Blood cadmium concentrations in the general population of Umbria, Central Italy

The aims of this study were (a) to assess blood cadmium (B-Cd) concentrations and to establish a tentative reference interval; (b) to identify significant determinants of B-Cd, in a population from Umbria, Central Italy, which was not occupationally exposed to cadmium (Cd). Four hundred and thirty-four healthy blood-donors volunteered to answer a questionnaire and provide a blood sample for B-Cd analysis, which was performed by graphite furnace atomic absorption spectrophotometry. Blood Cd concentrations ranged from non-detectable values, i.e. below 0.1 μg/l up to 3.4 μg/l and were not normally distributed. The median values and the 95th percentiles were 0.7 and 2.0 μg/l, respectively. Concentrations of B-Cd were more than double in smokers than in non-smokers, median values being 1.1 μg/l and 0.5 μg/l, respectively. In current smokers, B-Cd values correlated with the number of cigarettes smoked daily ( r s =0.40, P=0.0001) and with the cumulative exposure to cigarette smoke ( r s =0.35, P=0.0001). Concentrations of B-Cd correlated with age in the non-smokers, but not in the smokers and were significantly higher in women than in men only in the non-smokers. Both in smokers and non-smokers, B-Cd concentrations were similar in subjects living in urban or in rural areas. In the whole study population the lower and the upper tentative reference limit were