Detection of Food Allergens in School and Home Environments of Elementary Students.

Background: Little is known about environmental food allergen exposure on school surfaces.

Objective: To compare the distribution of major food allergens in floor dust and table wipe samples from elementary schools and dust samples from students' homes.

Methods: In this substudy of the School Inner-City Asthma Study-II, 103 table wipe samples and 98 floor dust samples from cafeterias and classrooms in 18 elementary schools were analyzed for milk, peanut, cashew, hazelnut, and egg using a multiplex array. Home kitchen floor and bed dust samples from 90 students were also analyzed.

Results: Food allergens were detectable in schools, but at significantly lower levels than in homes (P < .001). In schools, milk and peanut were detected in all table wipe samples; milk and egg were detected in all floor dust samples. Cafeteria table wipe samples contained significantly higher levels of milk, peanut, hazelnut, and egg, compared with classrooms. Cafeteria floor dust samples contained higher levels milk than classrooms. Peanut-restrictive policies did not consistently reduce environmental peanut exposure in schools. Peanut allergen was lower in dust from homes of students with peanut allergy (n = 5) compared with those without peanut allergy (n = 85) (P < .001). Reassuringly, peanut allergen in the schools of peanut-allergic students was not significantly different than in their homes.

Conclusion: Food allergens were readily detectable on tables and floors in elementary schools, but at levels lower than in students' homes. For peanut-allergic students, the levels of detectable peanut in their schools were not higher than their homes. The low levels of detectable food allergens in school environments are unlikely to result in severe allergic reactions.