Spatial Distribution and Environmental Implications of Informal Automobile Workshops in Osogbo, Nigeria

The increasing rate of informal establishments as well as their effects on their immediate environment requires scientific inquiry. It is against this background that this study analyses the spatial distribution and environmental health implications of informal automobile workshops in Osogbo, Nigeria. It also compares the effect of selected informal automobile workshops in different parts of the city. This is with a view to formulating strategies for improving the spatial characteristics of the informal automobile workshops, and reducing their impact on the environment both in the study area and other similar Nigerian cities.
A survey of major roads in the study area was carried out. Thereafter, these roads were functionally classified and thirteen of them were purposively sampled. Questionnaire was administered to automobile artisans in the twelve informal workshops identified on both sides of the selected roads. A more intensive study was carried out in four (4) relatively established informal automobile workshops from which appropriate samples were collected. This intensive study includes the collection as well as analysis of noise levels, air, water and soil samples for the determination of various contaminants emanating from the informal automobile workshops. Elements tested for in soil and water samples include Lead (Pb), Cadmium (Cd) and Iron (Fe) among others, while air sample was tested for CO2, CO, H2S and CH4. Noise levels from different informal automobile workshops were also determined. Results of the analysis were compared with those obtained from control samples as well as relevant standards. The health impacts of the workshops on residents were evaluated with the aid of questionnaire administered within 300 meters radius from the selected informal automobile workshops. Arcview GIS 3.2a was used in the analysis of geographical data (coordinates) to generate maps and distances between workshops, while nearest neighbor index was used to explain their spatial distribution pattern. ANOVA was used to test variations in the environmental effects of automobile activities in the selected workshops.
The study reveals that there is a total of 69 informal automobile workshops along major roads in Osogbo. With Rn index of 1.02(1st order), 1.60 (2nd order),