Biological effects of urban air pollution. 3. Lung tumors in mice.

Abstract

Various strains of mice were exposed to ambient or filtered Los Angeles air. Filters removed most pollutants except nitric oxide and carbon monoxide. Maximum levels during 1962--64 were: oxidants--< 0.5 ppM, NO/sub 2/--< 0.6 ppM, NO--1.2 ppM, CO--40 ppM, hydrocarbons--12 ppM, SO/sub 2/--0.02 ppM. Monthly averages were approximately an order of magnitude less. Aging mice exposed to ambient air seemed to have more lung adenomas although results were highly variable and significance could only be demonstrated by various groupings of site and age.