Effects of Air Pollution on Respiratory Events and Pain Crises among Children with Sickle Cell Disease in New York City.

Abstract

The disease burden of sickle cell disease (SCD) is highest among U.S. Black and Hispanic populations, who are often disproportionately represented in communities with poor air quality. There is limited data on the effects of air pollution exposure and social environmental factors on health outcomes in children with SCD. The objective of our study was to examine the associations between air pollution exposure and acute respiratory and vaso-occlusive pain crises (VOCs), and further study the associations stratifying by asthma status and neighborhood disadvantages. We conducted a retrospective study collecting data on outpatient sick and ED visits, and hospital admissions for respiratory events (i.e., respiratory tract infections, asthma exacerbation, acute chest syndrome), and hospitalizations for VOCs among children with SCD in a tertiary care center in New York City (NYC) from 2015-2018. Modeled data from the NYC Community Air Survey data using home addresses estimated street-level, annual-average exposure to air pollution (i.e., black carbon (BC), fine particulate matter (PM2.5), and nitrogen dioxide (NO2)). The area deprivation index (ADI): continuous national ranking percentile (1-100) was used, representing a composite index for neighborhood-level social disadvantage. We further dichotomized study participants at the upper tertile (high vs. low ADI). Multivariable Poisson regression in generalized estimating equation (GEE) models were used to estimate relative risks (RR), after adjusting for potential covariates. A total of 114 children with SCD were included in this study and had between 1-4 annual repeated measures of annual average air pollutants over a total of 425 visits. Overall, there were no significant associations between air pollution levels and acute respiratory and VOCs among children with SCD and when stratified by asthma status. We found significant interactions between air pollution levels and the continuous ADI variable on respiratory outpatient and frequent respiratory outpatient/ED visits (p<0.1). When stratified by high ADI, increased exposure to PM2.5 was significantly associated with more frequent respiratory outpatient/ED visits among children residing in higher ADI neighborhoods (RR (95% CI)= 1.13 (1.01, 1.27), p<0.05), but not among those in lower ADI neighborhoods. Increased exposure to NO2 was associated with more outpatient respiratory events for children in high ADI neighborhoods (RR (95%CI= 2.74 (1.24, 6.08), p<0.05), compared with low ADI neighborhoods. Air pollution exposures increased respiratory complications among children with SCD living in deprived neighborhoods.