Ecotoxicology and Environmental Safety ( IF 6.8 ) Pub Date : 2020-03-27 , DOI: 10.1016/j.ecoenv.2020.110478 Gustav Gbeddy 1 , Ashantha Goonetilleke 1 , Godwin A Ayoko 1 , Prasanna Egodawatta 1
Road dust is a key repository for PAHs and transformed PAH products (TPPs) generated from natural and anthropogenic sources in the urban environment. Eventhough PAHs and TPPs are prone to post-emission photochemical processes, very limited studies exist on the subject for road dust. This knowledge gap is of particular concern since some of the resultant TPPs are notably more carcinogenic than their precursor PAHs. This study evaluated the role of 254 nm ultraviolet (UV) photons on the photochemistry of PAHs and TPPs in road dust. The findings show that UV irradiation had varying effects on the fate of analytes, particularly naphthalene (NAP), phenanthrene (PHE), 7, 12-dimethylbenz(a)anthracene (DMBA), 1-hydroxypyrene (HPY), 1-nitropyrene (1NPY), pyrene (PYR) and 5-nitroacenaphthene (5NAC). Photochemical relationship was identified between PYR, 1NPY and HPY, and DMBA and benzo(a)anthracene. Unlike carbonyl-PAHs, parent PAHs, nitro-PAHs and hydroxy-PAHs can originate from photolysis. Photon irradiation durations of 3, 6 and 7.5 h had the most intense influence on the photolytic process with 7.5 h as optimum. The photochemical rate at optimum irradiation duration shows an increasing trend of NAP < PHE < 1NPY < DMBA < 5NAC < HPY with respective estimates of 0.08, 0.11, 0.21, 0.22, 0.43, and 0.59 mg kg−1 hr−1. Physicochemical properties of analytes such as index of refraction and vapour pressure (in logarithmic form) had an inverse effect on photolysis. The knowledge generated is significant for the in-depth understanding of the fate of PAHs and TPPs on urban road surfaces and contributes to the greater protection of human health and the environment.
中文翻译:
多元数据技术在道路灰尘中多环芳烃(PAHs)和转化的PAH产物光化学研究中的应用。
道路灰尘是城市环境中自然和人为来源产生的多环芳烃和转化后的多环芳烃产品(TPP)的重要储存库。尽管PAHs和TPPs易于排放后的光化学过程,但关于道路扬尘的研究却非常有限。由于某些合成的TPP比其前身的PAHs更具致癌性,因此这一知识差距尤为令人关注。这项研究评估了254 nm紫外线(UV)光子对道路灰尘中PAHs和TPPs的光化学的作用。研究结果表明,紫外线辐射对分析物的命运有不同的影响,尤其是萘(NAP),菲(PHE),7,12-二甲基苯并(a)蒽(DMBA),1-羟基py(HPY),1-硝基py( 1NPY),pyr(PYR)和5-硝基ac(5NAC)。在PYR之间发现了光化学关系,1NPY和HPY,以及DMBA和苯并(a)蒽。与羰基PAHs不同,母体PAHs,硝基PAHs和羟基PAHs可以源自光解。3、6和7.5 h的光子照射时间对光解过程的影响最大,最佳时间为7.5 h。最佳照射时间下的光化学速率显示NAP <PHE <1NPY <DMBA <5NAC <HPY的增加趋势,分别为0.08、0.11、0.21、0.22、0.43和0.59 mg kg-1小时-1。分析物的物理化学性质(例如折射率和蒸气压(对数形式))对光解有相反的影响。所产生的知识对于深入了解城市道路表面上的PAH和TPP的命运具有重要意义,并有助于更好地保护人类健康和环境。