Laboratory for Earth Surface Processes of Ministry of Education, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China.
College of Resources and Environment, Shanxi Agricultural University, Shanxi 030801, China.
Sci Total Environ. 2020 May 15;717:137261. doi: 10.1016/j.scitotenv.2020.137261. Epub 2020 Feb 11.
During a harvest period, a set of field samples, including ambient air (gaseous and particulate phases), dust fall, surface soil and peel-surrounding soil, and yellow carrot tissues (leaf, peel, and core), were collected in a vegetable bases near a large coking manufacturer in Shanxi Province, Northern China. Based on the determinations of the concentrations and compositions of 15 USEPA priority polycyclic aromatic hydrocarbons (PAHs), the statistical results determined by a factor analysis (FA), combined with the isomeric ratios of paired species and the local emission inventory, indicated that coal combustion and vehicular exhaust served as the main emission sources of PAHs in the local environment and in yellow carrot tissues and that the coking industry was a secondary source. In terms of the transport pathways of PAHs in the surrounding media and yellow carrot tissues, the simulation results of a structural equation model (SEM) showed that the PAHs in ambient air were closely associated with those in dust fall, and these in turn had a positive correlation with the PAHs in surface soil, due to air-soil exchange. Furthermore, the PAHs in yellow carrot leaf were mainly derived from those in dust fall via leaf surface absorption, while peel uptake played a dominant role in the accumulation of PAHs in the edible core of yellow carrot. This was different from the case of cabbage, which was characterized by the prevailing contribution from leaf surface absorption. The current study supplied additional evidence to explore the transport pathways of PAHs from environmental media to tissues of different vegetables (leafy vegetables and root vegetables). CAPSULE: A combination of structural equation modeling with factor analysis was employed to quantitatively identify the dominant transport pathways of PAHs among multiple surrounding media and the different tissues of yellow carrot.
在收获季节，在中国北方山西省的一个大型炼焦厂附近的蔬菜基地，采集了一组田间样本，包括环境空气（气态和颗粒相）、降尘、表层土壤和果皮周围土壤以及黄胡萝卜组织（叶、皮和芯）。基于对 15 种美国环保署优先多环芳烃（PAHs）浓度和组成的测定，因子分析（FA）的统计结果，结合配对种的同系物比值和当地排放清单，表明煤燃烧和机动车尾气是当地环境和黄胡萝卜组织中 PAHs 的主要排放源，而炼焦工业是次要排放源。就周围介质和黄胡萝卜组织中 PAHs 的传输途径而言，结构方程模型（SEM）的模拟结果表明，环境空气中的 PAHs 与降尘中的 PAHs 密切相关，而这些又与表层土壤中的 PAHs 呈正相关，这是由于空气-土壤交换所致。此外，黄胡萝卜叶中的 PAHs 主要来源于降尘中的 PAHs，通过叶片表面吸收，而果皮吸收在黄胡萝卜可食用芯中 PAHs 的积累中起着主导作用。这与白菜的情况不同，白菜的特征是主要通过叶片表面吸收。本研究为探索不同蔬菜（叶菜和根茎类蔬菜）的环境介质到组织中 PAHs 的传输途径提供了额外的证据。
Zotero 插件