Variation in the atmospheric concentrations of 214Pb with local meteorological conditions at the observation site. Observation at Kawasaki, Japan

Every four hours variations in atmospheric 214Pb concentrations were observed at Kawasaki, Japan. The monthly averaged concentration ranged from 1.3 to 4.1 Bq/m3. The variation patterns within 24 hours of the atmospheric concentration of short-lived 214Pb (half-life: 26.8 min) is similar to that of 212Pb (half-life: 10.6 h). The variation in atmospheric concentrations of 214Pb was observed to depend strongly on the local meteorological conditions in a short period. High concentrations of 214Pb tend to appear on the days with westerly wind from inland area, low wind velocity and without precipitation. (author)