Respiratory response of guinea pigs to ozone alone and with sulfur dioxide

Abstract

A guinea pig bioassay method for irritant response to address whether or not O2 and SO2 appeared to react to form H2SO4 in the respiratory tract was designed. Animals were exposed to 0.2, 0.4 and 0.8 ppm of each gas alone and to the combination at concentrations of 0.4 and 0.8 ppm. In these experiments SO2 alone produced no statistically significant alterations in respiration. All concentrations of O2 produced an increase in respiratory frequency. At the 2 higher concentrations the increase in frequency was accompanied by a decrease in compliance. The response to the combinations was the same as the response to those levels of O2 alone. No H2SO4 was detected in the chamber atmosphere. The biological data suggest that none was formed in the lung.