The study examined the spatio-temporal analysis of Lead (Pb) concentrations in bread in five selected bus terminals in Port Harcourt metropolis A total of one thousand and two hundred loaves of bread were exposed to air with two hundred in each bus terminals on Mondays and Fridays in the morning, afternoon, and evening for four weeks and used for laboratory analysis. Volume of vehicular counts was also determined in the morning, afternoon and evening across the selected bus terminals. Thirty samples of premium motor spirit (PMS) were randomly collected between July and September 2013 to determine the amount of Pb and octane rating present in the laboratory. The area of each bus terminal was determined by multiplying the length and the breadth of each bus terminals. Mean value of Pb concentration and octane ratings; the volume of vehicular counts, size of the bus was determined. ANOVA and regression analysis were used in the study. Result showed that the mean values of Pb concentrations in bread were highest in Flyover Mile 1 Park in the morning, afternoon and evening with a value of 0.464 g/g, 0.305g/g and 0.339g/g respectively. Generally, the Pb concentration in bread was highest in the morning (0.271g/g) and least in the evening (0.235g/g). A direct relationship existed between the concentration of Pb in bread in bus terminals and volume of vehicular counts (r2= 0.194). Similarly, the size of bus terminals accounted for 60.0% of the concentration of Pb in bread (r2 = 0.600). There was a significant variation in the Pb concentrations in bread recorded in the morning, afternoon and evening as F calculated was 10.451 at 0.5 significance level. Similarly, there was a significant variation in the Pb concentrations recorded in the selected locations as F calculated was 10.788 at 0.5significance level. Policy measured aimed at stopping the sale of bread at the bus terminals and the use of leaded petrol in the city is advocated.
Keywords: Bus terminals, Lead (Pb) concentration, Port Harcourt, Spatio-temporal, White bread
