Indoor Allergens And Asthma

National Institute Of Environmental Health Sciences

Investigators

Linked publications, trials & patents

Abstract

Our research program focuses on the role of the environment in the development and exacerbation of asthma and allergic diseases. In collaboration with investigators at the CDC/NCHS, we developed and implemented an allergy/asthma focused component for the National Health and Nutrition Examination Survey (NHANES). This component, included in NHANES 2005-2006, queried on allergy and asthma prevalence and morbidity, measured levels of common indoor allergens and endotoxin in bedroom dust, and quantified total and allergen-specific IgE levels in serum of more than 9,000 participants. Analysis of this large dataset has allowed us to 1) estimate nationwide prevalence of indoor allergen and endotoxin exposures, 2) estimate nationwide prevalence of allergic sensitization to indoor, outdoor and food allergens, 3) estimate nationwide prevalence of allergic diseases, including asthma, and 4) investigate the complex relationships between allergen and endotoxin exposures, allergic sensitization and allergic diseases. This component not only tested a greater number of allergens across a wider age range than prior studies but also provided quantitative information on the extent of allergic sensitization and exposures to indoor allergens and endotoxin. It established a second point-in-time estimate for evaluating allergen and endotoxin exposure trends in U.S. homes, the first being established in the National Survey of Lead and Allergens in Housing, which we completed in collaboration with the Department of Housing and Urban Development. NHANES data have enabled more robust and generalizable investigations of the role of allergen/endotoxin exposures and IgE-mediated sensitization in allergic diseases than previously possible. We have made significant advances in our understanding of the prevalence and determinants of indoor allergen/endotoxin exposures, and their relationships with allergic disease. We have demonstrated that exposure to indoor allergens and endotoxin is common but highly variable in U.S. homes. Our nationally representative findings highlight the impacts and importance of environmental factors in human health and disease, including asthma. We recently showed that exposure to indoor allergens may also represent a substantial, understudied contributing factor to poor sleep health among adults. The sleep microenvironment — the mattress, bed frame, bedding, pillows, and the air surrounding them — often contain indoor allergens from dust mites, pets, pests, and fungi. Given the substantial time people spend in bedrooms, exposure to these common allergens may contribute to sleep disordered breathing and other sleep disturbances. Using data from NHANES, we found that exposure to elevated pet allergen levels was associated with frequent snoring and trouble sleeping among Hispanic/Latino participants. Elevated exposure to fungal allergens was linked to sleep disorders among individuals with moderate socioeconomic status, and more sleep medication use among Hispanic/Latino participants. Furthermore, elevated pet and fungal allergen levels in bedrooms were associated with sleep disorders among women. These findings underscore the importance of indoor environment in sleep health; exposure to elevated levels of bedroom allergens was associated with multiple dimensions of sleep health, especially among minoritized racial/ethnic groups and women. Our collaborative work with CDC/NCHS and several other federal agencies resulted in the implementation of a new respiratory health and allergy focused component for the current NHANES survey cycle 2025-2026. The NHANES, which is one of the major national survey programs, estimates the prevalence of chronic health conditions and captures a wide variety of clinical and environmental data that can be used for health promotion and disease prevention. Our new component will provide the most comprehensive national-level data on asthma and allergies to date. Additional questions on asthma, allergies, and respiratory health will be used in conjunction with lung function and allergy testing data to advance our understanding of lung health and these chronic conditions across the entire lifespan. Most importantly, all these novel insights will be generalizable to the general U.S. population. We continue to study the complex relationships between allergen exposures, allergic sensitization, and disease in more detail, as the NHANES data allow for the investigation of many interesting relationships. Our research will lead to a better understanding of the characteristics of various environmental exposures and their role in allergic disorders, which in turn provides insights into development of effective environmental intervention approaches for the management of allergic diseases such as asthma.