Measurement and analysis of long-term variation of atmospheric Be activity concentrations in Dazaifu (western Japan).

Atmospheric Be activity concentration was continuously measured in Dazaifu (33°30'N, 130°30'E), western Japan, from 1999 to 2020, and its variation was analyzed. Aerosol samples were collected using quartz fiber filters. The filtered samples were punched into circles, pressed, and molded into a 2-mm-thick disk for accurate Be quantification.

Variation analysis of atmospheric Be activity concentrations with respect to precipitation.

Beryllium-7 activity concentrations in the atmosphere and precipitation were continuously measured every day between April 2011 and December 2015 in Dazaifu, western Japan. The measured data were quantitatively analyzed to determine the precipitation-induced variation in Be activity concentrations. The average concentrations on nonprecipitation and precipitation days were 5.

Analysis of Factors Contributing to the Increase in Be Activity Concentrations in the Atmosphere.

In March 2013, increased Be activity concentrations in the atmosphere were observed for successive days in Dazaifu, western Japan. The daily Be activity concentration ranged from 0.93 to 14 mBq/m, with a monthly average of 8.

Cosmogenic Be: Particle size distribution and chemical composition of Be-carrying aerosols in the atmosphere in Japan.

The particle size distributions of airborne aerosols with Be were measured using cascade impactors at Dazaifu, a city in western Japan, in 2018 to observe their seasonal variation. Beryllium-7 was found to be adsorbed to aerosols with a particle size of less than 2.1 μm; in general, particles sized 0.

Radon and thoron exposures for cave residents in Shanxi and Shaanxi provinces.

Measurements of natural radiation were carried out in cave dwellings distributed in the Chinese loess plateau. Those dwellings are located in Shanxi and Shaanxi provinces. Radon and thoron gas concentrations were measured using a passive integrating radon-thoron discriminative detector.