Air Pollution and Serum Interleukin-6 in Children

• In Event: Poster Session 04
  In Poster Session: PS 04 Topic - Biological Processes: Psychophysiology

Abstract

Background: Inflammatory cytokines such as interleukin-6 have increasingly gained attention as biomarkers linked to stress exposure and predictive of future disease (Miller, Chen, & Parker, 2011; Rohleder, Aringer, & Boentert, 2012). However, we lack a complete understanding of the relevant factors that are associated with elevated inflammatory markers, such as the impact of environmental contaminants. For instance, air pollution has been linked to increased risk of physical health problems with inflammatory underpinnings such as asthma and heart disease (Brunekeef & Holgate, 2002). Children may be especially susceptible to the effects of air pollution, given that, compared to adults, they have a higher intake of contaminants relative to their body weight (Salvi, 2007). PM2.5 is a measure of air quality that indicates the atmospheric presence of fine particles of 2.5 micrometers in diameter or smaller, which when inhaled can be detrimental to health (EPA, 2016). In the present study, we examined if air pollution indexed by PM2.5 and air quality index (AQI) were associated with a serum measure of inflammation in children.
Method: Participants were 93 children aged 9-11 years old (Mean age = 9.91 years, SD = 0.58, 42% female) in California. Families’ addresses were recorded and used to obtain average PM2.5 and AQI for their neighborhood during the day of a laboratory visit from records of the Environmental Protection Agency based on their locally installed monitors. Blood serum samples collected from children 30 minutes after arrival to a research laboratory were used for this analysis. Height and weight of the children were recorded in the laboratory and used to compute body mass index (BMI). Parents completed demographic information. Linear regressions were conducted to examine the associations between log-transformed interleukin-6 (IL-6), and both PM2.5 and AQI, adjusting for covariates (age, sex, total family income, and BMI).
Results: Analyses revealed a positive association between IL-6 and levels of PM2.5 (r = .28, p = .006), which remained significant when adjusting for age, sex, family income, and BMI (beta = 0.3, p = 0.003). IL-6 was significantly related to the daily AQI (r = .33, p = .003), which also remained significant when adjusting for covariates (beta = 0.29, p = .005).
BMI is a well-known correlate of inflammation. In our sample, BMI explained 9.9% of the variance in IL-6, whereas PM2.5 explained 10.9% of the variance in IL-6, independently of BMI and demographic covariates. In the AQI model, BMI explained 20.3% of the variation in IL-6, while AQI explained 7.7% of the variance in IL-6, independent of any covariates.
Conclusion: Indices of air quality near a child’s home were associated with IL-6, and may be considered in future risk models of inflammation in children as they provide unique information. Climate change, environmental justice, and the increasing prevalence of wildfires have warranted increased concerns about the impact of air quality and pollution on child health and potential risks for illness, such as COVID-19.

Authors

• Anna Parenteau, University of California - Davis
  Presenting Author

• Nicholas Alen, University of California - Davis
  Non-Presenting Author

• LillyBelle Ku'ulei Deer, University of Denver
  Non-Presenting Author

• Adam Nissen, University of California - Davis
  Non-Presenting Author

• Jennifer La, University of California, San Francisco
  Non-Presenting Author

• Alison Luck, Whitman College
  Non-Presenting Author

• Camelia E Hostinar, University of California - Davis
  Non-Presenting Author