THE EFFECT OF RELATIVE-HUMIDITY ON MOUSE ALLERGEN LEVELS IN AN ENVIRONMENTALLY CONTROLLED MOUSE ROOM

To determine the effect of humidity on the levels of the mouse allerge n Mus m 1, an experimental animal room was constructed to control envi ronmental variables. The sex, strain, age, and number of mice was cons tant in the room, so that the average daily production of Mus m 1 woul d not vary greatly. Six different levels of relative humidity from 15% to 65% were maintained for a minimum of a week each. Daily collection s of airborne particulates were eluted from filters and Mus m 1 conten t measured by immunological assay. Increasing relative humidity caused a decrease in Mus m 1 levels from a high of 3 ng/mg(3) at 15% humidit y to a low of 0.5 ng/m(3) at 65% humidity. Thus, reduction of airborne allergen levels can be achieved by careful attention to humidity cont rol, especially during the winter heating season when humidity levels may be low. This experimental room can be used to measure the effect o f other variables such as ventilation rate, caging, bedding, and work practices on the levels of mouse allergen in an animal facility.