西北地膜高投入地区土壤与玉米邻苯二甲酸酯(PAEs)含量水平与健康风险评估

Occurrence and risk assessment of phthalic acid esters (PAEs) in soils and agricultural products from farmlands associated with intensively plastic film mulching, Northwest China

在西北地膜高投入的甘肃、新疆和内蒙古等3省(区)选择地膜覆盖面积较大、地膜使用量较高的5个典型县,同步采集玉米产地的土壤和玉米,采用加速溶剂萃取-高效液相色谱串联质谱技术对土壤与玉米籽粒中6种优先控制的领苯二甲酸酯(PAEs)含量进行分析.结果表明,研究区域土壤中∑6PAEs含量为(0.532±0.175) mg·kg-1,区间为0.103—1.117 mg·kg-1.新疆∑6PAEs含量最高.DEP在所有土壤样品中均未检出,其余5种PAEs组分含量依次为DEHP> DnBP> DMP> BBP、DnOP.土壤PAEs均以DEHP和DnBP为主,其中DEHP占35%—65%,DnBP占24%—33%,其余PAEs组分含量和占比较低.研究区域玉米籽粒中∑6PAEs含量为(0.508±0.105) mg·kg-1,区间为0.206—0.966 mg·kg-1,玉米对PAEs的BCF为(1.245±0.716).新疆玉米籽粒中∑6PAEs含量最高.与土壤类似,玉米籽粒中PAEs均以DEHP和DnBP为主,两者合计占PAEs总量的63%—89%,其余PAEs组分含量和占比较低.相关性分析表明,玉米籽粒中PAEs、DnBP及DEHP含量与土壤中对应组分含量的相关性达到了显著性水平.调查区玉米PAEs含量及各组分含量均低于美国和欧洲的建议摄入标准,总体是安全的.成人和儿童的PAEs致癌风险分别为4.67×10-6和1.58×10-6,非致癌指数分别为8.46×10-2和7.60×10-2,均在可接受范围内.PAEs各组分中,对人体致癌和非致癌总风险贡献最大的均为DEHP.

From three northwestern provinces of Gansu, Xinjiang and Inner Mongolia with the mulching film being highly used, five typical counties where the mulching film is used in large area and amount were selected as the sample collection regions in our study. The soil and corn in the corn producing area were collected simultaneously. The contents of six high-priority controlled PAEs in the soil and corn samples were analyzed with LC-MS/MS, and we derived the following results: The content of ∑6PAEs in the soil of the regions under research was(0.532±0.175) mg·kg-1, ranging between 0.103 mg·kg-1 and 1.117 mg·kg-1, while the highest value came from Xinjiang. DEP was not detected in any of the soil samples, and the contents of the other five PAE components were in the order of DEHP > DnBP > DMP > BBP and DnOP. DEHP and DnBP were the main components of PAEs in the soils of the five counties, where DEHP accounted for 35%—65% and DnBP accounted for 24%—33%, while the contents and proportions of the remaining PAE components were relatively low. The content of ∑6PAEs in the maize grains of the regions under research was(0.508±0.105) mg·kg-1, ranging within 0.206—0.966 mg·kg-1. The BCF of corn to PAEs was 1.245±0.716. Xinjiang had the highest content of ∑6PAEs in the maize grains. Similar to the soil, the PAEs in the maize grains were mainly composed of DEHP and DnBP, the sum of which accounted for 63%—89% of the total PAEs, while the contents and proportions of the remaining PAE components were relatively low. The correlation analysis showed that the correlations between the contents of PAEs, DnBP and DEHP in the maize grains and the contents of the corresponding components in the soil were significant. In the survey, the content of total PAEs and that of each PAE component in the corn were lower than the recommended intake standards in the United States and Europe. It was safe in general. For adults and children, the carcinogenic risk of PAEs were 4.67×10-6 and 1.58×10-6, respectively, while the non-carcinogenic indices were 8.46×10-2 and 7.60×10-2, respectively, all of which were within the acceptable range. Among the components of PAEs, DEHP contributed the most to the total risk of carcinogenic and non-carcinogenic diseases for humans.