AMBIENT PM2.5 IN EAST AFRICA: A COMPREHENSIVE REVIEW OF DRIVERS, IMPACTS, MONITORING AND POLICY DIRECTIONS

Ambient fine particulate matter (PM₂.₅) has emerged as one of the most pressing environmental health challenges in East Africa, where rapid urbanization, industrial expansion, and reliance on biomass fuels converge to elevate exposure levels. Despite its recognized role in respiratory and cardiovascular morbidity, monitoring of PM₂.₅ across the region remains fragmented, with limited reference-grade stations and growing reliance on low-cost sensors and satellite-derived estimates. This review synthesizes evidence on PM₂.₅ monitoring approaches, key drivers, health and socio-economic impacts, and policy responses in East Africa. Literature from Kenya, Uganda, Tanzania, and Ethiopia points at transport emissions, informal settlements, and industrial clusters as dominant sources, while meteorological variability further shapes spatio-temporal patterns. Health studies consistently link PM₂.₅ exposure to increased prevalence of asthma, chronic obstructive pulmonary disease, and cardiovascular risks, with disproportionate burdens borne by vulnerable populations. Policy frameworks remain nascent, with weak enforcement and limited integration of air quality data into urban planning. The review identifies critical gaps in longitudinal monitoring, calibration of low-cost sensors, and linkage of health outcomes to exposure data. Addressing these gaps is very important for evidence-based interventions and for advancing regional air quality governance.