Radon Emanation and Physicochemical Parameters Assessment of Well Water in Selected Area in Ondo State, Nigeria

Abstract

In this study, water samples collected from hand-dug wells in Akoko area,
Ondo State, Southwestern Nigeria, were analyzed for radon concentration
using scintillation counter and physicochemical parameters such as
turbidity, conductivity, PH, total dissolved solid, and temperature by
chemical analysis. The concentration of radon was in the range 13.42 to
22.47 Bql-1 with a mean value of 17.25±2.03 Bql-1
. The radon
concentration in all the water samples was more than 11.1 Bql-1 which is
the maximum contamination limit proposed by the United State
Environmental Protection Agency. Likewise, all the samples had radon
activity concentration less than 100 Bql-1 WHO recommendation for
protecting the public from radon exposure due to drinking water supplies.
The estimated dose to the stomach varied from 4.10 to 6.87 (μSvy-1
) while
the dose to the lung varied from 4.05 to 6.79 (nSvy-1
) with an average dose
of 5.27±0.62 (μSvy-1
) and 5.21±0.61 (nSvy-1
) respectively. The total
effective doses attributable to inhalation and ingestion of radon in the dug
well water ranged from 37.88 to 63.43 (nSvy-1
) with an average value of
48.69± 5.72 (nSvy-1
). None of the water samples exceeded the individual
dose criterion of 0.1 mSy-1
, this showed that the water from the wells are
safe for drinking purposes. The physicochemical parameters results
showed various physical and chemical parameters ranged, temperature
(28.7-29.7)oC, PH (6.13-7.11), TDS (31.1-1210) mgl-1
, electrical
conductivity (46-1421) µscm-1
, turbidity (1.33-5.01) NTU. Most of the
physicochemical parameters are within the WHO safe limits.