Characteristics of Antimony Migration and Transformation and Pollution Evaluation in a Soil-Crop System Around a Tin Mine in Hunan Province

Abstract

This study used 193 sets of farmland soil and agricultural product samples collected from around a tin mine in Hunan Province, China, to explore the antimony (Sb) content characteristics and pollution status of soil and agricultural products and to provide a scientific basis for the prevention and control of soil antimony pollution in antimony mining areas and the safe use of farmland. We analyzed the amount of antimony in the soil, basic physical and chemical properties, and antimony content in agricultural products; studied the characteristics of antimony migration and transformation in the soil-agricultural product system; and conducted safety assessments on soil and agricultural products. The results showed that the soil ω(Sb) in the central area of the mine, the southern area of the mine, the central township area, the urban-rural transfer area, and the northern area of the mine reached (2348±2165), (1298±884.1), (311.8±526.5), (302.5±355.9), and (215.6±183.2) mg·kg-1, and the exceeding multiples reached 65.22, 36.06, 8.66, 8.40, and 5.99 times, respectively. The antimony enrichment coefficients of lettuce, scallion, cabbage, water spinach, garlic, and pea seedlings in agricultural products were 0.01-0.1, which indicated good antimony absorption capacity. The antimony enrichment coefficients of loofah, asparagus lettuce, pepper, carrot, bitter gourd, corn, eggplant, cowpea, and celery were less than 0.01, and the antimony absorption capacity was relatively poor. The safety assessment results showed that roots, allium, and garlic vegetables had a high risk of antimony pollution; leafy vegetables and legumes had a higher risk of antimony pollution; and solanaceous vegetables, melons, and fruit vegetables and corn (cereals) had a high risk of antimony pollution. Therefore, it is urgent to take soil antimony pollution control measures in the mining area. At the same time, in order to realize the safe use of agricultural land in the mining area, the farmland far away from the low antimony content of the soil in the central area of the mine should be selected as the planting area, and the agricultural products with weak antimony absorption capacity should be planted first.