Ambient particulate matter pollution and lung function among informal transport workers in Ghana

While fine particulate matter (PM2.5) is considered more harmful than coarse PM10, the relative health effects on lung function in high exposure occupational settings remains sparsely studied. We investigated the association between PM2.5 and PM10 with lung function among informal transport workers in Accra, Ghana. This population based cross-sectional study was conducted at two major transport stations over several months. Lung function was assessed with spirometry and assigned ambient PM exposures using long-term monitoring station data. To characterize long-term exposure, each participant was assigned the average ambient PM2.5 and PM10 concentrations for their study location corresponding to the month of their lung function. Modified Poisson regression with cluster-robust standard error was used to estimate adjusted prevalence ratios for air flow limitation (FEV1/FVC < 70%), controlling for demographic, occupational, lifestyle and meteorological confounders. A high prevalence of airflow limitation was observed. Increased exposure to coarse PM was associated with increased prevalence of airflow limitation, while fine PM showed a weaker relationship. Being overweight, consumer of alcohol, and higher ambient temperatures had protective associations in some analyses, whereas smoking was linked to airflow limitation in specific locations. Findings indicate that coarse PM was consistently associated with airflow limitation. This suggests that in urban transport stations coarse PM may be a critical but overlooked target for respiratory health protection policies.