The measurement of indoor 222 Rn is not as straightforward as commonly perceived. The most commonly used measurement method is a passive, short-term device using activated charcoal that collects gases, typically for 3–7 days. Short-term measurements are popular because a radon determination is often required by a homebuyer and the buying transaction needs to be completed within 30–60 days. From deployment to obtaining the result from a laboratory reading the passive short-term device can take about 2 weeks. Active measurements, in which a portable alpha-particle counter is placed within a house and air pumped through a scintillation cell have been compared to passive short-term measurements and found to be consistent. For transactions requiring faster or immediate results, active counting methods appear to be a reliable method for measurement.

Predicting indoor radon potential has gained in importance even asthe national radon programs began to wane. A cooperative study to produceradon potential maps was conducted by the Environmental Protection Agency(EPA), U.S. Geological Survey (USGS), Department of Energy (DOE), and LawrenceBerkeley Laboratory (LBL) with the latter taking the lead role. They developeda county-wide predictive model based dominantly on the National Uranium ResourceEvaluation (NURE) aerorad data and secondly on geology, both small-scale databases. However, that model breaks down in counties of complex geology anddoes not provide a means to evaluate the potential of an individual home orbuilding site. In this current study, soil-gas radon measurements on a largescale are shown to provide information for estimating radon potential at individualsites sort out the complex geology so that the small-scale prediction indexcan be validated. An example from Frederick County, Maryland indicates a positivecorrelation between indoor measurements and soil-gas data. The method doesnot rely on a single measurement, but a series that incorporate seasonal andmeteorological considerations.

Since the early 1980s, geological and structural mapping, gravity, and helium soil–gas studies have been performed in the eastern sector of the Vulsini Volcanic District (Roman Magmatic Province) in an attempt to locate potential geothermal reservoirs. This area is characterised by an anomalous geothermal gradient of >100°C/km, and by widespread hydrothermal mineralization, thermal springs, high gas fluxes, and fossil and current travertine deposits. The results of these surveys indicate the existence of a number of fault systems, with N–S and E–W structures that appear to be superimposed on older NW–SE and NE–SW features. Comparison of the results of the various studies also reveals differences in permeability and potential reservoir structures at depth.

Measurement of soil-gas radon (Rn) concentration is an important parameter in estimating soil Rn potential for a building site. Typically, field methods for grab samples (as contrasted with continuous flow systems) using a protable alpha-scintillometer only considered222Rn (T1/2= 3.8 d) and ignored220Rn (T1/2=55 s). Now the calculation permits the determination of the concentrations of both isotopes with a single series of readings. A sample is collected and within 1 minute is introduced into the counting system. A series of 1 minute counts begins immediately and continues for 10 minutes. If high220Rn concentrations are present, there will be a rapid decay followed by a steady ingrowth of222Rn progeny. If very little220Rn is present, the ingrowth will be seen immediately. In either case, a non-linear least square fitting program from Statgraphics is used to obtain both concentrations at time zero. When inexact timings ranging from 1 to 30 seconds were imposed on the measured data, the method proved to be very robust; the biases did not exceed 15 percent.

An examination of year-long, in-home radon measurement in Colorado from commercial companies applying typical methods indicates that considerable variation in precision exsts. This variation can have a substantial impact on any mitigation decisions, either voluntary or mandated by law, especially regarding property sale or exchange. Both long-term exposure (nuclear track greater than 90 days), and short-term (charcoal adsorption 4–7 days) exposure methods were used. In addition, periods of continuous monitoring with a highly calibrated alpha-scintillometer took place for accuracy calibration. The results of duplicate commercial analysis show that typical results are no better than ±25 percent with occasional outliers (up to 5 percent of all analyses) well beyond that limit. Differential seasonal measurements (winter/summer) by short-term methods provide equivalent information to single long-term measurements. Action levels in the U.S. for possible mitigation decisions should be selected so that they consider the measurement variability; specifically, they should reflect a concentration range similar to that adopted by the European Community.

Abstract Naturally Occurring Radioactive Materials (NORM) in the oil fields of the Apsheron* Peninsula (AP), Azerbaijan is widespread. NORM is a major source of environmental contamination of soils, surface and ground waters in Azerbaijan and the Caspian Sea. Geological formations at AP are composed of clays, sandstone, and limestone with radioactivity background within 6 μR/hr. At the tectonically disturbed zones of AP, radioactivity increases to 15-20 μR/hr. At some oil fields in South-Western area of AP and around iodine plants the level of radioactivity varies from 600 to 5,000 μR/hr. The origin of NORM in oil fields of AP is related to drilling, production, and processing operations. Other sources of contamination are oil well equipment where separation of contaminated water from oil and its subsequent reinjection into the oil field. There are no environmental regulations in Azerbaijan related to NORM. The state committee for Nature Protection is responsible for environmental protection of Azerbaijan but it is hoped that this paper will bring attention to the environmental community that pollution at AP and around the Caspian Sea is close to national disaster. In some oil fields, soil contamination is so extensive and elevated that it needs to be disposed of as low-level radioactive waste. The Azerbaijan government must have international assistance to clean-up its own environment. Azerbaijan needs financial support of international organizations and multinational oil companies, and involvement of industrialized nations for collecting field data and its interpretation for improving the environment at the Caspian Sea and its surroundings. Furthermore, experience gained from study of NORM in this region would be useful for researchers throughout the world. There is a very limited information about NORM and its health effects in literature.

A survey of radon-222 (Rn) in soil-gas and water at selected locations in Yellowstone National Park was initiated as part of Northwest College's Young Scholars' program. For two weeks in July 1993, four high school students and other researchers collected and analyzed nearly 100 samples of soil-gas and water. The three objectives of our reconnaissance of Rn in soil-gas and water in Yellowstone National Park were: (1) to engage talented high school students in challenging and enjoyable research, (2) to survey the variability of Rn in soil-gas and water in Yellowstone National Park, and (3) to provide the National Park Service with reconnaissance data on Rn in soil-gas and water. The research was conducted in four areas: (1) a study of Rn in water at public water-supply sources and in soil-gas near those sources, (2) a study of Rn in water and in soil gas near thermal areas, (3) a study of hourly and spatial variation of Rn in soil gas at West Thumb, and (4) a study of Rn in soil-gas and in water in the Mammoth area. With the help of National Park Service personnel, samples of soil-gas and water were collected for radon analysis from several public water supplies (Old Faithful, Madison, Norris, Lewis Lake, Mammoth, Lake, Bridge Bay, and South Entrance), West Thumb Geyser Basin, Boiling River, and other thermal areas. In Yellowstone National Park, most values of Rn in sampled supplies of public drinking water were above the range of average values (353-686 pCi/L) for public ground water supplies for the United States. The study of Rn in water at selected thermal areas indicated an inverse relationship between temperature and Rn concentration, as anticipated thermodynamically. No definitive relationship was noted between Rn concentrations in water and in soil-gas. At West Thumb Geyser Basin, the spatial variation in soil-gas Rn concentration was greater than the hourly variation. In the Mammoth area, an attempt was made to trace the underground course of Boiling River using Rn in soil-gas as an indicator. However, the thin soil overlying the travertine made it impossible to collect adequate samples of soil-gas. Although these studies indicated some variables (temperature, surface area, soil moisture, free exchange of water with air, uranium content of rock, and age of volcanic flow) that are affecting Rn concentrations in soil-gas and water, much work remains to be done on the spatial distribution and temporal variability of Rn concentrations in water and soil-gas in Yellowstone National Park.

There are 3 major objectives being addressed in this research. The first is to participate, by providing ground truth quality assurance, in the DOE/LBL/EPA cooperative study to determine a methodology to predict the areas where indoor radon concentrations have the highest probability of exceeding 20 pCi/L (750 Bq/m{sup 3}). The second is to examine 2 common types of homes (basement and non-basement) for radon entry by monitoring specific parameters under normal living conditions. The third task is to participate with other researchers in their studies using the techniques and experience developed by this principal investigator during previously funded times. Those researchers seek assistance in measuring soil permeability, determining the effect of meteorological parameters on radon entry, determining the diffusion characteristics of standard basement wall materials, developing a GIS (Geographic Information System) data base for predicting regional radon potential, and examining the contribution of regional solution-developed permeability in limestone to the radon potential of an area.

To the Editor: In a recent letter (June 9 issue),1 Dr. Chatterton asks how information from an epidemiologic article on the risks of lung cancer after exposure to radon by Pershagen et al. (Jan. 20...

This report presents data from sampling of near-surface soil porosity for its content of methane, carbon dioxide, nitrogen, and oxygen in an area overlying a deposit of producing coalbed methane from the Upper Cretaceous Fruitiand Formation in the San Juan Basin of southwestern Colorado.Most soil gas samples did not have detectable levels of methane.One explanation for this is that a recent, heavy rainstorm prior to sampling may have left most of the soil porosity waterlogged and reduced soil gas methane levels.However, elevated concentrations of methane occurred in two soil gas samples (several hundred to several thousand times methane in air) and two gas seep samples were about one-half methane and the balance carbon dioxide.Carbon dioxide concentrations are elevated above atmospheric concentration in all soil gas samples; however, the soil gas concentrations of this gas from plant metabolism in this area are unknown and may account for the elevated levels.

These reports are the culmination of a 3-year cooperative project involving, almost literally, a "cast of thousands."Sharon W. White and R

A technique using a small diameter probe and a portable alpha-particle scintillometer for sample collection and analysis has been developed. It is fast, efficient, cost-effective, and can be modified to accommodate a wide spectrum of sampling conditions. When soil-gas sampling for radon is combined with geophysical gamma-ray measurements, pedological characteristics of surficial materials, and geologic knowledge of bedrock, the combination forms a powerful technological basis for estimating radon potential of soils. The method can help provide information on a short time-frame so that local governments, land developers, and builders can take appropriate measures when planning new construction.