Abstract:
The greatest threat to human health and welfare in urban environments is air pollution; the population growth in Nairobi has continuously contributed to adverse implication on the transport system and traffic congestion. The increase in populatio n has been one of the key contributing factors to air pollution challenges among others which include; increased vehicle ownership, lack of proper traffic control and management, lack of good road planning and inefficient spatial distribution of land use. The fact is that air pollution has not been given any attention despite being the single most environmental world disaster due to lack of data hen ce no adequate policies governing the air quality in Kenya. Particulate matter (viz., PM2.5 and PM10) has become one of the prin cipal pollutants, according to recent news on health issues, air pollution related diseases have become a disaster worldwide. Recently, there have been increased cases of the air pollution-related diseases in Kenya. Therefore, this study has determined the concentration and likely health effects of particulate air pollutants. The PM10 and PM2.5 are at high concentrations (repirable particulate matter) above the permissible levels by EPA and EMCA. The main causal factors of PM2.5 and PM10 are untreated industrial emissions, geochemical processes and vehicular emissions. The concentration of PM10 and PM2.5 was established during morning and evenings for three days in a week during the study period. Sampling sites selected were categorized as industrial, controlled (CBD) and residential areas. Minivol air samplers were used for sample collection particulate matter. High concentrations were recorded during the day due to many activities during the day while low concentrations at night. Low concentrations at the weekends were observed compared to week days. The Minivol portable air sampler is an ambient air sampler for particulate matter. The concentrations of respirable particulate matter is above the permissible limits. (EMCA and EPA) while the composition of the particulate lead and aluminum is very high.