Short-term air pollution levels and sickle cell disease hospital encounters in South Carolina: A case-crossover analysis

Tong Wen; Robin C Puett; Duanping Liao; Julie Kanter; Murray A Mittleman; Sophie M Lanzkron; Jeff D Yanosky

doi:10.1016/j.envres.2024.118766

Short-term air pollution levels and sickle cell disease hospital encounters in South Carolina: A case-crossover analysis

Environ Res. 2024 Apr 5;252(Pt 1):118766. doi: 10.1016/j.envres.2024.118766. Online ahead of print.

Authors

Tong Wen¹, Robin C Puett², Duanping Liao¹, Julie Kanter³, Murray A Mittleman⁴, Sophie M Lanzkron⁵, Jeff D Yanosky⁶

Affiliations

¹ Division of Epidemiology, Department of Public Health Sciences, Penn State College of Medicine, Hershey, PA, USA.
² Maryland Institute for Applied Environmental Health, University of Maryland School of Public Health, College Park, MD, USA.
³ Division of Hematology and Oncology, University of Alabama Birmingham, Birmingham, AL, USA.
⁴ Department of Epidemiology, TH Chan Harvard School of Public Health, Boston, MA, USA.
⁵ Department of Medicine, Johns Hopkins School of Medicine, Baltimore, MD, USA.
⁶ Division of Epidemiology, Department of Public Health Sciences, Penn State College of Medicine, Hershey, PA, USA. Electronic address: jyanosky@pennstatehealth.psu.edu.

PMID: 38583660
DOI: 10.1016/j.envres.2024.118766

Abstract

Background: Sickle cell disease (SCD) is a genetic disorder and symptoms may be sensitive to environmental stressors. Although it has been hypothesized that exposure to outdoor air pollution could trigger acute SCD events, evidence is limited.

Methods: We obtained SCD administrative data on hospital encounters in South Carolina from 2002 to 2019. We estimated outdoor air pollutant (particulate matter<2.5 μm (PM_2.5), ozone (O₃), and PM_2.5 elemental carbon (EC) concentrations at residential zip codes using spatio-temporal models. Using a random bi-directional, fixed-interval case-crossover study design, we investigated the relationship between air pollution exposure over 1-, 3-, 5-, 9-, and14-day periods with SCD hospital encounters.

Results: We studied 8410 patients with 144,129 hospital encounters. We did not observe associations among all patients with SCD and adults for PM_2.5, O₃, and EC. We observed positive associations among children for 9- and 14-day EC (OR: 1.05 (95% confidence interval (CI): 1.02, 1.08) and OR: 1.05 (95% CI: 1.02, 1.09), respectively) and 9- and 14-day O₃ (OR: 1.04 (95%CI: 1.00, 1.08)) for both.

Conclusions: Our findings suggest that short-term (within two-weeks) levels of EC and O₃ and may be associated with SCD hospital encounters among children. Two-pollutant model results suggest that EC is more likely responsible for effects on SCD than O₃. More research is needed to confirm our findings.

Keywords: Air pollution; Case-crossover analysis; Elemental carbon; Hospital encounters; Sickle cell disease; Traffic-related air pollution.