Allergens in School Settings: Results of Environmental Assessments in 3 City School Systems

Abstract

Environmental allergens are major triggers for pediatric asthma. While children's greatest exposure to indoor allergens is in the home, other public places where children spend a large amount of time, such as school and day care centers, may also be sources of significant allergen encounters. The purpose of this article is to describe schoolroom allergen levels from 3 different geographic sites obtained from dust samples collected in the fall and in spring. Environmental dust samples were collected from elementary schools in Birmingham (AL), Detroit (MI), and Houston (TX), from 4 room locations, including the cafeteria, library, upper grades, and lower grades. Samples were assayed for dust mite (Dermatophagoides pteronyssinus and Dermatophagoides farinae), cat (Felis domesticus), and cockroach (Blatella germanica 2) allergen levels. Allergen levels varied by geographic location and type of schoolroom. Schoolroom settings differed by the type of flooring (hard and carpet), room characteristics and use (food service, library shelves with books, and general classroom with multiple types of materials [individual desks and different types of furniture]), and the average age of the schoolroom dwellers (younger vs. older children). Dust mite, cat, and cockroach allergens were present in all schoolrooms and all sites at varying levels by season and by type of room. Schools may be important sources of direct allergen exposure and reservoirs that could potentially contribute to allergic sensitization and disease exacerbation in children. Further studies are needed to carefully examine the environmental allergen load in schools and its effect on children.

Home and school environmental assessment and remediation

“…Cat and dog allergen are nearly ubiquitous in indoor spaces, and many studies have detected their presence in places not containing or permitting pets, particularly schools and daycare centers [3,[28][29][30]. Pet allergen is mainly carried into classrooms on the garments of pet owners, and the amount of cat allergen in a school has been shown to be proportional to the number of cat owners in class [30].…”

An Important Source for Cat and House Dust Mite Allergens: Day-Care Centers

“…In the studied facilities, the highest average concentrations were detected in Brazil and in some humid regions in the United States. [10][11][12] In contrast, very low dust mite allergen levels have been found in colder and drier climates. [13][14][15] Average yearly humidity in İzmir is 57.9%.…”

“…13,16,24,26 However, this relationship with carpeted floor was not present in all studies. 11 Although mite levels tend to exhibit seasonal fluctuations that parallel those in ambient relative humidity, additional factors, including human activities and heating, ventilation, and air conditioning may also influence indoor air humidity levels. 3 In keeping with this data, we found that Der p 1 concentration was higher in DCs with air-condition system for ventilation (0.67 µg/g vs. 0.45 µg/g; p=0.008).…”

Pyroglyphid Mites as a Source of Work-Related Allergens

“…Similarly high exposure to pyroglyphid mites was found in Polish and US libraries (28,32) and in New Zealand and UK cinemas (24,33); most dust samples exceeded the sensitisation threshold. In Polish libraries, the main source of mites were bookshelves, books, and upholstered chairs.…”

“…hotel chambermaids High Cinemas (24,33) all staff Moderate Fishing-boats (38) fi shermen Moderate Submarines, ships (39) all crew Moderate Libraries (28,32) librarians, cleaners Moderate Schools (46,47) teachers, cleaners Low-moderate* Day care centres (46) day care workers Low-moderate* Offi ces (20,21) offi ce workers, cleaners Low Churches (24) priests Low Airplanes (24) all crew Low Buses, trains, trams, taxies (34)(35)(36)(37) all crew Low Poultry farms (43) poultry farm workers Low …”