At the break of dawn in Lagos, Nigeria, a group of determined marathon runners sets out — not just to test their endurance, but to collect vital data on the city’s air quality. These runners are part of a movement called Cityzens, a youth-driven initiative that blends physical activity with citizen science. Armed with mobile sensors and an app, they document environmental conditions in real time, contributing to a database that helps researchers understand the sources and severity of pollution in Lagos.

Air quality in Lagos is a pressing concern, especially during the dry season when pollutants from traffic, open fires, and industrial emissions accumulate. The data collected by the runners reveals hotspots of dangerous pollution levels, particularly in areas like Ilashe and Makoko. 

As well as the athletes, residents across the city use the Cityzens app to report environmental issues, from burning garbage to poor waste management.

With Lagos generating 13,000 tons of waste daily and its landfills nearing capacity, the need for sustainable solutions is urgent. The Lagos Waste Management Authority (LAWMA) is responding with initiatives like mandatory waste separation and plans for biogas and recycling facilities. And while many residents can’t afford recycling bins and some neighborhoods are still underserved, LAWMA’s advocacy officers engage directly with communities, addressing complaints and promoting awareness.

Data gathered by citizens is presented to the Lagos Environmental Protection Agency, sparking dialogue and potential policy shifts. While progress may be gradual, the integration of citizen science into urban planning marks a powerful step toward a cleaner, healthier Lagos — driven by the people who live there.