• Journal of Soil and Groundwater Environment
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• v.16 no.6
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• pp.143-149
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• 2011

In order to figure out the characteristics of radionuclides concentrations of nine provinces, we analyzed uranium and radon in 681 samples of groundwater. Most of uranium concentrations in each province were less than $10{\mu}g/L$, and Gyeongnam, Jeonnam, Jeju provinces did not have groundwaters exceeding the US EPA drinking water MCL ($30{\mu}g/L$) of uranium. The ratio of radon values exceeding US EPA drinking water AMCL (4,000 pCi/L) was 22.6% (154/681) and Gyeongnam and Jeju provinces had no groundwaters exceeding the AMCL (alternative maximum contaminant level). Uranium and radon concentrations in groundwaters of Gyeonggi, Chungbuk, Jeonbuk, Chungnam mainly composed of the Mesozoic granite and the Precambrian gneiss were relatively high, but the concentrations of Gyeongnam and Jeju widely comprised of the sedimentary rock and the volcanic rock were relatively low. A week correlation between uranium and radon values showed in Gangwon, Chungbuk, Gyeonggi provinces.

• Journal of Environmental Policy
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• v.5 no.2
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• pp.49-67
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• 2006

The radionuclides in drinking water have been regulated in many countries. In USA, the regulation has been revised for over 30 years since radionuclides have been regulated under Safe Drinking Water Act(SDWA) from 1974. Today, USEPA is finalizing maximum contaminant level goal(MCLG) of zero for radionuclides, maximum contaminant level(MCL) and alternative maximum contaminant level(AMCL) of 300pCi/L and 4,000pCi/L for radon respectively, MCLs of $30{\mu}g/L$ for uranium, and MCLs of 5pCi/L for combined radium 226 and 228. In Canada, Maximum Acceptable Concentration(MAC) value for uranium is $20{\mu}g/L$. WHO revised the guideline value of uranium and radon to $15{\mu}g/L$ and 100Bq/L in september 2004, respectively. On this survey, it has been found that international regulations for radionuclides in drinking water have been established and improved steadily on the knowledge basis from the past decades' studies.

• Journal of Soil and Groundwater Environment
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• v.18 no.3
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• pp.82-92
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• 2013

This study has investigated naturally occurring radioactive materials (N.O.R.M; $^{238}U$, $^{222}Rn$) for 353 drinking groundwater wells in metamorphic rock areas in Korea. Uranium concentrations ranged from N.D (not detected) to 563.56 ${\mu}g/L$ (median value, 0.68 ${\mu}g/L$) 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 30 ${\mu}g/L$, which is the maximum contaminant level (MCL) by the US environmental protection agency (EPA), radon concentrations in 46 wells (13%) exceeded 4,000 pCi/L, which is the Alternative MCL (AMCL) by the US.EPA. The log-log correlation coefficient between uranium and radon was 0.32. The correlation coefficient between uranium and pH was 0.12 and the correlation coefficient between radon and temperature was -0.01. The correlation coefficient between uranium and $HCO_3$ was 0.09 and the correlation coefficient between uranium and Ca was 0.11. The median value of uranium was high Chung-Buk (1.78 ${\mu}g/L$), Gyeong-Buk (1.37 ${\mu}g/L$), In-Cheon (1.06 ${\mu}g/L$) 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 the highest (0.63) among provinces.

• The Journal of Engineering Geology
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• v.21 no.3
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• pp.259-269
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• 2011

Concentrations of uranium (U) and radon (Rn) were measured in groundwater from 74 wells in the Icheon area, with the aim of determining the range and distribution of concentrations in an area underlain by granite (in this case, the Icheon granite). U concentrations ranged from 0.02 to 1,640.0 ${\mu}g/L$ (median value, 2.03 ${\mu}g/L$) and Rn concentrations ranged from 40 to 23,400 pCi/L (median value, 4,649 pCi/L). U concentrations in 10.8% of the samples exceeded 30 ${\mu}g/L$, which is the maximum contaminant level (MCL) proposed by the US Environmental Protection agency (EPA), based on the chemical toxicity of U. In addition, U concentrations in 59.5% and 13.5% of the samples exceeded 4,000 pCi/L (the Alternative MCL (AMCL) of the US EPA) and 8,100 pCi/L (Finland’s guideline level), respectively. We found no significant correlations between U (Rn) and other constituents, except for U-$HCO_3$ (correlation coefficient of 0.71), U-Ca (0.69), U-Li (0.45), U-Sr (0.43), and U-F (0.42). U and Rn contents in the groundwater are low relative to those in areas in other countries with similar geological settings, possibly due to the inflow of shallow groundwater to the wells in the Icheon area.

• Environmental Analysis Health and Toxicology
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• v.17 no.4
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• pp.273-284
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• 2002

At present, the health risks associated with the natural radionuclides of ground water have become a concern as potential social problems. However, there are no regulatory actions or control strategies for such risks. Therefore, we have investigated and discussed the risks and associated management strategies for radionuclides in other countries. US EPA has proposed MCL (300 pCi/L) and AMCL (4,000 pCi/L) for radon, and 30 ppb for uranium, 15 pCi/L for gross-alpha and 5 pCi/L for radium as final MCLs. Also, Canada, WHO and European countries have their inherent management levels. Finally, we suggested several criteria for setting guidelines in our countries including exposure related criteria such as geological distribution, occurrence, exposure probability distribution, exposure population and multimedia exposure assessment, acceptable risk, and cost -benefit analysis. The national-scale exposure and risk assessment, and economic analysis should be conducted for producing and aggregating the representative information on these criteria.

• The Journal of Engineering Geology
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• v.29 no.4
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• pp.495-508
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• 2019

We measured the concentrations of natural radionuclides (uranium and radon) and major elements in groundwater collected from forty wells located in Wonju area to investigate the hydrochemistry and the occurrence of these radionuclides. The range of electrical conductivity (EC) value in the study area was 73~400 μS/cm. In addition to the increase of EC value, the content of cations and anions also tends to increase. Uranium concentrations ranged from 0.06~50.5 ㎍/L (median value, 1.55 ㎍/L) and radon concentrations ranged from 67~8,410 pCi/L (median value, 1,915 pCi/L). Uranium concentrations in 3 well, 7.5% of the samples, exceeded 30 ㎍/L, the maximum contaminant level (MCL) proposed by the US Environmental Protection Agency (EPA), based on the chemical toxicity of uranium. Radon concentrations in 9 wells, 22.5% of the samples, and 1 well, 2.2% of the samples, exceeded 4,000 pCi/L (AMCL of the US EPA) and 8,100 pCi/L (Finland's guideline level), respectively. Concentrations of uranium and radon related to geology of the study area showd the highest values in groundwater of the biotite granite area. Uranium and radon contents in the groundwater are comparatively low compared to those in other countries with similar geological settings. It is likely that the measured value was lower than the actual content due to the inflow of shallow groundwater by the lack of casing and grouting.

• Economic and Environmental Geology
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• v.51 no.6
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• pp.553-566
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• 2018

The occurrence of natural radionuclides like uranium and radon in groundwater was hydrochemically examined based on 40 well groundwaters in Mungyeong area. The range of electrical conductivity (EC) value in the study area was $68{\sim}574{\mu}S/cm$. In addition to the increase of EC value, the content of cations and anions also tends to increase. Uranium concentrations ranged from $0.03{\sim}169{\mu}g/L$ (median value, $0.82{\mu}g/L$) and radon concentrations ranged from 70~30,700 pCi/L (median value, 955 pCi/L). Only 1 out of 40 wells (2.5%) showed uranium concentration exceeding the maximum contaminant level (MCL; $30{\mu}g/L$) proposed by the US Environmental Protection Agency (EPA). Radon concentrations of eight wells (20%) exceeded AMCL(Alternative maximum contaminant level) of the US EPA (4,000 pCi/L). Four out of those eight wells even exceeded Finland's guideline level (8,100 pCi/L). When concentrations of uranium and radon were investigated in terms of geology, the highest values are generally associated with granite. The uranium and radon levels observed in this study are low in comparison to those of other countries with similar geological settings. It is likely that the measured value was lower than the actual content due to the inflow of shallow groundwater by the lack of casing and grouting.

• Economic and Environmental Geology
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• v.51 no.1
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• pp.27-38
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• 2018

Groundwaters in different rock types (Mesozoic granite, Precambrian gneiss, and schist) of Ganghwa island, Incheon City were characterized by using naturally occurring radioactive materials (NORM) and hydrogeochemical constituents. For the study, groundwater samples from 69 wells had been collected over eight years. Statistical methods were applied to relate hydrogeochemical components and NORM in the groundwater samples. The groundwater samples belonged to $Ca(Na)-HCO_3$ types. The uranium concentrations in three groundwater samples exceeded 30 ug/L of United States Environmental Protection Agency (US EPA) maximum contaminant level (MCL). The radon concentrations in 28 groundwater samples exceeded 4,000 pCi/L (picocuries per Liter) of US EPA alternative maximum contaminant level (AMCL). Gross-alpha in all the groundwater samples did not exceed 15 pCi/L of US EPA MCL. The average concentrations of uranium and radon in groundwater were the highest in granite area, and then gneiss, schist areas in order. In schist area, the correlation coefficient (R) between radon and $HCO_3$ is -0.40 and R between uranium and $SO_4$ is 0.54. In gneiss area, the R between radon and uranium is 0.55 and the R between uranium and $SO_4$ is 0.41. According to factor analysis, each geological area shows different chemical characteristics. The statistical analysis of whole groundwater resulted in nearly no significant relationship among uranium, radon and chemical constituents. Subsequently, more detailed studies on hydrogeological, geochemical, and geological characteristics related to NORM are required to better understand the behavior and fate of NORM.

• Journal of Environmental Science International
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• v.27 no.8
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• pp.651-663
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• 2018

The hydrochemistry of groundwater from 47 wells in the Chungwon area, Korea was analyzed to examine the occurrence of natural radionuclides like uranium and radon. The range of Electrical Conductivity (EC) value in the study area was $67{\sim}1,404{\mu}S/cm$. In addition to the high EC value, the content of cations and anions also tends to increase. Uranium concentrations ranged from $ND{\sim}178{\mu}g/L$ (median value, $0.8{\mu}g/L$) and radon concentrations ranged from 80~12,900 pCi/L (median value, 1,250 pCi/L). Uranium concentrations in one well, that is 2.8% of the samples, exceeded $30{\mu}g/L$, which is the Maximum Contaminant Level (MCL) proposed by the US Environmental Protection Agency (EPA), based on the chemical toxicity of uranium. Radon concentrations in three wells, that is 6% of the samples, and one well, that is 2.8% of the samples, exceeded 4,000 pCi/L (AMCL of the US EPA) and 8,100 pCi/L (Finland's guideline level), respectively. Concentrations of uranium and radon related to geology of the study area show the highest values in the groundwater of the granite area. The uranium and radon contents in the groundwater were found to be low compared to those of other countries with similar geological settings. It is likely that the measured value was lower than the actual content due to the inflow of shallow groundwater by the lack of casing and grouting.

• The Journal of Engineering Geology
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• v.23 no.4
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• pp.477-491
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• 2013

Natural radionuclides in groundwater in the Danyang area were investigated to characterize the behaviors of uranium and radon with respect to lithology and physico-chemical components, which can aid our understanding of their occurrence, properties, and origins. To this end, a total of 100 groundwater samples were collected and analyzed, and radionuclide levels were used to construct detailed concentration maps. The water type of the groundwater, assessed using a Piper diagram, is mainly Ca-Na-$HCO_3$. The concentrations of uranium range from 0.02 to $251.0{\mu}g/L$ (average, $3.85{\mu}g/L$) and only 1% exceed USEPA's MCL (Maximum Contaminant Level). Uranium is enriched in groundwaters of Cretaceous granites and Precambrian metamorphic rocks, whereas it is depleted in groundwaters of sedimentary rocks. The concentrations of radon range from 13 to 28,470 pCi/L (average, 2397 pCi/L). Only 15% of the samples exceed AMCL (Alternative Maximum Contaminant Level) of 4000 pCi/L. The radon concentration is highest in groundwater of Cretaceous granites and lowest in groundwater of sedimentary rocks. In conclusion, the distribution and occurrence of radionuclides are intimately related to the basic geological characteristics of the rocks in which the radiogenic minerals are primarily contained. The behavior of uranium is only weakly related to that of radon (correlation coefficient = 0.15). There are also weak correlations between radionuclides and the main chemical components, pH, EC, Eh, and well depth. Of note, the correlation coefficient between radon and $SiO_2$ is 0.68, and that between radon and $HCO_3$ is -0.48. Factor analysis shows that radionuclides behave somewhat independently of each other because there are no significant factors that control the behavior of chemical components as well as radionuclides. The detailed concentration maps during this study will be used to establish useful database of radionuclide distribution and geological properties throughout Korea.