In many schools, chalk, chalkboards, and brushes have been eliminated, partly because of asthma and allergies (and partly because I’m sure it’s easier to NOT have to clean up after the 30 times a day the brush would get dropped, am I right?). Other common environmental asthma triggers that you might expect to find in your child’s school or classroom include mold, pollen tracked in by kids through the non-winter months, and of course, dust. And then there are just general germs, cleaning chemicals, some art supplies, and even the classroom pet (schools still have those, right? I totally remember bringing Lucky the Gerbil home a time or two in elementary school!).
A recent study of 37 public schools in the northeastern US, which included elementary/middle schools (or kids aged 4-13 years), discovered some school allergens that might surprise parents, though.1 Since kids with pets bring animal dander to school with them on their clothing, these allergens were found in “common quantities”1. It may surprise you that cockroach and rat allergens were for the most part not detected in samples collected—however, while these triggers were not associated with worse asthma outcomes, other less-obvious triggers were.1
99.5% of the samples collected in schools contained mouse allergen1. Unlike the above triggers, though, which were present in “common quantities”—what might be found in a child’s everyday living environment at home—mouse allergen was present in significant quantities. To make matters worse, even after accounting for children’s home environments and other asthma related factors, children with asthma with higher exposure to mouse allergens at school, had greater asthma symptoms and lower lung function—meaning that mice may have a greater impact on asthma than we’d presume1. (Hmmm… Maybe that’s why I don’t like them!)
I’d never really thought about mouse allergies before (just like I try to think about mice as little as possible!). In a two-year study of bedrooms of children in the inner city (2008), 80% of children had detectable mouse allergen levels in their bedrooms2. Of a sample of 937 participants, 22% of children had allergy tests that indicated they were sensitive (allergic) to mice2 —150 these children positive to mouse or rat allergen (total approximately 206) were entered into an intervention study to reduce the asthma issues they had caused by the allergens in their bedrooms. Parents were educated regarding how do identify and clean molds, cockroach stains, and so on, and were provided with a HEPA-filter vacuum (specific to how much carpet was present in the home), impenetrable bed/pillow/mattress protectors for the child with asthma, an air purifier and filters for the study period, the funds to cover the cost of the extra electricity to run the purifier 24 hours a day for the year of the study3. Caregivers were assisted in completing cleaning tasks for the first time3.
It is noted that the impact of the intervention, including the installation of air purifiers in children’s bedrooms, may have been partially benefitted by tobacco smoke being filtered from the air via these purifiers2, as well as pet dander if animals were present in the home3. The intervention group had a 27% decrease in mouse allergen2 present in the bedroom—decrease in mouse allergen was lead to increased school attendance, better sleep, and decreased burden of asthma on the child’s caregiver, but was reported not to impact symptoms/symptom frequency or doctor, emergency or hospital stays2.
While structural issues may cause mice to be a greater problem in inner-city community homes and schools, this problem likely impacts children outside of urban inner city areas. Recognizing structural problems, and finding means to fix them if at all possible, may improve health outcomes for people with asthma—the methods explored in the home study as well may help to promote easier breathing for people with mouse allergies who cannot alter their living environment, although they can come with significant expense as well.
These studies investigated two different environments—however, for children with asthma, controlling just one environment, such as the home, may help with overall asthma control, even if they are still exposed at school. While tax dollars are often tight at public schools, it is worth contemplating if greater funds used to keep school environments more allergen-free for children might also decrease medical spending for low-income US children and their families who rely on Medicaid. (Although I’m totally not an economist.) The reduction in some asthma-related issues, however, makes the presence of mice in a home—known or unknown—something to think on if you have asthma, no matter your level of income.