Air Pollution in the City of Nairobi: Bridging Evidence with Policy
A quarter of the world population is exposed to unhealthy concentrations of air pollutants that causes adverse health effects in humans inhaling them leading to respiratory and cardiovascular diseases. As the fastest urbanizing continent, risks to air pollution in African cities is likely to increase in line with economic growth. In 2019, an estimated 1.1 million across Africa died because of air pollution. The City of Nairobi with an estimated population of 4.9 million, is rapidly growing and subjected to high exposure risk of ambient air pollution from anthropogenic factors. Of particular concern is the fine particulate matter with an aerodynamic diameter of 2.5 micrometers (PM2.5), a pollutant whose concentration is characterized by urbanization, industrialization, burning of wastes and use of biofuels. It is therefore of high public interest locally and globally, yet relatively little reliable long-term data exists that would inform policy making. The city for a long time also lacked a reference monitor that can support use of low-cost sensors more widely to increase data points.
Over the last 27 months, the University of Nairobi (UoN) has been undertaking research initiatives on air pollution, following the erection of a Beta Attenuation Monitor (BAM 1022) at its Parklands Campus, a designated Federal Equivalent (Gold) Monitor that facilitates data validity and accuracy to standardize the low-cost sensors (LCS). This was facilitated by the Eastern Africa Global Environmental and Occupational Health (GEOHealth) Hub for Research and Training. The hub is undertaking research and training focused on environmental and occupational health being simultaneously conducted in Ethiopia, Kenya, Rwanda, and Uganda. It is constituted by a consortium of four universities in eastern Africa, driving research initiatives including Addis Ababa University (AAU-Ethiopia), Makerere University (MU- Uganda), University of Nairobi (UoN-Kenya), and the University of Rwanda (UR-Rwanda). The training component is driven by a consortium of U.S.-based experts from Columbia University, Colorado School of Public Health, University of Southern California, University of Wisconsin – Madison, and the South Coast Air
The University of Nairobi GeoHealth team is currently running research on time series study of the ambient air quality and associated respiratory outcomes among lower primary school going children in the eight planning zones of the City of Nairobi (Dagoretti, Embakasi, Kamukunji, Kasarani, Langata, Makadara, Starehe, and Westlands) cause specific hospitalization and mortality in six hospitals, and household surveys among children tested for spirometry. Low-cost sensors (LCS), used by most entities in Nairobi to collect real-time air quality information provides spatial and temporal data. However, their accuracy is subject to biases and calibration dependencies, and may also be affected by meteorological conditions. The equipment and training at the GEOHealth UoN offer opportunity for collaboration and capacity building to other entities.
These efforts are very important and will provide ample knowledge and understanding of city’s air quality parameters and impacts on health. Therefore, it is necessary to use this information to start developing sub-city specific programs on air pollution control goals, targets and indicators based on the specific circumstances and priorities for each planning area. This will require further evidence that can be collaboratively generated among researchers and other air quality monitoring entities
