Molina Rueda Emilio, Carter Ellison, L'Orange Christian, Quinn Casey, Volckens John
Department of Mechanical Engineering, Colorado State University, Fort Collins, Colorado 80523, United States.
Department of Civil and Environmental Engineering, Colorado State University, Fort Collins, Colorado 80523, United States.
Environ Sci Technol Lett. 2023 Feb 8;10(3):247-253. doi: 10.1021/acs.estlett.3c00030. eCollection 2023 Mar 14.
Particulate matter (PM) air pollution is a major health hazard. The health effects of PM are closely linked to particle size, which governs its deposition in (and penetration through) the respiratory tract. In recent years, low-cost sensors that report particle concentrations for multiple-sized fractions (PM, PM, PM) have proliferated in everyday use and scientific research. However, knowledge of how well these sensors perform across the full range of reported particle size fractions is limited. Unfortunately, erroneous particle size data can lead to spurious conclusions about exposure, misguided interventions, and ineffectual policy decisions. We assessed the linearity, bias, and precision of three low-cost sensor models, as a function of PM size fraction, in an urban setting. Contrary to manufacturers' claims, sensors are only accurate for the smallest size fraction (PM). The PM and PM size fractions had large bias, noise, and uncertainty. These results demonstrate that low-cost aerosol sensors (1) cannot discriminate particle size accurately and (2) only report linear and precise measures of aerosol concentration in the accumulation mode size range (i.e., between 0.1 and 1 μm). We recommend that crowdsourced air quality monitoring networks stop reporting coarse (PM) mode and PM mass concentrations from these sensors.
颗粒物（PM）空气污染是一项重大的健康危害。PM对健康的影响与颗粒大小密切相关，颗粒大小决定了其在呼吸道中的沉积（以及穿透）情况。近年来，能报告多种粒径组分（PM、PM、PM）颗粒浓度的低成本传感器在日常使用和科学研究中大量涌现。然而，对于这些传感器在其所报告的整个粒径范围内的性能表现究竟如何，相关了解却很有限。不幸的是，错误的粒径数据可能会导致关于暴露的虚假结论、误导性的干预措施以及无效的政策决策。我们在城市环境中评估了三种低成本传感器型号的线性度、偏差和精度，作为PM粒径组分的函数。与制造商的说法相反，传感器仅对最小的粒径组分（PM）准确。PM和PM粒径组分存在较大的偏差、噪声和不确定性。这些结果表明，低成本气溶胶传感器（1）无法准确区分颗粒大小，（2）仅能在积聚模态粒径范围内（即0.1至1μm之间）报告气溶胶浓度的线性且精确的测量值。我们建议众包空气质量监测网络停止报告来自这些传感器的粗颗粒（PM）模态和PM质量浓度。
