Seismic activity persists at Mount Spurr, which scientists said could mean the Alaska volcano is poised for a possible eruption.

When a large volcano erupts, as Mount Spurr appears close to doing about 80 miles from Anchorage, Alaska, it can ...

The finest particles pose the greatest risk because they can penetrate deep into the lungs and cause death by asphyxiation in the worst cases. Mild, short-term symptoms often resolve with rest.