2014 - 2016年陕西省农村土壤重金属监测结果分析

目的 掌握陕西省三大区域农村土壤卫生状况，为进一步开展土壤环境监测、监管和建立风险防控体系提供科学依据。方法 于2014 - 2016年，连续3年对陕西省三大区域的30个涉农区县的农田土壤持续开展现场调查和土壤重金属铅、铬、镉的含量检测。数据按照关中平原、陕北高原和秦巴山区分别统计、分析与评价。结果 陕西省土样中重金属铅的达标率为100.00%。土样中重金属铬的达标率为99.44%，铬超标土样全部来自秦巴山区（合计10份）。全省土样重金属镉的达标率最低（83.55%），其中陕北高原（91.33%）的土样中重金属镉的达标率显著高于关中平原（79.48%）和秦巴山区（86.49%）（P＜0.05）。不同年度土壤重金属镉结果比较，关中平原土样中重金属镉的达标率逐年降低（P＜0.05），秦巴山区土样中重金属镉的达标率逐年升高（P＜0.05）。结论 陕西省土壤中重金属铅、铬的污染水平较低，关中平原和秦巴山区重金属镉的污染较为严重，关中平原土壤质量有逐年下降的趋势，需要有关部门的重视，及时采取针对性措施。

Analysis on monitoring results of heavy metals in rural soil in the Northern,Southern and Central regions of Shaanxi from 2014 to 2016

Objective The aim of this study was to master the status of rural soil sanitation in different regions of Shaanxi province, so as to provide scientific basis for further monitoring, supervision and establishing risk prevention and control system for soil environment. Methods From 2014 to 2016, field investigation of farmland soil and analysis of heavy metal lead, chromium and cadmium in soil were conduced in the 30 agricultural counties in Shaanxi province for three consecutive years. The data were statistically analyzed and evaluated according to the northern, central and southern regions. Results The qualified rates of heavy metal lead and chromium in soil samples in Shaanxi province were 100.00% and 99.44%, respectively. The soil samples of heavy metal chromium exceeding the standard were all from the southern region(total 10). The qualified rate of heavy metal cadmium in soil samples in Shaanxi province was the lowest (83.55%). The qualified rate of heavy metal cadmium in the soil samples of the northern region was 91.33%, which was significantly higher than that in the central(79.48%) and southern(86.49%) regions(P<0.05). Comparing soil heavy metal cadmium in different years, the qualified rate of heavy metal cadmium in soil samples in the central region decreased year by year (P<0.05), and the qualified rate of heavy metal cadmium in soil samples in the southern region increased year by year(P<0.05). Conclusion The pollution level of heavy metal lead and chromium in soil of Shaanxi was low. Cadmium pollution in the central and southern regions was more serious. The soil quality in the central region was declining year by year, therefore, it’s necessary for the relevant government departments to pay attention and take timely and targeted measures.