Activation Analysis of Airborne Dust. II.

Abstract

Instrumental neutron activation analysis by γ-ray spectrometry with a high resolution and large volume Ge (Li) detector followed by automatic data analysis with an electronic computer was applied to elemental analysis of airborne dust samples which were collected at four stations selected in Osaka and Sakai cities. Monthly average concentrations of various elements were determined during the period from March 1970 up to March 1971. For most elements, the highest concentration appeared in November to December and the lowest in August. A somewhat lower peak concentration appeared around June. Such a seasonal variation can be ascribed mainly to the meteorological conditions in Osaka district. Changeful variation was observed for several elements such as Zn, As, Se, Sb and Th, and was presumed to be closely related to industrial activities. Conspicuous area dependency was found, especially for concentrations of Se, As, Ba, La and Th. The main pollution source of Br is possibly the gas discharged from automobiles. Instrumental neutron activation analysis which easily makes it possible to get information about the abundance of so many elements will be quite effective fnr grasping the situations of air pollution.