Analysis of mobile monitoring data from the microAeth® MA200 for measuring changes in black carbon on the roadside in Augsburg

Abstract

Abstract. The portable microAeth® MA200 (MA200) is widely applied for measuring black carbon in human exposure profiling and mobile air quality monitoring. Due to it being relatively new on the market, the field lacks a refined assessment of the instrument's performance under various settings and data post-processing approaches. This study assessed the mobile real-time performance of the MA200 to determine a suitable noise reduction algorithm in an urban area, Augsburg, Germany. Noise reduction and negative value mitigation were explored via different data post-processing methods (i.e., local polynomial regression (LPR), optimized noise reduction averaging (ONA), and centred moving average (CMA)) under common sampling interval times (i.e., 5, 10, and 30 s). After noise reduction, the treated data were evaluated and compared by (1) the amount of useful information attributed to retention of microenvironmental characteristics, (2) the relative number of negative values remaining, (3) the reduction and retention of peak samples, and (4) the amount of useful signal retained after correction for local background conditions. Our results identify CMA as a useful tool for isolating the central trends of raw black carbon concentration data in real time while reducing nonsensical negative values and the occurrence and magnitudes of peak samples that affect visual assessment of the data without substantially affecting bias. Correction for local background concentrations improved the CMA treatment by bringing nuanced microenvironmental changes into view. This analysis employs a number of different post-processing methods for black carbon data, providing comparative insights for researchers looking for black carbon data smoothing approaches, specifically in a mobile monitoring framework and data collected using the microAeth® series of Aethalometer.

Investigation of COVID-19-related lockdowns on the air pollution changes in augsburg in 2020, Germany

“…For example, particulate matters (PMs), which refer to tiny particles in the air adsorbing polycyclic aromatic hydrocarbons (PAHs), heavy metals, and other volatile organic fragments, can be breathed into human lungs leading to pulmonary diseases ( Araujo, 2011 ) and enter blood circulation to induce cardiovascular diseases ( Lawal, 2017 ). Black carbon (BC) belongs to PMs and is generated from incomplete combustion ( Liu et al, 2021a ), which showed potential carcinogenic effects on human ( Arif and Parveen, 2021 ). O 3 is a very reactive and oxidative pollutant, which can damage the human skin, eyes, and mucosae ( World Health Organization, 2003 ) as well as cause inflammation in bronchia leading to respiratory diseases ( Kim et al, 2020 ; Szyszkowicz and Rowe, 2016 ).…”

Performance evaluation of portable dual-spot micro-aethalometers for source identification of Black Carbon aerosols: Application to wildfire smoke and traffic emissions in the Pacific Northwest

“…In this study, we calculated hourly concentration of eBC by time integrating the instrument's data collection frequency of 5-minute and found that the hourly averaged eBC concentrations from individual MA300 units were well correlated with the reference measurements. In future applications of the MA300, trade-offs between high temporal resolution and increased noise should be considered (Liu et al, 2021;Hagler et al, 2011), recognizing that temporal integration can alleviate the unit specific measurement noise. From the MA300's raw photometer readings, we identified presence of instrumental drift across the units.…”

“…Portable but effective instruments are often required for mobile monitoring, in-vehicle commuter exposure (Weichenthal et al, 2015;Apte et al, 2011), indoor personal exposure (Jeong and Park, 2017), and for monitoring wildfire smoke using unmanned aerial vehicles. (Aurell et al, 2021) Over the past decade, researchers have become increasingly interested in micro-aethalometers, as they are suitable for characterizing emissions in these challenging micro-environments (Alas et al, 2020;Aurell et al, 2021;Liu et al, 2021). The newly developed micro-aethalometer model MA300 (AethLabs) uses similar measurement techniques to the AE33 but with a smaller form factor, a built-in rechargeable battery, and a low-volume pump, making it suitable for indoor measurements and personal exposure analysis.…”

Review of black carbon emission factors from different anthropogenic sources

“…Pirjola et al 2016, Wren et al 2018, Järvinen et al 2019, Chambliss et al 2020, Lepistö et al 2022 and next-to-source experiments (e.g. Dallmann et al 2013, Liu et al 2021, Saarikoski et al 2021. Results of many field studies do not represent a single BC source, but e.g.…”