Variation in the Atmospheric Concentrations of ²¹⁴Pb with Local Meteorological Conditions at the Observation Site—Observation at Kawasaki, Japan—

Abstract

Every four hours variations in atmospheric ²¹⁴Pb concentrations were observed at Kawasaki, Japan. The monthly averaged concentration ranged from 1.3 to 4.1Bq/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:10.6h). 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.