Characteristics and health risk assessments of heavy metals in soils and vegetables in manganese mining areas in Tongren County, Guizhou Province, China

• Main Authors: JIANG Zong-hong, LU Feng, MA Xian-jie, CHEN Lan-lan, CHEN Miao
• Format: Article
• Language: zho
• Published: Agro-Environmental Protection Institute, Ministry of Agriculture 2020-03-01
• Series: Journal of Agricultural Resources and Environment
• Subjects: heavy metal, soil, vegetables, health risk evaluation
• Online Access: http://www.aed.org.cn/nyzyyhjxb/html/2020/2/20200218.htm
• ISSN: 2095-6819; 2095-6819

To explore the characteristics of manganese pollution in manganese mining areas, and evaluate the health risk of heavy metal pollution in vegetables, samples of soil and vegetables were collected in Yanglizhang, Baiyanxi, Penjiashan, and Pengcheng. These are manganese mining areas in Tongren County, Guizhou Province, China. Samples were collected from within a 2.0 km range, at different distances from the mining area. The composition and content of heavy metals in the soil and vegetables samples(including capsicums, cabbages, pumpkins, eggplants, and cowpeas) were analyzed and measured. Soil that was contaminated with heavy metals was evaluated using both the single pollution index method and the comprehensive pollution index method. The health risk assessment model was used to evaluate the chronic health risk caused by eating vegetables that were grown near mining areas. The results showed that the average content of Mn and Hg were 2.56 and 1.55 times, respectively, that of the soil background values in Guizhou, and the average Cd content was 2.20 times higher than that of the value specified in the <i>Soil Environmental Quality Risk Control Standard for Soil Contamination of Agricultural Land</i> (GB 15618-2018). An analysis of the comprehensive pollution index showed that the Penjiashan mining area was heavily polluted, the Yanglizhang mining area was moderately polluted, and the Baiyanxi and Pengcheng mining areas were slightly polluted. The results of health risk assessment of heavy metals in the vegetable samples showed that the average value of <i>R</i>_T(carcinogenic risk) was 4.31&#215;10^-6 a^-1, which was acceptable. The HI_T(non-carcinogenic risk) value was 4.21&#215;10^-9 a^-1, indicating that the risk of the occurrence of non-carcinogenic heavy metals in vegetables to human health was negligible. In other words, there have been varying degrees of heavy metal contamination in manganese mining areas, but the health risks by eating vegetables grown in these regions is still within an acceptable range.