Health effects of Mount St. Helens Volcano : Task 01 : Life span inhalation exposures of rats to Mount St. Helens volcanic ash : Final report

The objectives of the study were to investigate biological effects of chronic inhalation exposure to volcanic ash in the ratas a funtion of dose and cumulative exposure in summary there was no marked regression of lesions in the subgroups withdrawn from exposure at various intervals exception of lymphoreticular proliferation, which regressed in quartz exposed rats volcanic ash retained in the lungs of the rats at sacrifice clearly reflected the two different dose levelsand cumulative exposure