污灌区重金属污染对土壤的危害

Danger to Soil by Heavy Metals Pollution from Polluted Irrigation

由于土壤中重金属元素的含量对人体健康影响很大 ,淮阴市环境监测中心站于 1 993年至 1 997年选择某污灌区中 0 667hm2 的蔬菜田及其邻近的某一地下水灌区中 0 667hm2 的蔬菜田按梅花布点法分别布设 8个测点 ,对其土壤中的总镉、总汞、总砷、总铬和总铅进行监测。结果表明 ,地下水灌区 5年来综合污染指数变化不大 ,污染等级属安全级 ,说明该灌区没有受到重金属污染 ,而污灌区的综合污染指数逐年增高 ,1 995年、1 996年、1 997年均达警戒级 ,说明该污灌区土壤中的重金属有一定积累 ,农作物受到的污染不容忽视。指出在污灌区用适度的污水灌溉农田虽然可行 ,但长期利用污水灌溉 ,污水中的总镉、总铬和总砷等污染物在土壤中易产生沉积 ,对土壤产生一定污染 ,应采取有效的防治措施。

Cadmium, mercury, arsenic, chromium and lead were monitored by Huaiying Municipal Environmental Monitoring Station from 1993 to 1997 in a vegetable field of 0667 hm2 in polluted irrigation and in a vegetable field of 0667 hm2 in ground water irrigation with 8 related monitoring spots. The monitoring results showed that in those 5 years in field of ground water irrigation the comprehensive pollution index did not change much, the pollution was in safety category; while in field of polluted irrigation the comprehensive pollution index increased year by year, with its reaching warning category, which indicated that corresponding heavy metals were accumulated and crops were polluted. The article points out that longterm polluted irrigation deposited heavy metals in soil, which polluted the soil and need to be countermeasured.