Sara's Environmental Health : The 1980 Mount St. Helens Eruption

The 1980 Mount St. Helens Eruption

Overview of the Eruption: In May 1980, Mount St. Helens erupted. Mount St. Helens is located in Gifford Pinchot National Forest Washington, USA. According to History channel, St. Helens erupted between 1600s and 1700s and became quiet in 1857. Because the status of the activity in 1857, Mount St. Helens was assumed to be dormant. In March of 1980, there was a 4.1 magnitude earthquake. In April, there were rock slides. In May, a 5.1 magnitude earthquake occurred, and Mount St. Helens erupted. The eruption lasted 9 hours. The plume of ash reached 10 miles high. It killed everything within a 200 square mile area.

Impact: The eruption destroyed the entire forest. About 7000 large animals were killed including elk, deer and bears. Thousands of small animals were killed. Mudslide occurred caused by melted snow. It destroyed approximately 200 houses and contaminated rivers, lakes and creeks. 57 people died from this eruption or still considered missing.

Public health concerns: According to National Institute of Health library, this eruption caused respiratory illness from the ash. Ash fell as far as 930 miles, and 76% of the victims suffocated, 12% for thermal issue and 12% were trauma. The victims had significant psychiatric problem such as depression, hallucination and PTSD (Post-trauma stress disorder). The victims had asphyxiation from ash inhalation. Ash from the eruption was not acutely toxic but contained 3% to 7% crystalline free silica, which could cause potential pneumoconiosis.

Now, Mount St. Helens is only 8,363 feet tall- 1314 ft shorter than it was before.

The map of Gifford Pinchot National Forest Washington, USA, where Mount St. Helens eruption occured in 1980.