Department of Science Laboratory Technology, Moshood Abiola Polytechnic, Abeokuta, Ogun State P.M.B 2210, Nigeria.
Environ Sci Process Impacts. 2021 Jun 1;23(6):867-879. doi: 10.1039/d0em00445f. Epub 2021 May 4.
Ambient and indoor air pollution results in an estimated 7 million premature deaths globally each year, representing a major contemporary public health challenge, but one poorly quantified from a toxicological and source perspective. Indoor exposure represents possibly the greatest potential overall exposure, yet our indoor environments are still poorly understood, modelled and characterized. In rapidly growing cities, such as Lagos, Nigeria, environmental monitoring can play an important role in establishing baseline data, monitoring urban pollution trends and in environmental education. Classroom dust samples were collected from 40 locations from across the twenty local government areas (LGAs) of Lagos, in June 2019. The aim of the study was to assess the potential hazard posed by PTE in indoor dusts and to develop a suitable risk communication strategy to inform and educate the public, promoting environmental health literacy. Concentrations of total PTE in indoor dusts were assessed using Energy Dispersive X-Ray Fluorescence (ED-XRF) spectrometry. Oral bioaccessibility determinations using the unified BARGE method, and analysis by Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) were also performed on the dust samples to determine the fraction available for absorption in the gastrointestinal tract. Results showed that the indoor dust samples were largely uncontaminated, with only few exceptions (2 samples). Enrichment factor pollution trend for the total PTE concentrations was in the order of Pb > Zn > U > Cr > Cu > Ba > Mn > V > As > Cd > Ni > Al. Source apportionment studies using factor analysis suggests concentrations of Al, As, Fe, Mn, Ni, and U may be influenced largely by lithogenic factors, while Cd, Cu and Pb originated principally from anthropogenic sources. Chromium, V and Zn appear to originate from mixed sources of both lithogenic and anthropogenic origin. Our oral bioaccessibility determinations indicate that the assumption of 100% bioavailability based on pseudototal or total concentrations would overestimate the hazard potential of PTE in these indoor dusts. Zinc was the most bioaccessible PTE (mean of 88%), with Mn (57%), Pb (48%), Ba (48%), Al (41%), As (37%), Cu (36%), Ni (28%), Cr (10%) and Fe (7%) the least bioaccessible. Human health risk assessment, for both children and adults using the bioaccessible fraction, showed values to be within acceptable risk levels.
全球每年约有 700 万人因环境和室内空气污染而过早死亡，这是当前主要的公共卫生挑战之一，但从毒理学和污染源的角度来看，这一问题还没有得到充分的量化。室内暴露可能是最大的潜在暴露源，但我们对室内环境的了解、建模和描述仍很有限。在拉各斯等快速发展的城市，环境监测可以在建立基准数据、监测城市污染趋势以及开展环境教育方面发挥重要作用。2019 年 6 月，从拉各斯 20 个地方政府区（LGA）的 40 个地点采集了教室灰尘样本。本研究的目的是评估室内灰尘中 PTE 的潜在危害，并制定合适的风险沟通策略，以告知和教育公众，提高环境健康素养。采用能量色散 X 射线荧光光谱法（ED-XRF）对室内灰尘中的总 PTE 浓度进行评估。还使用统一的 BARGE 方法进行了口腔生物可给性测定，并通过电感耦合等离子体光学发射光谱法（ICP-OES）对灰尘样本进行了分析，以确定可在胃肠道中吸收的部分。结果表明，除了少数例外（2 个样本），室内灰尘样本基本没有受到污染。PTE 总浓度的富集因子污染趋势顺序为 Pb > Zn > U > Cr > Cu > Ba > Mn > V > As > Cd > Ni > Al。使用因子分析进行的源分配研究表明，Al、As、Fe、Mn、Ni 和 U 的浓度可能主要受成岩因素影响，而 Cd、Cu 和 Pb 主要来自人为来源。Cr、V 和 Zn 似乎来自成岩和人为源的混合来源。我们的口腔生物可给性测定表明，基于假总浓度或总浓度假设 100%的生物利用度会高估这些室内灰尘中 PTE 的危害潜力。锌是最具生物可给性的 PTE（均值为 88%），Mn（57%）、Pb（48%）、Ba（48%）、Al（41%）、As（37%）、Cu（36%）、Ni（28%）、Cr（10%）和 Fe（7%）的生物可给性最低。使用可给性分数对儿童和成人进行的人类健康风险评估显示，其值处于可接受的风险水平内。
