Prenatal Exposure to Ambient PM2.5 and Early Childhood Growth Impairment Risk in East Africa

Abstract

Height for age is an important and widely used population-level indicator of children's health. Morbidity trends show that stunting in young children is a significant public health concern. Recent studies point to environmental factors as an understudied area of child growth failure in Africa. Data on child measurements of height-for-age and confounders were obtained from fifteen waves of the Demographic and Health Surveys (DHS) for six countries in East Africa. Monthly ambient PM_2.5 concentration data was retrieved from the Atmospheric Composition Analysis Group (ACAG) global surface PM_2.5 estimates and spatially integrated with DHS data. Generalized additive models with linear and logistic regression were used to estimate the exposure-response relationship between prenatal PM_2.5 and height-for-age and stunting among children under five in East Africa (EA). Fully adjusted models showed that for each 10 µg/m³ increase in PM_2.5 concentration there is a 0.069 (CI: 0.097, 0.041) standard deviation decrease in height-for-age and 9% higher odds of being stunted. Our study identified ambient PM_2.5 as an environmental risk factor for lower height-for-age among young children in EA. This underscores the need to address emissions of harmful air pollutants in EA as adverse health effects are attributable to ambient PM_2.5 air pollution.

Keywords: East Africa; PM2.5; height-for-age; stunting.

Figure 1

Schematic diagram of the inclusion criteria for the final sample size.

Figure 2

Seasonal trend of prenatal PM_2.5 exposures stratified by child’s month of birth and by country. The horizontal black line shows the overall PM_2.5 population average (25.83 μg/m³), five times above the WHO annual recommended maximum level of 5 μg/m³.

Figure 3

Height-for-age standard deviation by child’s month of birth for each country.