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Am J Respir Crit Care Med
Am J Respir Crit Care Med
ajrccm
American Journal of Respiratory and Critical Care Medicine
1073-449X
1535-4970
American Thoracic Society

202405-1031LE
10.1164/rccm.202405-1031LE
Correspondence
Beyond Air Pollution: Addressing Multifactorial Contributors to Asthma Disparities in Black and Latinx Populations
Ou Jieying 1
Yuan Yiwen 1
Fu Xi 2
https://orcid.org/0000-0003-4799-0745
Sun Yu 1
1 State Key Laboratory of Swine and Poultry Breeding Industry, Guangdong Provincial Key Laboratory for the Development Biology and Environmental Adaptation of Agricultural Organisms, College of Life Sciences, South China Agricultural University, Guangzhou, Guangdong, People’s Republic of China; and
2 Guangdong Provincial Engineering Research Center of Public Health Detection and Assessment, NMPA Key Laboratory for Technology Research and Evaluation of Pharmacovigilance, School of Public Health, Guangdong Pharmaceutical University, Guangzhou, People’s Republic of China
Correspondence and requests for reprints should be addressed to Yu Sun, Ph.D., College of Life Sciences, South China Agricultural University, Guangzhou 510642, Guangdong, P. R. China. Email: sunyu@scau.edu.cn.
27 6 2024
1 9 2024
27 6 2024
210 5 696697
Copyright © 2024 by the American Thoracic Society
2024
https://creativecommons.org/licenses/by-nc-nd/4.0/ This article is open access and distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives License 4.0. For commercial usage and reprints, please e-mail Diane Gern (dgern@thoracic.org).
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pmcTo the Editor:

We read with great interest the recent study by Chambliss and colleagues published in the Journal (1). This study shows the impact of intraurban variability in air pollution on asthma-related emergency department (ED) visits among different ethnic groups. By analyzing census tract–level data within the Austin metropolitan statistical area, the authors demonstrated that air pollution concentrations, particularly PM2.5, PM10, and So2, are strongly associated with increased rates of asthma-related ED visits. Importantly, the study revealed that 24–32% of the increase in asthma ED visits between Black and Latinx populations and European Americans can be attributed to differences in air pollution exposure.

An interesting next step is to explore the factors explaining the remaining ∼68–76% of the increase in asthma ED visits among Black and Latinx populations. Although it may be intuitive to consider genetic risk explaining this disparity, our analyses suggest it is not the primary cause. We explored asthma-associated SNPs from the genome-wide association studies (GWAS) Catalog (240 SNPs with a P value < 1 × 10−6) and calculated polygenic risk scores, which aggregate the effects of multiple genetic variants, to quantify the genetic risk of asthma in different populations: PRS=∑i=1nlog(OR)⋅ Fi,

where n is the number of SNPs included in the score, OR is the odds ratio of the genotype for asthma from the GWAS Catalog, and Fi is the frequency of the genotype in populations obtained from the 1,000 Genomes Project and the gnomAD database.

Our analysis revealed that the genetic risk is higher in European populations than in Black and Latinx populations. This conclusion is drawn from genotype frequency data sourced from both the 1,000 Genomes Project (African 2.29, Latinx 2.70, and European 2.93) and the gnomAD database (African 2.33, Latinx 2.69, and European 2.88). This indicates a higher genetic predisposition among European Americans, and, therefore, other factors likely contribute to the increased asthma-related ED visits observed in Black and Latinx populations.

Environmental and lifestyle factors may play significant roles in the population disparity. First, psychosocial stressors, including chronic stress related to socioeconomic challenges and racial discrimination, are well documented to exacerbate asthma symptoms and increase the frequency of asthma attacks in African Americans (2). Mental health conditions such as anxiety and depression, prevalent in underserved communities, can complicate asthma management and contribute to higher ED visit rates.

Second, indoor environmental and community factors, including poor indoor air quality due to mold, dust mites, and secondhand smoke, are significant contributors to asthma. Minority populations are more likely to live in housing conditions that foster these indoor asthma triggers (3, 4).

Third, occupational exposure could be a notable factor. Minority populations are more likely to be employed in high-risk occupations, such as construction, manufacturing, and cleaning, where exposure to asthma triggers, such as dust, chemicals, and fumes, is common. This increased occupational exposure contributes significantly to the higher incidence of asthma-related ED visits (5, 6).

Fourth, disparities in asthma management education and health literacy impact asthma control, as many Black and Latinx individuals have less access to comprehensive education programs and lower health literacy, resulting in poorer self-management skills, more frequent exacerbations, and increased emergency visits.

To further elucidate the factors contributing to the increase in asthma ED visits among Black and Latinx populations, we suggest that Chambliss and colleagues examine their dataset for additional environmental and lifestyle factors, such as psychosocial stressors, occupational exposures, and asthma management education. This analysis could offer deeper insights into the multifaceted contributors to asthma disparities and highlight the need for targeted public health interventions. Such efforts would be effective to reduce asthma-related health disparities and improve overall health outcomes for minority populations.

Originally Published in Press as DOI: 10.1164/rccm.202405-1031LE on June 27, 2024

Author disclosures are available with the text of this letter at www.atsjournals.org.
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References

1. Chambliss SE Matsui EC Zàrate RA Zigler CM The role of neighborhood air pollution in disparate racial and ethnic asthma acute care use Am J Respir Crit Care Med
2. Carlson S Borrell LN Eng C Nguyen M Thyne S LeNoir MA et al. Self-reported racial/ethnic discrimination and bronchodilator response in African American youth with asthma PLoS One 2017 12 e0179091 28609485
3. Keet CA McCormack MC Pollack CE Peng RD McGowan E Matsui EC Neighborhood poverty, urban residence, race/ethnicity, and asthma: rethinking the inner-city asthma epidemic J Allergy Clin Immunol 2015 135 655 662 25617226
4. Bose S Madrigano J Hansel NN When health disparities hit home: redlining practices, air pollution, and asthma Am J Respir Crit Care Med 2022 206 803 804 35696342
5. Torén K Blanc PD Asthma caused by occupational exposures is common: a systematic analysis of estimates of the population-attributable fraction BMC Pulm Med 2009 9 7 19178702
6. Henneberger PK Redlich CA Callahan DB Harber P Lemière C Martin J et al. ATS Ad Hoc Committee on Work-Exacerbated Asthma An official American Thoracic Society statement: work-exacerbated asthma Am J Respir Crit Care Med 2011 184 368 378 21804122
