MEASUREMENTS OF RADON CONCENTRATIONS AND EVALUATIONS OF INGESTION AND INHALATION DOSE IN WATER RESOURCES SAMPLES IN ILORIN, OFFA AND ORO KWARA STATE NIGERA.

The Radon concentrations in locally hand dug Tributaries and Streams water samples were collected within the crystalline rock areas of Ilorin, Offa, Oro and their surrounding environment across six(6) Local Government Areas of Kwara State, Northcentral Nigeria. The study aimed to understand the distribution and levels of radon in water sources and how they may impact the environment. The results of Radon concentrations measurements obtained within theare as existing in Southwestern Nigeria Precambrian Basement Complex ranged from 0.82 to 14.10 Bq/l in Offa,3.36 to 9.54 Bq/l in Oro and 1.00 to 10.26 Bq/l in Ilorin Study Areas. The findings of this investigation revealed that the Radon concentrations in all the domestic water samples are above the maximum radionuclides contaminant permissible levels of 0.11 Bq/l recommended by the Standards Organization of Nigeria SON but lower than the maximum contaminants limits(MCL) value of 11.1Bq/l recommended by the United States Environmental Protection Agency(USEPA). Annual effective doses to the stomach cells from the ingestion and inhalation of water respectively ranged from 0.64 - 1.73 M Suy and 0.77 - 2.33 M Svy evaluated for Ilorin study area, 0.86 - 2.96 M Suly and 0.38 - 6.52 M Suy in Offa while 0.70 -2.0 - and 0.85- 2.40 M Svy were determined for Oro. These results are beyond the International Committee on Radiation Protection(ICRP) maximum permissible levels of 3-10 mSvy. Hence, the outcome of this investigation revealed that the adioactive radon concentrations in the study areas could pose serious danger: than other water contaminants/pollutants in these environments. Therefore , regula monitorings are recommended to control the ingestion and inhalation doses due to intake of the commonly used water for domestic chores in the parts of Kwara State Studied