This study aims to measures and develops emission factors of CO, HC, NOx, and soot from HDV trucks and buses using remote sensing technology. The device applies absorption spectroscopy to directly measure vehicle exhaust emissions from the roadside, allowing traffic to continue without interruption. It records emission data for each vehicle in less than one second. Testing was conducted at 19 highway and toll road locations in Jakarta over 58 days, using a 2020 M752 version 3.1 remote sensing device. From a valid sample of 4,774 HDV trucks and 2,029 buses, the median emission factors for CO, HC, NOx, and soot for diesel HDV trucks are 3.65, 0.24, 3.51 and 0.117 g/km, respectively; for diesel buses, 3.70, 0.23, 5.53 and 0.122 g/km; and for CNG buses, 5.90, 0.91, 1.10 and 0.005 g/km. Across all three vehicle types, median emission factors decreased with newer production years. Median soot emissions are zero for diesel buses produced after 2015 and CNG buses manufactured between 2007 and 2015 and after 2015. Diesel and CNG buses emit less CO than diesel HDVs, with Isuzu diesel buses recording the lowest at 0.8 g/km. Diesel buses also record the lowest HC emissions, with Isuzu and Mercedes-Benz buses at 0.06 g/km. The lowest NOx and soot emissions are also observed in Scania and Zhongtong CNG buses, with NOx around 0.3 g/km and soot at 0 g/km. The findings of this study can inform air quality regulations, support urban transportation planning, and raise awareness of the health impacts of pollution, particularly from the transport sector in Jakarta, Indonesia.
Winter air pollution in Warsaw, Poland, was analyzed from 2016 to 2025 using hourly data from nine CIEP monitoring stations, meteorological observations from Okecie IMGW station, boundary layer heights from ERA5, and HYSPLIT backward trajectories. The study focused on PM10, PM2.5, NO2, and O3, with emphasis on black smog episodes. Air quality improved substantially over the decade: the frequency of good or very good (according to Polish air quality index thresholds) PM2.5 conditions increased from 10 to 12
AERONET Version 3 inversion products were used to classify optically defined aerosol regimes and examine their temporal distribution over Singapore during 2007–2023 using particle linear depolarization ratio (PLDR), dust ratio (Rd), fine-mode fraction (FMF), and single scattering albedo (SSA). Lower PLDR values were associated with fine-mode, relatively spherical particles characteristic of pollution-related aerosols, whereas higher PLDR values indicated non-spherical coarse particles associated with dust. The joint FMF-Rd distribution showed a predominance of fine-mode, low-dust aerosol conditions. Among the quality-assured AERONET inversion retrievals, dust-free pollution regimes, comprising strongly absorbing (SA), moderately absorbing (MA), weakly absorbing (WA), and non-absorbing (NA) regimes, accounted for 74
Volatile organic compounds (VOCs) are major contributors to indoor air pollution in hospitals, where disinfectants, sterilants, and pharmaceutical agents are used continuously. This study provides a multi-ward, multi-shift assessment of total VOC (TVOC) concentrations in a large university hospital using a calibrated photoionization detector (PID) with daily zero/span checks and inter-instrument consistency verification. Measurements were conducted between 10 April and 23 May 2023 (a 44-day spring field campaign) across 41 wards, a non-clinical reference building, and open air to distinguish healthcare-related emissions from background indoor sources. TVOC concentrations were compared with a 108 ppb screening threshold derived from the 500 µg/m3 TVOC reference used in LEED, WELL, and UBA frameworks, converted to PID units using a published GC–PID calibration model. Indoor TVOC levels were elevated in most clinical areas, with the highest median concentrations in operating rooms (857 parts per billion [ppb]) and the endoscopy ward (842 ppb). Mean indoor-to-outdoor (I/O) ratios exceeded 1 in all sampled wards, supporting the predominance of indoor sources. Significant spatial variability was observed across functional ward categories (Kruskal–Wallis p < 0.001), and temporal variation across work shifts was statistically significant in 26 of 41 wards (p < 0.05, Kruskal–Wallis with Dunn post-hoc comparisons), with morning shifts generally recording the highest TVOC levels. These findings demonstrate substantial VOC accumulation in procedure-intensive areas and highlight the need for improved ventilation management and targeted exposure-control strategies in healthcare environments.
