Microbiological Quality and Heavy Metal Concentrations in Slipper Oyster (Crassostrea iredalei) Cultured in Major Growing Areas in Capiz Province, Western Visayas, Philippines: Compliance with International Shellfish Safety and Sanitation Standards

Human health risk attributed to consumption of seafood and recreation swimming in Negombo Lagoon, Sri Lanka: An assessment on lagoon water and inhabitant oysters (Crassostrea cucullata Born, 1778)

The Negombo Lagoon is a coastal lagoon influenced by local communities that introduce waste into its ecosystem. This study examined seven sewage entry points, out of which five sites were chosen for oyster sampling based on availability. Physicochemical and microbiological parameters of water (measured in triplicate at each site, n = 84) and oyster samples (total length, TL > 6 cm, n = 30) were assessed. Variation in regional coliform contamination was analyzed employing a one-way analysis of variance (ANOVA). Results indicated that the northern part of the lagoon exceeded recommended coliform thresholds for swimming (total coliform concentration (TCC) < 126 most probable number (MPN)) and seafood consumption (TCC < 100 MPN/g), indicating the presence of Escherichia coli. Water quality indices affirmed fecal pollution, except in the southern part of the lagoon. Furthermore, the study found high oyster consumption (76.7 %), elucidating that oysters from the northern part of Negombo Lagoon pose health risks.

Quantitative determination of heavy metal contaminants in edible soft tissue of clams, mussels, and oysters

Aquatic environments are important sources of healthy and nutritious foods; however, clams, mussels, and oysters (the bivalves most consumed by humans) can pose considerable health risks to consumers if contaminated by heavy metals in polluted areas. These organisms can accumulate dangerously high concentrations of heavy metals (e.g., Cd, Hg, Pb) in their soft tissues that can then be transferred to humans following ingestion. Monitoring contaminants in clams, mussels and oysters and their environments is critically important for global human health and food security, which requires reliable measurement of heavy-metal concentrations in the soft tissues. The aim of our present paper is to provide a review of how heavy metals are quantified in clams, mussels, and oysters. We do this by evaluating sample-preparation methods (i.e., tissue digestion / extraction and analyte preconcentration) and instrumental techniques (i.e., atomic, fluorescence and mass spectrometric methods, chromatography, neutron activation analysis and electrochemical sensors) that have been applied for this purpose to date. Application of these methods, their advantages, limitations, challenges and expected future directions are discussed.