Impact of fine particulate matter air pollution (PM2·5) on Nigerian children's performance on tests of cognitive and neurobehavioral development at age seven years

Abstract

BACKGROUND: Elevated exposures to fine particulate matter (PM2·5) air pollution threaten child health and development. Kerosene and biomass cooking fuels are a source of PM2·5 in sub-Saharan Africa. Potential impacts on child cognitive and neurobehavioral development require investigation.

METHODS: In a cross-sectional observational study, September 2021 - March 2023, we assessed cognitive and neurobehavioral development in 208 Nigerian seven-year-old children using the performance-based KABC-II (neurocognition) and two parent questionnaires: VABS-3 (adaptive behavior) and SDQ (psychological adjustment). We collected data on sociodemographic covariates. We conducted 48-hour PM2·5 (µg/m3) exposure monitoring twice using two RTI MicroPEM™ sensors: indoor (in-home) and personal (body-worn). We examined the relationship between mean PM2·5 exposures and child developmental assessment scores using multiple linear regression, adjusting for child's age and sex, mother/caregiver's age and education, and household wealth.

FINDINGS: A two-fold increase in mean personal PM2·5 exposures was associated with 3·04-unit lower (95 % CI: -4·62, -1·46; p < 0·001) KABC-II scores and 2·18-unit lower (95 % CI: -4·79, 0·43; p = 0·10) VABS-3 scores, after adjustment for covariates. Children in households using clean fuels scored higher on both assessments, although the differences were not significant after adjustment. Those in households using exclusively polluting fuel had lower KABC-II scores after adjustment (-4·07, 95 % CI: -8·12, -0·02; p = 0·049). We found no associations between PM2·5 levels or fuel types and SDQ scores.

INTERPRETATION: Elevated personal PM2·5 exposures during middle childhood are associated with lower developmental assessment scores in Nigerian seven-year-old children. Household use of polluting cooking fuels contributes to these exposures.