山东寿光设施菜地土壤-农产品邻苯二甲酸酯(PAEs)污染特征调查

Phthalate acid esters(PAEs) pollution in soils and agricultural products of vegetable greenhouses in Shouguang City, Shandong Province

为探究寿光设施菜地PAEs污染分布特征及在农产品中的富集状况,采集了寿光某镇0~8年棚龄共16个大棚的设施菜地土壤和农产品,采用加速溶剂萃取-高效液相色谱串联质谱技术(LC-MS/MS),对土壤-农产品(黄瓜)中PAEs含量进行了分析,结果显示:在调查的大棚中,土壤中6种优先控制的PAEs总量(∑PAEs)范围为0.453~1.615 mg·kg^(-1),均值±标准差为1.197±0.361mg·kg^(-1)。以邻苯二甲酸二(2-乙基己基)酯(DEHP)和邻苯二甲酸正二丁酯(DBP)为主,其中DEHP占∑PAEs含量的45%~77%,DBP占17%~44%。参照美国优先控制PAEs化合物的控制标准,100%的土壤样品DBP含量超过控制标准,52%的土壤样品DMP含量超过控制标准,表明调查设施菜地土壤已存在一定程度PAEs污染风险。随着种植年限(棚龄)的增长,土壤∑PAEs并非呈现线性增长态势,5年棚龄的大棚土壤∑PAEs含量最高,5年后含量稍许下降,变化比较平稳。∑PAEs与DBP、DEHP、有机质、CEC含量之间存在显著的正相关,与p H之间存在显著的负相关性。调查的农产品(黄瓜)中∑PAEs含量为0.42~1.62 mg·kg^(-1),平均为1.09 mg·kg^(-1),平均富集系数为1.02,以DEHP和DBP为主,两者合计共占PAEs总量的53%~97%。调查的农产品中PAEs含量及各组分含量均低于美国和欧洲的建议摄入标准。

Phthalate acid esters（PAEs）are extensively used as plasticizers of plastic products. Therefore, these PAEs have accumulated in greenhouse soils. This study was conducted to understand PAEs pollution in soils and their enrichment in agricultural products from vegetable greenhouses in Shouguang City, Shandong Province. Soil and agricultural product（cucumber）samples from 17 vegetable greenhouses were collected, and content of 6 PAE compounds as priority pollutants were determined by LC- MS/MS. The total content of these 6 PAEs（∑PAEs）in soils ranged from 0.453 to 1.615 mg·kg^-1, and the mean value was 1.197±0.361 mg·kg^-1. DEHP and DBP were the main components of PAEs in the soils. DEHP accounted for 45%-77% of ∑PAEs, and DBP for 17%-44%. Based on the control standards of priority pollutants of PAEs（U. S. EPA）, DBP content in all soil samples and DMP in 52% soil samples exceeded the control standards, implying that these soils had certain pollution risks. ∑PAEs content in soils did not show significant correlation with age of vegetable greenhouses.The ∑PAEs content was the highest in the fifth year of planting, and changed little after that. ∑PAEs had a significant positive correlation with DBP, DEHP, organic matter and CEC content, but significantly negatively correlated with p H. ∑ PAEs content in cucumbers ranged from 0.42 to 1.62 mg·kg^-1, averaging 1.09 mg·kg^-1. The mean enrichment coefficient was 1.02. DEHP and DBP were the main components in cucumbers, accounting for 53% -97% of ∑ PAEs. Generally, the levels of PAEs in agricultural products were lower than the suggested standards in USA and Europe, implying a comparatively low health risk.