NAIROBI, Kenya – Nairobi has been ranked the third-most polluted major city in Africa, according to new air quality data from Swiss monitor IQAir, raising fresh alarm over the capital’s worsening environmental and health outlook.
On Tuesday, the city placed 83rd globally with an Air Quality Index (AQI) reading of 92 — classified as “moderate” but still far above the World Health Organization’s (WHO) safe guideline of 5 µg/m³ for annual fine particulate matter (PM2.5).
IQAir data shows that Nairobi trails only Kinshasa in the Democratic Republic of Congo (AQI 199) and Cairo, Egypt, among Africa’s most polluted cities.
Kampala was also flagged among the worst performers, while Johannesburg (AQI 62), Dakar, and Accra emerged as the continent’s cleanest major cities.
Globally, Baghdad, Iraq (AQI 256), topped the list as the most polluted, while Sydney, Canberra, Auckland, Detroit, and Washington, D.C. ranked among the cleanest.
Health Risks Rising
The report identifies PM2.5 — tiny airborne particles small enough to enter the bloodstream and damage vital organs — as Nairobi’s dominant pollutant.
“In 2020, the average PM2.5 concentration in Nairobi was 14.7 µg/m³, about 1.5 times higher than the WHO’s recommended annual threshold,” IQAir said.
Health experts warn that prolonged exposure to dirty air is driving a surge in respiratory illnesses such as asthma and bronchitis, while also increasing the risk of heart disease, throat and lung cancer, miscarriages, and birth defects.
Hotspots of Pollution
IQAir’s data highlights pollution hotspots across Nairobi, including Dandora Phase 4 (AQI 112) and Kariobangi North Health Center (AQI 90).
The main contributors include vehicle emissions — particularly from older, poorly maintained cars — industrial output, construction activity, road repairs, and widespread open-air burning.
The findings come amid rising calls for urgent policy interventions to tackle air pollution in Kenya’s cities.
With more than five million vehicles now on the country’s roads and rapid urban expansion, environmental advocates warn that without stronger regulation, Nairobi risks sliding into more dangerous AQI categories that could put millions of residents at serious health risk.
