Abstract

Shipping activities are a major source of air pollution in port cities with the expected high population of port workers and related workforce being chronically exposed to air pollutants such as carbon monoxide (CO) and suspended particulate matters (SPM:PM10). These two priority air pollutants in addition to relative humidity (RH) and wind speed were monitored every month over a period of four years at Tin Can, Apapa Lagos, being the location of the busiest port in Nigeria. Results indicate that the highest monthly mean concentrations recorded throughout the study were 3.31 ppm and 258.6 µg/m3 for CO and PM10, respectively. While the value of CO was within the recommended threshold limits by the World Health Organization (WHO) and the Federal Ministry of Environment (FMEnv), the PM10 exceeded the WHO specified limit of 50 µg/m3 for a –24 h period of exposure. The ambient concentrations of the two air pollutants were higher in the dry season than their concentrations in rainy season. However, a significant seasonal variation was observed in the ambient concentrations of PM10. Regression analysis shows that wind speed contributes significantly (p<0.05) to the detectable concentration of CO while RH had no significant influence on CO availability in the study area. Conversely, RH significantly influenced the concentration of PM10 with a direct positive correlation between the climatic index and particulate matter while wind speed had no significant influence on suspended particles. The study established that there is no risk of acute human exposure to the air pollutants in the ports area. In spite of the low ambient concentrations recorded during the study, chronic exposure of workers or residents in port areas has its long-term health implications. Further study is required to monitor the indoor concentrations of these pollutants, which were possibly dispersed by wind from the lagoon and the ocean.