Measurements of Gross Alpha and Beta Radioactivity in Surface Soil, Mineral Rock and Consumable Water around Mining Sites in Benue State, Nigeria

The concentration of gross alpha and gross beta radioactivity in surface soil, mineral rock and consumable water around mining sites in Benue state, Nigeria have been measured using protean instrument corporation (PIC) MPC 2000DP detector. The average activity for gross alpha ranged between 4.20±2.00 Bq/kg (coal) – 11.8±4.00 Bq/kg (salt) in soil and in mineral rocks the activity varies between 1.11±0.70 Bq/kg (lead) to 5.20±3.00 Bq/kg (limestone). The gross beta has an average activity ranges between 739.6±542.0 Bq/kg (lead) – 1703.3±152.20 Bq/kg (limestone) in soil and values of 245.3±171.5 Bq/kg (coal) to 1004.5±98.5 Bq/kg (barite) was obtained for mineral rocks. The average activity concentrations of gross alpha and beta in soil were compared with other literature values. Correlations were made among the variables (gross alpha and gross beta) to prove the interdependency or direct relationship in the investigated samples. In water samples, the calculated average value of gross alpha and gross beta activities varies from 0.0078±0.0036 (barite) to 0.1620±0.2530 Bq/L (salt) and 0.2200±0.0123 (limestone) to 4.8500±0.1510 Bq/L (coal) respectively. The average activity concentrations of gross alpha in water in all mining fields were below the permissible levels stipulated by World Health Organization (WHO). The average annual committed effective dose from intake of water was calculated to study the dose level. The values obtained in limestone, barite, lead and salt mine fields were lower than the (WHO) recommended reference level (0.1mSv/y) while the value obtained in coal mine field was higher than the reference level. Consumable water around the coal mine field may pose a health risk as the ingested dose is quite high.