Impact of Four Large Fires on Air Quality in Sardinia (Italy) ^†

Fires are an integral part of Mediterranean ecosystems, where they have played an ecological role for thousands of years. Nevertheless, fires also have a series of negative and significant impacts on people, properties, and the environment, with disastrous consequences on structures, habitat, and loss of human life.

Fires also emit significant quantities of smoke and numerous pollutants such as carbon monoxide, methane, nitrous oxide, nitrogen oxides, volatile organic compounds, and particulate matter (PM) that affect air quality and can threaten human health, aggravating chronic heart and lung diseases.

This work analyses four cases of large fires (>1500 ha), characterised by different fuel types, that occurred in Sardinia (Italy) in the last fifteen years and their connection with air quality data recorded through air quality network stations close to the burned areas.

Each fire was described in terms of perimeter, area burned, and fuel types. Meteorological conditions at the synoptic and local scales were analysed. To investigate the trajectory of fire plume, the forward trajectories of air masses were computed with the HYSPLIT (hybrid single-particle Lagrangian integrated trajectory) model developed by NOAA’s Air Resources Laboratory (ARL). In order to evaluate the impact on air quality the values of CO, NO₂, O₃, SO₂, PM_2.5, and PM₁₀, recorded by the Survey and Air Quality Control Network of the Agenzia regionale per la protezione dell’ambiente della Sardegna (Arpas), were analysed and correlated with burned areas and fuel types involved.

Preliminary results showed different levels of correlation between air quality and fire event for the four cases analysed. This fact could be linked to different fuel typologies, different atmospheric conditions and probably, in large part, by the location and density of air monitoring stations.