Consistency of Urban Background Black Carbon Concentration Measurements by Portable AE51 and Reference AE22 Aethalometers: Effect of Corrections for Filter Loading
Consistency of Urban Background Black Carbon Concentration Measurements by Portable AE51 and Reference AE22 Aethalometers: Effect of Corrections for Filter Loading
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DOI：
10.4209/aaqr.2019.03.0145
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发表时间：
2020-01
影响因子：
4
通讯作者：
Nicola Masey;E. Ezani;Jonathan Gillespie;Fiona Sutherland;Chun Lin;Scott Hamilton;M. Heal;I. Beverland
中科院分区：
文献类型：
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作者：
Nicola Masey;E. Ezani;Jonathan Gillespie;Fiona Sutherland;Chun Lin;Scott Hamilton;M. Heal;I. Beverland
使用便携式设备监测黑碳暴露是研究与燃烧相关的空气污染物对健康影响的重要组成部分。我们在英国格拉斯哥的一个城市背景站点，从同一位置的重复便携式 AE51 空气质量计和英国政府参考 AE22 空气质量计（后者的数据使用标准程序针对过滤器变暗效应进行了校正）收集了 786 小时平均当量黑碳 (eBC) 测量值。联合部署期间的 AE51 和参考浓度高度相关 (R 2 ≥ 0.87)。应用先前报道的方法来校正 AE51 与过滤器负载相关的浓度低估，通常会导致值的高估（具体而言，校正后整个测量范围内两个 AE51 的归一化平均偏差值从 –2% 和 +3% 增加到 +14% 和 +25%）。我们仅发现有限且不一致的证据表明 AE51 气体浓度计（衰减 [AE51_ATN] ≤ ~52）与参考测量值相比低估了 eBC 浓度。因此，我们的观察结果表明，在 eBC 浓度较低的环境中，AE51_ATN 值相对较低，无需对过滤器负载进行校正，AE51 即可与参考 AE22 监测仪实现密切一致。
Monitoring exposure to black carbon with portable devices is an important part of researching the health impacts of combustion-related air pollutants. We collected 786 hourly averaged equivalent black carbon (eBC) measurements from co-located duplicate portable AE51 Aethalometers and a UK Government reference AE22 Aethalometer (the data for the latter were corrected for filter darkening effects using a standard procedure), at an urban background site in Glasgow, UK. The AE51 and the reference concentrations were highly correlated (R 2 ≥ 0.87) for the combined deployment periods. The application of a previously reported method for correcting the AE51’s underestimation of concentrations, associated with filter loading, generally led to an overestimation of values (specifically, the normalised mean bias values for the two AE51s increased from –2% and +3% to +14% and +25% across the full range of measurements after correction). We found only limited and inconsistent evidence that the AE51 Aethalometers (attenuation [AE51_ATN] ≤ ~52) underestimated the eBC concentrations compared to the reference measurements. Thus, our observations indicate that the AE51 can achieve close agreement with the reference AE22 monitor without applying corrections for filter loading at relatively low AE51_ATN values in environments with low eBC concentrations.