THREAT: Testing Harms Related to Exposure to Allergenic and Epithelial Toxins

Background: Allergic and inflammatory conditions have been increasing over the years. Many factors may play a role in this. Every day, people are exposed to pollution and chemicals in our foods, clothing, and all of the cleaning, hygiene, and other products we use. Studies have suggested there may be links between these environmental exposures and allergic and inflammatory illnesses. Researchers want to know more about how these exposures affect our health. Objective: To learn how everyday exposure to common substances affects people's health. Eligibility: Healthy people aged 18 to 80 years. Design: Participants will have 2 stays in the hospital. Each stay will last 7 days, and the stays will be spaced 4 to 6 weeks apart. During both stays, participants will remain confined to their room. They will eat only food from the menu, and they will use only provided products for personal care. (They may bring their own electronic devices, such as their phone and computer.) One stay will be in a pure room. Participants will breathe filtered air, eat unprocessed foods, and use personal care products with fewer chemicals. One stay will be in a room that allows exposure to common environmental chemicals. Some participants will be limited to only 1 type of exposure: chemicals thought to affect only skin, gut, or respiratory health. Some participants will be exposed to all 3 types. Participants will undergo testing. Blood, skin cell, urine, mouth swabs, and stool samples will be taken. They will have lung tests, smell tests, and tests that measure the health of their skin. These tests will be repeated in outpatient visits 2 weeks after each hospital stay....

NCT Number	NCT07271381
Lead Sponsor	National Institute of Allergy and Infectious Diseases (NIAID)
Conditions	Allergic, Inflammatory
Enrollment	120 participants
Start Date	2026-04-15
Primary Completion	2030-12-30 (estimated)
Study Completion	2031-01-30 (estimated)
Updated on ClinicalTrials.gov	2026-08-10