Assessment of reference ranges for blood Cu, Mn, Se and Zn in a selected Italian population

The reference ranges for blood Cu, Mn, Se and Zn of 215 adult subjects non-occupationally exposed and living in the Nuoro province (Sardinia, insular Italy) were assessed. Metals were determined by sector field inductively coupled plasma mass spectrometry after microwave-assisted acid digestion of blood. The blood reference ranges estimated as P5–P95 percentiles (geometric mean, GM) were 776–1495 μg/L (1036 μg/L) for Cu; 4.73–17.0 μg/L (8.91 μg/L) for Mn; 106–185 μg/L (140 μg/L) for Se and 4686–8585 μg/L (6418 μg/L) for Zn. These results were then stratified for sex, age, alcohol consumption, smoking habit and living area. The GM value of Cu was significantly higher in females (1127 μg/L) than in males (957 μg/L). Age, alcohol intake, smoking habit and residential area did not influence blood Cu. The GM of Mn was significantly higher in females (9.98 μg/L) respect to males (8.01 μg/L) and in drinkers (9.67 μg/L) compared to non-drinkers (8.38 μg/L). The other variables did not change the Mn data. Selenium concentrations did not differ significantly as a function of individuals factors. With reference to Zn, males had GM of 6804 μg/L and females of 6031 μg/L, and more blood Zn was found in subjects consuming alcohol (6618 μg/L) respect to abstainers (6155 μg/L). In addition, blood Zn was not affected by age, smoking habit and place of living.