en |
Determination of the radiation dose due to radon ingestion and inhalation
Ravikumar, P. & Somashekar, R. K.
Abstract
The distribution of radon in ground and surface
water samples in Sankey Tank and Mallathahalli Lake
areas was determined using Durridge RAD-7 analyzer with
RAD H2O accessory. The radiation dose received by an
individual falling under different age groups (viz.,
3 months; 1, 5, 10, 15 years and adult) depending upon
their average annual water consumption rate was attempted.
The mean radon activity in surface water of Sankey
Tank and Mallathahalli Lake was 7.24 ± 1.48 and
11.43 ± 1.11 Bq/L, respectively. The average radon
activities ranged from 11.6 ± 1.7 to 381.2 ± 2.0 Bq/L and
1.50 ± 0.83 to 18.9 ± 1.59 Bq/L, respectively, in 12
groundwater samples each around Sankey Tank and Mallathahalli
Lake areas. Majority of the measured groundwater
samples (viz., 100 % in Sankey Tank area and 75 %
in Mallathahalli Lake area) showed mean radon values
above the EPA’s maximum contaminant level of 11.1 Bq/L
and only 66.67 % of samples in Sankey Tank area showed
radon above the WHO and EU’s reference level of 100 Bq/
L. The overall radiation dose due to radon emanating from
water in the study area was increasing with increase in age
and water consumption rates, but significantly lower than
UNSCEAR and WHO recommended limit of 1 mSv/year
except for few groundwater samples in Sankey Tank area
(i.e., 0.92, 0.99 and 1.39 mSv/year). The radiation dose
rate received by bronchial epithelium via inhalation was
very high compared to that by stomach walls via ingestion.
Keywords
Aerator; Closed loop; Decay correction; Humidity; Desiccant; Polonium; Radioactivity
|