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The techniques developed for measuring tritium in various media are reviewed. The main emphasis is on measurements for surveillance and protection in environmental and occupational situations. Tritium measurements in specialized research applications are not treated in detail. Overviews are first provided of the physical characteristics of tritium; of the sources of and iypical levels of tritium concentrations in the natural environment; and of the radiation protection guides. The various measurement techniques are then discussed. (auth)

An air sampler that utilizes a thermoluminescent dosimeter to obtain a time-integrated measurement of airborne radon progeny was developed as a personal monitor for uranium miners. The sampler was adapted for use in homes in Grand Junction in connection with the uranium mill tailings survey. The requirements for a tamper-proof, inexpensive sampler, with a noise level not exceeding 35 db at one meter, introduced challenging design problems. The design, construction and subsequent operation of the samplers are discussed.

The evaporation velocity is calculated of radioactive substances that do not have a negligible vapor pressure under normal conditions of temperature and pressure. It is deduced that the maximum permissible concentration in air is readily attained for many compounds. A classification according to dangerousness is given based on an evaporation time which can be calculated for any compound under given conditions. (auth)

The radioactive-cloud immersion problem for beta-radiation has been treated schematically by assuming a semi-infinite air medium (source region) located adjacent to a semi-infinite water medium (tissue-equivalent target). The source region has been assumed to contain a uniform concentration of beta- emitting radionuclide, and calculations have been made of the absorbeddose distribution (depth dose) in the water target. A leakage correction has also been made to estimate the reduction of absorbed dose that would occur if the target had lateral dimensions small compared to the beta-particle range in air. Depth-dose calculations have been carried out for various source spectra (including beta-ray as well as discrete electron spectra) for /sup 83m/Kr, /sup 85m/Kr, /sup 85/Kr, /sup 87/Kr, /sup 88/Kr, /sup 88/Rb, /sup 131m/Xe, /sup 133m/ Xe /sup 133/Xe, /sup 135/Xe, /sup 137/Xe, /sup 137/Cs /sup 138/Xe and /sup 138/ Cs, being rare gases emitted by nuclear power plants into the atmosphere, and for /sup 3/H, /sup 14/C, /sup 35/S, /sup 125/I, /sup 24/Na, /sup 32/P, /sup 42/K, / sup 90/Y, /sup 60/Co, /sup 89/Sr, /sup 90/Sr, /sup 131/I, being comm only used radionuclides. (auth)

The techniques which have been developed for measuring /sup 222/Rn and its daughters in vanious media are reviewed. The main emphasis is on measurements for surveillance and protection in occupational and environmental situations. Measurements in specialized research applications are not treated in detail. Overviews are first provided of the physical characteristics of /sup 222/ Rn and its daughters; of the sources of and typical levels of concentrations in the natural environment and in occupational exposures; and of the radiation guides. The various measurement techniques are then discussed. (auth)

A review of data on the specific activity of 210Pb (pCi 210Pb/mg stable Pb) in the environment is presented. Experimental results on aerosol, plant, animal and human samples from Finland are reported. Large variations (18-2450 pCi/mg Pb) were observed for aerosol samples taken from various locations and under different meteorological conditions. Results for the biological samples revealed a much narrower range. A considerable decrease of specific activity was observed along the food chain plant—animal—man, thus indicating contamination of the food chain by technological (low-activity) lead. Arctic values of specific activity were observed to be generally higher than “normal” values. Human samples from southern Finland contained about 20pCi 210Pb/mgPb. Possibilities of utilizing specific activity measurements in lead pollution studies and in elucidating the origin of stable lead in the human diet are discussed.

Rates of uptake and loss of tritiated water (HTO) were measured in grass vegetation in the field after the plants had been exposed to an atmosphere containing HTO. Uptake of HTO from the atmosphere by leaves required 66 min to achieve 50% equilibrium activity while stems required 1970 min. Loss of HTO from leaves and stems during daylight however took place at rapid and comparable rates. The half time for loss in stems was 25 min while in leaves it was 35 min. Delabeling of contaminated leaves and stems in darkness took place at much reduced rates. The half time for delabeling of leaves in the dark was 400 min while for stems it was 2180 min. Rapid labeling and delabeling of plant tissue after exposure from the atmosphere takes place through leaf stomata and by direct transfer through the epidermis. Loss of HTO from plants is primarily dependent on transpiration. In the event of accidental HTO release to the atmosphere near the ground rapid contamination of vegetation could be expected, When the atmospheric source is dissipated, rapid decontamination could also be expected during periods of normal plant transpiration but not at night or other times when transpiration flow is not taking place.

Persistence of wind direction is a neglected subject. However, it is one of the significant parameters in dosage evaluation from short term releases of pollutants to the atmosphere. In this paper this topic is studied in detail using the continuous wind data from three nuclear power station sites in India. It is found from the analysis that longer persistence periods are less frequent. The frequency of occurrence of different persistence periods obeyed a log-normal distribution at two sites whereas at the third site, though the behaviour was qualitatively similar, no known analytic function could be fitted. The extrema and the averages of the wind speeds averaged over individual persistence periods, showed a dependence upon the persistence period as follows: 1. (1) the average maximum wind speed decreased with persistence; 2. (2) the average minimum wind speed increased with persistence; 3. (3) the average of the average wind speed first increased with increasing persistence and then tended to a stable value. Such analysis is useful in defining the worst meteorological conditions at nuclear station sites for applications in hazard evaluation. Some of the applications of the persistence analysis are discussed, and it is shown that dosage at any site from short term (h) continuous release of fission products has a maximum and that this maximum, which is different for different sites, can be used to grade the sites. An expression for return periods of persistences has been derived. This expression gives the return period in actual time units.

A sensitive real-time airborne dust mass monitor has been developed. Its operation is based on the measurement of beta-radiation absorption by aerosol particles collected onto a small area by means of inertial impaction. The device collects particles of unity density larger than 0.3 µm in diameter with nearly 100% efficiency at a flowrate of 20 liters/minute. A typical atmospheric mass concentration of 100 µg/m3 can be evaluated in less than one minute, using a one millicurie C14 source.

The incidence of nuclear antibodies was investigated in 64 relatives of patients with systemic lupus erythematosus and in 101 unrelated individuals from an isolated community in Southern Nevada with a “microepidemic” of the disease. The incidence of nuclear antibodies in relatives was significantly higher than that in unrelated controls, but the observed incidence was influenced by the dilution factor of the serum used for screening and the age and sex of individuals. Twenty-five percent of relatives had nuclear antibodies compared with 7.9% in unrelated controls at a serum dilution of 1 in 5; the incidence was 10.9% and 1.9%, respectively, when sera were screened at 1 in 10. At the latter dilution, the incidence of antibodies in male and female relatives over the age of 40 years was similar, whereas the incidence in young female relatives was significantly higher than male relatives in the same age range. The possible effect of certain environmental factors in individuals genetically predisposed to the formation of nuclear antibodies is discussed.

The outputs and mass median droplet diameters of useful aerosols and the effect of solvent evaporation on the concentration of nebulizer solutions have been measured for four nebulizers of designs which have been employed for inhalation studies. Outputs ranging from 2.3 to 30.4 microliters of solution per liter of jet air were observed, with corresponding mass median droplet diameters of 1.4 to 5.4 microns. For jet pressure drops of 2.5 to 30 psi, from 7 to 10 microliters of solvent (water), in excess of that associated with the aerosol, was carried away per liter of jet air. The effects of baffling and of augmenting the jet air with additional flow through a vent were also determined.

The reports of the Federal Radiation Council and the Manual Chapters of the U.S. Atomic Energy Commission present radiation guides and regulations establishing levels that should not be exceeded in normal, or planned, operations. To assure that exposures will not exceed the levels stipulated by the guides and regulations (except in accidents or emergencies), Oak Ridge National Laboratory has established operating levels generally somewhat below the recommended maximum levels. Control measures are initiated when the operating levels are exceeded. The action points and corresponding control measures discussed in this paper are those established and applied at ORNL with proved effectiveness.

(1964). Bases and Criteria for Air Quality Standards. Journal of the Air Pollution Control Association: Vol. 14, No. 1, pp. 22-26.

A point-to-plane electrostatic precipitator of simple design is described. It was developed as a particle size sampling instrument for use with the electron microscope. The standard operating conditions as well as special design and technical points are described and illustrated. Tests of the instrument have been made using the thermal precipitator as a standard. These comparisons have indicated no important limitation of the point-to-plane precipitator as a particle size sampler. Other advantages and disadvantages of the instrument based on our experience are given. Most of these points are documented by photographs. None of the negative qualities of the sampler appear general or restrictive. Conversely, there are specific attributes which make the point-to-plane electrostatic precipitator a valuable, if not indispensable, tool in aerosol studies.

The Central Electricity Generating Board has been monitoring the environment of civil nuclear power reactors since 1957. The history of the monitoring programme is described, and the modifications that have resulted from operational experience are discussed together with those required as a result of amendments to the legislation affecting environmental surveys. The “tackishade”, device developed for detecting airborne radioactivity, is described.

The radon hazard is presumed to be lung cancer induced by alpha irradiation of basal cells in the bronchial epithelium. The effective dose is calculated by a relatively complete analysis which includes (1) the distribution of atmospheric activity by size and daughter, (2) the prediction of a

In a Symposium on Radiation and Terrestrial Ecosystems it is appropriate to discuss the interception and retention of airborne materials in plants only insofar as these processes influence the total radiation dose to which members of ecosystems may be subject. Consideration is given to the c

The measurement of the gamma ray spectra from the radioactive fallout produced by the fifth and sixth Chinese nuclear test explosions were made with a Ge (Li) detector. Many nuclides were identified in the gamma ray spectra without any chemical processing. The fission products as 85mKr, 91Sr-91mY, 95Zr-95Nb, 97Zr-97Nb, 99Mo-99mTc, 103Ru 131I, 132Te-132I, 133I-133Xe, 139Ba, 140Ba-140La, 141Ce, 143Ce, and 147Nd were identified. In addition to them, 237U and 239Np produced from 238U were also identified.

Previous reports have shown a small but definite increase of cancer of the lung among uranium miners in a defined study group. In the present study all men with cancer of the lung found during a 16-yr period were analyzed. The cases were collected in an area covering 15 counties, embracing the uranium industry in Western Colorado and Eastern Utah. Comparison of the tumor cell types revealed the uranium miners to have a high proportion (57 per cent) of the undifferentiated variety of tumors; 76 per cent of these were of the oat cell type. The comparison group, matched for age and smoking, had only 18 per cent of the undifferentiated cell type tumors. Only 37 per cent of the lung tumors of the uranium miners were of the epidermoid variety in contrast to 62 per cent for the control group. The difference in cell type cannot be attributed to cigarets or age. Differences in survival time, symptoms and tumor location were also noted.

This study was undertaken on behalf of Shellstar Limited in 1966, who planned to build a fertilizer plant on the south side of the Mersey estuary. The chief problems arose from its closeness to the town of Helsby, some of whose houses are on high ground within a mile of the site. There was also the risk of a haze of ammonium compounds of a kind already experienced on Tees-side. From a study of records selected from suitably chosen meteorological office stations and a knowledge of the topography and the behaviour of fog and winds in the Merseyside area it was found that in very stable conditions the air drift was away from Helsby and that although the most common wind was from the site towards Helsby this was normally more unstable and fresher than average. The fogs on Merseyside are of a quite different nature from those on Tees-side and no chemical haze problem is expected. The case illustrates the importance of making the correct correlations of meteorological elements because the prima facie implications of long-term averages of individual elements are quite misleading in this case. None of the important problems in this case were soluble by use of dispersion formulae. During the study it became obvious that although there is often a serious reduction in visibility in the south Merseyside area from distant pollution, domestic pollution in Helsby is the worst problem there. Other major sources are the BICC works in Helsby, Ince Power Station, Stanlow Refinery, and road and rail traffic. The traffic was also a substantial source of noise. The new plant would not be a source as bad as any of these.

A realistic evaluation of dosages from continuous sources should use finite wind direction persistance. In this paper, a plume model for release in finite wind persistance period is developed. Relations are derived for computing dosage during the period of persistent wind direction and that due to the transit of the oblique plume in the changed wind direction at the end of the persistance period. The derivations take into account the change in diffusion conditions before and after the wind direction change. Some approximate relations are compared with the numerically integrated dosages computed on a CDC 3600 computer. It is found that the agreement is quite satisfactory.

Comparisons are made of lung cancer data from five groups of miners exposed to a wide range of levels of air-borne radioactive particles. Partly because of variable quality of the data for the different groups, alternative estimates of lung cancer risk are used: incidence or mortality rates, ratio of observed to expected rates and proportion of lung cancer to all deaths. These three criteria agree that lung cancer in mining groups tends to be directly proportional to mean radiation exposure. After assuming linearity of this relationship and absence of a dose-rate effect, it is estimated that one rad to the bronchial walls of one million persons produces about one lung cancer per year, and that the average integral dose required to produce one lung cancer is 1.3 × 105 gm rad. An exposure of 120 WLM (estimated to equal 360 rad) appears to double the lung cancer incidence characteristic of the general population.

A method is described for the simultaneous determination of each of the short-lived daughters of random-222. The method entails sampling the atmosphere of interest through a filter and carrying out α-spectrometry on the activity collected on the filter. The spectrometry measurements must be made both during and after sampling. From a knowledge of the RaA and RaC disintegrations occurring on the filter it is possible to calculate the atmospheric ceoncetrations of RaA, RaB and RaC. The determinations made by the method indicate that its accuracy is sufficient to obtain meaningful results with the smallest daughter product concentrations usually found in the atmosphere.

Three different two-stage samplers were calibrated using monodisperse aerosols produced by a spinning-disk aerosol generator. One, using a horizontal elutriator as the size selector, agreed with the criteria defining “respirable dust” adopted by the British Medical Research Council. The other two, using small cyclones as size selectors, agree with criteria proposed by the Los Alamos Conference and the ACGIH when operated at approximately half their initially recommended flow rates. Operation of these cyclones at the initially recommended flow rates underestimates the inhalation hazard.

A study was made of the relationship between I/sup 131/ concentrations in air, vegetation, milk, and cattle thyroids in the vicinity of Hanford during the period January 1961, through April, 1963. Some insight into mechanisms of I/ sup 131/ passage down the food chain to man is provided and the rate at which I/ sup 131/ concentrations decrease following relatively acute depositions of fallout materials is illustrated. The major source of the I/sup 131/ was fallout of debris from nuclear weapons tests. Concentrations noted during periods of testing were 10--100 times those found when no testing was in progress. Fresh milk constituted the principal mode of intake of I/sup 131/for persons residing in the Hanford environs. Concentrations in milk sample collected from 10cal dairy farms averaged about 50 pC I/sup 131//1 during 1961, and 40 pC/1 during 1962. The potential radiation dose received by a small child (with a 2 g thyroid) via milk consumption was estimated to be about 400 times that received via inhalation during the period under study. For an adult (with a 20 g thyroid) the ratio of thyroid exposure via milk to that via inhalation was estimated to be about 40 to 1. (auth)