Estimating the contribution of atmosphere on heavy metals accumulation in the aboveground wheat tissues induced by anthropogenic forcing

摘要

The influence of atmosphere pollution on human health is receiving more and more concerns as strengthened anthropogenic activity had brought excessive pollutant into the atmosphere. To date, the quantitative estimation about the contribution of atmosphere on the accumulation of heavy metal in the edible cereal parts induced by anthropogenic forcing is scarce. Taking the Yangtze River Delta area, China as an example, this study estimates quantitatively the influence of atmosphere on the concentration of heavy metal in the aboveground wheat tissues induced by anthropogenic industrial activity at the regional scale. The results show that the aboveground wheat tissues in the southern Yangtze River Delta area accumulated much more heavy metals than that in the northern area, although there is no significant difference in the geological and climate conditions, soil types, agricultural manages, wheat cultivar and soil heavy metals concentrations (even heavy metals concentrations in wheat root) between the southern area and northern area. The mean concentrations of Pb, Zn, Cu and Cd in wheat grain in southern area have exceeded the thresholds of contamination levels. The present study suggests that the influence of atmosphere on the accumulation of Hg, Cd, Pb, Zn, Cu, Ni and Cr in the aboveground wheat tissues is greatly significant when high amounts of pollutant are measured in the atmosphere. Based on translocation coefficient of the element, it is estimated that atmospheric pollution induced by anthropogenic forcing might lead to the concentration of heavy metals in wheat straw and grain increase by approximately 100% and 354% (Hg), 64% and 293% (Pb), 122% and 160% (Cr), 50% and 38% (Cd) and 14% and 41% (Cu), respectively.