Outdoor respirable particulate matter and the lung function status of residents of selected communities in Ibadan, Nigeria

Abstract

Background: Ambient air pollution remains a major public health hazard in urban communities. In Nigeria, air quality management especially in the urban centres, is fraught with enormous challenges including limited data. We assessed the outdoor respirable particulate matter (PM10) concentration and the pulmonary function status of residents in four selected communities in Ibadan. Methods: A cross-sectional study design was employed. Four locations – Ojoo Park (OP = high traffic area), Bodija Market (BM = commercial area), Oluyole Estate (OE = industrial area) and the University of Ibadan (UI = academic community – reference) – were selected based on varying intensities of urban activity. PM10 levels were recorded in the morning and afternoon for 12 weeks between January and March 2008. Lung function status (FEV1) of 140 randomly selected participants was measured. Daily mean of PM10 levels were compared with WHO guideline limits. Data analysis was done using descriptive, χ2, ANOVA and Spearman-rank correlation tests at 5% level of significance. Results: For all sites, PM10 concentration was generally higher in the afternoon. The highest daily mean PM10 concentration was recorded at BM, followed by OP, OE and UI. These values when compared with WHO guideline limits showed: BM eightfold > OP sevenfold > OE sixfold > UI fivefold ( p < .05). Weekly mean PM10 levels and mean FEV1(obs) gave the following order: UI > OE > OP > BM. There was a significant negative correlation between PM10 burden and FEV1(obs) across the study locations ( r =-0.371, p < .05). Conclusion: Most of the locations with higher particulate burden were observed to have declining lung function status. A longitudinal study to establish more robust associations is advocated.