Assessment of Heavy Metal and Hydrocarbon Contamination in Selected Bus Stations in Nairobi

The project “Assessment of heavy metals and hydrocarbons in dust in selected bus stations in Nairobi” aims to investigate the selected bus stations in Nairobi may be a significant source of air pollution in the city. The selected bus station that act as the sample locations include Machakos Country bus, Railway bus station, Westlands, Ngara and Donholm bus stations. The research and study also aimed at comparing the selected bus stations in terms of pollution to find out which type of motor vehicle produces the most pollution and whether there is an effective way to reduce the amount of pollution drastically. The data obtained quantifies hydrocarbons and heavy metals in order to obtain the level of pollution. In the study of heavy metals, the Atomic absorption spectroscopy method was used to find the existence of heavy metals such as Copper, Cadmium and Arsenic. For the study of hydrocarbons, the Gas chromatography-Mass spectroscopy was used for analysis. Hydrocarbons that were investigated include Total petroleum hydrocarbons and BTEX. In addition to these hydrocarbons, oil and grease was investigated using the Hexane Extractable Material (HEM). The method used the gravimetric method using the Soxhlet apparatus.

This particular project was possible due to the fact that dust, a particulate matter acts as a vector for many pollutants including solid and liquid chemicals due to the interaction with atmosphere. Some literal work that use almost the same concept as this particular project include a research study carried out from the EPA’s Nationwide Urban Runoff Study in the 1980’s.from this particular work, close monitoring was done and two major researches stood out for their work. Schueler and Shepp’s work aimed to look for what they termed as hotspots. They however focused on gas stations, convenience stores, all day parking lots and residential parking areas.

This study revealed that there are hydrocarbons e.g. nonadecane and heavy metals e.g. lead in these selected areas. The recommendation would be to find more environmental friendly fuels for these motor vehicles.

Fourth Year Projects-2014-Waiyigo.pdf10.44 KB