Nairobi Launches Clean Air Initiative as PM2.5 Pollution Exceeds WHO Limits

Nairobi City County has unveiled a comprehensive Clean Air Action Plan after air quality monitoring data confirmed that fine particulate pollution (PM2.5) in the capital regularly exceeds World Health Organisation safe limits by a factor of 4.2. The data, collected from a network of 38 monitoring stations installed across the city between 2024 and 2025, shows average annual PM2.5 concentrations of 42 micrograms per cubic metre against the WHO guideline of 5 micrograms — a gap that public health specialists warn is causing measurable harm to the respiratory health of the city's estimated 5.3 million residents.

"Nairobi's air is making people sick. This is not a future risk — it is happening now, in our hospitals, in our schools, in the lungs of our children," said Nairobi Governor Sakari Kivuvani at the launch of the plan. "We have spent enough time documenting the problem. This action plan is about solving it."

The Major Sources

The monitoring network data, analysed by the University of Nairobi's Department of Environmental Science in collaboration with the Clean Air Fund, identifies vehicle emissions as the dominant pollution source, contributing 52 per cent of total PM2.5 loading in the city. Nairobi's vehicle fleet has grown by 38 per cent since 2018, and a substantial proportion of imported second-hand vehicles from Japan and the United Kingdom operate with catalytic converters that are damaged or removed to reduce maintenance costs. Matatus — the ubiquitous minibus taxis that carry approximately 60 per cent of Nairobi's commuters — are disproportionately represented among the highest-emitting vehicles.

Open biomass burning accounts for a further 24 per cent of PM2.5, driven by charcoal production in peri-urban areas, crop residue burning in the agricultural zones surrounding the city, and waste incineration at informal dumpsites. Industrial sources, including the industrial area factories and construction sites, contribute the remaining 24 per cent.

Health data presented at the launch underscored the urgency. Kenyatta National Hospital has recorded a 27 per cent increase in paediatric asthma admissions over the past three years, and the Nairobi Metropolitan Health Directorate estimates that air pollution is now a contributing factor in approximately 4,800 premature deaths in the city annually. Lower respiratory infections remain one of the top five causes of outpatient visits at Nairobi public health facilities.

The Action Plan

The Clean Air Action Plan runs to 2030 and contains 44 specific interventions across four sectors. On vehicle emissions, the county will work with the Kenya Revenue Authority to enforce Euro III emission standards for all newly imported vehicles from January 2027, while the National Transport and Safety Authority will begin a phased roadworthiness campaign targeting the oldest quartile of the matatu fleet. The county has also allocated Ksh 890 million to expand electric bus services on six trunk routes — complementing the ongoing SGR-linked Bus Rapid Transit project — with Safaricom's 5G network providing real-time fleet management data.

On biomass burning, the plan offers subsidised LPG gas conversion kits to 120,000 households currently using charcoal in informal settlements, targeting Mathare, Kibera, Korogocho, and Mukuru as priority zones. A ban on open waste burning within the city's administrative boundaries will be enforced by an expanded Environment Inspectorate, with fines of between Ksh 50,000 and Ksh 500,000 for commercial violators.

Industry will be required to install real-time emission monitoring equipment under a new county air quality by-law gazetted last week, with data reported directly to the county's air quality management dashboard, which will be publicly accessible online. The county has partnered with the Kenyan chapter of the African Clean Air Programme to train 200 air quality officers over the next eighteen months.

Funding totalling Ksh 4.3 billion is expected from county own-source revenues, a World Bank urban resilience grant, and the Climate Investment Funds' urban programme. Environmentalists have welcomed the plan but cautioned that its success will depend on whether national government agencies — particularly the Kenya National Highways Authority and NTSA — align their programmes with the county's targets. "Air does not respect county boundaries. This plan needs national government co-ownership to work," said Dr Grace Wanjiku of the Kenya Air Quality Coalition.