Modification of the Effect of Ambient Air Pollution on Pediatric Asthma Emergency Visits

Abstract

Background Children may have differing susceptibility to ambient air pollution concentrations depending on various background characteristics of the children. Methods Using emergency department (ED) data linked with birth records from Atlanta, Georgia, we identified ED visits for asthma or wheeze among children aged 2–16 years from 1 January 2002 through 30 June 2010 (n=109,758). We stratified by preterm delivery, term low birth weight, maternal race, Medicaid status, maternal education, maternal smoking, delivery method, and history of a bronchiolitis ED visit. Population-weighted daily average concentrations were calculated for 1-hour maximum carbon monoxide and nitrogen dioxide; 8-hour maximum ozone; and 24-hour average particulate matter less than 10 microns in diameter, particulate matter less than 2.5 microns in diameter (PM2.5), and the PM2.5 components sulfate, nitrate, ammonium, elemental carbon, and organic carbon, using measurements from stationary monitors. Poisson time-series models were used to estimate rate ratios for associations between three-day moving average pollutant concentrations and daily ED visit counts and to investigate effect-measure modification by the stratification factors. Results Associations between pollutant concentrations and asthma exacerbations were larger among children born preterm and among children born to African American mothers. Stratification by race and preterm status together suggested that both factors affected susceptibility. The largest estimated effect size (for an interquartile-range increase in pollution) was observed for ozone among preterm births to African American mothers: rate ratio=1.138 (95% confidence interval=1.077–1.203). In contrast, the rate ration for the ozone association among full-term births to mothers of other races was 1.025 (0.970–1.083). Conclusions Results support the hypothesis that children vary in their susceptibility to ambient air pollutants.

Exposure to traffic-related air pollution and acute bronchitis in children: season and age as modifiers

“…Online supplementary figure 3 presents the RRs for IQR increases in pollutant levels occurring the next day from the single-pollutant model. Apart from NO 2 , statistically significant effect estimates were observed, whereas the RRs for future pollution levels were not sensitive to changes of dfs for time t (from 6 to 8), which could be due to a factor that varied systematically with short-term changes in air pollution levels, such as pollen concentrations 36. Besides, model misspecification could also cause the elevated associations with future pollution levels 33…”

Disparities in emergency department visits in American children with asthma: 2006–2010

“…The concentration of particulate matter (PM10) and ozone (O3) have been positively linked to asthma-related ED visits and hospital admissions (23, 24), decreased lung function (25–28), and fatalities from respiratory diseases (29). We used the Air Trends Data issued by the United States Environmental Protection Agency (30), which measures five common air pollutants or criteria pollutants: carbon monoxide (CO), ozone (O3), nitrogen dioxide (NO2), particulate matter (PM), and sulfur dioxide (SO2).…”

Two Mechanisms: The Role of Social Capital and Industrial Pollution Exposure in Explaining Racial Disparities in Self-Rated Health

“…These are described, in-depth, in Table 1. These indicators were originally developed by Putnam and colleagues [58] based on existing theoretical knowledge of distinctions among various types of social capital and refined using a multi-step factor analytic process. More complete details regarding the methodology used to construct these social capital measures can be found in the Social Capital Benchmark Study methodology documents [58].…”

“…These indicators were originally developed by Putnam and colleagues [58] based on existing theoretical knowledge of distinctions among various types of social capital and refined using a multi-step factor analytic process. More complete details regarding the methodology used to construct these social capital measures can be found in the Social Capital Benchmark Study methodology documents [58]. In order to combine both the public health and sociological social capital frameworks, we categorized social capital measures into the following five components: bonding, bridging, linking, cognitive, and structural, which are detailed in Table 1.…”

“…However, they also found Hispanics were more likely than Whites to be admitted for Congestive Heart Failure when PM 2.5 levels were high. Another study done in Atlanta, Georgia showed the associations between ozone and preterm birth were significantly stronger for children born to African American mothers [58]. On the other hand, a study done in Arkansas showed that the effect of PM 2.5 on cardiovascular and respiratory emergencies was stronger for Whites.…”