Pollutant Exposure and Asthma Exacerbations in Adolescence: Moderation by Support from Adults in the Home?

• In Event: 2-026 - Studying the Impact of the Family on Children’s Health Through Multiple Levels of Analysis

Integrative Statement

Exposure to outdoor air pollution is a major risk factor for asthma exacerbation in children and adolescents (Guarnieri & Balmes, 2014). While population-level interventions such as policies to reduce air pollution improve lung function, the causal association between outdoor air pollution and asthma outcomes is small and heterogeneous (Gasana et al., 2012). Unpacking the heterogeneity in outcomes is crucial to developing multi-faceted asthma control strategies (Beaseley et al., 2015), and the family social environment is one possible entryway (Kaugars et al., 2004). Stressful family environments has been shown to magnify the association between air pollution and worse lung function in children (Chen et al., 2008). In contrast, support in the home, defined as interpersonal interest, involvement and adult availability may have an opposite, buffering effect – protecting children from the detrimental effects of environmental exposures on health.

This study examines whether support buffers associations between ozone (O3) pollution exposure and asthma symptoms among adolescents, using data from the 2003 California Health Interview Survey (CHIS). CHIS is a biannual population-based random-digit telephone survey on health, health behaviors and health services, conducted with adults and children (California Health Interview Survey, 2003). For the 2003 survey, respondents’ residential addresses were linked to data from the nearest outdoor air monitoring station. Air monitoring stations measures pollutants in the ambient air, including O3. We examined data from adolescents 12-18 years old who (1) reported current asthma and endorsed having an asthma attack during the past 12-mo, and (2) lived within 5 miles an air monitoring station.

Out of the 4010 adolescents who completed the survey, 209 were currently asthmatic and lived within 5 miles of an air monitoring station. O3 was quantified as a 12-month average of 8 hour daily maximum values (scaled by 10ppb; Meng et al., 2012). Support was assessed as the average of adolescent responses to 6 items (e.g., there is an adult who “…cares about your work,” “…listens to you”). Outcomes were based on adolescent report of past 12-mo asthma symptom frequency, ranging from 1=not at all to 5=every day. Of the 209 adolescents in the current analysis, 39.9% reported having symptoms every month, week or day (i.e., persistent symptoms). We tested O3, support and the O3 x support as predictors in logistic regression model predicting persistent or intermittent frequency of asthma symptoms.

Results indicated a significant interaction between O3 and support in the prediction of asthma symptom frequency (see Table 1). As displayed in Figure 1, higher level of support was associated with lower probability of youths having persistent asthma symptoms, only among those living in high O3 areas. This interaction remained significant in the adjusted model controlling for age, gender, race/ethnicity, poverty status, insurance status and medication status.

Supportive homes may help to reduce asthma symptoms among adolescents exposed to high levels of O3. Future studies should examine possible mediating pathways such as lower innate immune inflammation. In addition, findings highlight the potential value of testing family-level strategies that may complement existing asthma control population-level and person-level strategies.

Authors

• Theodore F Robles, UCLA
  Non-Presenting Author

• Sunhye Bai, The Pennsylvania State University
  Presenting Author

• Ying-Ying Meng, UCLA
  Non-Presenting Author