[Blood copper, zinc, calcium, magnesium and iron distribution in rural China aged 6-12 in 2002 and 2012].

OBJECTIVE: To investigate the distribution and changes of blood copper, zinc, calcium, magnesium and iron in Chinese rural children aged 6 to 12 years in 2002 and 2012. METHODS: A total of 3420 blood samples were randomly selected from the China Nutrition and Health Survey 2002 and 2012. Metal concentrations in whole blood were determined by inductively coupled mass spectrometry(ICP-MS) after the dilution of 0. 5%(V/V) HNO_3 and 0. 05%(V/V) Triton-X-100. The changes between 2002 and 2012 of blood five elements concentration in children of 6-12 years in rural China were compared. RESULTS: The median of blood levels of copper, zinc, calcium, magnesium and iron in 2002 were 1. 02(95% CI 0. 79-1. 32), 4. 88(95% CI 3. 17-6. 77), 58. 59(95% CI 44. 97-74. 24), 41. 56(95% CI 33. 01-52. 28) and 423. 21(95% CI 338. 83-540. 69) mg/L, respectively. And in 2012, the median values were 1. 00(95% CI 0. 75-1. 31), 5. 12(95% CI 3. 17-7. 37), 63. 36(95% CI 41. 14-79. 16), 41. 78(95% CI 30. 89-52. 53) and 422. 06(95% CI 297. 83-522. 56) mg/L, respectively. There were significant differences in blood copper, zinc, calcium and iron levels in general, gender and age. There were also significant area differences in the distribution of copper, zinc, calcium, magnesium and iron, but the changes were opposite. CONCLUSION: In 2002 and 2012, there were differences in the blood distribution of Cu, Zn, Ca, Mg and Fe of children aged 6-12 in rural China in terms of general, gender, age and area.