Shellfish and Residual Chemical Contaminants: Hazards, Monitoring, and Health Risk Assessment Along French Coasts

Abstract

In this review, we address the identification of residual chemical hazards in shellfish collected from the marine environment or in marketed shellfish. Data, assembled on the concentration of contaminants detected, were compared with the appropriate regulatory and food safety standards. Moreover, data on human exposure and body burden levels were evaluated in the context of potential health risks.Shellfish farming is a common industry along European coasts. The primary types of shellfish consumed in France are oysters, mussels, king scallops, winkles,whelks, cockles, clams, and other scallops. Shellfish filter large volumes of water to extract their food and are excellent bioaccumulators. Metals and other pollutants that exist in the marine environment partition into particular organs, according to their individual chemical characteristics. In shellfish, accumulation often occurs in the digestive gland, which plays a role in assimilation, excretion, and detoxification of contaminants. The concentrations of chemical contaminants in bivalve mollusks are known to fluctuate with the seasons.European regulations limit the amount and type of contaminants that can appear in foodstuffs. Current European standards regulate the levels of micro-biological agents, phycotoxins, and some chemical contaminants in food. Since 2006, these regulations have been compiled into the "Hygiene Package." Bivalve mollusks must comply with maximum levels of certain contaminants as follows:lead (1.5 mg kg-1), cadmium (1 mg kg-1), mercury (0.5 mg kg-1), dioxins (4 pg g-1 and dioxins + DL-PCBs 8 pg g-1), and benzo[a]pyrene (10 μp.g kg-1).In this review, we identify the levels of major contaminants that exist in shellfish(collected from the marine environment and/or in marketed shellfish). The follow-ing contaminants are among those that are profiled: Cd, Pb, Hg, As, Ni, Cr, V,Mn, Cu, Zn, Co, Se, Mg, Mo, radionuclides, benzo[a]pyrene, PCBs, dioxins and furans, PAHs, TBT, HCB, dieldrin, DDT, lindane, triazines, PBDE, and chlorinated paraffins.In France, the results of contaminant monitoring have indicated that Cd, but not lead (< 0.26 mg kg-1) or mercury (< 0.003 mg kg-1), has had some non-compliances. Detections for PCBs and dioxins in shellfish were far below the regulatory thresholds in oysters (< 0.6 pg g-l), mussels (< 0.6 pg g-1), and king scallops (< 0.4 pg g-1). The benzo[a]pyrene concentration in marketed mussels and farmed shellfish does not exceed the regulatory threshold. Some monitoring data are available on shellfish flesh contamination for unregulated organic contaminants.Of about 100 existing organo stannic compounds, residues of the mono-, di-, and tributyltin (MBT, DBT, and TBT) and mono-, di-, and triphenyltin (MPT, DPT,and TPT) compounds are the most frequently detected in fishery products. Octyltins are not found in fishery products. Some bivalve mollusks show arsenic levels up to 15.8 mg kg-1. It seems that the levels of arsenic in the environment derive less from bioaccumulation, than from whether the arsenic is in an org...

Arsenic in the human food chain, biotransformation and toxicology – Review focusing on seafood arsenic

“…mussels that typically contain 0.9-3.4 mg As/kg dw [36]. Arsenosugars are probably a biotransformation product of inorganic arsenate that initially is taken up by the algae from seawater.…”

Safety assessment of seafood with respect to chemical pollutants in European Seas

“…The concentrations of PCBs and dioxins in shellfish were far below the regulatory thresholds in oysters (<0.6 pg g -l ), mussels (<0.6 pg g -1 ), and king scallops (<0.4 pg g -1 ). The benzo[a]pyrene concentration in marketed mussels and farmed shellfish did not exceed the regulatory threshold (Guéguen M. et al 2011).…”

“…Maximum levels of certain toxic compounds established for edible bivalve molluscs are as follows: lead (1.5 mg kg -1 ), cadmium (1 mg kg -1 ), mercury (0.5 mg kg -1 ), dioxins (4 pg g-1 and dioxins + DL-PCBs 8 pg g -1 ), and benzo[a]pyrene (10 μp.g kg -1 ) (Guéguen M. et al 2011). The authors identify the levels of major contaminants that exist in shellfish in France (collected from the marine environment and in marketed shellfish).…”

Influence of Thermal Preparation Method on Mineral Composition of Mussels

“…Mussels are an excellent aquaculture candidate, but they accumulate a wide range of metals in the meat (Romeo et Marine resources for human consumption have grown rapidly worldwide with the widespread use of seafood, which is recognized as important sources of protein, minerals and vitamins (Heu et al, 2003;Storelli, 2008;Hellberg et al, 2012). Shellfish has many nutritional advantages, but at the same time it poses health risks such as heavy metal contamination because they filter large quantities of water to extract their food and are good bioaccumulators (Guéguen et al, 2011;Grotto et al, 2012;Hellberg et al, 2012).…”