Some observations on the concentrations of short-lived decay products of radon and thoron in the monsoon rains of Bombay, India

Journal Article · Tue Aug 20 00:00:00 EDT 1985 · J. Geophys. Res.; (United States)

DOI:https://doi.org/10.1029/JD090iD05p08155· OSTI ID:5203479

Rangarajan, C; Eapen, C D

The concentrations of radon decay products /sup 214/Pb(RaB) and /sup 214/Bi(RaC) and thoron daughter /sup 212/Pb(ThB) have been measured in rainfall at Bombay. The presence of short-lived /sup 218/Po(RaA) is indicated in a few samples. The levels of /sup 214/ Pb varied from 300 to 7000 pCi (11-260 Bq) per liter, while the activity ratios of /sup 214/Bi//sup 214/Pb are in the range of 0.5-1.5. From these values of the ratios a cloud drop lifetime, from nucleation to deposition, of 20--60 min is estimated. The concentrations of /sup 212/Pb varied from 2 to 30 pCi (0.075-1.1 Bq) per liter. The levels of radon and thoron daughter products are lower in Bombay summer rainfall compared with other areas due to their reduced concentrations in the maritime monsoon winds. Approximate estimates of scavenging ratios based on the surface air concentrations are 85 +- 65 (1 standard deviation) and 30 +- 20 (1 standard deviation) for radon and thoron daughters, respectively.

• Research Organization: Air Monitoring Section, Division of Radiological Protection, Bhabha Atomic Research Centre, Bombay, India
• OSTI ID: 5203479
• Journal Information: J. Geophys. Res.; (United States), Journal Name: J. Geophys. Res.; (United States) Vol. 90:D5; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

500300* -- Environment
Atmospheric-- Radioactive Materials Monitoring & Transport-- (-1989)
54 ENVIRONMENTAL SCIENCES
ACTINIDE COMPOUNDS
ACTIVITY LEVELS
ASIA
ATMOSPHERIC CHEMISTRY
CHEMISTRY
CLOUDS
DECAY
DEVELOPING COUNTRIES
DROPLETS
ELEMENTS
FLUIDS
GASES
HYDROGEN COMPOUNDS
INDIA
LIFETIME
NONMETALS
OXYGEN COMPOUNDS
PARTICLES
QUANTITY RATIO
RADON
RAIN WATER
RARE GASES
THORIUM COMPOUNDS
WATER