Samson Murangiri Mukaria^1,, Raphael G Wahome¹, Michael Gatari¹, Thuita Thenya¹, Kiemo Karatu¹

Motor air pollution has become a problematic issue both within as it contributes to environmental degradation. It is evident that air crises in cities continue to rise partly because of the increasing levels of motor vehicle emissions. With the expansion of the economic base, cities such as Nairobi also expand paving the way for an increase in motor vehicle ownership and use, which lead to higher rates of pollution. Given that exposure to pollutants is harmful to human health, the traffic police are vulnerable because members are constantly uncovered to motor vehicle fumes. The survey interviewed a purposive and non-random stratified sample of 127 police officers, according to their seniority, years of employment and work experience, from the target population of traffic police working in major road junctions within the CBD, Nairobi Kenya. The sampled junctions were Kamukunji, Railways terminal, University way and Uhuru roundabouts. In addition, from the leadership rank, five (5) key informants were also interviewed. Data was collected using self-administered questionnaires. Discussions were held with the key informers. The findings show that there are that the high concentrations of PM2.5 in Nairobi major roundabouts is attributed to vehicular traffic congestion and worsened with poorly maintained and old vehicles. The significantly high values obtained compared to World Health Organization 24 hr guideline of 25 µg m-3 (2000) creates a severe health issues to regular pedestrians and workers around those areas. The study exposes that there are association between fine particulates and motor vehicles (r = 0.93), signifying that vehicular emissions is foremost source of fine particles in the atmosphere.

particulate matters, PM_2.5, motor vehicle pollution, exposure