Overview
This Italian-language paper summarizes five years of official controls on mussels, carpet-shell clams and cupped oysters in Sardinia, by species and by production area. Lead was the most abundant of the three metals, and only one sample exceeded an EU maximum level (lead, during area classification). Concentrations were higher in winter and spring.
Key numbers
- Carpet-shell clams (Ruditapes spp., n = 91): lead 0.274 ± 0.024 (SE), median 0.188; cadmium 0.034, median 0.028; mercury 0.006 mg/kg fresh weight (Tabella 1, p. 184).
- Mussels (n = 864): lead 0.206, cadmium 0.099, mercury 0.009 mg/kg; oysters (n = 29): lead 0.108, cadmium 0.148, mercury 0.017 mg/kg (Tabella 1).
- Sulcis-Iglesiente production area: lead mean 0.477, median 0.394 mg/kg, the highest area (Tabella 2, p. 185).
Methods (brief)
Edible part, microwave acid digestion (EPA 3052) and ICP-MS (EPA 6020A) with bismuth and indium internal standards. Reagent blanks and CRM 278 and DOLT-2 in each run; ISO/IEC 17025 accredited. Detection limits are not printed. Means are given with standard errors, medians and interquartile ranges.
Evidence Fitness
A large official dataset with direct raw clam (Ruditapes) results and accredited QA. Area results pool species. Raw clams are a proxy for clam-chowder; that thin page is not linked.