A system for exposing laboratory animals to cotton dust aerosol that is stabilized with feedback control.
Frazer-DG; Robinson-V; DeLong-DS; Rose-D; Tucker-J; Weber-KC; Olenchock-SA; Jayaraman-K
Cotton dust: proceedings of Eleventh Cotton Dust Research Conference, Beltwide Cotton Research Conferences, January 7-8, 1987, Dallas, Texas. Jacobs RR, Wakelyn PJ, eds. Memphis, TN: The National Cotton Council of America, 1987 Jan; :74-78
A system was developed for exposing small laboratory animals to respirable cotton dust using a Pitt-3 generator with an operator controlled feedback loop. A water seal compressor was used as the air source for the suspension of the cotton dust; the cotton dust generator used acoustical energy to disperse particles into the air stream. The resonant frequency of the generator was 27.5 hertz. After exiting the mixing chamber, the aerosol passed through a chamber containing a miniram, a light scattering aerosol monitoring device for the detection of a combined scattering signal from the particles within its sensing volume. An operator used the data output to control the amount of dilutant air that was added to the cotton aerosol in the mixing chamber. Exposure system performance was evaluated by mass/concentration of cotton dust versus time, cotton dust aerosol size distribution versus time, cotton dust endotoxin measurements, sequential electron micrographs of cotton dust, and exposure chamber environment. The use of the operator controlled feedback loop greatly improved the mass concentration stability of the exposure system; 30 grams of bulk cotton dust were required for a 6 hour exposure period. There were no significant changes in count distribution or endotoxin levels of cotton dust aerosol samples during exposure. The temperature and humidity of the exposure chamber were well regulated. The authors conclude that this system is very well suited for future cotton dust exposure studies.
Cotton-dust; Laboratory-animals; Exposure-chambers; Acute-exposure; Dust-exposure; Exposure-methods; Aerosols; Aerosol-generators
Cotton dust: proceedings of Eleventh Cotton Dust Research Conference, Beltwide Cotton Research Conferences, January 7-8, 1987, Dallas, Texas