Inhalation studies of Mt. St. Helens volcanic ash in animals. II. Lung function, biochemistry, and histology

Environ Res. 1985 Jun;37(1):72-83. doi: 10.1016/0013-9351(85)90050-7.


Rats were exposed by inhalation to 9.4 mg/m3 size-fractionated volcanic ash for 5 days (2 hr/day) and examined for changes in pulmonary function and histology for periods of up to 1 year. Fine-mode volcanic ash, SO2, and a combination of ash and SO2 produced no observable effects in normal rats and rats with elastase-induced emphysema. However, there was a mild irritant response to SO2 which was not influenced by the volcanic ash. Rats injected intratracheally with fine-mode volcanic ash or saline showed no evidence of pulmonary alterations after 6 months. Those injected with coarse-mode volcanic ash showed minor pulmonary functional changes, histologically detectable alveolitis, and small increases in lung weight. In contrast, quartz-injected rats showed large alterations in pulmonary function, lung weight, hydroxyproline levels, and large areas of lung consolidation and fibrosis.

MeSH terms

  • Animals
  • Carbon / toxicity*
  • Hydroxyproline / analysis
  • Lung / drug effects*
  • Lung / pathology
  • Lung / physiology
  • Rats
  • Rats, Inbred Strains
  • Respiration / drug effects
  • Sulfur Dioxide / toxicity
  • Washington


  • Sulfur Dioxide
  • Carbon
  • Hydroxyproline