Ambient Airborne-Solids Concentrations Including Volcanic Ash at Hanford, Washington Sampling Sites Subsequent to the Mount St. Helens Eruption

摘要

A major eruption of Mount St. Helens, state of Washington, USA, occurred on May 18, 1980. The resulting volcanic ash plume was transported to the east. The Hanford area, northwest of Richland, Washington, was within the southern edge of the fallout plume. Airborne solid concentrations and airborne particle size distributions were measured at two sites in the Hanford area, a southern and northern site. During the initial sampling day (May 19), the average concentration for respirable particles, < 5.5- mu m diameter, was 1430- mu g/m exp 3 at the southern site; the total collection was 2610- mu g/m exp 3 . The respirable content of the total airborne solids was 55%. At both sites average airborne solid concentrations decreased to 10- to 20- mu g/m exp 3 in December. (ERA citation 07:023101)