Queen's University Belfast

Academic Institute

Neil Rowland

E052

Maternal exposure to outdoor air pollution during pregnancy is associated with a range of adverse birth outcomes. However, it is not clear what causes this relationship, nor is it clear how far it represents the effects of unobserved confounding factors associated with both infant health and pollution exposure. Additionally, less is known about the effects of certain pollutants, and about the effects of pollution on certain infant health outcomes. To address these literature gaps, this project will link province-wide outdoor air pollution data to Northern Ireland Maternity Service (Northern Ireland Regional Maternity system (NIMATS)) data to investigate whether babies are harmed by the level of pollution their mother is exposed to during pregnancy. The Northern Ireland Regional Maternity system (NIMATS) contains demographic and clinical information on infants and mothers, including numerous birth outcomes and the mother’s Admissions and Dischargest medical and obstetric history. Infant health will be measured in multiple ways, including outcomes at birth (e.g. birth weight) and outcomes after birth (e.g. experience of any respiratory-related postnatal health complications). Pollution exposure will be defined as the annual average level of outdoor air pollution at a mother’s postcode address in the year of pregnancy. Variables describing a mother’s health status and demographic characteristics, collected routinely during a mother’s contact with maternity services, will be used to provide contextual information for each birth. Additionally, rainfall and temperature data will also be linked to account for the influence of weather conditions on pollution levels. The relationship between pollution exposure and infant health will be measured using regression analysis.

To understand which steps people can take to improve their infant’s health, a scientific understanding of how these pollutants affect infant health is required. Although the academic literature offers guidance, it is not clear whether findings from studies conducted in other countries can be generalized to the Northern Ireland context. It is therefore important to develop a domestic evidence base that can be used to inform domestic policymaking. This project hopes to provide such evidence. No published study or report has investigated the impact of maternal pollution exposure on infant health in Northern Ireland. However, one study has examined the relationship between air pollution and child health more generally. Thompson (2001) measured the relationship between daily emergency admission rates for acute asthma episodes at the Royal Belfast Hospital for Sick Children and daily fluctuations in average pollution levels in Belfast. They found that Benzene was the only pollutant independently associated with admission rates. Note, however, that this study used aggregated data – not person-level data – and focused on one particular outcome (asthma exacerbations). The present study will complement Thompson’s study and offer unique evidence for Northern Ireland about the health impacts during the early stages of life.

04/10/2019

TRE