A cohort study of 1.9 million infants links exposure to fine particulate matter (PM2.5) to an increased risk of emergency department visits during the first year of life, with preterm and full-term infants being most susceptible during their fourth and fifth months.
An assessment on exposure to fine particulate matter (PM2.5) and emergency department (ED) visits during the first year of life yielded a positive association between PM2.5 exposure and all-cause, infection-related, and respiratory-related emergency department visits.1
The risk of emergency department visits was elevated for both preterm and full-term infants, with the greatest odds of all-cause emergency department visits occurring during the fourth and fifth months of life. The investigation also evaluated the susceptibility of preterm infants to adverse events of PM2.5 exposure.
Findings showed that for each 5-μg/m3 increase in PM2.5 exposure, the odds of an emergency department visit for any cause were greater among both groups of infants. Elevated odds were also observed for infection-related and respiratory-related ED visits.
Preterm and full-term infants, ages 18 to 23 weeks were associated with the greatest odds of all-cause ED visits. The study concludes that increased PM2.5 exposure was associated with an increased risk of ED visits for both preterm and full-term infants during the first year of life, suggesting that strategies aimed at reducing PM2.5 exposure for infants may be warranted.
Anaïs Teyton, MPH, Herbert Wertheim School of Public Health and Human Longevity Science, University of California, San Diego, and investigators stated that the findings of this study were consistent with previous research linking air pollution to adverse health outcomes in infants and children.
Exposure to air pollution has been associated with increased risk of respiratory infections, asthma, and other respiratory diseases in children. Preterm infants are known to be at increased risk of respiratory illnesses and other health problems. These findings indicated that they may be more susceptible to the adverse events of air pollution.
The individual-level cohort study analyzed data from the Study of Outcomes in Mothers and Infants cohort. A total of 1,983,700 infants born in California between 2014-2018 were included.
Investigators employed an ensemble model which combined multiple machine learning algorithms to estimate weekly PM2.5 exposure at the infants’ residential ZIP code at birth. Logistic regression models with a discrete time approach were used to assess PM2.5 exposure and time to emergency department visits during each week of the first year of life and across the entire year.
The study assessed preterm birth status, sex, and payment type for delivery as effect modifiers.
There were multiple strength of this study, including a large sample size and use of machine learning algorithms to estimate PM2.5 exposure. However, the study also has some limitations. Other air pollutants, such as nitrogen dioxide, which may also contribute to adverse health outcomes, were not considered.
Additionally, the investigation relied on emergency department visits as a proxy for health outcomes, which may not have captured all instances of illness or disease. There was no investigation of potential mechanisms underlying the association between PM2.5 exposure and ED visits, and more research is needed to understand the biological pathways through which air pollution affects health.
Investigators concluded that increased exposure to PM2.5 is associated with an increased risk of ED visits for both preterm and full-term infants during the first year of life, and the team acknowledged the need for continued efforts to reduce air pollution and improve air quality, particularly in areas with high levels of pollution.
Furthermore, a better understanding is needed regarding the mechanisms underlying the association between air pollution and health outcomes, and to identify effective interventions to reduce the adverse events of air pollution on infants and children.