典型塑料生产加工地块土壤邻苯二甲酸酯及多环芳烃污染特征和健康风险

为探究塑料生产加工造成的土壤污染,采用气相色谱-质谱联用法分析了南方典型塑料生产加工地块土壤中邻苯二甲酸酯(PAEs)和多环芳烃(PAHs)的含量水平,并开展健康风险评价。结果表明:PAEs化合物中仅邻苯二甲酸二(2-乙基己基)酯(DEHP)被检出,检出率为80.6%,平均值为16.0 mg·kg^-1,最高值为1300 mg·kg^-1,该值是迄今为止我国土壤中检出PAEs化合物的最高值。15种优控PAHs化合物均有不同程度地检出,总检出率为33.1%,检出总量为0~35.4 mg·kg^-1,平均值1.7 mg·kg^-1。以《土壤环境质量建设用地土壤污染风险管控标准(试行)》(GB 36600—2018)第一类用地筛选值进行评价,DEHP、苯并(a)芘(BaP)和二苯并(a,h)蒽(DahA)超标,超标率分别为1.4%、5.0%和1.4%。DEHP在管材车间超标,与聚氯乙烯管材(PVC)生产和存储有关;BaP和DahA在原料仓库超标,且BaP还在油墨仓库及印刷复合车间超标,与煤和重油作为燃料使用以及油墨释放PAHs化合物有关。3种超标化合物含量和检出率均随土层深度的增加明显降低。健康风险评价显示,DEHP、BaP和DahA的非致癌风险均在可接受范围,但部分样品的DEHP(1.4%)和BaP(2.8%)的致癌风险超过可接受风险水平,主要由经口摄入和皮肤接触造成。研究表明塑料生产加工可导致较为严重的土壤PAEs和PAHs污染。

Pollution characteristics and health assessment of phthalate esters and polycyclic aromatic hydrocarbon in soils of plastic-producing site

In order to clarify the soil pollution induced by plastic producing, contents of phthalate esters(PAEs) and polycyclic aromatic hydrocarbons(PAHs) were investigated in soils of typical plastic-producing site in southern China. Furthermore, the health assessments of the target compounds were also conducted. Results showed that only Di-2-ethyl hexyl phthalate(DEHP) was detected among PAE compounds, with 80.6% of detection rate, 16.0 mg·kg^-1 of mean content, and 1 300 mg·kg^-1 of maximum detected contents. Such a content (1 300 mg·kg^-1) is the maximum content of PAE compounds detected in China soil so far. Fifteen PAH compounds were detected to some extent, with 33.1% of detection rate, 0~35.4 mg·kg^-1 of detected content, and 1.7 mg·kg^-1 of mean content. Based on the Soil Environment Quality-Risk Control Standard for Soil Contamination of Development Land(GB 36600-2018), the detected contents of DEHP, Benzo(a) pyrene(BaP), and Dibenzo(a, h) anthracene(DahA) exceeded the screening values of the fist-class land, with the over-limit ratios of 1.4%, 5.0%, and 1.4% for DEHP, BaP, and DahA, respectively. DEHP exceeded the screening value in pipe material warehouse, which was associated with storage and use of PVC materials. BaP and DahA exceeded the screening value in materials warehouse, and the similar issue for BaP also occurred in printing ink warehouse and printing recombination workshop. This could be attributed to the fact that coal and crude oil were used as fuels and printing ink was applied, which could release PAH compounds. The detected rates and contents of DEHP, BaP and DahA obviously decreased with the increasing soil depth. Health assessment showed that non-carcinogenic risks of DEHP, BaP and DahA were within the acceptable range, but carcinogenic risks of DEHP in 1.4% sample and BaP in 2.8% sample exceeded the acceptable level, which were mainly attributed to oral intake and skin exposure. The findings of this study indicated that plastic producing could cause severer pollution of PAEs and PAHs in soils.