Research Program Area: Health & Exposure
Topic Areas: Health Effects of Air Pollution
These investigations dealt with further clarification of links between ozone inhalation and lung diseases increases in allergic lung disease occurred among our test populations of mice following inhalation of ozone, thus establishing a cause and effect relationship between the toxic inhalant and enhancement of a specific health problem. Allergic enhancement was detected in an experiment with an ozone concentration of 0.13 ppm. When the ozone level was reduced to 0.10 ppm, the effect disappeared. The ozone threshold is now considered to be a concentration less than 0.13 ppm and greater than 0.10 ppm. An adjuvant substance was used to increase the effectiveness of the antigen (allergen) for inducing immunology responses in the body. The adjuvant was inactivated Bordetella pertussis cells. This is the same material that is used to immunize against whooping cough in children. In mice receiving adjuvant. there was a significant enhancing effect for allergic sensitization from ozone at the level of 0.10 ppm. Work, was begun to study the allergic enhancement by ozone in an animal model where the allergic reaction would be analogous to an asthma attack in human subjects. Three preliminary trials led to the development of a protocol for the aerosol sensitization of guinea pigs and the elucidation of disease responses in the lungs. In past experiments an ozone effect was detected as an alteration in the severity of viral pneumonia wherein the ozone exposed animals experienced a milder influenza process. It was considered likely that inhaled ozone could inactivate virus as ft was transferred from infected to non-infected cells in the airways, An experiment was run at the ozone level of 0.16 ppm to determine if the observed effect would persist. This ozone concentration was chosen because it is frequently encountered in the environment and because in vitro studies showed that it had only a minimal, and delayed, effect for influenza virus inactivation. The experiment revealed that the ozone effect had persisted, and significantly less mortality occurred in the ozone exposed animals.
For questions regarding this research project, including available data and progress status, contact: Research Division staff at (916) 445-0753
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