[Relationship between longevity and soil environment in Xiayi County, Henan Province, China].

Based on field investigation and laboratory analysis, exploration was done of distribution of macro and micro elements in the soils and distribution of longevity population in Xiayi County, Henan Province, China, and relationship between the spatial variation of the distribution of soil elements and the distribution of the longevity population. It was found that longevity population was distributed in a belt running across Xiayi county from northeast to southwest. In the northeast part, the longevity rate (over 95 years old) reached 187 per million and while in the northwest part, it was only 83. The concentrations of heavy metals such as Cd, Cr, Cu, Ni, Pb, Zn in Xiayi soils were (0.177 +/- 0.057), (63.9 +/- 7.48), (23.6 +/- 5.63), (29.5 +/- 3.80), (21.8 +/- 3.37) and (64.80 +/- 8.81) mg x kg(-1), respectively, all up to the criteria for grade II soils in the National Standard for Soil Environment Quality of China; Moreover, the soils in longevous areas were rich in Cr, Zn, K and Mg. K and Mg in Xiayi soils were 1.30 and 1.79 as times as high as the background value of Henan Province and 1.21 and 2.62 times that of the country, respectively. In Liji, Huodian and Zhongfeng where the centenarian rate was relatively low, the soils were low in Cu, Se and Zn, but high in Na. The findings clearly indicate that the soil rich in Cr, Zn, K and Mg and free of any heavy metal pollution is a major contributor to the longevity in the area, while uneven distribution of Se, Zn, Cu and Na in the soil is the key factor affecting the distribution of longevity population in Xiayi County.