February 15-18, 2009 Washington State Convention Center Seattle ...

HEAVY METALS IN THE BIVALVE MOLLUSC FROM NORTH-EAST ITALY
Daniela Marchis, Maria Cesarina Abete*, Monica Caffara, Ilaria Giorgi, Renata Tarasco, Maria Letizia Fioravanti
and Marino Prearo
State Veterinary Institute
Via Bologna
148 - 10154 Turin – Italy
Bivalve molluscs are supposed to be very good pollution markers, as they can tolerate a wide range of environmental factors
and can concentrate some chemical contaminants, as heavy metals. From February to May 2006, periodic samplings of Tapes
philippinarum, in Goro-Porto Garibaldi area, near Ferrara, and of Chamelea gallina, along the coast nearby Rimini (North-East
Italy, Emilia Romagna region) were carried out. 240 C. gallina individuals in 4 different samplings and 540 T. philippinarum
individuals in 9 different samplings were collected.
The aim of this study was to evaluate the amount of some heavy metals which are ruled by Regulations EC 1881/2006 and EC
629/2008 (Cadmium, Lead and Mercury). Moreover, the Chromium level was also detected, as this trace element, which at the
moment has no maximum residue limit in food, appears to be widespread in the environment. Following microwave digestion,
all the samples were analyzed for Cadmium, Lead and Chromium by atomic absorption spectrometry with Zeeman background
corrector. Limits of quantification (LOQ) were 0.01 mg/kg for Cadmium, 0.04 mg/kg for Lead and 0.05 for Chromium. Mercury
was detected using Direct Mercury Analyzer (TDA-AAS) and LOQ was 0.07 mg/kg. C. gallina samples showed a Cadmium
mean concentration of 0.014 mg/kg (SD 0.013), a Chromium mean concentration of 0.4 mg/kg (SD 0.0028), and a Lead mean
level of 0.07 mg/kg (SD 0.021). In all samples Mercury concentration was below the LOQ.
T. philippinarum individuals showed to be contaminated as follow: Cadmium mean concentration 0.007 mg/kg (SD 0.003);
Chromium mean concentration 1.26 mg/kg (SD 0.65), and Lead mean level 0.145 mg/kg (SD 0.064). Mercury appeared to
show a mean concentration above the LOQ (0.11 mg/kg) in one pool only, whilst in all the other samples it was below the LOQ
value.
All samples were compliant to the EU legislation, as all concentrations resulted below the maximum residue limits. Therefore,
these clams meet the requirements for consumers. Nevertheless, as Chromium contamination appears to be constant in both
species, further investigations on water and on other aquatic organisms should be carried out.