Long-Term PM₂.₅ Exposure and Attributable Mortality in Tbilisi, Georgia: A Health Impact Assessment Using AirQ+
DOI:
https://doi.org/10.52340/GBMN.2026.01.01.187Keywords:
Air pollution, AirQ+, Health impact assessment, Mortality, PM₂.₅Abstract
BACKGROUND. Long-term exposure to fine particulate matter (PM₂.₅) is a major environmental risk factor for premature mortality. However, evidence quantifying the health burden attributable to PM₂.₅ exposure in Georgia remains limited. OBJECTIVES. To estimate the impact of long-term PM₂.₅ exposure on natural all-cause mortality in Tbilisi and evaluate potential health benefits under hypothetical pollution-reduction scenarios. METHODS. We conducted a health impact assessment using the WHO AirQ+ software and multi-year air-quality and mortality data for Tbilisi during 2019-2024. Annual PM₂.₅ concentrations from fixed monitoring stations were used to calculate a six-year mean concentration of 17.3 µg/m³. The analysis focused on natural all-cause mortality among adults aged ≥30 years using concentration-response functions recommended for AirQ+. Attributable mortality was estimated for current exposure levels and for hypothetical PM₂.₅ reduction scenarios, including reductions of 5 µg/m³, 10 µg/m³, and attainment of the WHO annual air quality guideline value of 5 µg/m³. RESULTS. Long-term PM₂.₅ exposure was estimated to account for 9.0% (95% CI: 6.9%-10.1%) of natural all-cause deaths among adults aged ≥30 years in Tbilisi, corresponding to approximately 1,081 premature deaths annually (95% CI: 828-1,204). Reducing PM₂.₅ concentrations by 5 µg/m³ and 10 µg/m³ was associated with decreases in attributable mortality to 654 and 210 premature deaths annually, respectively. Under the WHO guideline scenario, no additional PM₂.₅-attributable mortality was estimated within the model framework. CONCLUSIONS. PM₂.₅ exposure represents a substantial public health burden in Tbilisi. The findings indicate that reductions in ambient PM₂.₅ concentrations could prevent a considerable number of premature deaths and support the need for strengthened air-quality management and progressive alignment with WHO guideline values.References
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