Effect of Activated Charcoal Fibers on the Survival of the House Dust Mite, Dermatophagoides pteronyssinus: A Pilot Study

House dust mites produce potent allergens that exacerbate asthma in sensitized patients, whom are recommended to practice allergen avoidance within their home environment. We tested the effect of activated charcoal impregnated fibers on house dust mite survival. One hundred live adult house dust mites (Dermatophagoides pteronyssinus) were added to eight culture dishes preequilibrated at room temperature ( ) and 70% humidity ( ) containing house dust mite food and active charcoal fibers. At 10 minute intervals, live and dead house dust mites were counted. All house dust mites instantly attached to the activated charcoal fibers and started to shrink almost immediately. There were no live house dust mites present as early as 40 minutes in some dishes while after 190 minutes all house dust mites were dead. In conclusion, activated charcoal fibers, if incorporated into bedding items, have the potential to control house dust mites in the indoor environment. 1. Introduction House dust mites (HDMs) produce potent allergens that can exacerbate asthma in sensitized patients [1]. HDM sensitized patients are generally recommended to practice allergen avoidance within their home environment, especially in the bedroom where they spend about one-third of their lives in close proximity to allergen-laden bedding items [2]. Commonly recommended HDM avoidance methods include covering all bedding with HDM impermeable materials. Although various studies have shown clinical efficacy of occlusive covers [3, 4], a recent large trial concluded they were ineffective [5]. Additionally, a recent systematic review has concluded that chemical and physical methods for reducing HDM allergens are not recommended [6]. However, this study has been criticized regarding its inclusion and exclusion criteria and evaluation of the studies [7]. Occlusive bedding covers, recommended by allergy and asthma societies worldwide, are expensive and alternative methods have been sought to reduce exposure to HDM allergens in bedding. We have previously shown that activated charcoal powder added to HDM food suppresses breeding of the HDM, Dermatophagoides pteronyssinus in the laboratory setting thus offering a potential new method for HDM control [8]. However, activated charcoal powder is messy and difficult to incorporate into bedding items. We therefore tested the effects of fibers impregnated with activated charcoal on HDM survival. 2. Methods To each of eight culture dishes, diameter 50？mm, height 15？mm (Corning, USA), 0.02？g of HDM food consisting of wheat germ (40%), granulated yeast (40%),