Citation

Gili J, Viana M, Hopke PK. Sci. Total Environ. 2024; ePub(ePub): ePub.

Copyright

(Copyright © 2024, Elsevier Publishing)

DOI

10.1016/j.scitotenv.2024.172747

PMID

38677434

Abstract

Galicia (NW Spain) is one of the most fire-prone regions in Southern Europe. In the summer of 2022, a total of thirteen wildfires exceeding 500 ha were reported in this area, with ten of these large fires occurring in the Ourense region. To study the impacts of wildfire smoke plumes on ambient air PM(2.5) concentrations, a network of 18 PurpleAir monitors was deployed across the Galicia region during July and August 2022. The PM(2.5) concentration data were then used as input to test the applicability of quasi-empirical orthogonal functions (QEOFs obtained with Positive Matrix Factorization (PMF)) to characterize the spatial variability of wildfire smoke impacts on air quality. HYSPLIT back-trajectory analysis and Concentration-Weighted Trajectory (CWT) models were implemented, and the results from these tools were combined with source contributions. As a result, 19 wildfires were identified and linked with peak ambient PM(2.5) concentrations (>300 μg/m(3) of PM(2.5); 1-h mean). Specifically, the Folgoso do Courel fire emerged as a significant contributor to these high concentrations and played an important role in influencing a significant number of the identified factors. Moreover, the results also suggested that emissions from fires in Portugal reached the study area, contributing additional impacts on air quality. These results demonstrated that this approach was useful in identifying the emission source areas contributing to observed PM(2.5) concentrations during wildfire events. The PM(2.5) concentration maps resulting from the CWT analysis were also valuable in understanding the short- and long-term exposures to PM(2.5) from wildfire smoke.

Language: en

Keywords

Exposure; Forest fire; Particulate matter; Smoke; Source apportionment