Abstract:
According to NIOSH, sulfuric acid (H2SO4) is the most widely used chemical in industry, and is employed in the manufacture of fertilizers, petroleum refining, electroplating and acid cleaning, in storage batteries and as a starting material for a great many other chemicals. In industry, aerosols of H2SO4 may be generated mechanically or by condensation, and particles range in size from submicrometer to about 10 micrometers.
The hypothesis of this study is that a well-characterized H2SO4 aerosol, with chemical and physical properties representative of work place and ambient urban air, adversely affects the structure and function of human respiratory epithelial cells, which in turn may lead to bronchial reactivity, chronic bronchitis and other pathophysiologic responses.
The current study sought to develop a technique for studying the effects of acid aerosols on in vitro systems. To facilitate such studies it was necessary to build an exposure system which generates a well-characterized aerosol and deposits it evenly over cultures of human epithelial cells. This system was used to expose cells to two doses of sulfuric acid aerosol, generated from 0.16 M and 1.6 M H2SO4 solutions. The 0.16 M solution simulates the sulfuric acid concentration of naturally occuring droplets in the atmosphere. The 1.6 M concentration was used for comparison. Effects of the acid exposures were determined with an assay measuring changes in membrane permeability.