Environmental Radon Research Articles

Albert Joseph Howard Jr

Albert Joseph Howard Jr, Jarvis Professor of Physics at Trinity College in Hartford, Connecticut, died at his home in New Haven, Connecticut, on 7 June 2003 as a result of a massive heart attack. Born on 22 February 1937 in New Haven, Al resided in the New Haven area all his life. He received his BS in physics in 1958 and his PhD in physics in 1963, both from Yale University. His thesis research, under the guidance of W. W. Watson and one of us (Bromley), involved the thermal-column separation of noble-gas isotopes. These he then used in a series of studies of the structure of light nuclei, in experiments carried out at the 3-MV Van de Graaff accelerator at Brookhaven National Laboratory. Thus began a long and productive career in experimental nuclear physics. In 1962, even before he had completed his doctorate, Al was appointed assistant professor of physics at Trinity. He set up a small laboratory that provided generations of students with substantial early introductions to the art of experimental nuclear physics, particularly gamma and alpha spectroscopy. Concurrently, Al maintained an active and productive research collaboration with one of us (Parker) at the Wright Nuclear Structure Laboratory at Yale and studied nuclear reactions essential to the understanding of stellar nucleosynthesis. Over the years, he also ran experiments with groups at Brookhaven and at Princeton University, sometimes with the participation of Trinity undergraduates. Al served three terms (1974–78, 1987–90, and 1996–2000, and for the academic year 2001–02) as chairman of Trinity’s physics department, served on a full complement of college committees, and carried a full—and often heavy—teaching load. Yet his continual and varied research programs resulted in well over 50 published papers. Trinity recognized Al’s distinguished scholarship by naming him Dana Research Professor for 1985–87.Together with Wayne Strange, the physics laboratory coordinator at Trinity, Al spent much of his last decade refining techniques for accurate determination of environmental radon levels and of radon emanation rates from solids.We remember Al as an avid golfer, a friend of animals, and a teacher and friend always ready to help colleagues and students. He combined a keen sense of humor with uncompromising dedication to the welfare of his department. He is sorely missed both at Trinity and at Yale.Albert Joseph Howard JrMARY B. HOWARDPPT|High resolution© 2004 American Institute of Physics.

Study of the radon concentrations in drinking water from three main cities of Shaanxi Province, China

This paper presents the results of radon concentration measurements in the drinking water from the municipal water supply system and private wells of Xi’an, Xianyang and Baoji city of Shaanxi province of China. The measurements were carried out on 38 samples. Radon levels in drinking water in Xi’an, Xianyang and Baoji were found to be 5.78, 13.04 and 15.01 k Bq m−3, respectively. The AM radon concentration of private well water from Xianyang and Baoji is 28.84 k Bq m−3 and 38.85 k Bq m−3, respectively, which is 2.56 times and 3.14 times as high as that of tap water radon, respectively. The radiation risk of radon in water would be due to degassing and not due to drinking water. The domestic use of showers, humidifiers, and cooking, washing up, laundering, etc. may lead to an additional increase of the radon concentration in the indoor air. The observed radon concentration in drinking water from three main cities of Shaanxi Province can contribute to a 4.86 to 32.63% increase in indoor radon concentration and can cause 0.068±0.016 mSv y−1 to 0.177±0.045 mSv y−1 extra annual effective dose to males, 0.060±0.014 mSv y−1 to 0.155±0.039 mSv y−1 to females. The mean annual effective dose equivalents to males and females of Xianyang and Baoji from well water account for 25.94 to 39.75% of environmental radon and radon daughters annual effective dose equivalents. The radon concentrations in the well water from Xianyang and Baoji will bring a definite additional risk to the population.

Environmental radon monitoring: comparing drawbacks and performances of charcoal canisters, alpha-track and E-PERM detectors

Nowadays there are mainly three types of detectors available for measuring radon concentrations: charcoal canisters, alpha-tracks and E-PERMs. We carried out measurements with the three types of detectors and we tested their performances over a wide range of radon concentrations, temperatures and humidities. We compared the results obtained with the different detectors and we critically evaluated the results.

Feasibility for Mapping Radon Exhalation Rate from Soil in China

Radon exhalation rate from soil is one of the most important factors for evaluation of the environmental radon level. For rough estimation of the nationwide radon exhalation rate from soil in China, a simple model was derived under the review and analysis of several previous works on radon exhalation theories. To show the feasibility of the model, some nationwide databases were summarized and discussed, and a trial estimation was made and compared with the measured data for Beijing. The results show that it is possible to map the radon exhalation rate from soil in China based on the present databases.

Radon concentration in Jordanian drinking water and hot springs

The radon concentration in Jordanian drinking water and hot springs has beenmeasured using the electret-passive environmental radon monitoring method. Thisstudy maps out Jordanian water sources from the north to the south as wellas the area around the capital Amman and the Jordan valley. Samples from 30sources were collected and analysed during the period from November 2001 toJune 2002. We have found that 60% of the drinking water sources have radonconcentrations above the proposed US Environmental Protection Agency limit of11 Bq l−1; these are mostly situated in the northern region of the country. Fortunately,these sources supplied only a small number of people since they weremainly located in rural areas. Tap water in the capital Amman, whereapproximately 35% of the population live, has a very low radon concentration,3.9 Bq l−1. However, the isolated northern drinking water wells did show a radon level as high as117 Bq l−1. Hot springs in Jordan have a radon level ranging between 63 and81 Bq l−1, again mainly in the northern region. In general we conclude that Jordanian drinkingwater is safe as far as radon concentration is concerned with the exception of a few isolatedlocal drinking water wells.

Environmental health of children

Pediatric primary health care providers are responsible for providing comprehensive care to children. This includes assessing for and identifying the effect of environmental hazards on children's health and managing conditions that may result from exposure to environmental toxins. This article begins by reviewing the unique developmental, biologic, and behavioral characteristics of children and age-specific issues that make them particularly vulnerable to toxins. It then provides the reader with general assessment and management strategies related to environmental toxins, including an assessment tool that can be used in a pediatric primary care office. The qualities of selected toxins that have been implicated in childhood illnesses are discussed. Routes of exposure, signs and symptoms of toxicity, and assessment and management approaches are presented specifically for lead, mercury, environmental tobacco smoke, particulate matter, asbestos, radon, molds, and pesticides. Because prevention is the best intervention in environmental health, the article emphasizes ways pediatric providers can work with caregivers to prevent or minimize exposure.

Radon Exposure and its Health Effects

About half the natural radiation dose to humans is due to radon and its decay products. It is well known that exposure to high levels of radon causes lung cancer, but as yet, there is still little data on the effect of long-term exposure to low levels of environmental radon. The studies by our radon research group at the NIRS are directed toward determining the health effects of low level exposure to environmental radon. In this paper, our current studies on radon are reviewed.

Dosimetric assessment of radon in a vegetable system.

An alpha-dose calculation due to radon uptake in anthers of Tradescantia, clone 4430, has been performed. Probability distribution density of the dose in the pollen mother cells was calculated by means of a model that simulates the interaction of separate alpha-particles with these cells. It is shown that alpha-radiation from either radon or its decay products surrounding the buds does not reach pollen mother cells because of the short-range alpha-particles. However, it is suggested that radon diffuses through the gap structure of the bud to the anther from which a radon-gas adsorption process takes place. Absorbed-dose calculations in the anther are discussed as well as their relationship to the experimental results of micronucleus induction in pollen mother cells. The radon concentration interval used (0.85 kBq m(-3)-98.16 kBq m(-3)) is equivalent to the exposure to an average environmental radon concentration (40 Bq m(-3)) for 2.3 months or 22.1 years, respectively. The lowest radon concentration to induce micronuclei was 12.1 kBq m(-3), which is 15 times in excess of that adopted for old buildings in Canada.

A theoretical model for the microdosimetry of discontinuous distributions of heavy particle tracks.

A novel approach to solving microdosimetry problems using conditional probabilities and geometric concepts has been developed. This approach is valid for cases where a convex site is immersed in uniform or discontinuous distributions of heavy charged particle tracks and assumes no restrictions in site geometry or the kind of randomness. These conditions are relevant to the study of microdosimetry in applications such as neutron capture therapy (NCT), irradiation experiments using heavy ion particle beams, environmental radon, or occupational exposure to radioactive materials. Expressions applicable to the case of surface-distributed sources of tracks are presented that may represent situations such as NCT, where boron compounds are bound to the membranes of cellular nuclei. Microdosimetric spectra, specific energy averages, and mean number of 10B capture reactions for cell inactivation are calculated, showing their dependence on 10B localisation.

Radon Levels in China

This paper reviewed and summarized the results and problems of a nation-wide environmental radon survey which was carried out from 1984 to 1990 in China. Indoor radon concentrations were measured in 10,811 dwellings, and which covered 26 provinces and cities all over China. The range of indoor radon concentrations was <LLD-386.8Bq·m−3, the average was 22.5 Bq·m−3 and 19.6 Bq·m−3 for arithmetic mean and geometric mean, respectively. Both outdoor radon concentrations and indoor radon progeny concentrations were also reported. Even though the grab sampling was taken as the main method of the survey, it was still a valuable reference.

Radon and thoron progeny levels in air samples at Udagamandalam region of Nilgiris in India

Measurement of concentration of radon and thoron daughter products in various indoor environment covering four seasons of a year in Udagamandalam Taluk of Nilgiris biosphere has been carried out using a high volume air sampler to asses the inhalation dose to the population which delivers higher dose than the radon and thoron gas alone. The potential alpha-energy concentrations of the radon and thoron progeny ranged from 0.97 to 12.72 mWL and from 1.63 to 15.83 mWL with a geometric mean of 6.02 and 7.89 mWL, respectively, taking all seasons into account. These measurements have yielded a wealth of data on the variation among the indoor radon and thoron progeny in various places during different seasons. The radon and thoron progeny levels are higher in winter seasons and are less in summer season with autumn and spring data lie in between winter and summer. Using the dose conversion factor for indoor exposures given in UNSCEAR 93 report the internal equivalent dose to the inhalation of radon progeny is evaluated to be 1357 mSv.y–1 and the corresponding annual effective dose equivalent value has been found to be 2.13 mSv.y–1. It can be observed that the mean value of radon is higher than the Indian average. Also it is found the radon and thoron progeny levels are higher in the case of houses built with rock and granite and in tiled type houses of nearly 100 years old. The levels are less in the case of houses built with brick and cement. The observed results for different types of houses and seasons are discussed in this paper.

Study on a new method for reducing radon level in indoor air

The aim of this study is to develop a new technique for reducing high radon level in indoor air by method of membrane permeation using a hollow fiber module. The experiment has been carried out for MERASILOX-S module of fine hollow fibers of silicon rubber that has high permeability constant and MHF hollow fiber module made of thin segment polyurethane membrane. The radon permeability constants of hollow fiber membranes have been estimated from the decrease rate of radon concentration in a radon permeation system. The apparent permeability constant depends on the flow rate through the outside and the inside of hollow fibers. The apparent permeability constants of MERASILOX-S and MHF module membranes were 3.9×10 -9 m 2. s -1 and 1.1×10 -9 m 2. s -1 at the flow rate above 5.0 L . min -1 . However, the permeation velocity of MHF module is grater than that of MERASILOX-S module. The radon concentration in a 50 m 3 room of concrete building could be reduced to about 1/10 by using a MHF module with membrane area of 18 m 2 . The use of pressure different between the inside and the outside of hollow fibers might be applied to reduce the environmental radon concentration.

The present status of the radon program in the United States of America

The indoor radon program in the US. started in the early 1970's in response to Congressional Hearings that recommended the initiation of radon measurements in certain parts of the united States where enhanced radon caused by contaminated uranium and radium tailings was suspect. In the mid 1970's, the Department of Energy (DOE), Environmental Measurements Laboratory (EML), conducted the first indoor radon survey in the New York City Metropolitan area. The two year study recommended that radon surveys should be expanded throughout the US. for better assessment of the radiation exposure of the general public to radon and its decay products. In 1984, well documented findings of very high concentrations of radon in homes located on the Reading Prong in Pennsylvania generated public interest in radon measurements and prompted the Environmental Protection Agency (EPA), to initiate a program to address the newly discovered public health problem. In 1988, EPA was assigned the task to implement the Indoor Radon Abatement Act (IRAA), which established a long-term national goal to reduce indoor levels to those found outdoors. In the 1980's , DOE funded many radon research projects on the health effects of environmental radon, instrument development and measurement quality. Unfortunately by the end of fiscal year 1998, DOE, the principal radon research agency stopped funding radon projects.

Environmental lead-210 and bismuth-210 accrue selectively in the brain proteins in Alzheimer disease and brain lipids in Parkinson disease.

We studied the occurrence of the environmental radon daughters, 210Po (alpha particles), and 210Bi (beta particles), in the protein and lipid fractions of cortical gray and subcortical white matter from the frontal and temporal lobes of human brains of persons with Alzheimer disease (AD), persons with Parkinson disease (PD), smokers, or persons with no previous evidence of clinical neurologic disease (controls). We found a 10-fold increase in 210Po and 210Pb radioactivity in the protein fraction from both the cortical gray and subcortical white matter in AD and smokers, and a similar increase in the lipid fraction in PD. The pathognomonic distribution of the radon daughters to the lipids in PD and to the proteins in AD was inferred to reflect the increase of local chlorine availability to which radon daughters bound selectively. Cigarette smoking strongly increases radon daughter retention in the central nervous system.

A Continuous Radon Progeny Monitor with a Vacuum Vessel by Alpha Spectrometry

A continuous monitor for accurately measuring long-term concentrations of low environmental radon progeny was developed in order to estimate the environmental influence of radon around a closed uranium mine. It is important to measure radon progeny concentration because almost all dose from radon is caused by its short-lived progeny. The various features of the monitor are a large sampling flow rate with 80 1.min -1 and the use of alpha energy spectrometry in a vacuum vessel. These have been adopted to obtain high sensitivity and resolution. Use of a long roll-type membrane filter and a reliable automatic system enabled continuous measurement for more than one month. The measurements using the monitors around the closed mine were carried out and the environmental effect was estimated to be less than 1 mSv.y -1 .

Determination of Ambient Gamma Radiation Levels using Electret Ion Chambers

Electret ion chambers are widely used for the measurements of indoor and outdoor radon concentrations as well as gamma radiation levels. Long-term electrets and standard ion chambers constituting the electret-passive environmental radon monitor system were mounted in a plastic analysis jar to investigate the ambient gamma exposure rates in some research laboratories. Control measurements were simultaneously performed by means of a high pressure ionisation chamber. The mean ratio of electret ion chamber measurements was 1.07. The agreement between the two methods can be considered as good. The agreement was of the order of 7%. The gamma radiation levels recorded over a one year span are presented. The significance of the results is discussed together with comments on the comparison of the figures obtained through the two methods.

Environmental Radon and Thoron Progeny Concentrations in Fujan Province of China

Surveys of environmental radon and thoron progeny concentrations were carried out with the filter method in Fujian Province of China, where very high concentrations of 238 U and 232 Th in soil had been reported. The mean values of equilibrium-equivalent radon and thoron concentrations (EEC Rn and EEC Tn ) were 12.9 Bq.m -3 and 0.87 Bq.m -3 indoors, 9.7 Bq.m -3 and 0.39 Bq.m -3 outdoors in the general living environment. Very high concentrations of both radon and thoron progeny were observed in underground places and railway tunnels. The mean additional effective doses due to the inhalation of radon and thoron and their progeny were estimated to be 7.75 mSv.a -1 and 22.2 mSv.a -1 for workers in those places mentioned above. Furthermore, the diurnal/seasonal variations and height distributions of radon and thoron progeny were also studied.

Leukemia after exposure to benzene: temporal trends and implications for standards.

Benzene is a human leukemogen. Risk assessment, and the setting of occupational and environmental standards, has assumed that risk is constant in time after a unit of exposure. Leukemia risk is known to vary with time after exposure to ionizing radiation. A matched case-control study of leukemia risk in relation to the temporal pattern of benzene exposures was performed using data from the National Institute of Occupational Safety and Health. Leukemia risk following exposure to benzene varied with time in a manner similar to that following exposure to ionizing radiation. More recent exposures were more strongly associated with risk than were more distant ones. There was no significant relation between leukemia death and benzene exposures incurred more than 20 years previously. Recent analyses of specific occupational and environmental carcinogens, including benzene and radon, have indicated that cancer risk tends to decline as the time from exposure increases. This suggests that standards for the control of occupational or public risk must be selected to control exposures over a narrower time frame than the usual lifetime one. In the case of benzene, it would appear that risk is attributable primarily to exposures incurred during the previous 10 to 20 years, with exposures in the most recent 10 years being the most potent. To limit risk, exposures must be controlled during that interval. It is important that epidemiologists explore the temporal pattern of risk in their studies to facilitate the risk assessment of other carcinogens.

Occupational exposure to carcinogens in the European Union

OBJECTIVESTo construct a computer assisted information system for the estimation of the numbers of workers exposed to established and suspected human carcinogens in the member states of the European Union...

An Aggregate Public Health Indicator to Represent the Impact of Multiple Environmental Exposures

We present a framework to aggregate divergent health impacts associated with different types of environmental exposures, such as air pollution, residential noise, and large technologic risks. From the policy maker's point of view, there are at least three good reasons for this type of aggregation: comparative risk evaluation (for example, setting priorities), evaluation of the efficiency of environmental policies in terms of health gain, and characterizing health risk associated with geographical accumulation of multiple environmental exposures. The proposed impact measure integrates three important dimensions of public health: life expectancy, quality of life, and number of people affected. Time is the unit of measurement. "Healthy life years" are either lost by premature death or by loss of quality of life, measured as discounted life years within a population. Severity weights (0 for perfect health, 1 for death) are assigned to discount the time spent with conditions associated with environmental exposures. We combined information on population exposure distribution, exposure response relations, incidence, and prevalence rates to estimate annual numbers of people affected and the duration of the condition, including premature death. Using data from the fourth Dutch National Environmental Outlook, we estimated that the long-term effects of particulate air pollution account for almost 60% of the total environment-related health loss in the Netherlands as modeled here. Environmental noise accounts for 24%, indoor air pollution (environmental tobacco smoke, radon, and dampness, as well as lead in drinking water) for around 6%, and food poisoning (or infection) for more than 3%. The contribution of this set of environmental exposures to the total annual burden of disease in the Netherlands is less than 5%.