Sensors (Jun 2024)

Performance Assessment of Two Low-Cost PM<sub>2.5</sub> and PM<sub>10</sub> Monitoring Networks in the Padana Plain (Italy)

  • Giovanni Gualtieri,
  • Lorenzo Brilli,
  • Federico Carotenuto,
  • Alice Cavaliere,
  • Tommaso Giordano,
  • Simone Putzolu,
  • Carolina Vagnoli,
  • Alessandro Zaldei,
  • Beniamino Gioli

DOI
https://doi.org/10.3390/s24123946
Journal volume & issue
Vol. 24, no. 12
p. 3946

Abstract

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Two low-cost (LC) monitoring networks, PurpleAir (instrumented by Plantower PMS5003 sensors) and AirQino (Novasense SDS011), were assessed in monitoring PM2.5 and PM10 daily concentrations in the Padana Plain (Northern Italy). A total of 19 LC stations for PM2.5 and 20 for PM10 concentrations were compared vs. regulatory-grade stations during a full “heating season” (15 October 2022–15 April 2023). Both LC sensor networks showed higher accuracy in fitting the magnitude of PM10 than PM2.5 reference observations, while lower accuracy was shown in terms of RMSE, MAE and R2. AirQino stations under-estimated both PM2.5 and PM10 reference concentrations (MB = −4.8 and −2.9 μg/m3, respectively), while PurpleAir stations over-estimated PM2.5 concentrations (MB = +5.4 μg/m3) and slightly under-estimated PM10 concentrations (MB = −0.4 μg/m3). PurpleAir stations were finer than AirQino at capturing the time variation of both PM2.5 and PM10 daily concentrations (R2 = 0.68–0.75 vs. 0.59–0.61). LC sensors from both monitoring networks failed to capture the magnitude and dynamics of the PM2.5/PM10 ratio, confirming their well-known issues in correctly discriminating the size of individual particles. These findings suggest the need for further efforts in the implementation of mass conversion algorithms within LC units to improve the tuning of PM2.5 vs. PM10 outputs.

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