Ngeno,NoahKitur, Esther2026-04-212026-04-212026-04Ngeno, N., & Kitur, E. (2026). Distance-decay Relationships of Air Pollutant Concentrations Near Open Waste Burning Sites in Nairobi, Kenya: Evidence from Kibera. Asian Journal of Geographical Research, 9(2), 125–147. https://doi.org/10.9734/ajgr/2026/v9i23902582-2985https://ir-library.ku.ac.ke/handle/123456789/32947Research ArticleOpen waste burning in informal settlements contributes to localized air pollution, posing significant health risks. This study investigated the distance-decay relationship of air pollutant concentrations near open waste burning sites in Kibera, Nairobi City County, Kenya. Air samples were collected at 21 sampling points across three distance ranges (0–500 m, 500–1000 m, and >1000 m) from active burning sites over a two-month period in 2025. Pollutants measured included PM₂. ₅, SO₂, CO₂, and CH₄, using calibrated portable and fixed air quality monitors. Data were analyzed using linear regression and one-way ANOVA to examine relationships between pollutant concentrations and distance. PM₂. ₅ levels were highest within 0–500 m, reaching 150 µg/m³ ten times the WHO 24-hour guideline of 15 µg/m³ and decreased to 45 µg/m³ beyond 1000 m. SO₂ exhibited a similar decline from 55 ppb to 15 ppb. Regression analysis indicated a significant negative relationship between distance and pollutant concentration (R² = 0.530), while ANOVA confirmed differences across zones (F = 49.521, p < 0.001). CO₂ and CH₄ showed more gradual declines but remained...enArticle