DETERMINATION OF RADON- 222 CONCENTRATIONS AND EFFECTIVE DOSE BY INGESTION IN GROUND AND SURFACE WATER SOURCES FROM IDAH AND ENVIRONS, NIGERIA

Groundwater (well and borehole) and surface water samples from various locations of Idah and environs including have been investigated for their 222Rn concentrations by Liquid Scintillation Counter (Packard Tri-Carb LSA 1000TR) manufactured by Packard Instrument Company. The mean concentration ranges from 4.70 Bq/L to 24.0 Bq/L for borehole samples, 5.70 Bq/L to 13.60 Bq/L and 1.90 Bq/L to 4.50 Bq/L for well and surface water respectively were found. The average mean concentration of 10.23 Bq/L and 12.28 Bq/L were found for borehole and well waters respectively which were above the maximum contaminant limit of 11.1 Bq/L set by USEPA and 10.0 Bq/L by UNSCEAR and WHO. The average mean concentration of 3.05 Bq/L was found for surface water making it safe drinking and domestic use. The average total effective dose by ingestion was found to be 0.0412mSv/y which is lower than the recommended limit for members of the public of 1.0 mSv/y and intervention level of 3 – 10 mSv/y by ICRP.