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Head Start classrooms have lower-than-expected allergen concentrations

Children enrolled in Head Start preschool programs often spend 6 to 8 hours of every weekday in a classroom. Classroom exposure to allergens, such as mold, cat, dog, mouse, or cockroach can lead to the development of allergies. In turn, allergies can result in increased risk of symptoms due to asthma, the most common chronic childhood health condition.

To determine the prevalence of allergen exposure in Head Start facilities, researchers examined concentrations of common allergens in dust samples collected in classrooms in 33 Pulaski County, Arkansas, Head Start centers between April 1 and June 30, 2003. They found dog and mouse allergens in all (100 percent) of the facilities, dust mites in 27 (82 percent), cat allergens in 23 (70 percent), cockroach allergens in 7 (21 percent), and mold spores in 31 (94 percent).

Despite the nearly ubiquitous presence of common allergens, concentrations were generally low. High concentrations of dust mites were present in 11 (33 percent) centers, however, researchers found high cockroach concentrations in only 2 (6 percent) and high mouse allergen concentrations in 1 (3 percent) center. This was an unexpected finding since the authors expected high levels of cockroach and mouse allergens at centers where children ate in their classrooms.

They suggest that low allergen levels may be explained, in part, due to the majority (67 percent) of centers employing professional services to clean the rooms. The researchers concluded that exposure to low dose allergen concentrations in a preschool setting may play an important role in development of allergies and asthma in young children. This study was funded in part by the Agency for Healthcare Research and Quality (HS11062).

See "Classroom aeroallergen exposure in Arkansas Head Start centers," by Tamara T. Perry, M.D., Perla A. Vargas, Ph.D., Jeremy Bufford, M.D., and others in the April 2008 Annals of Allergy, Asthma, and Immunology 100, pp. 358-363.

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