Organotin compounds result from the addition of organic moieties to inorganic tin.Thus, one or more tin-carbon bonds exist in each organotin molecule. The organo-tin compounds are ubiquitous in the environment. Organotin compounds have many uses, including those as fungicides and stabilizers in plastics, among others in industry. The widespread use of organotins as antifouling agents in boat paints has resulted in pollution of freshwater and marine ecosystems. The presence of organotin compounds in freshwater and marine ecosystems is now understood to be a threat, because of the amounts found in water and the toxicity of some organotin compounds to aquatic organisms, and perhaps to humans as well. Organotin com-pounds are regarded by many to be global pollutants of a stature similar to biphenyl,mercury, and the polychlorinated dibenzodioxins. This stature results from the high toxicity, persistence, bioaccumulation, and endocrine disruptive features of even very low levels of selected organotin compounds.Efforts by selected governmental agencies and others have been undertaken to find a global solution to organotin pollution. France was the first country to ban the use of the organotins in 1980. This occurred before the international maritime organization (IMO) called for a global treaty to ban the application of tributyltin (TBT)-based paints. In this chapter, we review the organotin compounds with emphasis on the human exposure, fate, and distribution of them in the environment. The widespread use of the organotins and their high stability have led to contamination of some aquatic ecosystems. As a result, residues of the organotins may reach humans via food consumption. Notwithstanding the risk of human exposure, only limited data are available on the levels at which the organotins exist in foodstuffs consumed by humans. Moreover, the response of marine species to the organotins, such as TBT, has not been thoroughly investigated. Therefore, more data on the organotins and the consequences of exposure to them are needed. In particular, we believe the following areas need attention: expanded toxicity testing in aquatic species, human exposure, human body burdens, and the research to identify biomarkers for testing the toxicity of the organotins to marine invertebrates.

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Heavy metal concentrations in black mussels (Mytilus galloprovincialis) collected from Cape Town Harbour were determined using energy dispersive X-ray fluorescence (EDXRF) and inductively coupled plasma-mass spectrometry (ICP-MS). EDXRF showed that tissue portions of the mussels contained K, Ca, Fe, Cu, Zn, Si, Sr, Al and Au, while the shell portion contained K, Ca, Fe, Cr, Zn, Si and Sr. In addition to these metals, EDXRF also revealed the presence of Al in the shells of the largest mussels. Highest concentrations of Cu and Zn were recorded in the tissues of the smallest mussels. Due to poorer detection limits of EDXRF, ultra-trace elements (Mn, Pb, As, Hg, V, Cr, Sn, Cd, Ni and Co) were determined in mussels using ICP-MS. The average metal concentrations found in the mussels are as follows; Pb (7.30 ± 0.67), Cd (1.98 ± 0.13), Hg (4.92 ± 0.60), As (6.94 ± 0.04), Sn (2.63 ± 0.13), Ni (1.88 ± 0.05), Cr (3.54 ± 0.05), V (4.17 ± 0.23), Co (0.74 ± 0.01) and Mn (35.20 ± 1.46). ANOVAs, Pearson correlation and principal component analysis (PCA) were employed in data analysis. The order of the abundance of metals in the mussels isThe average metal concentrations found in the mussels were higher than the permissible Food and Agriculture Organization (FAO) limits and other international guidelines.

This study investigated the use of lysosomal responses of hemocytes of the common garden snail, Helix aspersa, as biomarker of stress due to exposure to the fungicide copper oxychloride. The neutral red retention (NRR) time assay was employed for this purpose. Two groups of snails were exposed to 80 microg g(-1) and 240 microg g(-1) copper oxychloride in their food, respectively, for a period of 6 weeks. They were compared with a control group to which no copper oxychloride was added. The two groups exposed to the fungicide exhibited significantly higher (p < 0.001) whole body copper concentrations (200.85 +/- 53.5 and 272.24 +/- 67.15 microg g(-1) dry mass, respectively), and significantly shorter (p < 0.001) NRR times (10.22 +/- 3.53 and 2.67 +/- 2.83 min, respectively), after 6 weeks, compared to the control group (67.85 +/- 31.08 microg g(-1) dry mass and 24.44 +/- 8.35 min). In both exposure groups NRR times became progressively shorter as body copper concentrations increased over time. Thus, both exposure concentration and exposure time of copper oxychloride were shown to be important factors influencing lysosomal responses (and therefore NRR times) of H. aspersa hemocytes. It was concluded that these responses in this species, as measured by the NRR time assay, could be considered a useful cellular biomarker of stress resulting from exposure to copper oxychloride.

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