This New Investigator Award study seeks to examine associations of long-term maternal exposures to PM2.5, NO2, and environmental noise with adverse birth outcomes in Accra, Ghana. The investigators also seek to determine the effect of these exposures on the risk of lower respiratory infections in infants.
Poster abstract for HEI Annual Conference 2023
Urban Air Pollution in Sub-Saharan Africa: A Study of Prenatal Exposures, Birth Outcomes, and Lower-Respiratory Infections in Infants
Raphael E Arku
Department of Environmental Health Sciences, School of Public Health and Health Sciences, University of Massachusetts, Amherst, USA
Background. Growing cities in sub-Saharan Africa (SSA) experience high levels of ambient air pollution from a complex mix of sources, which strongly influence the pollutant mixture and patterns. Additionally, urban noise pollution is also an emerging public health concern in growing SSA cities. However, sparse long-term city-wide air pollution data limits policy mitigation efforts and assessment of the health and climate effects. In the first study of its kind in West Africa, we combined large-scale field measurement at 146 monitoring location with geographical and population variables in models and mapped fine-scale spatiotemporal variations and inequalities in ambient fine particulate matter (PM2.5), black carbon (BC) and oxides of nitrogen (NO/NO2) concentrations and environmental noise in the Greater Accra Metropolitan Area (GAMA). GAMA is one of the fastest sprawling metropolises in SSA and home to about six million residents. Research mostly from populations in exposure settings quite different from those in urban SSA has demonstrated that these pollutants affect children in uniquely damaging ways, including death in infancy, and presents future health and socioeconomic risks to survivors. Lack of data in SSA population represents a major gap in our global knowledge on air pollution health effects. Leveraging our unique GAMA dataset, this study aims to quantify the effects of long-term maternal and early prenatal exposures to PM2.5 and NO2 (and their interaction with environmental noise) pollution on preterm birth, term birthweight and term low birthweight in Accra, Ghana. The study also aims to assess the impact of those exposures on respiratory infections in infants.
Methods. The study population involves ~1,500 pregnant women to be recruited at antenatal care clinics of major facilities in Accra. We have identified ~30 facilities that are well distributed geographically across the GAMA AND have recorded at least 1000 births/year in 2021, resulting in roughly 60,000 births annually across these facilities. We will recruit participants from the 30 facilities to have a more representative sample in terms of the population, exposures, and season. We will geocode maternal residence and collect other individual and household level covariates. Birth outcomes and pregnancy-specific and routine medical history will be documented. Following birth, project nurses trained by a respiratory physician will follow the infants via bi-weekly phone calls to document episodes of respiratory infections within the first 18th month of life. All documented episodes, symptoms, and diagnosis as assessed by the study nurses will be adjudicated by the physician, and then classified them according to WHO case definition.
Results. Both air and noise pollution levels in Accra far exceeded international guidelines and varied widely by spatial and temporal factors. The city core and densely populated and poorer areas experience the highest levels. Associations of the annual, seasonal, and trimester specific exposures with the birth and respiratory outcomes will be examined.