Assessment of Traffic-Related Air Pollution: Case Study of Pregnant Women in South Texas

Traffic-related air pollution is associated with spontaneous extremely preterm birth and other adverse perinatal outcomes

BACKGROUND

Although there is growing awareness of the relationship between air pollution and preterm birth, limited data exist regarding the relationship with spontaneous preterm birth and severe neonatal outcomes.

OBJECTIVE

This study aimed to examine the association between traffic-associated air pollution exposure in pregnancy and adverse perinatal outcomes including extremes of preterm birth, neonatal intensive care unit admissions, low birthweight, neonatal respiratory diagnosis, neonatal respiratory support, and neonatal sepsis evaluation.

STUDY DESIGN

This was a retrospective cohort study of singleton pregnancies of patients residing in a metropolitan area in the southern United States. Using monitors strategically located across the region, average nitrogen dioxide concentrations were obtained from the Environmental Protection Agency Air Quality System database. For patients living within 10 miles of a monitoring station, average exposure to nitrogen dioxide was estimated for individual patients' pregnancy by trimester. Logistic regression models were used to assess the effect of pollutant exposure on gestational age at birth, indicated vs spontaneous delivery, and neonatal outcomes while adjusting for maternal age, self-reported race, parity, season of conception, diabetes mellitus, body mass index, registered Health Equity Index, and nitrogen dioxide monitor region. Adjusted odds ratios and 95% confidence intervals were calculated for an interquartile increase in average nitrogen dioxide exposure.

RESULTS

Between January 1, 2013 and December 31, 2021, 93,164 patients delivered a singleton infant. Of these, 62,189 had measured nitrogen dioxide exposure during the pregnancy from a nearby monitoring station. Higher average nitrogen dioxide exposure throughout pregnancy was significantly associated with preterm birth (adjusted odds ratio, 1.94; 95% confidence interval, 1.77-2.12) and an increase in neonatal intensive care unit admissions, low birthweight infants, neonatal respiratory diagnosis, neonatal respiratory support, and neonatal sepsis evaluation. This relationship persisted for nulliparous patients and spontaneous preterm birth, and had a greater association with earlier preterm birth.

CONCLUSION

In a metropolitan area, increased exposure to the air pollutant nitrogen dioxide in pregnancy was associated with spontaneous preterm birth and had a greater association with extremely preterm birth. A greater association with neonatal intensive care unit admissions, low-birthweight infants, neonatal respiratory diagnosis, neonatal respiratory support, and neonatal sepsis evaluation was found even in term infants.

Publication trends in research on particulate matter and health impact over a 10-year period: 2009-2018

Exposure to ambient particulate matter is a major health risk factor for numerous diseases, including those of the cardiovascular and respiratory varieties. The aim of this study was to estimate the latest global research activities regarding particulate matter and health impact. We performed a bibliometric analysis of this field's scientific publication trends over a decade (2009-2018). Publications were retrieved from the Scopus and Web of Science databases using the search terms "particulate matter," "fine particulate matter," "health impact," and their synonyms. The literature on health impact in the research fields of particulate matter (PM10) and fine particulate matter (PM2.5) trended to significantly increase over the decade in consideration. It appears to have been led by researchers of the United States and China. Worldwide research on particulate matter and health effects has focused primarily on respiratory and cardiovascular diseases. The precursors to and components of particulate matter (such as nitrogen dioxide, polycyclic aromatic hydrocarbon, sulfur dioxide, and black carbon) were also popular research topics in this field. Research on children, older adults, and pregnant women, who are most vulnerable to the health effects of air pollution, has increased dramatically over the past 10 years. Our findings provide the information necessary to predict unmet research topics and future research needs.

Near-Road Traffic-Related Air Pollution: Resuspended PM2.5 from Highways and Arterials

Recent studies suggest that the transportation sector is a major contributor to fine particulate matter (PM_2.5) in urban areas. A growing body of literature indicates PM_2.5 exposure can lead to adverse health effects, and that PM_2.5 concentrations are often elevated close to roadways. The transportation sector produces PM_2.5 emissions from combustion, brake wear, tire wear, and resuspended dust. Traffic-related resuspended dust is particulate matter, previously deposited on the surface of roadways that becomes resuspended into the air by the movement of traffic. The objective of this study was to use regulatory guidelines to model the contribution of resuspended dust to near-road traffic-related PM_2.5 concentrations. The U.S. Environmental Protection Agency (EPA) guidelines for quantitative hotspot analysis were used to predict traffic-related PM_2.5 concentrations for a small network in Dallas, Texas. Results show that the inclusion of resuspended dust in the emission and dispersion modeling chain increases prediction of near-road PM_2.5 concentrations by up to 74%. The results also suggest elevated PM_2.5 concentrations near arterial roads. Our results are discussed in the context of human exposure to traffic-related air pollution.