Environmental impact of vehicular traffic in Nigeria: health aspects.

Blood lead levels were analysed and pulmonary function tests were performed on Nigerian traffic wardens, comprising sixty from Lagos (ages 24-52 years; 27 +/- 6), thirteen from the sparsely populated university town of Ile-Ife (ages 22-40 years; 27 +/- 8) and a control group of twenty-four subjects (age 19-55 years; 31 +/- 8). Perkin-Elmer Zeeman 3030/HGA 600 AAS was used for blood analysis. The mean lead level in Lagos wardens was 18.1 +/- 6.4 micrograms/dl, which was significantly higher than the level of 10.2 +/- 2.7 micrograms/dl in Ife wardens and 12.9 +/- 7.0 micrograms/dl obtained in the controls (P < 0.001). However, there was no significant difference between the levels of blood lead in Ife traffic wardens and normal controls. Significant differences (P < 0.0005) in spirometric measurements--peak flow rate (PEFR), forced expiratory volume in 1 second (FEV1) and forced vital capacity (FVC)--were observed between traffic wardens and control subjects. The noise levels measured along traffic roads exceeded the threshold for hearing damage.