| dc.description.abstract | Air pollution studies in Nairobi are indicating a rising trend in the particulate matter loading. The trend is mainly attributed to increased volume of motor vehicles, the physical change of the environment, agricultural and industrial activities. In this study, total suspended particulate matter sampling at the Nairobi industrial area and inside one workplace are reported. Included also are the results of analysis of water samples and effluents collected from a sugar factory, a tannery, and mercury (Hg) analysis in some beauty creams sold in Nairobi. The samples were analysed for heavy metal content using Energy Dispersive X-ray Fluorescence (EDXRF) while the suspended particulate matter (SPM) concentrations were determined by gravimetric technique. Total reflection x-ray fluorescence (TRXF), atomic absorption spectrophotometry and PIXE analytical techniques plus the use of Standard and Certified Reference Materials (SRM's and CRM's) were used for quality control, analysis and evaluation of the accrued data. Air sampling in the industrial area was done twice (Wednesday and Saturday) every week for a period of two months (November and December, 1996) and twice monthly for a period of six months (January-June 1997). Each sample covering approximately 24 hours, was collected using the 'Gent' Stacked Filter Unit (SFU), for day and night times. The SPM were found to vary from 16 to 83 mgm-3 during the sampling period. The analysis of dust collected inside a workplace showed that there was poor filtration of the air pumped into the building and that there was a need for improvement of the air conditioning unit plus reduction of emissions from a neighbouring tyre factory. Beauty creams analysed showed that there is some mercury present in significant amounts (0.14 - 3.0%). The results of these mercury levels are presented for various brands of cosmetics sold in some market outlets in Nairobi. The health implications on the presence of mercury in some of these beauty creams is also discussed. The presence of sulphur (0.9-439 μg/ml) in the water samples from the River Nyando showed that waste from the factories was certainly affecting the water quality of the river. These high levels were registered at a waste treatment pond in the factory. Heavy metal analysis of the water samples collected from River Nyando along the sugar and agro-chemical food industries showed phosphorus and lead (Pb) were below detection limits which ranged from 30-180 μg/ml and 30-150μg/ml respectively. The occurrence of these high levels of sulphur during some sampling visits, suggests some random release of industrial wastes into the river and poor effluent control measures by the industries. Other parameters affected by the industrial wastes included the conductivity, salinity and BOD. From this study, it is evident that industrial activities and some of their products, motor vehicles and the physical change of the environment are contributing significantly to environmental pollution in Kenya. Particulate matter loading and lead (Pb) levels are found to be higher than those from a previous studies. Whereas it is difficult to pinpoint the exact cause of these increases, the increase in motor vehicle volume, worsening state of our roads, lack of an effective inspection and maintenance programme of motor vehicles and industries in the country, lack of enforcement, supervision and implementation of the Kenya Factory Act provisions, are some of the major causes of this increase. There is therefore a great need for further studies geared towards epidemiological investigations especially among the factory workers, the children and the elderly | en_US |
