齐齐哈尔市城区土壤中有机氯农药残留研究

Study on the Residues of Organochlorine Pesticides in the Soil of Qiqihar City

本研究以齐齐哈尔市主城区(龙沙区、建华区、铁锋区、富拉尔基区、梅里斯达斡尔族区)表层土壤为研究对象,对不同功能区土壤中有机氯农药(OCPs)的残留状况进行分析。采用网格布点法共采集79份土壤样品,采用气相色谱法(GC-ECD)检测DDTs类、HCHs类、氯丹类、艾氏剂类共15种OCPs残留。结果表明,齐齐哈尔市主城区土壤中15种OCPs均有不同程度的残留,其中DDTs类、HCHs类是研究区域土壤中OCPs污染的主要物质,检出率分别为94.94%、87.34%。DDTs类的残留含量介于ND-79.97μg/kg,平均含量为14.25μg/kg。HCHs类的残留含量介于ND-37.52μg/kg,平均含量为10.46μg/kg。总OCPs的残留含量介于1.88~95.77μg/kg,平均含量为25.78μg/kg。不同行政区划土壤中DDTs类、HCHs类、总OCPs残留量差异均有统计学意义(F=15.72,P<0.0001;F=11.39,P<0.0001;F=19.82,P<0.0001)。从总体残留量上看,富拉尔基区>梅里斯达斡尔族区>铁锋区>建华区>龙沙区。从土壤样品中OCPs的检出种类上看,只检出1类的占16.46%,同时检出2类的占51.90%,同时检出3类的占24.05%,同时检出4类的占7.59%,不同行政区域土壤中DDTs类、HCHs类、氯丹类、艾氏剂类OCPs检出情况存在差异(P=0.0229)。综上所述,根据我国土壤环境质量标准GB15618-1995,一级土壤中DDTs和HCHs的标准限值为50μg/kg,二级土壤的标准限值为500μg/kg,本研究采集的所有土壤样品中HCHs残留量均未超出一级土壤的标准限制,DDTs残留量均未超出二级土壤的标准限制,说明齐齐哈尔市主城区的土壤较为清洁,但仍具有一定的OCPs污染风险。从OCPs总体残留量和检出种类看,富拉尔基区、梅里斯达斡尔族区、铁锋区、建华区、龙沙区的污染程度依次递减,提示应重点关注富拉尔基区、梅里斯区土壤环境质量,防止污染情况加剧。本研究结果可以为本地区的生态环境建设及风险评价提供理论依据。

In this study,the surface soil in the area of Qiqihar City was used as the research object to analyze the residual status of Organochlorine Pesticides(OCPs).A total of 79 soil samples were collected by the grid method,and the residual status of 15 OCPs were detected by GC-ECD.The results showed that 15 kinds of OCPs in the soil in the area of Qiqihar City had different levels of residues.Among them,DDTs and HCHs were the main substances contaminated by OCPs in the soil in the study area,and the detection rates were 94.94%and 87.34%,respectively.The residual content of DDTs was between ND-79.97μg/kg,and the average content was 14.25μg/kg.The residual content of HCHs was between ND-37.52μg/kg,and the average content was 10.46μg/kg.The residual content of total OCPs was between 1.88-95.77μg/kg,and the average content was 25.78μg/kg.There were statistically significant differences in DDTs,HCHs,and total OCPs residues in soils of different administrative divisions(F=15.72,P<0.0001;F=11.39,P<0.0001;F=19.82,P<0.0001).In terms of detection types,only 1 type was detected accounted for 16.46%,2 types were detected at the same time accounted for 51.90%,3 types were detected at the same time accounted for 24.05%,and 4 types were detected at the same time accounted for 7.59%.There were statistically significant differences in the detection of OCPs in the soil of different administrative regions(P=0.0229).In summary,according to the soil environment quality standard GB15618-1995 in China,the standard limit of HCHs and DDTs in the first-class soil was 50μg/kg,and the standard limit of second-class soil was 500μg/kg.The residual amount of HCHs in all soil samples collected in this study did not exceed the standard limit of the first-class soil,and the residual amount of DDTs did not exceed the standard limit of the second-class soil,indicating that the soil in the area of Qiqihar City was relatively clean,but still had a certain risk of OCPs pollution.From the perspective of OCPs residues and detected species,the pollution levels in Fulaerji District,Meilisidaur District,Tiefeng District,Jianhua District,and Longsha District were decreasing successively,suggesting that we should focus on the soil environmental quality of Fulaerji District and Meilisidaur District to prevent aggravation of pollution.The results of this study can provide a theoretical basis for the ecological environment construction and risk assessment of the region.