Burden of Mortality Attributable to Long-Term Exposure to PM2.5 in Addis Ababa, Ethiopia: A Health Impact Assessment Using AirQ+

Health impact assessments of ambient particulate matter remain far less developed in sub-Saharan African cities, despite fine particulate matter (PM2.5) being a significant contributor to premature mortality globally. This study quantified the public health burdens of adult mortality associated with long-term PM2.5 exposure in Addis Ababa, Ethiopia, under different counterfactual air quality scenarios. Hourly PM2.5 data were collected across nine monitoring stations from 2022 to 2023. AirQ+ tool was utilized to estimate attributable natural-cause and cardiovascular disease (CVD) mortality among adults aged ≥ 30 years. Spatial analysis showed mean concentrations ranging from 15 µg/m3 to 33 µg/m3, with an overall mean of 26.74 µg/m3, exceeding the WHO annual guideline by more than fivefold. Seasonal peaks occurred from June to August and diurnal maxima at 7:00 AM. In 2022, attributable natural-cause deaths ranged from 1489 (6.16%) at the less stringent WHO Interim Target 3 (15 µg/m3) to 3169 (13.11%) at the WHO Air Quality Guidelines (5 µg/m3). In 2023, the range was 1544 (6.40%) to 3218 (13.33%). For specific chronic endpoints, PM2.5 concentration level was responsible for between 509 and 1071 CVD deaths in 2022, and between 535 and 1126 CVD deaths in 2023 across the counterfactual scenario. These results highlight the substantial health burden posed by ambient PM2.5 in Addis Ababa and emphasize the urgent need for targeted interventions.