Background: Professional use of hypochlorite (bleach) has been associated with respiratory symptoms. Bleach is capable of inactivating allergens, and there are indications that its domestic use may reduce the risk of allergies in children.
Objective: To study the associations between household use of bleach and atopic sensitization, allergic diseases, and respiratory health status in adults.
Methods: We identified 3626 participants of the European Community Respiratory Health Survey II in 10 countries who did the cleaning in their homes and for whom data on specific serum IgE to 4 environmental allergens were available. Frequency of bleach use and information on respiratory symptoms were obtained in face-to-face interviews. House dust mite and cat allergens in mattress dust were measured in a subsample. Associations between the frequency of bleach use and health outcomes were evaluated by using multivariable mixed logistic regression analyses.
Results: The use of bleach was associated with less atopic sensitization (odds ratio [OR], 0.75; 95% CI, 0.63-0.89). This association was apparent for specific IgE to both indoor (cat) and outdoor (grass) allergens, and was consistent in various subgroups, including those without any history of respiratory problems (OR, 0.85). Dose-response relationships (P < .05) were apparent for the frequency of bleach use and sensitization rates. Lower respiratory tract symptoms, but not allergic symptoms, were more prevalent among those using bleach 4 or more days per week (OR, 1.24-1.49). The use of bleach was not associated with indoor allergen concentrations.
Conclusion: People who clean their homes with hypochlorite bleach are less likely to be atopic but more likely to have respiratory symptoms.