[Comparison of 51 element contents in normal human lung tissue over twenty years]

Changes in content and distribution of elements in human tissues may reflect changes in environmental backgrounds, and are closely related to human health. To investigate the change in element background in normal lung tissue in different stage, we used ICP-MS, ICP-AES and GFAAS to determine 51 element contents in normal human lung samples of 1982-83 year (n = 7) and compare with those of 2004-05 year (n = 16). Samples were from healthy male adults who died suddenly, and were treated with microwave digestion and wet digestion method. The results show that the contents of 23 elements (Na, Mg, P, K, As, Mo, Ag, Ba, Bi, Y, La, Ce, Pr, Nd, Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu) are significantly higher, and 6 elements (Zn, Ga, Ge, Se, Au and Zr) are significantly lower in the 2004-05 samples than those in the 1982-83 samples. This difference would be related to the changes in environmental backgrounds and people's living habit during twenty years. The distinctive decrease in contents of the 2004-05 samples for most measured rare earth elements (REEs) may be due to more rational usage of REEs in present, while were the soil and corps were largely abused in 1980s in China. The significant increase in contents of some useful micro-elements (Zn and Se ) in the present samples maybe because of the increased intake of these elements as people own more health consciousness. Besides, the increased contents of heavy metal Pb, Cd, Cr and Ni in the present samples may be related to the deterioration of air quality as industrialization course. More than half of measured elements have been significantly changed over twenty years, indicating that some normal value ranges of element contents should be adjusted according to the difference.