'Big' Data Meets 'Thick' Data

Nakuru, Kenya – June 2025 — Since the RESPIRA-AQM launch workshop on May 6, our network of community ambassadors has moved from the plenary halls at the university into the everyday spaces of life in Nakuru. Across the city’s 11 wards, they have been listening, asking questions, and collecting stories from residents about what pollutes the air they breathe. From fish markets to factories, dusty roads to dumpsites, a layered portrait of environmental exposure emerged that is full of sharp everyday insights about air pollution in Nakuru.

These narratives now intersect with a major technical milestone: the installation of 20 new air quality sensors across Nakuru. In collaboration with Sensors.Africa, the Kenya Meteorological Department (KMD), Nakuru County and City officials, local residents, and other key partners, these sensors were strategically deployed to capture real-time air pollution data across the city’s diverse neighbourhoods. The sensor network forms a critical backbone of the Early Warning System (EWS) we are developing. This system will integrate community-generated reports, satellite imagery and ground sensor data into a user-friendly platform called AngaWatch. Through this app, citizens can report pollution incidents, consult live air quality data, and receive alerts or updates from Nakuru’s meteorologist on anticipated pollution levels in the coming 24 hours.

The stories logged by community members help ground the data gathered via sensors. People speak of blocked drains, the sting of burning waste, and the normalisation of foul smells and bad air. Some report bloated stomachs, persistent headaches, and corroding iron roofs—physical symptoms and signs they associate with air pollution. A few have even moved house due to worsening respiratory conditions. Citizens question why open sewage persists near clinics or why certain schools are surrounded by burning waste. Others expand definitions of pollution to include noise, crowding, and emotional distress. These lived accounts call for inclusive, responsive environmental governance—where “big data” from sensors and “thick data” from residents are equally recognised as valid forms of evidence.

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