Calibration and validation-based assessment of low-cost air quality sensors

The Science of The Total Environment, Journal Year: 2025, Volume and Issue: 977, P. 179364 - 179364

Published: April 15, 2025

Air pollution poses a significant threat to public health. Low-cost air quality sensors (LCSs) can provide data foundation for monitoring, particularly supplementing the regulatory monitoring network and identifying local issues. However, performance varies considerably, questions remain regarding reliability accuracy of LCS data. We evaluated accuracy, stability precision six LCSs over three-month period collocation with reference instruments at two locations. A mathematical workflow including calibration validation was developed stability, incorporating combination environmental factors (e.g., temperature, relative humidity), linear nonlinear regression, followed by evaluation Bland-Altman plots. For particulate matter, from found be reliable after simple regression (R2 > 0.9 both validation). gas nitrogen dioxide, carbon monoxide, Ozone, methods that met requirements also performed well using models 0.7 validation), whereas machine learning models, such as random forest, could not pass validation, require cautious application. In non-laboratory environments, into function may lead subsequent instability. Regarding between LCSs, unstable measurement biases among devices have been observed. Linear method is recommended preferred onsite caution advised when due increased uncertainty. Furthermore, deploying it important consider their varying responses high or low pollutant concentrations.

Language: Английский

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Measurement report: A complex street-level air quality observation campaign in a heavy-traffic area utilizing the multivariate adaptive regression splines method for field calibration of low-cost sensors

Atmospheric chemistry and physics, Journal Year: 2025, Volume and Issue: 25(8), P. 4477 - 4504

Published: April 24, 2025

Abstract. As part of the TURBAN project, “Legerova campaign” investigated air quality and meteorology in a traffic-dense area Prague, Czech Republic, from 30 May 2022 to 28 March 2023. The study deployed network 20 low-cost sensor (LCS) stations measure NO2, O3, PM10 PM2.5 concentrations, complemented by advanced meteorological instruments such as microwave radiometer Doppler lidar. Ensuring data LCS measurements presented significant challenges. Initial field tests at reference monitoring station revealed strong correlations between raw (r > 0.90 for NO2 PM2.5, r 0.80 O3 PM10). However, individual biases were observed. Applying multivariate adaptive regression splines (MARS) method effectively reduced enhanced alignment with all pollutants (R2 0.88–0.97). During campaign, ageing technical issues identified through double mass curve analysis final testing. highest concentrations recorded streets dense building blocks traffic lights, corresponding peak patterns (with medians 20–34 ppb). Aerosol generally low (medians < 25 µg m−3 sites), less temporal spatial variability than NO2. Elevated levels occurred primarily during temperature inversions, often linked local sources, short, non-local episode. This highlights MARS reliable tool calibration networks provides valuable on urban its dynamics high spatiotemporal resolution.

Language: Английский

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Evaluation and Correction of PurpleAir Temperature and Relative Humidity Measurements

Atmosphere, Journal Year: 2024, Volume and Issue: 15(4), P. 415 - 415

Published: March 27, 2024

The PurpleAir PA-II sensor provides low-cost in situ measurements of meteorological variables including temperature and relative humidity (RH), as well fine particulate matter (PM2.5) real time. sensors have been used several studies investigating intracity differences PM2.5. While the adoption use has many benefits, care must be taken to ensure proper calibration testing. This is true not only for PM2.5 but also RH given synergistic health impacts from extreme heat air pollution exposure. Here, we compare continuous a Campbell Scientific 107 probe Vaisala HMP45C probe. All three instruments were co-located December 2021 June 2023 Asheville, North Carolina. We found that an overall high bias 2.6 °C root mean square error (RMSE) 2.8 °C. Applying linear regression correction reduces RMSE 1.0 °C, while applying constant 4.4 suggested by 2.2 Our low −17.4% uncorrected 18.5%. A improves 4.5%. 4% 14.8%. present new factors differ those PurpleAir, which overcorrect undercorrect bias. show our improve estimates dewpoint (RMSE 0.6 0.9 °C) compared corrections PurpleAir.

Language: Английский

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The Impact of Air Pollution from Industrial Fires in Urban Settings: Monitoring, Modelling, Health, and Environmental Justice Perspectives

Environments, Journal Year: 2024, Volume and Issue: 11(7), P. 157 - 157

Published: July 21, 2024

Industrial fires at facilities including waste management sites, warehouses, factories, chemical works, and fuel storage depots are relatively frequent occurrences. Often, these occur adjacent to urban communities result in ground-level airborne pollutant concentrations that well above guideline values. Land, water, livestock, crops may also be contaminated by the emissions firefighting activities. Moreover, impacted tend have a higher proportion of minority ethnic populations as individuals with underlying health vulnerabilities those lower socio-economic status. Nevertheless, this is an aspect air quality under-researched, so review aims highlight public hazards associated industrial need for effective, coordinated, response. We range monitoring techniques been utilised such role dispersion modelling predicting plume trajectories estimating population exposure. recommend establishing 1 h values particulate matter facilitate timely interventions, we regulatory technical controls sites prone fires, particularly sector.

Language: Английский

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Interventions for reducing exposure to air pollution from landscape fires in a changing environment: A systematic review

The Science of The Total Environment, Journal Year: 2025, Volume and Issue: 966, P. 178621 - 178621

Published: Feb. 1, 2025

Language: Английский

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The Impact of Industrial Fires in Urban Settings: Monitoring, Modelling, Health, and Environmental Justice Perspectives

Published: June 10, 2024

Industrial fires at facilities including waste management sites, warehouses, factories, chemical works and fuel storage depots are relatively frequent occurrences. Often, these occur adjacent to urban communities result in ground-level airborne pollutant concentrations that well above guideline values. Land, water, livestock crops may also be contaminated by the emissions firefighting activities. Moreover, impacted tend have a higher proportion of minority ethnic populations, individuals with underlying health vulnerabilities, as those lower socio-economic status. Nevertheless, this is an aspect air quality under-researched, so review aims highlight public hazards associated industrial need for effective, coordinated, response. We range monitoring techniques been utilised such role dispersion modelling predicting plume trajectories estimating population exposure. recommend establishing 1-h values particulate matter facilitate timely interventions we regulatory technical controls sites prone fires, particularly sector.

Language: Английский

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A methodology for estimating indoor sources contribution to PM2.5

Environmental Science Processes & Impacts, Journal Year: 2024, Volume and Issue: unknown

Published: Jan. 1, 2024

Exposure to indoor PM 2.5 originating from sources is relevant, and chemical speciation data necessary estimate this exposure. This work proposes a new approach quantify such

Language: Английский

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