Nairobi, Kenya’s capital, is the largest city in East Africa and home to over 5.3 million residents. By 2035, this population is projected to reach ~8 million, increasing pressure on the city’s infrastructure and environment. As East Africa’s economic and transport hub, Nairobi ranks first regionally in the Global Business Cities Index 2022. It boasts a thriving tech ecosystem, earning it the nickname ‘Silicon Savannah.’
However, this rapid growth has led to serious air pollution challenges, with the city’s PM2.5 concentrations 2019 being 4.2 times higher than WHO-recommended levels.
Pillars
At Breathe Cities-Nairobi, we tackle these challenges with a holistic, multi-pillar approach that prioritises data-driven action, community engagement, and sustainable policies:
Data and Research
Expand the availability of local air quality data through the use of innovative new technologies and research into causes of air pollution to provide local governments with evidence for implementing and enforcing new policies.
Stakeholder and Community Engagement
Develop a campaign and collaborate with community organisers to build awareness and support for air quality action, especially for communities most affected by air pollution.
Technical Policy Assistance
Support Nairobi City County to develop and deliver clean air policies by providing technical assistance and capacity building to support policymakers in identifying and implementing solutions.
Lesson Sharing
As part of the global Breathe Cities initiative, we collaborate with other cities around the world to share successes, solutions, and learnings from Nairobi on a global scale.
Scope
Road transport contributes 40% of PM2.5 emissions, worsened by an ageing vehicle fleet, weak emission controls, and gridlocked roads. Though only 12.8% of residents own cars, over 70% rely on old, fuel-inefficient matatus.
This combination of outdated vehicles and an inadequate transport network has made Nairobi one of the most congested cities in the world. During peak hours, the city’s population swells from 4.5 million to over 6 million, intensifying gridlock and emissions.
Illegal waste dumping and burning cause 25% of PM2.5 pollution. Nairobi generates 3,000 tonnes of waste daily, but 62% is disposed of illegally. The Dandora landfill, operating beyond capacity, fuels toxic emissions through methane leaks and spontaneous fires.
Medical waste disposal is also a crisis; 250 health facilities generate 150 tonnes monthly, yet only one legal incinerator exists. Unregulated burning at night worsens air quality.
Factories contribute 15% of PM2.5 emissions, especially in metal recycling, cement production, and tanneries. Many operate with outdated, unregulated processes, releasing harmful pollutants.
Stronger emission controls and cleaner industrial practices are essential for a healthier city.

