A simple dynamic flow-through exposure system for assessment of biological activity of complex organic mixtures to mammalian cells in vitro.

A system for in vitro exposure of lung epithelial cells and Chinese hamster ovary cells maintained at an air-medium interface to volatile organic compounds has been developed. The system has been used for exposure of cells to phenol (vapor pressure at 40 degrees C = 1.6 mm Hg) and to a complex mixture of organic compounds (vapor pressure range at 32 degrees C = 0.17 to 269 mm Hg). A linear relationship was found between vapor generator air flow rate (0.25 to 1.0 L/min at 39 degrees C) and exposure chamber phenol concentration. The relationship between generator air flow rate (0.5 to 1.0 L/min at 39 degrees C) and concentration of the complex mixture in the exposure chamber was also linear. Gas chromatographic analyses of chamber exhaust indicated that a majority of the compounds present in the crude mixture had been volatilized and made available to the cells in the chamber. This exposure system appears suitable for screening of complex mixtures of volatile organic pollutants for biological activity in mammalian cells in culture.