| Popis: |
This study has investigated naturally occurring radioactive materials (N.O.R.M; 238 U, 222 Rn) for 353 drinking groundwaterwells in metamorphic rock areas in Korea. Uranium concentrations ranged from N.D (not detected) to 563.56µg/L(median value, 0.68µg/L) and radon concentrations ranged from 108 to 11,612 pCi/L (median value, 1,400 pCi/L).Uranium and radon concentrations in the groundwater generally are similar to USA with similar geological setting.Uranium concentrations in 9 wells (2.6%) exceeded 30µg/L, which is the maximum contaminant level (MCL) by the USenvironmental protection agency (EPA), radon concentrations in 46 wells (13%) exceeded 4,000 pCi/L, which is theAlternative MCL (AMCL) by the US.EPA. The log-log correlation coefficient between uranium and radon was 0.32. Thecorrelation coefficient between uranium and pH was 0.12 and the correlation coefficient between radon and temperaturewas −0.01. The correlation coefficient between uranium and HCO 3 was 0.09 and the correlation coefficient betweenuranium and Ca was 0.11. The median value of uranium was high Chung-Buk (1.78µg/L), Gyeong-Buk (1.37µg/L), In-Cheon (1.06µg/L) for each province. On the other hand, the median value of radon was high In-Cheon (2,962 pCi/L),Chung-Buk (2,339 pCi/L), Jeon-Buk (2,165 pCi/L) for each province. Jeon-Buk for log-log correlation coefficient is thehighest (0.63) among provinces. Key words :NORM (Uranium, Radon), Metamorphic rock, Groundwater, Correlation coefficient, MCL and AMCL |
