Ambient concentrations and dosimetry of inhaled size-segregated particulate matter during periods of low urban mobility in Bragança, Portugal

• Published in: Atmospheric pollution research Vol. 13; no. 9; p. 101512
• Main Authors: Cipoli, Yago Alonso, Targino, Admir Créso, Krecl, Patricia, Furst, Leonardo Campestrini, Alves, Célia dos Anjos, Feliciano, Manuel
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-09-2022; Turkish National Committee for Air Pollution Research and Control. Production and hosting by Elsevier B.V
• Subjects: Exposure assessment; Lockdown; Mobile monitoring; MPPD dosimetry Model; Size-segregated particulate matter; Lockdown; Mobile monitoring; MPPD dosimetry Model; Size-segregated particulate matter; Exposure assessment
• ISSN: 1309-1042; 1309-1042
• DOI: 10.1016/j.apr.2022.101512

The restrictive measures in place during the COVID-19 pandemic provided a timely scenario to investigate the effects of human activities on air quality, and the extent to which mobility reduction strategies can impact atmospheric pollutant levels. Real-time concentrations of PM1, PM2.5 and PM10 were measured using a mobile platform in a small city of Portugal, during morning and afternoon rush hours, in two distinct phases of the pandemic: emergency phase (cold period, lockdown) and calamity phase (warm period, less restricted). The Multiple-Path Particle Dosimetry Model (MPPD) was used to calculate the PM deposition for adults. Large spatio-temporal variabilities and pronounced changes in mean PM concentrations were observed, with lower concentrations in the calamity phase: PM1 = 2.33 ± 1.61 μg m−3; PM2.5 = 5.15 ± 2.77 μg m−3; PM10 = 23.30 ± 21.53 μg m−3 than in the emergency phase: PM1 = 16.85 ± 31.80 μg m−3; PM2.5 = 30.92 ± 31.93 μg m−3; PM10 = 111.27 ± 104.53 μg m−3. These changes are explained by a combination of meteorological factors and local emissions, mainly residential firewood burning. Regarding regional deposition, PM1 was the main contributor to deposition in the tracheobronchial (5%) and pulmonary (12%) regions, and PM10 in the head region (92%). In general, total deposition doses were higher for males than for females. This work quantitatively demonstrated that even with a 38% reduction in urban mobility during the lockdown, the use of firewood for residential heating is the main contributor to the high concentrations of PM and the respective inhaled dose.
•Spatial and seasonal variability in PM levels were noticed during the COVID-19 pandemic.•During the lockdown, residential wood burning contributed to an increase in the levels of all PM fractions.•The highest PM deposition dose was observed for males during the lockdown.•Depositions in the head and pulmonary regions were mainly dominated by PM10 and PM1, respectively.