北京郊区农田土壤中HCH残留调查及评价

THE INVESTIGATION AND EVALUATION OF HCH RESIDUES IN SOILS OF BEIJING SUBURBS

北京郊区农田分析区的土壤样品中,均有不同程度的各种HCH异构体检出。在所测样品中,HCH异构体平均含量由高到低排序为σ-HCH、β-HCH、γ-HCH、α-HCH,而且在各个样品中γ-HCH都没有占据主导地位,说明在土壤中没有新的HCH进入。与商品HCH进行比较,w(α-HCH)和w(γ-HCH)明显下降,w(β-HCH)和w(σ-HCH)却相对上升了,分析得出异构体之间的降解转化速率由大到小排序为α-HCH、γ-HCH、σ-HCH、β-HCH。初步评价近年没有新的HCH来源污染本区,但仍有一定风险。

HCHs were detected in the soil of analytic area in the suburbs of Beijing. The concentrations of HCHs in the samples are σ- HCH 〉β-HCH 〉γ-HCH 〉α-HCH and the T-HCH in all the samples is not the main component of residues, suggesting that no new HCHs have entered soil of the studied area. Compared with the commercial HCHs, the contents of HCHs isomers have changed considerably, the content of α-HCH and γ-HCH have decreased while β-HCH and σ-HCH have increased. The degeneration ratios of isomers are α-HCH 〉 γ-HCH 〉 σ-HCH 〉β-HCH. Although there are no new HCHs that can pollute this area, the risk remains existent.