丹江口水库迁建区土壤有机氯农药的分布特征及风险评价

利用GC-MS检测了丹江口水库迁建区26个表层土壤样品中的有机氯农药(OCPs),并对其分布特征、组成及来源进行了探讨,评价了OCPs的污染水平和生态风险.结果表明,丹江口水库迁建区土壤OCPs总含量范围为nd～249.37 ng.g-1,平均值为24.82 ng.g-1.其中HCHs与DDTs的含量较高,分别为nd～69.68 ng.g-1和nd～104.53 ng.g-1.土壤中的DDTs含量明显高于HCHs.OCPs可能主要来源于早期残留、大气沉降及近期新的含OCPs物质的输入等.土壤中有机质与OCPs总量之间无显著性相关关系,说明土壤中OCPs含量还受其他因素的影响.与国内其他区域表层土壤相比,丹江口水库迁建区土壤OCPs含量处于中等偏低水平.分析认为,丹江口水库迁建区土壤中有机氯农药风险较低,但局部土壤仍有一定风险.

Distribution Characteristics and Risk Evaluation of Organochlorine Pesticides in Soil from Relocation Areas of the Danjiangkou Reservoir

Twenty-six surface soil samples collected in Danjiangkou Reservoir were analyzed for organochlorine pesticides (OCPs) residues by GC-MS. The distribution characteristics, compositions and origin of OCPs were discussed. Pollution level and potential ecological risks of OCPs were also evaluated. The results showed that the concentration rang of total OCPs in soil was nd-249.37 ng·g^-1 (with a mean of 24.82 ng·g^-1). The recent occurrence levels in soil were nd-69.68 ng·g^-1 for HCHs and nd-104.53 ng·g^-1 for DDTs. DDTs concentrations in soil were higher than those of HCHs. The OCPs residues in soil were mainly originated from the early residues, atmospheric deposition and recent input of OCPs components. The correlation between OCPs contents and organic matter contents in soil was not significant, indicating that the contents of OCPs in soil were also affected by other factors. Compared with other soil samples from different regions, the contents of OCPs in soil of relocation areas of the Danjiangkou Reservoir were at medium-low level. The study suggested that the OCPs in soil of relocation areas of the Danjiangkou Reservoir are in a state of low danger, whereas OCPs still display risks locally in some places.