Heavy metal and microplastic contamination in green mussels (Perna viridis) collected from an important aquaculture area in Java, Indonesia: Bioaccumulation and risk assessment

The present study analyzed the potential health effects of co-exposure to heavy metals (HMs) and microplastics (MPs) in green mussels, Perna viridis , which are cultivated in important areas throughout Indonesia's northern Java coastline. The findings showed that, with the sole exception of Pb, which is slightly exceed the permissible upper limits, the levels of most HMs (Cd, Hg, Cr, Cu, and As) found in the tissues of green mussels fall within the acceptable upper thresholds set by the various international bodies. The level of HMs analyzed in the tissues of green mussels were found to be below the provisional tolerable weekly intake levels. The observed levels for the target hazard quotient and hazard index concerning Pb, Cd, Hg, Cr, Cu, and As in the green mussels’ tissues were observed to be below 1. This indicates neither single heavy metal as well as their collective existence causes a substantial non-carcinogenic threat to consumers. The established cancer risk levels for arsenic, lead, and chromium fall within the permissible thresholds, suggesting an absence of potential carcinogenic risk to humans. The tissue of P. viridis at the Semarang site exhibited the lowest level of MPs, while the MPs concentrations in the tissues from the Pasuruan, Gresik, and Jakarta sites showed no significant differences. The MPs detected within the tissues of green mussels at all examined locations were primarily comprised of black particles measuring under 100 µm. In the tissues of green mussels, eight distinct polymer types have been identified: polyurethane, polyethylene, polypropylene, polyamide, polystyrene, polyvinyl chloride, polyvinyl alcohol, and polymethyl methacrylate. All four study sites exhibited a polymer hazard index classified as III, signifying a high hazard category.