Accumulation rate analysis of the heavy metal Pb in farmland soils of a gold mining area

With heavy metal Pb in farmland soil of a gold mining area as the research object, the test results of some samples collected in 2004 or 2012 as the basis for computing Pb accumulation rate, and the period of 2004-2012 as the calculation interval, the authors mainly studied the accumulation rate of Pb. Comparative analysis and sum-average arithmetic method were used to analyze the features of the Pb accumulation rate, and the results show that the Pb accumulation process mainly resulted from human activities of mineral exploitation. The average accumulation rate of the farmland soil Pb in the whole area was 31.8mg/kg. Choosing some pollution sources such as ore dressing plant, smeltery, wastewater irrigation area, tailings storehouse and both sides of highway, the authors analyzed the temporal-spatial accumulation features of the pollution sources of heavy metal Pb near farmland soil. The results indicate that the Pb accumulation contribution of the ore dressing plant to the farmland soil was the biggest. Its accumulation rate was four times that of average accumulation rate of the whole area. The results obtained by the authors have important significance for preventing and controlling the heavy metal pollution and protecting human health.