43.6), trialkyl (<0.1-31.8), and dialkyl (<0.1-9.2), with a dominance of ethyl derivatives. The organolead level in mussels is shown to be a better indicator of pollution with organic lead than that in seawater, whereas the total lead level cannot serve this purpose as it comes from other sources. Trimethyllead amounts in mussels and seawater are highly correlated; thus, mussels provide a good bioindicator for this chemical species. Correlation between alkyllead levels suggests the possible environmental methylation of lead. Bioconcentration factors between mussels and water for individual alkyllead compounds are, on average, lower than those for total lead, indicating less efficient bioaccumulation of organic lead.