Search

People spend most of their time in indoor environments without knowing about the air quality in these spaces. In this study, indoor low-cost sensors were used (for 5 months) to assess the comfort and air quality patterns in two indoor households. To strengthen the robustness of the considered approach and build confidence in the obtained comfort and indoor air quality (IAQ) levels, the sensor measurements were also compared against information from reference monitoring equipment; in which, high correlation coefficients were obtained (> 0.85) and also low errors (on average 22%). The IAQ results were strongly influenced by the residents' activity and behaviour, the outdoor weather conditions, and indoor/outdoor air pollution sources. Overall, the recommended values of temperature and relative humidity for the occupant's comfort in indoor environments were not fulfilled. The highest particulate matter (PM) levels were recorded at the weekend (on average +14% higher), while maximum CO 2 and CO levels were obtained on the weekdays (on average +9% higher). PM daily profiles followed the outdoor concentrations with the maximum levels at the end of the night and the lowest values in the early morning/mid-afternoon. The highest and lowest CO 2 concentrations were registered in the early morning (< 1536 ppm) and mid-afternoon (< 627 ppm), respectively, while the CO daily profiles showed a high impact of outdoor emissions, with the minimum concentrations up to 0.81 mg m -3 (at 10 a.m. or 6 p.m.), and a maximum concentration of 1.87 mg m -3 (at 10 p.m.). Real-time comfort conditions and IAQ levels are a powerful approach to providing fast decisions to minimise human exposure and prevent negative health impacts., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Background: Air quality deteriorates significantly during wildfire events, which poses a risk for the health of affected human populations. The Mediterranean Basin was strongly impacted by wildfires during the 2021 fire season, particularly in Greece. Aims: This work aims at estimating the impact of the Greek wildfires of August 2021 on the air quality in Athens. Methods: The numerical modelling system WRF-APIFLAME-CHIMERE, which comprises a meteorological model, a smoke emissions model and a chemical transport model, was employed in estimating the hourly three-dimensional distribution of particulate matter (PM), CO and O3 concentrations during the wildfires. The performance of the modelling system was evaluated by comparing modelled results with air quality observations and atmospheric optical depth measurements. Key results: Good agreement between measured data and model results was found, with results obtained with a higher-resolution computational grid performing the best. Conclusions: The calculated values indicate concerning hourly and daily levels of air pollution, above the limit values for human health protection, during the analysed days within and around Athens. Implications: The results highlight the importance of implementing a strategy for human health protection during wildfire events affecting populated areas. This modelling approach could be a basis for a smoke forecasting system. Air quality deteriorates significantly during wildfire events. The numerical modelling system WRF-APIFLAME-CHIMERE was applied to estimate the impact of the 2021 August wildfires on the air quality of Athens. Calculated values indicate concerning levels of air pollution during the wildfires with potential impacts on health. [ABSTRACT FROM AUTHOR]

Abstract: In summer 2009, emissions of trace gases and aerosols from several wildfires occurring in Portugal were sampled. A portable high-volume sampler was used to collect sequentially, on quartz fibre filters, coarse (PM2.5–10) and fine (PM2.5) smoke particles. Tedlar air sampling bags have been used for complementary chemical characterisation of the gaseous phase. The carbonaceous content (elemental and organic carbon, EC/OC) of particulate matter was analysed by a thermal-optical transmission technique. The levels of almost 50 elements were quantified by inductively coupled plasma-mass spectrometry. The water-soluble ions were obtained by ion chromatography. Emission factors of species that are favoured by the smouldering phase (e.g. CO) were above the values reported in the literature for biomass burning in other ecosystems. The CO emission factors were 231 ± 117 g kg−1 biomass (dry basis) burned. Emissions of compounds that are promoted in fresh plumes and during the flaming phase, such as CO2, were generally lower than those proposed for savannah and tropical forest fires. The CO2 emission factors ranged from about 1000 to 1700 g kg−1. Total hydrocarbons, PM2.5, PM10 and OC presented variable emissions, but in general substantially higher than values reported for wildfires in African and Amazonian biomes. The emission factors obtained in Portugal were as follows (in g kg−1 biomass, dry basis): 6–350 for total hydrocarbons, 0.5–42 for PM2.5, 1–60 for PM10, and 0.2–42 for OC (in PM10). The organic carbon-to-elemental carbon ratios measured in the present study largely exceeded those obtained by other researchers. The aerosol mass was dominated by organic matter (OC/PM2.5 = 50 ± 18%, OC/PM2.5–10 = 36 ± 18%). The metal elements represented, on average, 1.23 and 0.91%, while the measured water-soluble ions accounted for 2.6 and 2.1% of the PM2.5 and PM2.5–10 mass, respectively. Carbonates accounted for 0.15–3.1% (average = 0.83%) of PM2.5–10. The dominant elements were B, Ti, Mn, Cu, Zn, Zr and Ba. [Copyright &y& Elsevier]