OBJECTIVETo investigate the level of zinc (Zn) and copper (Cu) in whole blood among general population from 8 provinces in China, and to analyze the characteristics of distribution among different regions.

METHODSThis cross-sectional study was performed in 8 provinces from eastern, middle and western China between 2009 and 2010, including 13 110 subjects from 24 regions, and the blood and urine samples were collected. The ICP-MS was applied to test the content of ICP-MS in blood samples, and the results were used to analyze the characteristics of contents and distributions of Zn and Cu among population from different ages, genders and regions groups.

RESULTSTotally, the mean (95%CI) contents of Cu and Zn in blood were 795 (791-799)µg/L and 3 996(3 976-4 015) µg/L, respectively. The characteristics of distribution of Cu content were as followed, the content of males were lower than it of females (male:767 µg/L; female: 822 µg/L, t = -13.302, P < 0.01). The contents of blood Cu in groups of people aging 6-12, 13-16, 17-20, 21-30, 31-45 and 46-60 years old were separately 860(853-868), 758(748-769), 734(728-734), 782(774-790), 811(795-827) and 820(815-826) µg/L. The differences showed statistical significance (F = 78.77, P < 0.01). The blood Cu content of people in eastern China (800µg/L) were also significantly higher than it in middle (774 µg/L)and western China (782 µg/L) (F = 10.94, P < 0.01). Distribution of blood Zn content showed characteristics as follows: the Zn content was higher in males than in females (male 4 085 µg/L and female 3 908 µg/L, t = 8.78, P < 0.01). The contents of blood Zn in groups of people aging 6-12, 13-16, 17-20, 21-30, 31-45 and 46-60 years old were separately 3 306 (3 261-3 350), 3 888 (3 839-3 937), 3 948 (3 902-3 994), 4 272(4 228-4 315), 4 231(4 180-4 281) and 4 250 (4 205-4 294)µg/L, which showed significant statistical differences (F = 233.68, P < 0.01). The blood Zn content of people in eastern China (3 938 µg/L) were significantly lower than it in middle (4 237 µg/L)and western China (4 105 µg/L) (F = 53.16, P < 0.01). In addition, the study also compared the relation between content of Cu and Zn and the frequency of eating seafood. The results found that the frequency of eating seafood could influence the content of Cu and Zn (Cu: F = 13.54, P < 0.01; Zn: F = 200.20, P < 0.01).

CONCLUSIONThe contents and distributions of Cu and Zn in blood differs among people from different groups in ages, genders and regions. The baseline data of this study provided reliable scientific evidence for further research.