Impact of Ambient Air Pollution on the Respiratory Health of Children With Sickle Cell Anemia in Atlanta, Georgia

Abstract

O-29C4-4 Background/Aims: Children with sickle cell disease (SCD) comprise a potentially susceptible, yet largely unstudied, sub-group. SCD is an inherited, autosomal recessive blood disorder and is one of the most prevalent genetic disorders in the United States. The aim of the pilot study is to determine if elevated concentrations of personal exposures to air pollutants are associated with adverse respiratory health effects in children with SCD. To our knowledge, this is the first panel study in the United States, examining these potential associations in this population. Methods: We conducted a panel study of 7 homozygous children with SCD in Atlanta, GA from 2008–2009. Repeated measurements of 24-hour integrated personal exposures to fine particulate matter (PM2.5) and nitrogen dioxide (NO2) were collected for 2 seasons, with 12 samples per season. Before and after each sampling period, children underwent an assessment of their pulmonary inflammatory response, airway resistance, and respiratory symptoms. Lung function data were also collected at the beginning and end of each week. Results: The mean age of the participants was 9 years (range: 7–12 years). Preliminary 24- hour mean personal PM2.5 and NO2 exposure concentrations were 15.0 ± 25.5 μg/m3 and 0.23 ± 0.14 ppm, respectively. Exhaled nitric oxide measurements for all participants ranged from <5 to 57.5 ppb. Overall, daily NO2 concentrations were strong (r = 0.77) and positively correlated with exhaled nitric oxide measurements made after the sampling period. Exhaled nitric oxide was negatively correlated with PM2.5. When examined by child, correlations were moderate-to-strong (r < 0.80) but varied by pollutant. Conclusion: The initial findings suggest that associations exist between children's exhaled nitric oxide levels and exposures to PM2.5 and NO2. Complete analysis, including lung function and other markers of airway inflammation and resistance will also be presented to help elucidate the variability and the strength of this association among the children.