ANALYSIS · 02 APR 2025
The air our cities breathe: the case for county monitors
Chapter volunteers kept a grid of forty low-cost sensors reporting for eight months — and produced the longest continuous public air-quality dataset these cities have ever had.
For eight months, chapter volunteers in Nairobi, Kisumu and Nakuru kept a grid of forty low-cost sensors reporting — and produced the longest continuous public air-quality dataset any of these cities has ever had. What it recorded were the episodes a single reference monitor, when it works, routinely misses: morning spikes along the corridor roads, evening plumes over the informal settlements, the slow accumulation of bad air that a city learns to call normal.
A problem you can measure is a problem you can end.
The gap is not scientific; it is fiscal. County air-quality monitoring is mandated. The line item does not exist. So the burden drifts to volunteers and research grants — heroic, and unsustainable.
Our recommendation to county assemblies is blunt: fund the monitors, then publish the data in the open where the profession can argue with it. A monitoring network for a county costs less than a single kilometre of tarmac. The health returns compound for a generation. Of everything in Kenya’s environmental agenda, this is the most measurable problem — and the most solvable.