Levels and human exposure to volatile methylsiloxanes (VMSs) in mussels

Volatile methylsiloxanes (VMSs), a class of low molecular weight siloxanes, can enter the marine environment from several sources, potentially harming the coastal ecosystems. To infer their impact, mussels (Mytilus galloprovincialis) were used given their ability to act as biomonitors of several contaminants in water bodies. Samples from the Oporto/Aveiro coast (Portugal) collected in 3 different months were analyzed for VMSs, using a QuEChERS methodology ("Quick, Easy, Cheap, Effective, Rugged, and Safe") validated with mean recoveries of 86 ± 6% and followed by GC-MS quantification. VMSs were detected in all the samples, and cyclic siloxanes were detected in higher concentrations, namely D5 and D6, reaching 53 ± 12 ng/g_ww and 27.2 ± 0.8 ng/g_ww, respectively. However, there was no clear geographic or temporal trend on their presence. Depuration of mussels was tested in samples from Ria de Aveiro lagoon (Portugal) and the reduction in VMSs content was significant in all cases (mean 69 ± 12%), minimizing human exposure to these contaminants through ingestion. The annual intake of VMSs, in the worst-case scenario (fresh wild mussels) is at a vestigial level (maximum of 3.95 × 10^-4 mg/kg_bw for D5), suggesting mussel consumption is unlikely to pose risk to human health via VMSs.