An Assessment of Potential Heavy Metal Contaminants in Bivalve Shellfish from Aquaculture Zones along the Coast of New South Wales, Australia

Evaluation of shellfish aquaculture for potential contaminants is essential for consumer confidence and safety. Every three years, between 1999 and 2014, bivalve shellfish from aquaculture zones in up to 31 estuaries across 2,000 km of Australia’s east coast were tested for cadmium, copper, lead, mercury, selenium and zinc. Inorganic arsenic was included in the analyses in 2002, and total arsenic was used as a screen for the inorganic form in subsequent years. Concentrations of inorganic arsenic, cadmium, lead and mercury were low and did not exceed maximum limits mandated in the Australia New Zealand Food Standards Code. As maximum limits have not been assigned to copper, selenium and zinc, accepted international dietary guidelines were used as a benchmark. Dietary exposure assessments for these elements demonstrated that shellfish from the aquaculture areas investigated do not present a food safety risk. Continued surveillance is essential, given increasing pressure on Australia’s coastal resources.