LEAD ACCUMULATION IN THE ROADSIDE SOILS FROM HEAVY DENSITY MOTOR WAY TOWNS OF EASTERN ETHIOPIA

The levels of lead pollution in the roadside soils of the heavy density motor ways of Eastern Ethiopia, in particular; Modjo, Bishoftu and Adama towns were studied. Soil samples were collected from a total of 22 sampling sites while the control samples were obtained from places about 1 km away from the main roads of each town. Concentrations of lead, in soil samples, were determined using flame atomic absorption spectrometer and the average concentrations of lead were found to be 93.3 +/- 1.0, 79.4 +/- 0.6 and 80.6 +/- 0.4 mu g/g for Modjo, Bishoftu and Adama towns, respectively. The concentrations of lead in soils sampled 1 km away from the main road for each town were: 13.5 +/- 0.3, 19.6 +/- 0.7 and 20.8 +/- 0.8 mu g/g for Modjo, Bishoftu and Adama towns, respectively. The contamination factors for the average lead concentrations of Modjo, Bishoftu and Adama towns were 6.9, 4.0 and 3.8, respectively. Besides, the correlations between the lead level and the traffic density of the corresponding roads were found to be r (4) = 0.82, p < 0.05 for Modjo, r (5) = 0.32, p < 0.05 for Bishoftu and r (9) = 0.81, p < 0.05 for Adama.