Streuber Dillon, Park Yoo Min, Sousan Sinan
Environmental Health Sciences Program, Department of Health Education and Promotion, College of Health and Human Performance, East Carolina University, Greenville, NC 27858, USA.
Department of Geography, Planning, and Environment, East Carolina University, Greenville, NC 27858, USA.
Aerosol Air Qual Res. 2022 Aug;22(8). doi: 10.4209/aaqr.220119. Epub 2022 Jun 1.
Low-cost aerosol sensors open routes to exposure assessment and air monitoring in various indoor and outdoor environments. This study evaluated the accuracy of GeoAir2--a recently developed low-cost particulate matter (PM) monitor--using two types of aerosols (salt and dust), and the effect of changes in relative humidity on its measurements in laboratory settings. For the accuracy experiments, 32 units of GeoAir2 were used, and for the humidity experiments, 3 units of GeoAir2 were used, alongside the OPC-N3 low-cost sensor and MiniWRAS reference instrument. The normal distribution of slopes between the salt and dust aerosols was compared for the accuracy experiments. In addition, the performance of GeoAir2 in indoor environments was evaluated compared to the pDR-1500 reference instrument by collocating GeoAir2 and pDR-1500 at three different homes for five days. For salt and dust aerosols smaller than 2.5 μm (PM), both GeoAir2 (r = 0.96-0.99) and OPC-N3 (r = 0.98-0.99) were highly correlated with the MiniWRAS reference instrument. However, GeoAir2 was less influenced by changes in humidity than OPC-N3. While GeoAir2 reported an increase in mass concentrations ranging from 100% to 137% for low and high concentrations, an increase between 181% and 425% was observed for OPC-N3. The normal distribution of the slopes for the salt aerosols was narrower than dust aerosol, which shows closer slope similarities for salt aerosols. This study also found that GeoAir2 was highly correlated with the pDR-1500 reference instrument in indoor environments (r = 0.80-0.99). These results demonstrate potential for GeoAir2 for indoor air monitoring and exposure assessments.
低成本气溶胶传感器为在各种室内和室外环境中进行暴露评估和空气监测开辟了道路。本研究使用两种气溶胶（盐和灰尘）评估了最近开发的低成本颗粒物（PM）监测仪GeoAir2的准确性，以及相对湿度变化对其在实验室环境中测量结果的影响。在准确性实验中使用了32台GeoAir2，在湿度实验中使用了3台GeoAir2，同时还使用了OPC-N3低成本传感器和MiniWRAS参考仪器。在准确性实验中比较了盐气溶胶和灰尘气溶胶之间斜率的正态分布。此外，通过在三个不同家庭中将GeoAir2和pDR-1500并置五天，与pDR-1500参考仪器相比，评估了GeoAir2在室内环境中的性能。对于小于2.5μm（PM）的盐气溶胶和灰尘气溶胶，GeoAir2（r = 0.96 - 0.99）和OPC-N3（r = 0.98 - 0.99）与MiniWRAS参考仪器都具有高度相关性。然而，GeoAir2受湿度变化的影响比OPC-N3小。虽然GeoAir2报告低浓度和高浓度下质量浓度增加幅度在100%至137%之间，但OPC-N3观察到的增加幅度在181%至425%之间。盐气溶胶斜率的正态分布比灰尘气溶胶更窄，这表明盐气溶胶的斜率相似性更高。本研究还发现，GeoAir2在室内环境中与pDR-1500参考仪器高度相关（r = 0.80 - 0.99）。这些结果证明了GeoAir2在室内空气监测和暴露评估方面的潜力。
