W e gratefully acknowledge the valuable technical assistance of L. de la Fonteyne-Blankestijn,Klerk, M. A. van Rees-Verhoef, J . A. Scholz, S . C. P. de Waal-Jacobs, I. Bos, P. 1-1. B. Fokkens, 1. Downloaded by [University of Sydney Library] at 13:46 15 August 2015 904
J . A. M. A. D O R M A N S E l AL.ozone exposure in male rats with age corroborates this suggestion. Ozone exposure decreased the clearance of Listeria bacteria in lungs. There was no significant difference between the various age groups in the resistance to Listeria infection after ozone exposure. It can therefore be concluded that specific toxicity indices including lung tissue damage, increased permeability, and inflammation point to a more pronounced responsiveness of younger animals to ozone. No gender-related differences in the response to ozone were observed for any of the parameters examined. These data support the view that age is a significant predictor of the pulmonary response to ozone, with younger subjects being more sensitive.