Wekumbura Chandima, Hettiarachchi Ganga M, Sobin Christina
Department of Agronomy, Kansas State University, Manhattan, Kansas, USA.
Department of Public Health Sciences, University of Texas at El Paso, El Paso, Texas, USA.
J Environ Sci Health A Tox Hazard Subst Environ Eng. 2023;58(2):127-138. doi: 10.1080/10934529.2023.2178206. Epub 2023 Feb 25.
Established methods for using standardized dust wipes to collect and measure total lead in household dust are readily available but the use of dust wipes to measure bioaccessible lead (BaPb) is less clear. This study compared two in vitro methods for estimating the proportion of BaPb in dust collected into dust wipes including the US-EPA's bioaccessible assay (IVBA) method at two pH (1.5 and 2.5) values; and the physiologically based extraction test (PBET 2.5 pH). Two types of simulated household dust samples (Pb-soil contaminated and Pb-paint contaminated) each with three Pb concentrations were created. Equal amounts of simulated dust were applied to a smooth surface and collected following the standard EPA dust wipe protocol and were analyzed for BaPb and total Pb (ASTM-E1644-17, ICP-OES). Estimated BaPb levels differed significantly by the method of extraction. Mean percent BaPb were IVBA pH 1.5, > 90% (Pb-paint) and 59-63% (Pb-soil); IVBA pH 2.5 78-86% (Pb-paint) and 45-50% (Pb-soil); PBET pH 2.5 56 to 61% (Pb-paint) and 41-50% Pb-soil). Particularly for lead-paint contaminated dust, PBET showed significantly greater discrimination as suggested by the broader range of BaPb values and closer approximation to total lead concentrations in simulated household dust samples.
使用标准化灰尘擦拭布收集和测量家庭灰尘中总铅的既定方法很容易获得，但使用灰尘擦拭布测量生物可利用铅（BaPb）的情况尚不太明确。本研究比较了两种体外方法，用于估计收集在灰尘擦拭布中的灰尘中BaPb的比例，包括美国环境保护局（US-EPA）在两个pH值（1.5和2.5）下的生物可利用性分析（IVBA）方法；以及基于生理学的提取试验（PBET 2.5 pH）。创建了两种类型的模拟家庭灰尘样本（铅污染土壤和铅污染油漆），每种样本有三种铅浓度。将等量的模拟灰尘施加到光滑表面上，按照美国环境保护局（EPA）的标准灰尘擦拭规程进行收集，并对BaPb和总铅进行分析（ASTM-E1644-17，电感耦合等离子体发射光谱法）。提取方法的BaPb估计水平差异显著。BaPb的平均百分比为：IVBA pH 1.5，>90%（铅污染油漆）和59-63%（铅污染土壤）；IVBA pH 2.5，78-86%（铅污染油漆）和45-50%（铅污染土壤）；PBET pH 2.5，56至61%（铅污染油漆）和41-50%铅污染土壤。特别是对于铅污染油漆的灰尘，PBET显示出明显更大的区分度，如BaPb值范围更广以及更接近模拟家庭灰尘样本中的总铅浓度所表明的那样。
