Assessment of Heavy Metal Pollution in Cultivated Soils and Rice Grains on the South Bank of Taihu Lake, China
摘要
Heavy metal pollution was surveyed in 2019 and 2021 in cultivated soils from suburban areas, industrial surroundings, and main agricultural lands on the south bank of Taihu Lake. Overall, based on the Chinese national soil environmental quality standard grade II criteria, 21.71, 6.98, 0.78, and 0.78% of suburban and industrial surrounding soils exceeded the standards for mercury (Hg), cadmium (Cd), nickel (Ni), and copper (Cu), while those of main agricultural soils were 4.40, 4.98, 13.60, 5.41%, respectively. The comprehensive pollution indices of soils in the suburban and industrial surrounding area were 0.696 and 0.660, respectively. In contrast, the comprehensive pollution index was 0.648 in soils that were far from the point pollution sites (CK). For locally produced rice grains, the proportions of samples exceeding the Chinese National Food Safety and Health Criteria standards were 12.06% for Hg, 10.64% for Cd, and 17.73% for Zn. Overall, heavy metal pollution was more severe in soils within the suburban areas than the other areas. The survey in 2021 showed that the comprehensive pollution indices of soils in vegetable base, grain function area, modern agricultural park, long−term application of organic manure were 0.748, 0.685, 0.618 and 0.662, respectively. Therefore, suburban area was a priority for preventing and remediating heavy metal pollution, and vegetable bases were the key areas of heavy metal pollution in farmland.