Feasibility and results of joint PM2.5 and lung function ambulatory monitoring in children, a cross sectional observational study, Abidjan

BackgroundChildren are largely exposed to air pollution in low- and-middle income countries, yet data on exposure and respiratory effects of air pollution remain limited. This study aims to assessed the feasibility and outcomes of joint portable PM2.5 monitors exposure and together with ambulatory spirometry in children living in Abidjan. MethodsCross-sectional observational sub-study among children aged 7-17 years: children were asked to wear a portable PM2.5 sensors and to perform 2x3 daily flow-volume curves using a portable spirometer for 7 days. We described the proportion of acceptable measurements, ppFEV1, and hourly geometric mean PM2.5 concentrations. ResultsAll 29 children (18 (62.1%) female, median age 12 years) performed spirometry with a median of 36 [29-42] curves per child, and 1101 (90.4%) of 1218 expected flow-volume curves obtained; 313 (28.4%) valid non-duplicate curves were analyzed. The median ppFEV1 was 79.6% [71.5-87.4]. The values of ppFEV1 in the morning were lower than in the evening (p < 0.001). Of 146,160 expected PM2.5 measurements, 93,689 (64.1%) were obtained; 6,328 aberrant data were excluded. The median hourly PM2.5 concentrations were 164.2 [107.0 - 272.2] {micro}g/m3. PM2.5 levels varied throughout the day with pollution peaks observed in the morning. A significant decrease in ppFEV1 was observed between 0 and 2 hours post-exposure, after an interquartile range increase of 120.9 {micro}g/m3 in PM2.5 exposure ({beta} = -2.21; CI [-3.74; -0.69]). ConclusionAmbulatory spirometry and portable PM2.5 measurements are feasible in African children. High PM2.5 exposure and individual variability highlight the need for further research on lung function and air pollution effects.