大気中の塵の走査型電子顕微鏡による形態観察

Aerosol dusts observed in August, September and November 1991 over Matsue, Shimane, were collected by air-sampler. The dust samples were examined by using X-ray powder diffraction (XRD) and scanning electron microscopy-Energy dispersive X-ray analysis (SEM-EDX). XRD data show that aerosol dusts are mainly composed of amorphous materials with sulfur, sulfate (barite, gypsum, etc.) and halite, SEM observation revealed that the amorphous materials were derived from pollen of Altemisia, Bougainvillea Spectabilis, Sciadopitys Verticillata, Crypomeria Japonica, scales, carbonaceous soot aggregates and volcanic glass. SEM with EDX showed that cubic barite and platy gypsum were agregated with volcanic glass contain high concentration of S, Ca or Ba. The most likely source of these aerosol dusts come from volcanic ash, such as Sakurajima or Unzen in Kyushu. Various pollen in the aerosol suggest that the dust components are seasonal changed. Based on these microanalyticial observations, the circulation of aerosol system and component in atmosphere influence greatly on local environmental condition.