Journal of Atmospheric Pollution, 2017, Vol. 5, No. 2, 62-68 Available online at http://pubs.sciepub.com/jap/5/2/4 ©Science and Education Publishing DOI:10.12691/jap-5-2-4 Particulate Matter from Motor Vehicles in Nairobi Road Junctions Kenya Samson Murangiri Mukaria * , Raphael G Wahome, Michael Gatari, Thuita Thenya, Kiemo Karatu Wangari Mathaai Institute, College of Agriculture and veterinary science, University of Nairobi *Corresponding author: sammurangi@yahoo.com Abstract 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. Keywords: particulate matters, PM 2.5 , motor vehicle pollution, exposure Cite This Article: Samson Murangiri Mukaria, Raphael G Wahome, Michael Gatari, Thuita Thenya, and Kiemo Karatu, “Particulate Matter from Motor Vehicles in Nairobi Road Junctions Kenya.” Journal of Atmospheric Pollution, vol. 5, no. 2 (2017): 62-68. doi: 10.12691/jap-5-2-4. 1. Introduction Motor vehicle road traffic is a critical basis of destructive discharges of particulate contamination in urban areas of the emergent world, where economic development, combined with an absence of powerful transportation and proper land utilization planning is bringing about expanding motor vehicle proprietorship and traffic overcrowding. These phenomenon and components combine to make air contaminations very high near roads. Urban development is required to proceed at a fast pace in the creating scene, especially in sub-Saharan Africa [1] as rustic populaces keep on migrating to urban communities looking for business and desires of better living conditions. In the event that nothing is done to diminish discharges and to better arrangement for urbanization, this pattern can be required to additionally worsen effectively genuine air worth issues in sub- Saharan African urban areas and in addition the wellbeing impacts that go with rising population. Fine particulate matter (PM 2.5 ), produced by fuel ignition (e.g., that of engine vehicles) has been connected to an widespread variety of health complication, putting in mind that more than 800,000 passing in urban communities around the globe becomes affected [2]. In any case, little data is available concerning levels of particulate air pollutions which occur in urban inhabitants in Africa. This information crevice blocks health sway appraisals, the improvement of financially savvy methodologies to lessen the health burden because of open air contamination and the capacity to impact urban mode of transport and arranging strategies related to air quality and health. Motor vehicle discharges incorporate a scope of toxins, including particulate matter (PM). PM 2.5 is of specific hugeness on the grounds that examination on health impacts in urban regions has shown relationship between both here and now and long haul normal surrounding PM 2.5 concentrations and an assortment of antagonistic health results. These incorporate expanded post neonatal newborn child mortality and unexpected losses identified with heart and lung maladies. On account of their little sizes, PM 2.5 particles can be inhaled into the lungs where they apply antagonistic impacts. In 2005, the World Health Organization (WHO), in acquaintance of known health impacts, set a 24-hour normal rule of 25 μg/m3 and a yearly normal rule of 10 μg/m 3 . PM 2.5 incorporates dark carbon (BC), or residue, which caused by inadequate burning sources which