Ecological security evaluation of Cu in soils in the Huanghuai plain, Henan, China

On the basis of an analysis of the distribution characteristics of the Cu content in soils and wheat seeds in the Huanghuai plain, Henan, the Cu pollution in wheat seeds in the study area is evaluated by using the monomial pollution index. The results show that the average monomial Cu pollution index Pi of wheat seeds in this area is 0.473, suggesting that the wheat seeds in this area have not been polluted by Cu. The authors also analyze the relation between the Cu content in soils and that in wheat seeds and think that the cumulative Cu content in wheat seeds has no significant correlation with the total Cu content in soils but shows a significant correlation with the effective Cu content in soils. So the authors use effective Cu in soils as the index of ecological security evaluation of Cu in soils to construct a model of response relationships between Cu in wheat seeds and effective Cu in soils and determine the security limit of effective Cu in soils.