Children 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 aimed to assess the feasibility and outcomes of joint ambulatory monitoring of exposure to fine particulate matter (particles with a diameter of less than 2.5 µm (PM_2.5)) and spirometry in children living in Abidjan, Côte d’Ivoire.

We did a cross-sectional observational study among children aged 7–17 years. After a baseline spirometry, children were asked to wear portable PM_2.5 sensors and to perform 2x3 daily flow–volume curves using a portable spirometer for 7 days. We described the proportion of acceptable measurements, per cent predicted forced expiratory volume (ppFEV₁), and hourly geometric mean PM_2.5 concentrations, and analysed the cumulative delayed effects of PM_2.5 on ppFEV₁ using distributed lag non-linear models.

Of 29 children enrolled, 18 (62.1%) were female, median age 12 years, all performed spirometry with 1101 (90.4%) of 1218 expected flow-volume curves obtained. Of these, 625 (51.3%) acceptable curves were received and 313 valid, non-duplicate curves were analysed. The median ppFEV₁ was 79.6% (71.5–87.4), with lower values in the morning than in the evening (p2.5 measurements, 93 689 (64.1%) were obtained; 6328 aberrant data were excluded. The median hourly PM_2.5 concentrations were 164.2 (107.0–272.2) µg/m³. PM_2.5 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 IQR increase of 120.9 µg/m³ in PM_2.5 exposure (β=–2.21; CI –3.74 to –0.69).

Ambulatory spirometry and PM_2.5 measurements are feasible with portable devices in African children. High PM_2.5 exposure and individual variability in lung function highlight the need for further research on the respiratory effects of air pollution in children.