Good Nicholas, Mölter Anna, Peel Jennifer L, Volckens John
Department of Mechanical Engineering, Colorado State University, Fort Collins, CO, USA.
Department of Environmental and Radiological Health Sciences, Colorado State University, Fort Collins, CO, USA.
J Expo Sci Environ Epidemiol. 2017 Jul;27(4):409-416. doi: 10.1038/jes.2016.71. Epub 2016 Dec 21.
The AE51 micro-Aethalometer (microAeth) is a popular and useful tool for assessing personal exposure to particulate black carbon (BC). However, few users of the AE51 are aware that its measurements are biased low (by up to 70%) due to the accumulation of BC on the filter substrate over time; previous studies of personal black carbon exposure are likely to have suffered from this bias. Although methods to correct for bias in micro-Aethalometer measurements of particulate black carbon have been proposed, these methods have not been verified in the context of personal exposure assessment. Here, five Aethalometer loading correction equations based on published methods were evaluated. Laboratory-generated aerosols of varying black carbon content (ammonium sulfate, Aquadag and NIST diesel particulate matter) were used to assess the performance of these methods. Filters from a personal exposure assessment study were also analyzed to determine how the correction methods performed for real-world samples. Standard correction equations produced correction factors with root mean square errors of 0.10 to 0.13 and mean bias within ±0.10. An optimized correction equation is also presented, along with sampling recommendations for minimizing bias when assessing personal exposure to BC using the AE51 micro-Aethalometer.
AE51 微型黑碳仪是评估个人接触颗粒态黑碳（BC）的一种常用且实用的工具。然而，很少有 AE51 的用户意识到，由于 BC 在滤膜基质上随时间积累，其测量结果存在偏低偏差（高达 70%）；先前关于个人黑碳暴露的研究可能也受到了这种偏差的影响。尽管已经提出了校正微型黑碳仪颗粒态黑碳测量偏差的方法，但这些方法尚未在个人暴露评估的背景下得到验证。在此，对基于已发表方法的五个黑碳仪负载校正方程进行了评估。使用实验室生成的不同黑碳含量的气溶胶（硫酸铵、石墨乳和美国国家标准与技术研究院柴油颗粒物）来评估这些方法的性能。还对一项个人暴露评估研究中的滤膜进行了分析，以确定校正方法对实际样本的效果。标准校正方程产生的校正因子的均方根误差为 0.10 至 0.13，平均偏差在±0.10 以内。还提出了一个优化的校正方程，以及在使用 AE51 微型黑碳仪评估个人 BC 暴露时最小化偏差的采样建议。
