Determination of geochemical baseline and pollution of soil heavy metals in Suzhou, China

Abstract

To investigate the enrichment of soil heavy metals, 50 soil samples were collected and the vanadium (V), chromium (Cr), zinc (Zn), lead (Pb), copper (Cu) and arsenic (As) contents were measured by using an X-ray fluorescence spectrometer. The environmental geochemical baseline values of heavy metals were determined by using standardised methods, and the pollution and enrichment degrees of heavy metals were evaluated based on the geoaccumulation index method and enrichment factor method. The results show that the vanadium, chromium, copper, zinc, lead and arsenic contents vary widely, with mean values of 81.32, 65.54, 17.16, 49.28, 20.04 and 11.68 mg/kg, respectively. Except for arsenic, the average values of the other five elements are lower than the soil background values of Anhui Province. The results of the standard reference method indicate that the six heavy metal elements have a strong correlation with iron (Fe), and the baseline values of heavy metals are 81.33, 65.56, 17.18, 49.29, 20.04 and 11.67 mg/kg, respectively. The mean values of Igeofor the six heavy metals are less than 0, indicating that there is no pollution of heavy metals in the soil of Suzhou. The average enrichment factor is greater than 1, with slight enrichment, and the interference of human activities on soil heavy metals is not obvious.