Control strategies for aeroallergens in an animal facility.
BACKGROUND
Prevalence of the occupational disease laboratory animal allergy could be reduced if aeroallergen reduction strategies are identified.


OBJECTIVE
To reduce worker exposure to Mus m 1, an allergen from laboratory mice, the effect of filter cage tops, increased room ventilation, negatively pressurized ventilated cages, and ventilated cage-changing tables were evaluated.


METHODS
Aeroallergen was collected in the ambient air and in the breathing zone and quantified by using a competitive immunoassay.


RESULTS
When mice were housed in unventilated cages, ambient allergen was reduced from 5.1 ng/m3 with no cage top to 1.3 ng/m3 with a simple filter-sheet top and 0.8 ng/m3 with a fitted filter-bonnet top (P <. 05). Room ventilation was increased from 6 to 10, 15, and 20 air changes per hour and had little effect on aeroallergen levels and no impact on airborne particulate matter. When mice were housed in ventilated cages, ambient allergen was significantly reduced from 1. 1 ng/m3 at positive cage pressure to 0.3 ng/m3 at negative cage pressure (P <.05). Negative cage pressure combined with handling animals under a ventilated table reduced breathing zone allergen from 28 ng/m3 with neither control strategy in place to 9 ng/m3 (P <. 05). Use of a ventilated table controlled bacterial contamination, measured as colony forming units, found in negatively pressurized cages.


CONCLUSIONS
Three aeroallergen control strategies are use of filter cage tops, operation of negatively pressurized cages, and use of ventilated changing tables.
Reeb-Whitaker
C K
CK
Jackson Laboratory, Bar Harbor, Maine 04609, USA.
Harrison
D J
DJ
Jones
R B
RB
Kacergis
J B
JB
Myers
D D
DD
Paigen
B
B
D000397:Air Pollution / Q000517:prevention & control*; D000818:Animals; D000830:Animals, Laboratory / Q000276:immunology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009784:Occupational Diseases / Q000276:immunology*