Last modified: 2020-02-10
Abstract
Background: At present, the quality of ambient air has become a serious concern in low and middle income countries, including Ethiopia. The present study aimed to examine the associations between daily mortality rates and ambient air pollution () for hospital patients in Addis Ababa, Ethiopia.
Methods: The current study is one of the components of the Global Environmental and Occupational Health () Hub for Eastern Africa Project. A daily count of admitted hospital patient mortality data linked with time-series study on ambient were obtained for the period April 1st – March 31st, 2018 from six hospitals in Addis Ababa. The number of deaths was obtained from daily hospital databases. Ambient particulate matters monitor was measured using MetOne® Beta Attenuation Monitor () to measure concentirations. The main statistical method used was Poisson regression analysis using generalized additive model (GAM) with smoothing function of daily mean temperature, and relative humidity each at 6 df; and cubic spline for time trends with 8 df obtained from the data.
Results: A total of 959 deaths due to non-accidental cases were included in the study. Of which, 155 are cardiovascular, 78 are respiratory, while the remaining 726 are from other causes of deaths. The daily concentrations levels varied between 15 μg/ to 131 μg/ The annual average concentration was 43.56 ± 14.72 μg/which has exceeded the air quality standard of 10μg/annual mean. GAM adjusted only for the meteorological variables alone provide a significant air pollution impact at lag 4 on all-cause mortality which can be interpreted as a 11.4% increases in mortality associated with a 10 μg/increase in . Significant findings were observed when we stratify the data analyses by gender and age as well.
Conclusions: The is significantly associated with all cause and cause-specific mortality. This indicated that as air pollution increases, the health concern increases as well. The annual concentration is about four times air quality guidelines. There is an urgent need for intervention and long-term effect studies to produce to improve the air quality in Addis Ababa, Ethiopia.
Keywords: Air pollution, Concentration, Time-series Study, Poisson, Generalized Additive Model (GAM).
Funding Sources: The study was generously supported by NIH Fogarty International/USA and IDRC of CANADA.