Allergen levels in inner city homes: baseline concentrations and evaluation of intervention effectiveness

Allergens in house dust are risk factors for asthma causation and exacerbation, and asthma interventions often focus on exposure reduction using methods that may not be sustainable over time in low-income communities. A randomized controlled trial with up to six home visits was used to evaluate the effectiveness of two interventions focused on reducing dust loading and allergen concentrations in 47 low-income inner-city households in Minneapolis, MN. The interventions, which included education and relatively inexpensive cleaning procedures, were developed using a community-based participatory consultation process with focus groups held in English, Somali, and Spanish to incorporate community feedback from participants into protocols and study design decisions. Change in levels of cat, cockroach, dust mite, and culturable fungi as well as overall dust loading were evaluated by measuring the difference in concentrations before and after the cleaning intervention, and mixed models were used to assess the effect of education and cleaning on baseline allergen levels during the final three home visits. The cleaning intervention significantly lowered dust loading in all households and culturable fungi levels in single family homes, reduced cat allergen concentrations in homes with cats, but had no significant effect on cockroach allergen levels. The cleaning intervention also modestly decreased the frequency of observed allergen concentrations above suggested health benchmarks for cat, cockroach, and fungi. The cleaning and education interventions had similar effects on baseline allergen levels measured during subsequent home visits; both interventions significantly reduced baseline levels of cat and fungal allergens observed in pre-cleaning samples, but had no significant effect on cockroach allergen levels. Overall, the cleaning intervention modestly reduced potential exposure to risk factors associated with asthma mortality and morbidity in a way that can be implemented by most homeowners or renters, independent of education, income, or the ability to speak English.