An inhalation exposure system for the oil dispersant COREXIT(R) EC9500A.
Goldsmith-WT; McKinney-W; Jackson-M; Law-B; Bledsoe-T; Siegel-P; Frazer-D
FASEB J 2011 Apr; 25(Meeting Abstracts):1016.1
An automated whole body inhalation exposure system capable of exposing 12 rats was designed to examine the potential health effects of the oil dispersant (COREXIT EC9500A [CE]) used during the Deepwater Horizon oil spill. A computer-controlled syringe pump injected the CE into an atomizer where droplets and vapor were formed and mixed with diluent air. The aerosolized CE was passed into a customized exposure chamber where a calibrated light scattering instrument estimated the real-time particle mass concentration of the aerosol in the chamber. A custom software GUI was developed to record and control parameters during the exposures. Software feedback loops controlled the chamber aerosol concentration and pressure throughout each exposure. Particle size of the dispersant aerosol was measured and shown to have a number peak at 271 nm and a mass peak at 961 nm. The method used to determine the chamber concentration was a modification of the acidified methylene blue spectrophotometric assay for anionic surfactants. Filter samples were extracted in 5 mL water/filter using sonication for 30 min and diluted 1/10 for analyses. CE filter content was extrapolated from a standard plot using the original CE (4-130 nL/mL water) material and adjusted for density. Five automated 5 hour animal exposures were performed that produced controlled and consistent CE concentrations (27.1 +/- 2.9 mg/m3).
Exposure-chambers; Exposure-assessment; Exposure-methods; Aerosols; Aerosol-generators; Aerosol-particles; Dispersion
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