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  Environmental Policy Issues

Radon in Drinking Water Issues
(Released February 2000)

 

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  1. Assessment of human exposures to natural sources of radiation in Kenya

    Mustapha, AO; Patel, JP; Rathore, IVS

    Radiation Protection Dosimetry [Radiat. Prot. Dosimet.], vol. 82, no. 4, pp. 285-292, 1999

    Exposures to various components of the natural background radiation in Kenya were estimated using measured activity concentrations of natural radionuclides and conversion factors. Contributions to the total effective dose include: 0.1 to 2.0 mSv.y super(-1) from terrestrial gamma radiation; 0.2 to 0.7 mSv.y super(-1) and a per capita of 0.4 mSv.y super(-1) from cosmic radiation; and 0.4 to 6.0 mSv.y super(-1) from inhalation of radon ( super(222)Rn). Radon concentrations also range from 5 to 1200 Bq.m super(-3) in indoor air and from 1 to 410 Bq.1 super(-1) in drinking water. Considering the population distribution in relation to living habits of the people and to the relief and the geology in Kenya, it is concluded that the average annual effective dose in Kenya is higher than the global average. Ingestion of volcanic ash by some people, particularly pregnant women, was also identified as an additional (unusual) internal exposure pathway.

  2. Council examines risk of radon in drinking water

    Crow, P

    Waterworld, vol. 14, no. 10, p. 1,7, Dec 1998

    A National Research Council study has concluded that radon in household water poses few risks to human health, although it does increase residents' overall exposure to the gas. The group urged the Environmental Protection Agency to set a standard of 150 becquerel per liter of water. The study, "Risk Assessment of Radon in Drinking Water," was requested by Congress. It said ingesting water that contains radon is much less of a health risk than inhaling radon.

  3. Radon risk in drinking water downplayed

    Denn, J

    Water Technology [Water Technol.], vol. 21, no. 11, pp. 48-49, Nov 1998

    A definitive study from the National Research Council says radon in drinking water poses little danger to humans, less than earlier estimates made by the US Environmental Protection Agency, However, radon in air remains a health threat.

  4. Uncertainty and variability analysis in multiplicative risk models

    Rai, SN; Krewski, D

    Risk Analysis [RISK ANAL], vol. 18, no. 1, pp. 37-45, Feb 1998

    Currently, there is a trend away from the use of single (often conservative) estimates of risk to summarize the results of risk analyses in favor of stochastic methods which provide a more complete characterization of risk. The use of such stochastic methods leads to a distribution of possible values of risk, taking into account both uncertainty and variability in all of the factors affecting risk. In this article, we propose a general framework for the analysis of uncertainty and variability for use in the commonly encountered case of multiplicative risk models, in which risk may be expressed as a product of two or more risk factors. Our analytical methods facilitate the evaluation of overall uncertainty and variability in risk assessment, as well as the contributions of individual risk factors to both uncertainty and variability which is cumbersome using Monte Carlo methods. The use of these methods is illustrated in the analysis of potential cancer risks due to the ingestion of radon in drinking water.

  5. Risk assessment of radon in drinking water

    NATIONAL ACADEMY PRESS, 1998, 286 pp

    This study, required under the Safe Drinking Water Act amendments of 1996, takes a new look at risks posed to human health by waterborne radon. Noting that most of the radon that enters a building comes directly from soil, the report adds that radon is also found in well water and will enter a building whenever this water is used. Radon is often released from the water and mixes with the indoor air, adding to the total inhalation risk. The report examines to what extent ingested radon, dissolved in drinking water, is a health risk, and to what degree radon released from water into air increases the health risk from inhalation. The report covers the occurrence of radon in the U.S.; biologic basis of risk estimation; ingestion and inhalation risks; mitigation of radon in air and in water; and multimedia approach to risk reduction. A key finding is that drinking water which contains radon has a much lower health risk than inhaling radon. The report estimates that the risk of stomach cancer caused by drinking water containing dissolved radon is extremely small and would probably result in about 20 deaths per year (compared to 13,000 deaths from stomach cancer arising from other causes).

  6. Alkaline single cell gel electrophoresis and human biomonitoring for genotoxicity: a study on subjects with residential exposure to radon

    Hellman, B; Friis, L; Vaghef, H; Edling, C

    Mutation Research-Genetic Toxicology and Environmental Mutagenesis [Mutat. Res.-Genet. Toxicol. Environ. Mutag.], vol. 442, no. 2, pp. 121-132, 25 Jun 1999

    Based on theoretical estimates and various correlation studies, it has been suggested that ingestion of radon in drinking water represents an increased risk for cancer. Such a risk has never been conclusively shown in epidemiological or experimental animal studies, however, and it has been questioned whether the radon level in the drinking water is of any significance in terms of overall radon exposure. Using primary DNA damage as a biological marker for an ongoing exposure to ionising radiation, the present study was undertaken to investigate whether people with different types of residential radon exposures differed with regard to their levels of DNA damage in circulating lymphocytes. DNA damage was measured in coded blood samples from 125 residents living in 45 households with different levels of radon-222 in the drinking water (10-2410 Bq/l) and indoor air (35-1025 Bq/m super(3)) using alkaline single cell gel electrophoresis (the `Comet' assay). Increased levels of radon in indoor air (>200 Bq/m super(3)) were found to be associated with an increased level of DNA damage in peripheral lymphocytes (P less than or equal to 0.05). No such correlation was seen for the radon concentrations in the drinking water, and there was no obvious relationship between the radon levels in drinking water and in indoor air. The results of the present study suggest that measures taken to reduce residential radon exposures should be focused on reducing radon levels in indoor air rather than minimising radon levels in drinking water.

  7. Alkaline single cell gel electrophoresis and human biomonitoring for genotoxicity: a study on subjects with residential exposure to radon

    Hellman, B; Friis, L; Vaghef, H; Edling, C

    Mutation Research-Genetic Toxicology and Environmental Mutagenesis [Mutat. Res.-Genet. Toxicol. Environ. Mutag.], vol. 442, no. 2, pp. 121-132, 25 Jun 1999

    Based on theoretical estimates and various correlation studies, it has been suggested that ingestion of radon in drinking water represents an increased risk for cancer. Such a risk has never been conclusively shown in epidemiological or experimental animal studies, however, and it has been questioned whether the radon level in the drinking water is of any significance in terms of overall radon exposure. Using primary DNA damage as a biological marker for an ongoing exposure to ionising radiation, the present study was undertaken to investigate whether people with different types of residential radon exposures differed with regard to their levels of DNA damage in circulating lymphocytes. DNA damage was measured in coded blood samples from 125 residents living in 45 households with different levels of radon-222 in the drinking water (10-2410 Bq/l) and indoor air (35-1025 Bq/m super(3)) using alkaline single cell gel electrophoresis (the `Comet' assay). Increased levels of radon in indoor air (>200 Bq/m super(3)) were found to be associated with an increased level of DNA damage in peripheral lymphocytes (P less than or equal to 0.05). No such correlation was seen for the radon concentrations in the drinking water, and there was no obvious relationship between the radon levels in drinking water and in indoor air. The results of the present study suggest that measures taken to reduce residential radon exposures should be focused on reducing radon levels in indoor air rather than minimising radon levels in drinking water.

  8. Formation of radon-bearing waters near the town of Cheboksary

    Tikhonov, AI; Skvortsov, SE; Egorov, SP; Ivanov, AF; Vasil'ev, AV; Nikolaev, AK; Orlov, SA

    Geochemistry International [Geochem. Int.]; Geokhimiya [Geokhimiya], vol. 37, no. 2, pp. 171-176; no. 2, pp. 201-206, Feb 1999

    In the aquifers confined to the Permian sediments near the town of Cheboksary, we found Rn concentrations exceeding the maximum permissible concentration (MPC) for drinking water. The anomalous zone is accompanied by high U content in the groundwaters and an elevated level of gamma -activity at the surface. The data obtained show that the anomalous zone can extend to the Cheboksary Lake, where a local positive geomagnetic anomaly exists within the generally negative background. This anomaly is caused by a long-term dissipation of deep Fe-rich fluids along a fault. It is suggested that the extinction of fish in the Cheboksary Lake in 1996 was induced by a short-term extensive influx of the Rn-bearing waters of the activation of a neotectonic zone in a year of elevated solar activity. This neotectonic zone extends west-east near the town of Cheboksary. Monitoring of the Rn concentration in the development wells is necessary.

  9. Occurrence of radon in the drinking water of Dehradun City, India

    Ramola, RC; Choubey, VM*; Saini, NK; Bartarya, SK

    Indoor+Built Environment [Indoor Built Environ.], vol. 8, no. 1, pp. 67-70, Feb 1999

    In this paper, the results of measurements of radon ( super(222)Rn) in the drinking water of Dehradun City are presented. The radon was measured in water samples taken from the tube wells and hand pumps which are the usual sources of water supply in the city. The recorded radon concentrations in 19 water samples from different hand pumps were found to vary from 27 to 154 Bq/l with an average of 67 Bq/l, while radon concentrations in 49 water samples from different tube wells were found to vary from 26 to 129 Bq/l with an average of 59 Bq/l. The results are compared with international recommendations for human exposure. These recorded values were found to be above the average of the recommendations but well below the highest recommended value of 400 Bq/l. In general, the drinking water of Dehradun city is contaminated by radon at a concentration which is reasonably uniform over the study area.

  10. Occurrence of radon in the central region groundwater of Saudi Arabia

    Alabdula'aly, AI

    Journal of Environmental Radioactivity [J. Environ. Radioact.], vol. 44, no. 1, pp. 85-95, 1999

    Radon levels were measured in eight water supply municipalities of the Central Region of Saudi Arabia. Samples were collected from 77 wells and 6 treatment plants supplying drinking water to over 500 000 inhabitants. The well water radon level was in the range of 0.89-35.44 Bq/l with an overall weighted geometric mean value of 8.80 Bq/l. Most of the raw water radon was removed by the plants' treatment processes. Aeration and filtration resulted in 60.5% radon removal compared to a removal in the range of 78.7-96.5% in treatment plants containing reverse osmosis or electrodialysis processes along with aeration. The plants' product water contains radon levels in the range of 0.15-5.71 Bq/l whereas two water systems with no treatment contain levels of 2.07 and 1.19 Bq/l.

  11. Radiological assessment of drinking water of the Chittagong region of Bangladesh

    Alam, MN; Chowdhury, MI; Kamal, M; Ghose, S; Islam, MN; Anwaruddin, M

    Radiation Protection Dosimetry [Radiat. Prot. Dosimet.], vol. 82, no. 3, pp. 207-214, 1999

    The specific activity of super(222)Rn, super(226)Ra, super(232)Th and super(40)K in drinking water of the Chittagong region of Bangladesh was measured using high resolution gamma spectrometry. The specific activity of super(222)Rn in the drinking water ranged from 2.04 plus or minus 0.51 to 9.39 plus or minus 2.06 Bq.l super(-1) and the mean activity was 4.46 plus or minus 1.95 Bq.l super(-1). The mean specific activity of super(226)Ra was found to be 0.043 plus or minus 0.017 Bq.l super(-1), the mean activity of super(232)Th was 0.19 plus or minus 0.05 Bq.l super(-1), and the mean super(40)K activity was 4.16 plus or minus 1.58 Bq.l super(-1). No super(134)Cs and super(137)Cs activity was detected in any of the samples of drinking water from the region. From these data the age-dependent associated effective doses due to the ingestion of these isotopes as a consequence of direct consumption of drinking water has been calculated. The average adult effective dose due to intake of drinking water was 56.2 mu Sv.y super(-1) for super(232)Th, 7.6 mu Sv.y super(-1) for super(226)Ra and 16.7 mu Sv.y super(-1) for super(40)K.

  12. The chemistry of Norwegian groundwaters: I. The distribution of radon, major and minor elements in 1604 crystalline bedrock groundwaters

    Banks, D; Frengstad, B; Midtgaerd, AK; Krog, JR; Strand, T

    Science of the Total Environment [Sci. Total Environ.], vol. 222, no. 1-2, pp. 71-91, 15 Oct 1998

    A quality-controlled hydrogeochemical dataset of 1604 groundwater samples from Norwegian crystalline bedrock aquifers has been obtained and subject to analyses of radon (scintillation counting), major and minor elements (ion chromatography and ICP-AES), pH and alkalinity. Cumulative probability curves may be constructed to assess the risk of given parameters violating drinking water norms. Parameters such as radon and fluoride show clear lithological correlation, occurring at high concentrations in granites and low concentrations in anorthosites. Other parameters exhibit a lower degree of correlation with aquifer geochemistry (e.g. pH, major ions) and are likely to be governed by more universal thermodynamic equilibria (the calcium carbonate system) and kinetic factors. On a national basis 13.9% of the bedrock groundwaters exceed the recommended action level for radon, while 16.1% exceed the drinking water norm for fluoride. Considering pH, sodium, radon and fluoride together, 29.9% of all wells violate drinking water maximum concentrations for one or more of these parameters.

  13. Removal of natural radionuclides from drinking water by point of entry reverse osmosis

    Huikuri, P; Salonen, L; Raff, O

    MEMBRANES IN DRINKING AND INDUSTRIAL WATER PRODUCTION, Elsevier Science B.V., P.O. Box 211, 20 Sep 1998, pp. 235-239, Desalination , vol. 119, no. 1-3

    A small commercial POE (point of entry) reverse osmosis (RO) equipment was tested for removing simultaneously water radioactivity and salinity from a bedrock water in a private household. The functioning of this equipment was monitored over an eight month period. The RO equipment was able to remove most of the elements almost completely. The reduction of main water constituents was above 94%, except for gaseous radon.

  14. Distribution of radon-222 in community groundwater systems: analysis of type I left-censored data with single censoring point

    Barry, TM; Brattin, WJ

    Human and Ecological Risk Assessment [Hum. Ecol. Risk Assess.], vol. 4, no. 2, pp. 579-603, Apr 1998

    Community groundwater systems serve as the primary source of household water for over 81 million people in the United States. In many residences, groundwater may contain significant concentrations of radon-222, serving as a potential source of human exposure. An extensive database of measured radon concentrations in community groundwater systems is available from the National Inorganic and Radionuclides Survey (NIRS). However, estimation of key descriptive statistics and distribution functions for these data is complicated by the fact that the data are censored, that is, a portion of the NIRS samples have concentrations below the minimum reporting level of 100 pCi/L. A variety of parameter estimation techniques were investigated for fitting the NIRS data, including maximum likelihood and regression methods. In general, the NIRS data were found to be well-described by lognormal distributions. The resulting lognormal distributions, along with quantitative estimates of uncertainty, are presented for five groundwater system sizes and for eight geographic regions.

  15. A study on the radon concentrations in water in Jeddah (Saudi Arabia) and the associated health effects

    Tayyeb, ZA; Kinsara, AR; Farid, SM

    Journal of Environmental Radioactivity [J. ENVIRON. RADIOACT.], vol. 38, no. 1, pp. 97-104, 1998

    Several studies have shown that water-borne super(222)Rn contributes to indoor air concentrations. A passive radon measurement method was employed to determine radon activity concentrations in the water of Jeddah city (Saudi Arabia). Tap water, flushing water and drinking water, including natural mineral water, artificial mineral water and distilled water, have been investigated for their radon concentrations. It is observed that the radon concentration in natural mineral water samples is the highest and that in flush water, it is the lowest. From these measurements, the corresponding annual effective dose for the stomach and the lung are determined. It is found that the annual effective dose resulting from direct consumption of water is far greater than that due to inhalation of radon emanated from tap water and flushing water. Moreover, it is also seen that the annual effective dose resulting from inhalation of radon emanated from tap water and flushing water is negligible compared to the total annual effective dose for indoor radon in Jeddah.

  16. Measurement of super(222)Rn concentration in Kenyan groundwater

    Otwoma, D; Mustapha, AO

    Health Physics [Health Phys.], vol. 74, no. 1, pp. 91-95, Jan 1998

    Groundwater samples from different parts of Kenya have been analyzed for their super(222)Rn concentrations. Samples were drawn from municipal supplies, springs, wells and bore holes in different geological terrains. In the analysis, conventional liquid scintillation counting, using the Packard protocol for measuring radon in water, was employed. This is the first time these water sources are being tested for radioactivity. The preliminary results are presented, and they showed that super(222)Rn is the main contributor to the radioactivity in most portable waters in Kenya. super(222)Rn activity concentrations range from 0.8 plus or minus 0.5 to 371.7 plus or minus 33.5 Bq L super(-1).

  17. Radon-222 and related activities in surface waters of the English Lake District

    Al-Masri, MS; Blackburn, R

    Applied Radiation and Isotopes [Appl. Radiat. Isot.], vol. 50, no. 6, pp. 1137-1143, Jun 1999

    Activities of radon-222 in selected surface waters of the English Lake District have been determined. Very wide variations were observed. The activity present in lakes and streams depends on the nature of the bedrock or sediment, the presence of faulting, the degree of turbulence, and the supply of fresh water from tributaries and ground waters. Radium-226 and uranium-238 activities were found to be comparable but in no case was it found that radon-222 is significantly supported by dissolved radium-226.

  18. Groundwater flow system in the valley of Toluca, Mexico: An assay of natural radionuclide specific activities

    Segovia, N; Tamez, E; Pena, P; Carrillo, J; Acosta, E; Armienta, MA; Iturbe, JL

    Applied Radiation and Isotopes [Appl Radiat Isot], vol. 50, no. 3, pp. 589-598, Mar 1999

    Natural radionuclides and physicochemical parameters have been evaluated groundwater samples from boreholes belonging to the drinking water supply of the Toluca City, Mexico. The results obtained for radon system and radium, together with the physicochemical parameters of the studied samples, indicate a fast and efficient recharge pattern. The presence of a local and a regional groundwater flows was also observed. The local flow belongs to shallower water, recognized by its low radon content and dissolved ions, as compared with the regional, deeper groundwater flow with a longer residence time.

  19. Use of super(222)Rn and super(226)Ra to trace groundwater discharge into the Chesapeake Bay

    Hussain, N; Church, TM; Kim, G

    Marine Chemistry [Mar. Chem.], vol. 65, no. 1-2, pp. 127-134, 1 May 1999

    Activities of super(222) Rn and super(226) Ra were measured in water samples from the Chesapeake Bay during two summers and one winter in 1995 and 1997 in order to develop a potential groundwater tracer. A major estuary to the Bay, the Potomac, was also sampled for these nuclides during 1997 in order to assess their inputs to the Bay. The super(222) Rn activities ranged between about 20 and 140 dpm/100 l within the Chesapeake Bay. Higher activities were encountered at the northern end of the Bay. In the upper Potomac, activities as high as 200-300 dpm/100 l were observed. These activities are twice to as much as two orders of magnitude higher than coastal ocean super(222) Rn . The activities generally decrease with salinity and depth to the south and show little change between summer and winter. The super(222) Rn activities are much in excess of its parent super(226) Ra which suggests an active disequilibrated source of super(222) Rn to these waters. Considering the short half-life of super(222) Rn (3.8 days) and its limited exchange with the atmosphere, another important source is suggested to be the exchange of groundwater in lower salinity regions of the Bay or its tributaries. The inverse trend of super(222) Rn against salinity is consistent with a fresh groundwater end member from the Chesapeake Bay watershed. The super(222) Rn concentrations of the Potomac tributary are even greater than in the Bay, increasing from 47 dpm /100 l at the Bay entrance to about 280 dpm/100 l upstream and suggest an even more significant groundwater discharge. Calculations suggest as much as 10% of freshwater inputs to the Chesapeake Bay could be from groundwater.

  20. Electrostatic radon detector designed for water radioactivity measurements

    Wang, Jian-Xiong; Andersen, Tom C; Simpson, John J

    Nuclear Instruments & Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment [NUCL INSTRUM METHODS PHYS RES SECT A], vol. 421, no. 3, pp. 601-609, 1 Feb 1999

    The Sudbury Neutrino Observatory contains 1000 t of ultra-pure heavy water and 7000 t of very pure light water. In order to achieve the goal of determining accurately the total number of neutrinos emitted by the sun regardless of type, the radioactivity in the water must be maintained with a radiopurity of less than 10 super(-14) g/g of super(232)Th and super(238)U in secular equilibrium with their daughters. This paper describes the design and application of an electrostatic radon detector which determines the amount of radon emanating from a column containing MnO sub(2) used to extract radium from the water. This electrostatic radon detector has a total efficiency of 35% for detecting super(222)Rn and 22% for super(220)Rn.

  21. Development of high sensitivity radon detectors

    Takeuchi, Y; Okumura, K; Kajita, T; Tasaka, S; Hori, H; Nemoto, M; Okazawa, H

    Nuclear Instruments & Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment [NUCL INSTRUM METHODS PHYS RES SECT A], vol. 421, no. 1-2, pp. 334-341, 21 Jan 1999

    High sensitivity detectors for radon in air and in water have been developed. We use electrostatic collection and a PIN photodiode for these detectors. Calibration systems have been also constructed to obtain collection factors. As a result of the calibration study, the absolute humidity dependence of the radon detector for air is clearly observed in the region less than about 1.6 g/m super(3). The calibration factors of the radon detector for air are 2.2 plus or minus 0.2 (counts/day)/(mBq/m super(3)) at 0.08 g/m super(3) and 0.86 plus or minus 0.06 (counts/day) /(mBq/m super(3)) at 11 g/m super(3). The calibration factor of the radon detector for water is 3.6 plus or minus 0.5 (counts/day)/(mBq/m super(3)). The background level of the radon detector for air is 2.4 plus or minus 1.3 counts /day. As a result, one standard deviation excess of the signal above the background of the radon detector for air should be possible for 1.4 mBq/m super(3) in a one-day measurement at 0.08 g/m super(3).

  22. Crafting a regulation for radon in drinking water

    Pontius, Frederick W

    Journal / American Water Works Association [J Am Water Works Assoc], vol. 91, no. 5, p 8p, 1999

    Radon is a naturally occurring radioactive gas. The US Environmental Protection Agency (USEPA) was required by the 1986 Safe Drinking Water Act (SDWA) amendments to regulate radon in drinking water. Since then, regulation of radon in drinking water has been the subject of continuing debate, congressional action, and, more recently, USEPA efforts to craft a proposed regulation. The key issues in anticipation of USEPA's proposed rule are examined.

  23. Environmental radioactivity: a case study in Himachal Pradesh, India

    Virk, HS; Sharma, N; Bajwa, BS

    Journal of Environmental Radioactivity [J. Environ. Radioact.], vol. 45, no. 2, pp. 119-127, 1999

    A radon survey has been carried out in the soil-gas and indoor air of some villages situated in the vicinity of areas known for uranium mineralisation in Himachal Pradesh (H.P.). Both active and passive techniques were used for radon monitoring inside the dwellings. The highest value, 75 400 plus or minus 2620 Bq m super(-3), of radon in soil-gas was found in the village of Samurkhurd. The mean values of indoor radon concentration for the village of Ramera, Asthota, and Galot were found to be 249 plus or minus 14, 200 plus or minus 16 and 161 plus or minus 13 Bq m super(-3), respectively. The average annual exposure doses due to radon and its daughter products to the inhabitants of these villages amount to 4.3 plus or minus 0.2, 3.4 plus or minus 0.3 and 2.8 plus or minus 0.2 mSv, respectively. Indoor radon levels are within the safe limits in most dwellings but call for mitigation of the radon health hazard in some others. A radon and helium survey of thermal springs in the Parbati and Kullu valleys of Himachal Himalaya was also carried out. The maximum values of radon (716.3 Bq 1 super(-1)) and helium (90 ppm) activities were recorded in a thermal spring at Kasol in Parbati valley. In general, high radon and helium values are correlated with high uranium concentrations in the soil of the area in the environs of the thermal springs.

  24. Radon Removal from Groundwater Using Ultrasound

    LeGore, LJ; Brutsaert, WF

    Journal of New England Water Works Association [J. N. England Water Works Assoc.], vol. 112, no. 4, pp. 291-304, Dec 1998

    Radon is a radioactive gas and is a drinking water contaminant regulated by the Safe Drinking Water Act. Although there are existing methods for radon removal, this study was undertaken to explore the feasibility of using ultrasound to enhance radon removal from groundwater. Laboratory experiments using surface aeration, bubble aeration, and spray aeration were performed to compare gas removal rates with and without the application of ultrasound. In all the experiments performed in this study, the application of ultrasound increased the removal rate of radon from groundwater.

  25. Drinking water from crystalline bedrock aquifers - not just H sub(2)O

    Midtgard, AK; Frengstad, B; Banks, D; Krog, Reidar J; Strand, T; Siewers, U; Lind, Bjorn

    Mineral Soc Bull, no. 121, pp. 9-16, Dec 1998

    A project has been undertaken to provide a national overview of the quality of Norway's drinking water from wells drilled in bedrock, and to obtain insight into the link between lithology and groundwater chemistry. The study yields valuable information on the distribution of some anthropogenic pollutants, confirming that nitrite contamination is seldom a serious threat to Norwegian groundwaters, and that acid rain has hitherto had little effect on the groundwater resources exploited by Norwegian wells.

  26. The chemistry of Norwegian groundwaters: II. The chemistry of 72 groundwaters from Quaternary sedimentary aquifers

    Banks, D; Midtgaerd, AK; Frengstad, B; Krog, JR; Strand, T

    Science of the Total Environment [Sci. Total Environ.], vol. 222, no. 1-2, pp. 93-105, 15 Oct 1998

    Seventy-two samples of groundwater derived from Norwegian Quaternary (largely glaciofluvial or glacial) aquifers were analysed for a wide range of major and minor hydrochemical parameters. The waters exhibit a relatively uncomplex evolution from Na-Cl dominated, immature waters (which reflect marine salts in precipitation) to Ca-HCO sub(3) dominated waters via calcite dissolution. The median pH of these waters is 7.37, in contrast to similar waters from crystalline bedrock aquifers with a median pH of 8.07. The water samples provide little evidence of significant acidification or sulphatisation of groundwaters by 'acid rain'. In fact, a positive correlation emerges between non-marine sulphate and alkalinity/pH, suggesting dominantly lithological sources for non-marine sulphate. No groundwaters from Quaternary deposits exceed maximum recommended concentrations for Rn, F super(-) and Na, while 10% fall outside the required pH range. This again contrasts with bedrock aquifers where 30% of waters are non-compliant with respect to one or more of these parameters.

  27. Hydrogeologic Controls on Radon-222 in a Buried Valley-Fractured Bedrock Aquifer System

    Veeger, AI; Ruderman, NC

    Ground Water, vol. 36, no. 4, pp. 596-604, Aug 1998

    A field study was conducted to evaluate the distribution of radon ( super(222)Rn) and the hydrogeologic controls on its occurrence in the glacial and fractured rock aquifers of the Pawcatuck River Basin, Rhode Island. A total of 91 ground water samples were collected and analyzed for major chemical constituents as well as uranium and super(222)Rn. The three bedrock types underlying the study area include the Proterozoic Esmond and Sterling gneisses, and the Devonian Scituate Granite, each having average uranium contents of 1.9 ppm, 3.3 ppm, and 4.1 ppm, respectively. All wells sampled in this study yielded radon levels above the proposed U.S. EPA limit of 300 pCi/L. Wells in areas underlain by the Esmond Suite had the lowest radon content (range 500 to 30,400 pCi/L, median 1400 pCi/L), areas underlain by the Sterling Suite were not significantly different but showed slightly higher concentrations (range 700 to 27,300 pCi/L, median 1600 pCi/L), and the areas underlain by the Scituate Suite had significantly higher levels (range 1600 to 83,500 pCi/L, median 5900 pCi/L). High fluoride and alkalinity concentrations in ground water were found to be hydrogeochemical markers for elevated radon concentrations. These markers are believed to represent chemical reactions that produce remobilization of uranium in the host crystalline rock to more favorable siting along grain and fracture boundaries. Physical characteristics such as porosity and the location of uranium are controlling factors in the distribution of radon between surficial and bedrock wells, with bedrock aquifers exhibiting higher radon concentrations than surficial-materials aquifer in this basin.

  28. Natural radioactivity levels in Andalusian spas

    Duenas, C; Fernandez, MC; Enriquez, C; Carretero, J; Liger, E

    Water Research [Water Res.], vol. 32, no. 8, pp. 2271-2278, Aug 1998

    Gross- alpha and gross- beta activity, super(222)Rn, super(226)Ra and super(224)Ra of waters from several spas of Andalusia (Spain) were performed in order to determine their radioactivity. Radon concentration ranged from 0.225 to 130 Bq/l. super(226)Ra and super(224)Ra concentrations ranged from 2 to 1367 mBq/l and from 2 to 122 mBq/l respectively. Correlations between the super(222)Rn and super(226)Ra concentrations and gross- alpha activity were obtained. A correlation between super(224)Ra concentrations and gross- beta activity was also found.

  29. Radon daughter disequilibria and lead systematics in the western North Atlantic

    Hussain, N; Church, TM; Veron, AJ; Larson, RE

    Journal of Geophysical Research. D. Atmospheres [J. Geophys. Res. (D Atmos.)], vol. 103, no. D13, pp. 16,059-16,071, Jul 1998

    Concentrations of super(222)Rn and super(210)Pb were measured in the North Atlantic troposphere in 1989 between April 12 and 28, during the Sulfide Experiment (SEX) Cruise I, and those of super(222)Rn, super(210)Pb and super(210)Po, between October 24 and November 9, during the SEX Cruise II. Concentrations of super(210)Pb and super(210)Po were also measured in the rain water, surface seawater, and marine microlayer collected during the SEX Cruise II. Other data used and published previously include stable lead and its isotopes on parallel samples. Low super(222)Rn contents, of the order of 0.1 and 0.3 Bq m super(-3), were found in the marine air, while continental air showed nearly 10 times higher concentrations of super(222)Rn. These results corroborate with the air mass trajectory analyses and continental signatures of stable lead isotopes. Significant correlation is found between super(222)Rn and super(210)Pb on the aerosol, indicative of excess continental super(222)Rn supporting the ingrowth of super(210)Pb from the atmosphere, in spite of its first-order removal by precipitation. Correlation between super(210)Pb and stable Pb on the aerosol and in the precipitation document the source of pollutant lead from the continental surface. Mean residence times of marine aerosol based on super(210)Pb is estimated to be 5.4 plus or minus 1.8 days during the April cruise and 19.7 plus or minus 1.9 days during the October cruise. Corresponding deposition velocity for super(210)Pb is estimated to be 1.9 plus or minus 1.9 cm s super(-1), a value that suggests the dominant role of precipitation scavenging, or aerosol scavenging by larger host phases such as dust or sea salt. Excess super(210)Po activities are found on the aerosol relative to what would be expected based on super(210)Pb and the aerosol residence times. In surface seawaters, deficiencies of super(210)Po are observed. Mechanisms of super(210)Po enrichment in atmospheric aerosol may include enrichments from the organic components of marine microlayer, sea-salt aerosol, dust, or air-sea exchange of volatile organo-polonium species.

  30. Assay of super(222)Rn in water samples by a modified integral counting method

    Murase, Y; Homma, Y; Murakami, I; Handa, K

    Applied Radiation and Isotopes [Appl. Radiat. Isot.], vol. 49, no. 5-6, pp. 861-865, Jun 1998

    super(222)Rn activity concentrations in water collected from 163 private wells and 14 springs in Tokyo were measured with a liquid scintillation spectrometer using a modified integral counting method. The activity concentrations of super(222)Rn range from 0.2 to 22.9 Bq/L and average 4.8 Bq/L. The errors due to the air luminescence counts and the interferences from super(220)Rn and super(219)Rn are discussed and evaluated. super(222)Rn samples of 0.2 Bq/L can be assayed within an overall uncertainty of 3.1%. The liquid scintillation method involving agitation of the sample water directly with a liquid scintillation cocktail was compared with the present method and evaluated.

  31. Radon emission from hydrothermal springs at Tantloi

    Das, NK; Ghose, D; Sinha, B

    7th International Symposium on Radiation Physics--ISRP7, Elsevier Science Ltd., Pergamon, Jun 1998, pp. 611-612, Radiation Physics and Chemistry , vol. 51, no. 4-6

    Radon is invariably associated with the escape of water and free gas from thermal springs. At Tantloi, Santhal Paragana, Bihar, where the gas escaping the spring vents is large (about 40,000 1 day super(-1)), studies in associated radon emanations assume particular importance. We have made a comprehensive study of the radon concentration and its rate of emanation from the springs and parameters influencing its release. The water temperature typically varies from 65 to 69 degree C. Because the movement of radon in the three phases, free gas, soil and water is implicitly governed by the lithology of the underlying area, spring parameters, meteorological and tectonically-induced factors detailed study was made of the respective emanation rates and dominant factors controlling the emission and associated variations.

  32. Radon geochemical anomaly at Bakreswar thermal springs

    Ghose, D; Paul, D; Sastri, RC

    7th International Symposium on Radiation Physics--ISRP7, Elsevier Science Ltd., Pergamon, Jun 1998, pp. 613-614, Radiation Physics and Chemistry , vol. 51, no. 4-6

    Natural radioactivity in hot springs is principally on account of radon released with the bubbling emanations and its seepage through adjacent soil surface. At Bakreswar, Birbhum, West Bengal, a cluster of seven springs spread over an area 15,000 m super(2) have water temperature varying from 76 to 42 degree C. The hydrated rock formation below soil, is highly sheared and brecciated allowing continuous escape of trapped volatiles. super(222)Rn is transported from the "shallow crustal fraction" by two mechanisms; (a) by diffusion and (b) pressure driven by stable gases of deeper origin. The springs exhibit a large scale escape of helium and other gaseous volatiles. We have been monitoring the compositional variations in stable and active gases in soil depth at various locations around the springs with a view to recording influencing parameters and to determine involved local crustal and medium conditions affecting transmission.

  33. Seasonal variations of super(226)Ra and super(222)Rn in mineral spring waters of Aguas da Prata, Brazil

    De Oliveira, J; Mazzilli, B*; De Oliveira Sampa, MH; Silva, B

    Applied Radiation and Isotopes [Appl. Radiat. Isot.], vol. 49, no. 4, pp. 423-427, Apr 1998

    In this paper the activity concentrations of super(226)Ra and super(222)Rn were assayed in the mineral spring waters of Aguas da Prata in order to evaluate the seasonal variations of such radionuclides. The results obtained were related to the chemical composition of the water as well as to the lithology of the aquifer and temperature. Higher activity concentrations up to 1.8 x 10 super(3) mBq L super(-1) for super(226)Ra and 1.2 x 10 super(2) Bq L super(-1) for super(222)Rn have been observed in waters with low levels of soluble salts. Waters which present high levels of carbonate and sulphate salts showed maximum values of 2.5 x 10 super(2) mBq L super(-1) for super(226)Ra and 2.7 x 10 super(1) Bq L super(-1) for super(222)Rn. This behaviour is mainly due to the physico-chemical properties of these radionuclides in water as well as to the lithologic structure of the aquifers.

  34. Aeration and limestone contact for radon removal and corrosion control

    Spencer, CM

    J. N. England Water Works Assoc., vol. 112, no. 1, pp. 60-69, Mar 1998

    The paper outlines the design and operation of aeration followed by passage through a limestone contactor for removal of radon and control of corrosion in a Maine groundwater. Limestone has advantages over more conventional chemical additions for small systems. Many small utilities in Maine use groundwater as a source of public water supply. Groundwater in Maine and throughout New England generally contains radon at levels higher than 1,000 pCi/L and has dissolved carbon dioxide in excess of atmospheric equilibrium concentrations. The excess of carbon dioxide depresses the pH value and makes the groundwater quite corrosive. Addition of chemicals for pH and alkalinity adjustment is hindered by interference with excess carbonic acid from the dissolved carbon dioxide. Passage of water with excess carbon dioxide through a limestone contactor often results in treated water pH values below the desired target because the carbonate ions in the limestone cannot dissolve in the carbon dioxide saturated raw water. Aeration has been shown to remove excess carbon dioxide along with radon. Passage of aerated water through a limestone contactor results in much higher treated water pH and stable treated water alkalinity and radon values. The limestone contactor is less expensive to operate and maintain than more conventional chemical feed systems.

  35. Radon removal: Its effect on short-lived radon progeny and implications for effective dose

    Swedjemark, GA; Linden, AH

    Radiation Protection Dosimetry [Radiat. Prot. Dosimet.], vol. 80, no. 4, pp. 405-409, 1998

    Radon removal can, with a good effect, be used to remove radon from well water. For installations based on aeration only the radon gas is removed, not the radon progeny. The aim of the study is to get an indication of the effect on short-lived progeny and possibly of implications for the effective dose. The short-lived radon progeny have been investigated in the raw and the cleaned water from six private wells where radon aerator systems based on aeration and recirculating of the water have been installed. The results from this pilot study indicate that the short-lived radon progeny in some cases follow the water to the tap for consumption to such an extent that the problem with the remaining short-lived progeny should be considered. The extent of the study is not sufficient for general conclusions. However, it is important to stress that the effective dose from the short-lived progeny is always lower than it would have been from the radon, when no radon removal is used.