Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China.
Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; School of Environment, Nanjing Normal University, Nanjing 210023, China; State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, China; Aarhus Institute of Advanced Studies, Aarhus University, 8000 Aarhus C, Denmark.
Sci Total Environ. 2022 Feb 25;809:151101. doi: 10.1016/j.scitotenv.2021.151101. Epub 2021 Oct 21.
Phthalate pollution in plastic greenhouses (PGs) has aroused concerns. However, mechanisms and factors of vegetables planted in PGs (VPGs) accumulating phthalates from soil and air are unclear. To fill the gap, 19 PGs in Shaanxi, the largest vegetable production province in northwestern China, were selected to probe this issue. 35 soil samples, 48 air samples, and 26 VPG samples were collected in winter and summer. Medians of sum of 7 phthalate concentrations (∑ PAEs) in PG soil, air, and VPGs were 73.9 μg kg, 5300 ng m, and 1053 μg kg dry weight, respectively. ∑ PAE concentrations in PG environmental media in winter were higher than summer, with the significant difference in VPGs. Sum concentrations of bis (2-ethylhexyl) phthalate (DEHP) and di-n-butyl phthalate (DnBP) accounted for 76.8% and 82.3% of the ∑ PAEs in soil and VPGs. DnBP and DEHP concentrations in VPGs were significantly correlated to those in air and soil, with correlation coefficients (R) of 0.89 and 0.96 to air and 0.68 and 0.59 to soil. Log-transformed soil-air partition coefficient (log K) and fugacity fraction (log ff) of DnBP decreased while log K and log ff of DEHP increased from winter to summer, though DnBP in soil volatilized to air while DEHP in air sank to soil within the year. These issues were caused by air temperature changes and the application of plastic films. Furthermore, DnBP concentrations in VPGs were positively correlated to K values of DnBP (R = 0.87) while those of DEHP were negative (R = -0.82). Therefore, VPGs could uptake more phthalates from air than from soil, especially for edible parts of leafy and solanaceous VPGs. Applying phthalates free agricultural films and precision management such as adjusting air temperature in PGs could be considered to ensure VPG safeties.
聚氯乙烯（塑料）大棚中的邻苯二甲酸酯污染引起了关注。然而，种植在聚氯乙烯大棚中的蔬菜（简称 VPG）从土壤和空气中积累邻苯二甲酸酯的机制和因素尚不清楚。为了填补这一空白，在中国西北部最大的蔬菜生产省份陕西，选择了 19 个聚氯乙烯大棚进行了此项研究。在冬季和夏季分别采集了 35 个土壤样本、48 个空气样本和 26 个 VPG 样本。聚氯乙烯大棚土壤、空气和 VPG 中 7 种邻苯二甲酸酯浓度之和（∑ PAEs）的中位数分别为 73.9μgkg、5300ngm 和 1053μgkg 干重。冬季聚氯乙烯大棚环境介质中的∑ PAE 浓度高于夏季，VPG 中的差异具有统计学意义。土壤和 VPG 中邻苯二甲酸二（2-乙基己基）酯（DEHP）和邻苯二甲酸二正丁酯（DnBP）的浓度之和分别占∑ PAEs 的 76.8%和 82.3%。VPG 中 DnBP 和 DEHP 浓度与空气和土壤中的浓度显著相关，与空气的相关系数（R）分别为 0.89 和 0.96，与土壤的相关系数分别为 0.68 和 0.59。冬季到夏季，DnBP 的土壤-空气分配系数（log K）和逸度分数（log ff）减小，而 DEHP 的 log K 和 log ff 增大，尽管 DnBP 从土壤挥发到空气中，而 DEHP 在一年内从空气中沉降到土壤中。这些问题是由空气温度变化和塑料薄膜的应用引起的。此外，VPG 中 DnBP 的浓度与 DnBP 的 K 值呈正相关（R=0.87），而 DEHP 的浓度则呈负相关（R=-0.82）。因此，VPG 从空气中吸收的邻苯二甲酸酯比从土壤中吸收的多，尤其是叶菜类和茄果类 VPG 的可食用部分。考虑应用无邻苯二甲酸酯的农用薄膜和精准管理（如调整聚氯乙烯大棚内的空气温度），可以确保 VPG 的安全。
