Microplastics in House Dust and Pediatric Respiratory Health

Microplastics are 1 to 5,000 μm particles that result from the degradation of plastics or from manufactured microbeads. They account for 70% of the marine pollutants and have been widely detected in fish and seafood. Microplastics are now ubiquitously found in our environment, making human exposure nearly universal. The indoor environment, where children spend most of their time, contains significantly more microplastics than outdoors. Inhalation of contaminated house dust as a route of exposure to microplastics has raised concerns for respiratory health due to the ability of various microplastics types to cause inflammation, oxidative stress, and reduced alpha-1 antitrypsin and to exacerbate the allergenicity of other allergens such as dust mites. Yet, studies to characterize house dust microplastics and identify their predictors in the U.S. are lacking and the respiratory effects of microplastics in humans have not been investigated to date, especially in children who are at higher exposure to house dust particles and chemicals. Therefore, we propose to quantify microplastics in house dust collected from children who participated in the Cincinnati Childhood Allergy and Air Pollution Study (CCAAPS), a multiethnic prospective cohort with extensive data on respiratory symptoms, lung function measurement and allergic sensitization. In Specific Aim 1, we will quantify microplastics concentrations and loadings by size, shape and polymer type and identify sociodemographic and housing characteristics predictive of the exposure. In Specific Aim 2, we will determine the cross-sectional association of house dust microplastics with respiratory conditions (asthma, allergic rhinitis in past 12 months and wheezing episodes in past 12 months), lung function and positive skin prick reaction to allergens at child age of 7 years. Then, we will determine the longitudinal association of house dust microplastics at child age of 7 years with respiratory conditions, pulmonary function and specific IgE against various allergens at child age of 12 years. Finally, we will test the hypothesis that house dust microplastics exacerbate the respiratory and/or allergenic effects of house dust mites and endotoxins in both the cross-sectional and longitudinal association analyses. Upon completion, we will have determined house dust microplastics levels and predictors as well as potential respiratory and allergenic effects. This will be the second and the largest study on house dust microplastics in the U.S. and the first on the respiratory effects of microplastics in humans. Project Number: 1R21ES038274-01 | Fiscal Year: 2026 | NIH Institute/Center: National Institute of Environmental Health Sciences (NIEHS) | Principal Investigator: Angelico Mendy | Institution: UNIVERSITY OF CINCINNATI, CINCINNATI, OH | Award Amount: $459,770 | Activity Code: R21 | Study Section: Environmental Determinants of Disease Study Section [EDD] View on NIH RePORTER: https://reporter.nih.gov/project-details/11286730