Air quality and attributable mortality among city dwellers in Kampala, Uganda: results from 4 years of continuous PM2.5 concentration monitoring using BAM 1022 reference instrument

Air pollution is a known risk factor for non-communicable diseases that causes substantial premature death globally. Rapid urban growth, burning of biomass and solid waste, unpaved sections of the road network, rising numbers of vehicles, some with highly polluting engines, contribute to the poor air quality in Kampala.BACKGROUNDAir pollution is a known risk factor for non-communicable diseases that causes substantial premature death globally. Rapid urban growth, burning of biomass and solid waste, unpaved sections of the road network, rising numbers of vehicles, some with highly polluting engines, contribute to the poor air quality in Kampala.To provide evidence-based estimates of air pollution attributable mortality in Kampala city, with focus on ambient fine particulate matter (PM2.5).OBJECTIVETo provide evidence-based estimates of air pollution attributable mortality in Kampala city, with focus on ambient fine particulate matter (PM2.5).We utilized a time series design and prospectively collected data on daily ambient PM2.5 concentration levels in micrograms per cubic meter (μg/m3) using a Beta Attenuation Monitor (BAM-1022) in Kampala city, Uganda. We combined the PM2.5 data with all-cause mortality data obtained from the Uganda Bureau of Statistics and the Ministry of Health in Kampala. We calculated attributable risk estimates for mortality using the WHO AirQ+ tools.METHODSWe utilized a time series design and prospectively collected data on daily ambient PM2.5 concentration levels in micrograms per cubic meter (μg/m3) using a Beta Attenuation Monitor (BAM-1022) in Kampala city, Uganda. We combined the PM2.5 data with all-cause mortality data obtained from the Uganda Bureau of Statistics and the Ministry of Health in Kampala. We calculated attributable risk estimates for mortality using the WHO AirQ+ tools.Overall, the annual average concentration for PM2.5 for the period of 4 years, 2018-2021, was 39 μg/m3. There was seasonal variation, with the rainy season months (March-June and October-December) having lower values. PM2.5 concentrations tend to be highest in the morning (09.00 h) and in the evening (21.00 h.) likely due to increased vehicular emissions as well as the influence of weather patterns (atmospheric temperature, relative humidity and wind). Saturday has the most pollution (daily average over 4 years of 41.2 μg/m3). Regarding attributable risk, we found that of all the deaths in Kampala, 2777 (19.3%), 2136 (17.9%), 1281 (17.9%) and 1063