The ozone in smog can impair immunity in human lungs. A laboratory study now indicates that the pollutant can do the same in toads.
Michael R. Dohm and his colleagues at the University of Hawaii at Hilo placed cane toads (Bufo marinus), collected locally, into a chamber for 4 hours with air containing 0.2 to 0.8 part per million (ppm) ozone. That's well above the 0.01 ppm ozone concentration typical of Hilo. But it's within the range of exposures in many major cities worldwide and the air that drifts downwind from them.
At various intervals over the 2 days following the ozone exposure, Dohm's team collected macrophages from the amphibians' lungs and tested them for ozone damage. Macrophages are immune cells that, among other roles, engulf bacteria and other microscopic particles.