International Joint Research Center for Persistent Toxic Substances, Dalian Maritime University, Dalian, P R China.
Environ Sci Technol. 2010 Dec 15;44(24):9279-84. doi: 10.1021/es102791n. Epub 2010 Nov 17.
Endosulfan is a currently used organochlorine pesticide in China, with annual usage of 2300 t between 1994 and 2004. Concentrations of endosulfan (including α- and β-isomers and their metabolite endosulfan sulfate) were reported for surface soil collected in 2005 at 141 sites (6 background, 95 rural, and 40 urban) across China. The concentrations of total endosulfan (sum of α-endosulfan, β-endosulfan, and endosulfan sulfate) at all sites ranged from BDL (below detection limit) to 19000 pg/g dry weight (dw), with geometric mean (GM) 120 pg/g dw. Rural soils had the highest total endosulfan concentrations, with GM 160 pg/g dw, followed by urban soils (GM = 83 pg/g dw) and background soils (GM = 38 pg/g dw). The observed soil concentrations of α-endosulfan (GM = 6.5 pg/g dw) were much lower than those of β-endosulfan (GM = 49 pg/g dw) and endosulfan sulfate (GM = 47 pg/g dw). The fractional abundance of α-endosulfan F(α-endo) [α-endosulfan/(α-endosulfan + β-endosulfan)] for all soils ranged from 0.00040 to 0.91, with GM 0.10, much lower than those in technical products (ranged from 0.67 to 0.7), which most likely reflects that α-endosulfan is more volatile and degrades faster than β-endosulfan in soil. Consequently, half-life of β-endosulfan in soil is expected longer than α-endosulfan. Significant correlation between endosulfan sulfate and its parent isomers suggested that the presence of endosulfan sulfate originated from its parent isomers. Based on multiple linear regression model, inventories of endosulfan sulfate in Chinese agricultural soil in 2004 with a 1/4° longitude × 1/6° latitude resolution are established. Comparison between field measurements and modeling results showed significant correlations between the modeled and measured endosulfan concentrations, and 89%, 83%, and 70% of monitoring data fell between the lowest and the highest modeled concentrations for α- and β-endosulfan and endosulfan sulfate, respectively. The good agreement lends credibility to modeled soil concentrations of endosulfan. To our knowledge, this is the first soil concentration inventory for endosulfan sulfate, which paves the way for further study on its environmental behavior.
在中国，硫丹是一种目前仍在使用的有机氯农药，1994 年至 2004 年的年使用量为 2300 吨。2005 年在中国各地的 141 个地点（6 个背景点、95 个农村点和 40 个城市点）采集了表层土壤，并报告了其中的硫丹（包括α-和β-异构体及其代谢物硫丹硫酸盐）浓度。所有地点的总硫丹（α-硫丹、β-硫丹和硫丹硫酸盐之和）浓度范围为 BDL（低于检测限）至 19000pg/g 干重（dw），几何平均值（GM）为 120pg/g dw。农村土壤的总硫丹浓度最高，GM 为 160pg/g dw，其次是城市土壤（GM=83pg/g dw）和背景土壤（GM=38pg/g dw）。α-硫丹（GM=6.5pg/g dw）的土壤浓度明显低于β-硫丹（GM=49pg/g dw）和硫丹硫酸盐（GM=47pg/g dw）。所有土壤中α-硫丹的分数丰度 F（α-endo）[α-硫丹/（α-硫丹+β-硫丹）]的范围为 0.00040 至 0.91，GM 为 0.10，明显低于技术产品中的值（范围为 0.67 至 0.7），这很可能反映出α-硫丹在土壤中比β-硫丹更易挥发且降解速度更快。因此，β-硫丹在土壤中的半衰期预计长于α-硫丹。硫丹硫酸盐与其母体异构体之间的显著相关性表明，硫丹硫酸盐的存在源于其母体异构体。基于多元线性回归模型，建立了中国农业土壤中 2004 年硫丹硫酸盐的清单，具有 1/4°经度×1/6°纬度的分辨率。实地测量与模型结果的比较表明，α-和β-硫丹以及硫丹硫酸盐的模型浓度与实测浓度之间存在显著相关性，分别有 89%、83%和 70%的监测数据位于最低和最高模型浓度之间。良好的一致性使硫丹的模型土壤浓度具有可信度。据我们所知，这是硫丹硫酸盐土壤浓度的首个清单，为进一步研究其环境行为奠定了基础。
