4 research outputs found
New implications in the use of imposex as a suitable tool for Tributyltin contamination: experimental induction in Hexaplex trunculus (Gastropoda, Muricidae) with different stressors
Imposex, i.e. the development of additional
male sex organs (penis and/or vas deferens), in
females of gonochorist marine and freshwater gastropods,
is known to be caused by tributyltin (TBT), and
it has been widely used as a biomonitoring tool in
environmental surveys for TBT pollution assessment.
In this study, we experimentally tested the potential to
induce imposex by another endocrine disruptor
(polychlorinated biphenyls [PCBs] mixture—Aroclor
1260). Adults of Hexaplex trunculus with low
imposex level, coming from an Italian Marine Protected
Area, were injected separately with different
doses of tributyltin chloride (TBTCl) and Aroclor
1260. The compounds were dissolved in ethanol and
the organisms were narcotised by immersion in
MgCl2 solution before injection. Before and after the
experiment, butyltin compounds (BuTs) and PCB
tissue concentrations were determined. A significant
increase in imposex with respect to non-treated
organisms was observed in all treatments, including
artefact controls. No clear correlation was observed between BuTs and PCB tissue concentrations and indices of imposex incidence. Based on these results, no assumption can be formulated about PCB effect on
imposex development. Nevertheless, they suggest that the imposex level increase, at least in H. trunculus, in laboratory conditions might not be caused by TBT only, but it would rather be a non-specific response to different stress stimuli
History on organotin compounds, from snails to humans
Organotin compounds are industrial chemicals used as biocides, polyvinyl chloride stabilizers and industrial catalysts for the manufacture of silicone and polyurethane foams. Despite multiple applications, organotin notoriety is due to tributyltin, a potent biocide used in antifouling paints. Because of the intensive use of tributyltin for the protection of ships’ hulls, tributyltin has been largely released into waters, resulting in adverse and even bizarre effects on aquatic organisms, such as imposex in gastropods. However, organotins include other compounds such as tributyltin derivatives, phenyltins and octyltins. Organotin use in plastics, silicone and foams results in their occurrence almost everywhere, e.g., clothes, toys, wallpaper, food containers, household piping and medical devices. Hence, humans are exposed to organotins not solely through ingestion of contaminated seafood but also through direct contact with treated products and by inhalation and ingestion of dust. As a consequence, organotins have been detected in human samples. Toxicity data reveal that organotins are endocrine disruptors, immunotoxicants, carcinogens and obesogens. Here, we review the levels, fate and effects of organotin compounds toward wildlife and humans, starting with a description of organotin applications, with particular incidence in antifouling paints. The global contamination of the marine environment and the deleterious effects of tributyltin onto nontarget organisms are addressed, with particular attention to the imposex phenomenon. The restrictions on tributyltin use in antifouling paints are also described alongside with the new regulations for organotins in consumer products. The sources and pathways of organotins in the environment are discussed, studies in human exposure are presented, and future research is proposed