Assessment of health impacts of vehicular pollution on occupationally exposed people in Lagos metropolis, Nigeria

This study assessed the concentration of Nitrogen Oxide (NOx), Sulphur Oxide (SOx), Carbonmonoxide (CO), Benzene, Toluene, MP-Xylene and O-xylene (BTEX,) Total Suspended Particulate, (TSP) and Particulate Matter (PM; PM10 and PM2.5) in the ambient air at selected locations in Lagos, Nigeria. The health impact of these pollutants was investigated among exposed group of people (especially CarbonmonoxyHemoglobin (COHb), and pulmonary function). The health profile of the general populace was also examined for cases of ailments related to air pollution. The mean level of TSP was lowest at Unilag (130.6 +/- 44.5 ug/m(3)) the control, while the highest concentration was measured at Mazamaza (1171.7 +/- 355.1 ug/m(3)) throughout the study period. The CO level measured was in the order of Ikotun (3.40 +/- 1.3 ppm) > Ikeja (1.70 +/- 0.4 ppm) > Unilag (0.10 +/- 0.0 ppm). Mean SO2 concentration ranged with a highest value at Oshodi (116.3 +/- 27.3 ppb) to a lowest level at Unilag (9.40 +/- 0.9 ppb) while the NO2 concentration ranged from a highest value of (138.6 +/- 78.4 ppb) for Oshodi to a lowest value of (8.76 +/- 3.0 ppb) for Unilag. The concentration of gaseous pollutants that are linked with cancers; benzene, Toluene, MP-Xylene and O-xylene showed the highest level at Mazamaza. At this location, the concentrations of the pollutants were in the order of 17.58 +/- 8.8, 36.92 +/- 19.6, 21.57 +/- 10.5 and 8.03 +/- 3.9 (ppb), respectively. On the other hand, Unilag had the lowest level of each of these pollutants (3.47 +/- 3.84, 5.3 +/- 6.0; 3.37 +/- 3.4 and 1.27 +/- 1.5 ppb). ANOVA result showed that each pollutant varied significantly among the selected locations (p < 0.05). The broad-profile of diagnosed health problems among residents that visited public hospitals showed high prevalence of upper respiratory tract infection (45.3%) followed by asthma (18.9%), broncho-pneumonia (14.8%) and pneumonia (5.6%). For more than 30% of the occupationally exposed, exposure had lasted 6 - 10 y, accounting for the higher concentration of CO (1.18 +/- 0.43 ppm) in their breath compared to the control (0.63 +/- 0.59 ppm).