Urinary biomarkers of environmental exposures and asthma morbidity in a school inner city asthma study
Marissa Hauptman1, Medina S Jackson-Browne2, Stefanie Busgang3
1Division of General Pediatrics, Boston Children's Hospital, Boston, MA, USA; Region 1 New England Pediatric Environmental Health Specialty Unit, Boston, MA, USA; Harvard Medical School, Boston, MA, USA.
Insights
Urinary biomarkers showed an inverse association with pediatric asthma symptoms in inner-city children, with varying effects based on race and ethnicity. These findings suggest potential benefits from certain environmental chemical exposures.
Area of Science:
- Environmental health
- Pediatric allergy
- Toxicology
Background:
- Pediatric asthma burden is unequally distributed across US populations.
- Inner-city children face a disproportionate risk of asthma and allergic diseases.
- Understanding environmental factors is crucial for addressing health disparities.
Purpose of the Study:
- To investigate the association between urinary biomarkers and asthma morbidity in children.
- To examine if these associations differ by child race, ethnicity, and sex.
- To explore the impact of environmental chemical exposures on pediatric asthma.
Main Methods:
- 152 children with asthma from the School Inner-City Asthma Intervention Study (SICAS-2) were analyzed.
- Urinary metabolites of phenols, parabens, PAHs, and phthalates were measured.
- Weighted quantile sum regression models assessed chemical mixtures, controlling for covariates and analyzing effect modification by race/ethnicity.
Main Results:
- Participants were predominantly Hispanic/Latino and low-income.
- Significant interaction effects were observed, with differing analyte contributions based on allergen sensitivity.
- Reduced odds of asthma symptoms were noted in children of "other" races/ethnicities compared to Black, Non-Hispanic children.
Conclusions:
- Preliminary findings indicate an inverse association between environmental chemical exposure and asthma symptoms in inner-city children.
- This inverse association may be linked to personal care product and medication use.
- Further research is needed to fully elucidate the beneficial effects observed for most chemicals.
Background:
The burden of pediatric asthma and other allergic diseases is not evenly distributed among United States populations.
Objective:
To determine whether urinary biomarkers are associated with asthma morbidity, and if associations vary by child race, ethnicity and sex.
Methods:
This study includes n = 152 children with physician-diagnosed asthma who participated in the School Inner-City Asthma Intervention Study (SICAS-2). Metabolites of phenol, paraben, polycyclic aromatic hydrocarbons, and phthalate analytes were analyzed from urine samples collected at baseline. Asthma symptom days over the past 2 weeks were dichotomized to no asthma symptom days or any asthma symptom days. Cross-sectional regression models were adjusted for age, sex, number of colds, household income, prescription control, race and ethnicity, body mass index (BMI) percentile, and smoke exposure. Weighted quantile sum regression was used to analyze each chemical class and a total mixture effect, controlling for the same covariates. Analyses were conducted with the assistance of the National Institute of Environmental Health Sciences Children's Health Exposure Analysis Resource (CHEAR).
Results:
Participants were mostly Hispanic/Latino and low income with an average age of 7.83 years and the average maximum asthma symptom days over the past two weeks of 2.13 (standard deviation: 3.56). The maximum concentrations indicate extreme values for several chemicals, including bisphenol-3, 2,5-dichlorophenol, propyl and methyl parabens, triclosan, methyl paraben and cotinine. We found a significant interaction effect and differing contributions of analytes for children with allergen sensitivity versus those that did not. For stratified analyses assessing effect modification by child race and ethnicity, weighted quantile sum interaction models showed reduced odds of asthma symptoms to a greater magnitude in children of other races and ethnicities compared to Black, Non-Hispanic children.
Conclusions:
Preliminary analyses of the association between environmental chemical exposure and asthma symptoms among inner-city children revealed an inverse association, which may be due to personal care and medication use and can be understood further in future analyses. Beneficial effects were detected for most of the chemicals.
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