polonium and Lung-Neoplasms

To determine the tobacco industry's policy and action with respect to radioactive polonium 210 ((210)Po) in cigarette smoke and to assess the long-term risk of lung cancer caused by alpha particle deposits in the lungs of regular smokers.. Analysis of major tobacco industries' internal secret documents on cigarette radioactivity made available online by the Master Settlement Agreement in 1998.. The documents show that the industry was well aware of the presence of a radioactive substance in tobacco as early as 1959. Furthermore, the industry was not only cognizant of the potential "cancerous growth" in the lungs of regular smokers but also did quantitative radiobiological calculations to estimate the long-term (25 years) lung radiation absorption dose (rad) of ionizing alpha particles emitted from the cigarette smoke. Our own calculations of lung rad of alpha particles match closely the rad estimated by the industry. According to the Environmental Protection Agency, the industry's and our estimate of long-term lung rad of alpha particles causes 120-138 lung cancer deaths per year per 1,000 regular smokers. Acid wash was discovered in 1980 to be highly effectively in removing (210)Po from the tobacco leaves; however, the industry avoided its use for concerns that acid media would ionize nicotine converting it into a poorly absorbable form into the brain of smokers thus depriving them of the much sought after instant "nicotine kick" sensation.. The evidence of lung cancer risk caused by cigarette smoke radioactivity is compelling enough to warrant its removal.

Topics: History, 20th Century; Humans; Lung; Lung Neoplasms; Neoplasms, Radiation-Induced; Nicotiana; Polonium; Radiation Dosage; Risk; Smoke; Smoking; Tobacco Industry; United States

Topics: Drug Synergism; Environmental Exposure; Humans; Lung Neoplasms; Neoplasms, Radiation-Induced; Polonium; Radon; Smoking

Topics: Animals; Environmental Exposure; Humans; Iodine Radioisotopes; Lung Neoplasms; Neoplasms, Radiation-Induced; Nuclear Warfare; Phosphorus Radioisotopes; Plutonium; Polonium; Radioactive Hazard Release; Radioisotopes; Radium; Radon; Risk Factors; Thorium; Uranium

Topics: Air Pollutants; Air Pollutants, Occupational; Air Pollutants, Radioactive; Coal; Heating; Humans; Lung Neoplasms; Maximum Allowable Concentration; Neoplasms, Radiation-Induced; Occupational Diseases; Polonium; Power Plants; USSR

Radon gas is a major source of radiation exposure to the general public. Radon-222 is a product of uranium-238, present in varying concentrations in all soils. Radon enters buildings from soil, water, natural gas, and building materials. Its short-lived breakdown products, termed "radon daughters," include alpha-emitting solids that can deposit in the lungs. Firm evidence links lung cancer risk in miners with high exposure to radon daughters. The amount of risk associated with the much lower but chronic doses received in buildings is difficult to establish. By some extrapolations, radon daughters may be responsible for a significant number of lung cancer deaths. The existence or extent of synergism with smoking is unresolved. Local conditions can cause high levels of radon in some buildings, and measures that reduce indoor radon are of potential value.

Topics: Bismuth; Facility Regulation and Control; Housing; Humans; Lead; Lung Neoplasms; Neoplasms, Radiation-Induced; Polonium; Radioactive Pollutants; Radon; Radon Daughters; Risk Factors; Smoking

Topics: Bismuth; Carcinogens; Humans; Lead; Lung Neoplasms; Models, Structural; Nicotiana; Plants, Toxic; Polonium; Radon Daughters; Respiratory System; Smoke

Topics: Humans; Lung Neoplasms; Polonium; Tobacco Smoke Pollution

Topics: Bismuth; Construction Materials; Environmental Exposure; Housing; Humans; Lead; Lung Neoplasms; Maximum Allowable Concentration; Neoplasms, Radiation-Induced; Polonium; Public Health; Radon; Radon Daughters; Risk; Ventilation; Water Pollution, Radioactive

Topics: Adolescent; Adult; Air Pollution, Radioactive; Austria; Bismuth; Child; Child, Preschool; Health Resorts; Humans; Infant; Lead; Lung Neoplasms; Mining; Neoplasms, Radiation-Induced; Polonium; Radiation Dosage; Radon; Radon Daughters; Risk; United States; Uranium

Topics: Animals; Background Radiation; Body Burden; Carcinoma, Bronchogenic; Environmental Health; Fishes; Humans; Lichens; Lung Neoplasms; Mining; Neoplasms, Radiation-Induced; Plankton; Plants; Polonium; Radiation Dosage; Radioactive Fallout; Reindeer; Shellfish; Smoking; Uranium; Vehicle Emissions

Topics: Age Factors; Air Pollution; Animals; Benzopyrenes; Bronchial Neoplasms; Canada; Cricetinae; Dogs; Female; Food Contamination; Germany; Humans; Indians, North American; Inuit; Lung Neoplasms; Male; Mice; Nicotiana; Plants, Toxic; Polonium; Rats; Sex Factors; Skin Neoplasms; Smoking; Socioeconomic Factors; United Kingdom; United States

In the present investigation, the surface-deposited polonium activities were measured in houses in the Ukhimath region of Garhwal Himalaya, India. The surface-deposited (210)Po activity concentrations were found to vary from 0.7 to 15.40 Bq m(-2) with an average of 5.95 Bq m(-2). The radon concentration estimated on the basis of (210)Po activity was found to vary from 0.29 to 700 Bq m(-3) with an average value 242 Bq m(-3). The contemporary radon concentration in the area was found to vary from 13 to 181 Bq m(-3) with an average of 46 Bq m(-3). The annual effective dose due to (210)Po activity in houses in the Garhwal Himalaya region was found to vary from 0.61 to 13.33 mSv with an average of 5.15 mSv. Some worldwide studies have shown the relation between the increased risk of lung cancer and smoking habits. Data on smoking have also been collected from the same dwellings. The significance of this work is also discussed in detail from a radiation protection point of view.

Topics: Air Pollution, Indoor; Air Pollution, Radioactive; Gases; Glass; Housing; Humans; India; Lung Neoplasms; Models, Statistical; Neoplasms, Radiation-Induced; Polonium; Radiation Dosage; Radiation Monitoring; Radiometry; Radon; Risk; Surface Properties; Time Factors

Topics: Fertilizers; Humans; Lung; Lung Neoplasms; Nicotiana; Polonium; Smoke; Smoking; Tobacco Industry

The quantitative relationships between radon gas concentration, the surface-deposited activities of various radon progeny, the airborne radon progeny dose rate, and various residential environmental factors were investigated through a Monte Carlo simulation study based on the extended Jacobi room model. Airborne dose rates were calculated from the unattached and attached potential alpha-energy concentrations (PAECs) using two dosimetric models. Surface-deposited (218)Po and (214)Po were significantly correlated with radon concentration, PAECs, and airborne dose rate (p-values <0.0001) in both non-smoking and smoking environments. However, in non-smoking environments, the deposited radon progeny were not highly correlated to the attached PAEC. In multiple linear regression analysis, natural logarithm transformation was performed for airborne dose rate as a dependent variable, as well as for radon and deposited (218)Po and (214)Po as predictors. In non-smoking environments, after adjusting for the effect of radon, deposited (214)Po was a significant positive predictor for one dose model (RR 1.46, 95% CI 1.27-1.67), while deposited (218)Po was a negative predictor for the other dose model (RR 0.90, 95% CI 0.83-0.98). In smoking environments, after adjusting for radon and room size, deposited (218)Po was a significant positive predictor for one dose model (RR 1.10, 95% CI 1.02-1.19), while a significant negative predictor for the other model (RR 0.90, 95% CI 0.85-0.95). After adjusting for radon and deposited (218)Po, significant increases of 1.14 (95% CI 1.03-1.27) and 1.13 (95% CI 1.05-1.22) in the mean dose rates were found for large room sizes relative to small room sizes in the different dose models.

Topics: Air Pollutants, Radioactive; Air Pollution, Indoor; Housing; Humans; Iowa; Lung Neoplasms; Models, Theoretical; Monte Carlo Method; Neoplasms, Radiation-Induced; Polonium; Radiation Dosage; Radiometry; Radon Daughters; Regression Analysis; Surface Properties; Ventilation

²¹⁰Po and ²¹⁰Pb were discovered in tobacco in 1964. This was followed by detailed assessments of the nature of their deposition, and accompanying dose rates to the lungs of cigarette smokers. Subsequent studies revealed: (1) the sources and pathways through which they gain access to tobacco; (2) the mechanisms through which they preferentially deposit in key segments of the bronchial epithelium; and (3) the fact that the accompanying alpha radiation plays a synergistic role in combination with the chemical carcinogens, to increase the fatal cancer risk coefficient in cigarette smokers by a factor of 8 to 25. Nonetheless, it was not until 2009 that Congress mandated that the Food and Drug Administration require that the cigarette industry reveal the presence of these carcinogens. In the meantime, cigarette smoking has become not only the number one source of cancer deaths in the United States, but also a major contributor to heart disease and other health impacts. If the latter effects are included, smoking is estimated to have caused an average of 443,000 deaths and 5.1 million years of potential life lost among the U.S. population each year from 2000 through 2004. The estimated associated collective dose is more than 36 times that to the workers at all the U.S. nuclear power plants, U.S. Department of Energy nuclear weapons facilities, and crews of all the vessels in the U.S. Nuclear Navy. This unnecessary source of lung cancer deaths demands the utmost attention of the radiation protection and public health professions.

Topics: Carcinogens; Documentation; Federal Government; Government Regulation; Health; Health Education; History, 20th Century; History, 21st Century; Humans; Lead; Lung Neoplasms; Nicotiana; Polonium; Radiation Dosage; Smoking; Tobacco Industry; Tobacco Smoke Pollution; United States

An earlier study of mortality among male former employees at a tin smelter in Humberside, UK, had identified excess mortality from lung cancer, which appeared to be associated with occupational exposure.. The aim of the present study was to investigate the relationship between lung cancer mortality and quantitative measures of exposure.. Using available records of occupational hygiene measurements, we established exposure matrices for arsenic, cadmium, lead, antimony and polonium-210 ((210)Po), covering the main process areas of the smelter. We established work histories from personnel record cards for the previously defined cohort of 1462 male employees. Three different methods of extrapolation were used to assess exposures prior to 1972, when no measurement results were available. Lung cancer mortality was examined in relation to cumulative inhalation exposure by Poisson regression analysis.. No significant associations could be found between lung cancer mortality and simple cumulative exposure to any of the substances studied. When cumulative exposures were weighted according to time since exposure and attained age, significant associations were found between lung cancer mortality and exposures to arsenic, lead and antimony.. The excess of lung cancer mortality in the cohort can most plausibly be explained if arsenic is the principal occupational carcinogen (for which the excess relative risk diminishes with time since exposure and attained age) and if there is a contribution to excess mortality from an enhanced prevalence of smoking within the cohort. The implications of the dose-response for arsenic exposure for risk estimation merit further consideration.

Topics: Adult; Aged; Aged, 80 and over; Air Pollutants, Occupational; Antimony; Arsenic; Cadmium; England; Humans; Lead; Lung Neoplasms; Male; Metallurgy; Middle Aged; Occupational Diseases; Occupational Exposure; Polonium

The relation between increased risk of lung cancer and exposure to indoor radon is assessed in epidemiological studies. Both the quality and reliability of smoking data and the radon exposure data are of primary importance. Contemporary measurement of radon concentration in the dwellings of individuals in a case-control study is traditionally used to assess past history of radon exposure. These assessments are somewhat unreliable since presently measured radon concentration might not be representative for a given location long ago. The measurement of long-lived decay products from 222Rn remaining indoors on hard surfaces, such as glass, makes it possible to assess the exposure to indoor radon. At the Swedish Radiation Protection Institute, a combination of two different solid-state nuclear track detectors has been developed to assess the 210Pb activity implanted in glass surfaces by measuring 210Po alpha activity. This detector (a RETRO detector) is used in the Swedish radon epidemiological case-control study of non-smokers with the aim to provide an alternative estimate of individual radon exposure and to evaluate the usefulness of RETRO measurements. A total of 576 different objects were found and 568 were measured. For 225 individuals, we measured two personal objects that had been in the same person's possession for more than 20 years. The standard deviation of the average radon concentration obtained from these two objects had a median value of 13 Bq/m3 indicating a precision of exposure of approximately 20%. The correlation between 210Po surface activity measured earlier and the mean values of radon concentrations in a number of Swedish dwellings is used to estimate the historical, average radon concentration. This average correlation factor seems also to be valid for measurements in the non-smoker epidemiological study.

Topics: Air Pollutants, Radioactive; Air Pollution, Indoor; Air Pollution, Radioactive; Epidemiologic Methods; Glass; Housing; Humans; Lead Radioisotopes; Lung Neoplasms; Polonium; Radiometry; Radon; Retrospective Studies; Risk Factors; Surface Properties; Sweden

The efficacy of radioimmunotherapy of tumours with radiolabelled monoclonal antibodies (MAbs) depends on the amount of antibody taken up by the tumour and on its intratumoral distribution. In the case of MAbs directed against intracellular antigens, increasing the permeability of the cytoplasmic membrane may augment the bioavailability of the antigen for the antibody. This raises the question whether the induction of tumour necrosis by chemotherapy can enhance the tumour uptake of radiolabelled monoclonal antibodies. In this work, the effect of doxorubicin on the biodistribution of Po66, an MAb directed against an intracellular antigen, was studied in nude mice grafted with the human non-small-cell lung carcinoma cell line SK-MES-1. After injection on day 0 of 125I-labelled Po66, tumour radioactivity increased up to days 3-5, and then remained unchanged to day 14. The combined administration of 125I-labelled Po66 with 8 mg kg-1 doxorubicin, in two doses separated by 7 days, doubled the radioactivity retained by the tumour. Histological and historadiographic analysis showed, however, that the drug induced cellular damage. In the absence of doxorubicin, the accumulation of Po66 was restricted to some necrotic areas, whereas with doxorubicin the necrosis was more extensive and the antibody more evenly distributed. These results suggest that chemotherapy and immunoradiotherapy combined would enhance tumour uptake of radioisotope and promote more homogenous distribution of the radiolabelled MAb. This would promote eradication of the remaining drug-resistant cells in tumours.

Topics: Animals; Antibiotics, Antineoplastic; Antibodies, Monoclonal; Antibodies, Neoplasm; Antigens, Neoplasm; Carcinoma, Squamous Cell; Combined Modality Therapy; Doxorubicin; Drug Administration Schedule; Female; Humans; Immunoconjugates; Immunoglobulin G; Intracellular Fluid; Lung Neoplasms; Mice; Mice, Inbred BALB C; Mice, Nude; Neoplasm Transplantation; Polonium; Radioimmunotherapy; Tissue Distribution

A cohort of 3469 males with at least 1 y of underground uranium mining experience in New Mexico was assembled and mortality followed up through 31 December 1985. The mean and median cumulative exposures for the cohort were 0.39 J h m-3 and 0.12 J h m-3 (111.4 and 35.0 Working Level Months [WLM]), respectively. Overall, mortality in the cohort was significantly increased (standardized mortality ratio [SMR] = 1.1, 95% confidence interval [CI] = 1.02-1.2) relative to the general population of the state. By cause, significant increases were observed for lung cancer (SMR = 4.0, 95% CI 3.1-5.1) and for external causes of death (SMR = 1.5, 95% CI 1.3-1.7). The risk of lung cancer increased for exposure categories above 100 WLM; the excess relative risk increased by 0.5% per mJ h m-3, 95% CI 0.2-1.5 (1.8% per WLM, 95% CI 0.7-5.4). Data were consistent with a multiplicative interaction between smoking and exposure to Rn progeny in an exponential relative risk model. The risk of lung cancer varied substantially with age at observation; the odds ratios rose more steeply with exposure to Rn progeny for those less than age 55 y at observation.

Topics: Adult; Bismuth; Cohort Studies; Humans; Lead; Lung Neoplasms; Male; Middle Aged; Mining; Neoplasms, Radiation-Induced; New Mexico; Occupational Exposure; Polonium; Radon Daughters; Smoking; Uranium

Syrian Golden hamsters received 8 weekly intratracheal instillations of 0.2 microCi of the alpha-emitting isotope Po210 while being exposed to an atmosphere of 65% oxygen in the inspired air. Three months later, 42% of the animals had poorly differentiated lung carcinomas. On the other hand, no lung tumors were found in hamsters that received intratracheal instillations of Po210 and were kept in air. It is concluded that diffuse cell hyperplasia in the lung, caused by an inhalant, may constitute an additional risk factor in the pathogenesis of alpha-radiation induced lung cancer.

Topics: Animals; Cricetinae; Hyperplasia; Instillation, Drug; Lung; Lung Neoplasms; Male; Mesocricetus; Neoplasms, Radiation-Induced; Oxygen; Polonium

Lung cancer in U miners is thought to be related to the inhalation of particulate Rn daughters. Since the depth of penetration by alpha particles is short, the thickness of the epithelium lining the bronchial tree may be a critical factor in the development of cancers at specific sites in the lung. The objectives of the study were to measure the thickness of the epithelium at all levels of the human bronchial tree, to determine the distances of epithelial nuclei from the mucociliary surface, and to compare these parameters in smokers and nonsmokers. Twenty-nine surgically removed specimens were examined; 26 were from smokers. No significant differences were found between smokers and nonsmokers, allowing us to treat the 29 cases as a homogeneous group. With progressive divisions of the bronchi, the epithelium decreases in thickness, and distances of nuclei from the surface are also less in the peripheral bronchi. Allowing for artefacts of tissue preparation, the mean distance from the mucociliary surface to the underlying nuclei varies between 17 and 38 microns.

Topics: Aged; Bismuth; Bronchi; Epithelial Cells; Female; Humans; In Vitro Techniques; Lead; Lung Neoplasms; Male; Middle Aged; Mining; Neoplasms, Radiation-Induced; Polonium; Radon; Radon Daughters; Smoking; Uranium

The recessive oncogenesis model, according to which inactivation of both alleles of specific genes leads to cancer, has received much recent attention. A mathematical formulation of a two-mutation model for carcinogenesis, which includes the recessive oncogenesis model as a special case, was fitted to data from a large experimental study in which rats exposed to radon daughters developed malignant lung tumors. The model described the data well. The results indicate that fractionation of exposure increased the lifetime probability of tumor. Examination of the parameters of the model suggests that the effect of fractionation can be explained by the relative effects of radon daughters on the mutation rates and on the kinetics of growth of initiated cells. The first mutation rate is very strongly dependent upon the rate of exposure to radon daughters, the second mutation rate much less so, suggesting that the nature of the two mutational events is different. The model makes predictions which are testable in future experiments.

Topics: Animals; Bismuth; Lead; Lung Neoplasms; Models, Genetic; Mutation; Neoplasms, Radiation-Induced; Polonium; Radon; Radon Daughters; Rats; Rats, Inbred Strains

A case-control study was conducted to describe lung cancer risk in a cohort of New Mexico underground U miners. The subjects included 65 cases and 230 age-matched controls, most with exposures below 3.50 J h m-3 (1000 WLM). The risk for lung cancer was increased for all cumulative exposures to Rn progeny of 0.35 J h m-3 (100 WLM) or greater. The odds ratios were unchanged with control for cigarette smoking. With exclusion of subjects with exposures above 3.50 J h m-3 (1000 WLM), the estimated excess relative risk was 0.3% per mJ h m-3 (1.1% per WLM). The risk was greater for younger subjects and the data were consistent with a multiplicative interaction between cigarette smoking and exposure to Rn progeny.

Topics: Adult; Aged; Bismuth; Humans; Lead; Lung Neoplasms; Male; Middle Aged; Mining; Neoplasms, Radiation-Induced; New Mexico; Occupational Diseases; Polonium; Radon Daughters; Risk Factors; Uranium

The effectiveness of radon-daughter inhalation and irradiation with fission neutrons and gamma rays in the induction of lung carcinomas in Sprague-Dawley rats at low doses is compared. Earlier reports which compared radon-daughter inhalations and neutron irradiations over a wider range of doses were based on dosimetry for the radon-daughter inhalations which has recently been found to be faulty. In the present analysis, low-dose experiments were designed to derive revised equivalence ratios between radon-daughter exposures, and fission neutron or gamma irradiations. The equivalence is approximately 15 working level months (WLM) of radon daughters to 10 mGy of neutrons (the earlier value was 30 WLM to 10 mGy). The relative biological effectiveness (RBE) of neutrons is 50 or more at a gamma-ray dose of 1 Gy. In these experiments with low doses and exposures, the lifetime incidences can be estimated from the raw incidences, while the derivation of the time dependence of the prevalence is essential for the estimation of RBE values and equivalence ratios.

Topics: Administration, Inhalation; Animals; Bismuth; Carcinoma, Bronchogenic; Cobalt Radioisotopes; Gamma Rays; Lead; Lung Neoplasms; Male; Neoplasms, Radiation-Induced; Neutrons; Polonium; Radon; Radon Daughters; Rats; Rats, Inbred Strains; Relative Biological Effectiveness; Sarcoma, Experimental

In the evaluation of lung cancer risk from Rn daughters in the home environment, measurements of Rn concentration or potential alpha-energy concentration (PAEC) have served as proxies for actual radiation dose to the lungs. This paper uses a single-compartment room model, model parameters from a number of recent studies, and Monte Carlo analysis to explore the relative value of Rn concentration, PAEC, and room surface deposition, or plate-out, as estimators of lung dose. Results indicate that Rn concentration and PAEC are fairly good estimators, explaining roughly 50-70% of the variation in dose for the conditions studied, over the range of Rn concentrations considered (74-555 Bq m 3). The relative advantage of one measure over the other depends upon the variability in a number of factors across the houses being evaluated. Room surface activity deposition was not found to be superior to the traditional measures of Rn concentration and PAEC. Significant room for improvement remains in the development of simple home monitors providing an improved estimation of lung dose.

Topics: Air Pollutants; Air Pollutants, Radioactive; Alpha Particles; Bismuth; Housing; Humans; Lead; Lung Neoplasms; Monte Carlo Method; Neoplasms, Radiation-Induced; Polonium; Radiation Dosage; Radon; Radon Daughters; Risk

Chronic inhalation intake of benzo(a)pyrene (BP) and polonium-210 (210Po) together with aluminum oxide caused increase of tumor formation in the lungs of mice. Synergy of BP and 210Po carcinogenic effect was pointed out, it was characterized by summation and possible effect involution by tumor development rates and the duration of the latent period. BP and 210Po carcinogenic effectiveness depended on the type of dust carrier and probably on the presence of silicon dioxide and also carcinogenic metals. It was pointed out that further studies were necessary to determine an etiologic role of mineral dust chemical components in carcinogenic activity of the above substances and also carcinogenic effectiveness of dusts as carriers of chemical carcinogens and alpha-active radionuclides.

Topics: Administration, Inhalation; Aluminum; Aluminum Oxide; Animals; Benzo(a)pyrene; Cocarcinogenesis; Drug Synergism; Dust; Female; Lung; Lung Neoplasms; Mice; Neoplasms, Radiation-Induced; Polonium

An analytical method has been developed to calculate the local energy deposited by alpha particles emitted from radon daughters deposited on the mucus surface in the lung airways. For the particular cases of 218Po (Ra A) and 214Bi (Ra C'), microdose spectra have been evaluated in test spheres of 1 micron diameter which were taken to lie within airways of diameters 18,000, 3,500 and 600 microns. In each case, the contributions of the near and far wall were computed separately. The average microdosimetric parameters yF and yD have also been calculated. For the two smaller airways, yF and yD values were found to be about 110 and 135 keV microns-1 for 218Po and about 87 and 107 keV microns-1 for 214Bi respectively. The corresponding values were about 10% higher for the largest airway.

Topics: Alpha Particles; Bismuth; Humans; Lung Neoplasms; Polonium; Radiation Dosage; Radioisotopes; Radon

In order to achieve a balanced approach to risk assessment between carcinogenic and non-carcinogenic health effects one must examine the risk of disease or death in the general population exposed to a particular air pollutant that can be related quantitatively to intensity and duration of exposures (National Academy of Sciences, 1983). Such risk assessment should be based upon careful evaluation of scientific findings of dose-response relationships in the chronically exposed population. Quantitative assessment of environmentally produced disease in man has proven to be complex and demanding. A variety of factors play important roles in this task. As an example, there are induction-latency periods for chronic diseases, including cancer, which may range from five to twenty-five years. The diseases themselves, whether proliferative or degenerative, may follow several stages of progression. There is only sparse epidemiological data on serious health effects that may be due to environmental as compared to occupational exposures. Exposures to chemical or radiological air contaminants do not occur singly but to a multiplicity of agents, and disease processes are frequently markedly affected by the interaction of a variety of factors, particularly that of cigarette smoking. There is growing recognition of potentially sensitive subpopulations, including the elderly and the very young, but adequate techniques for assessing the magnitude of increased risks to these groups have not yet been developed.

Topics: Air Pollutants; Animals; Bismuth; Disease Susceptibility; Humans; Lead; Lung Neoplasms; Neoplasms, Radiation-Induced; Occupational Diseases; Polonium; Radon; Radon Daughters; Respiratory Tract Diseases; Risk Factors; Smoking; Vehicle Emissions

Results are reported of epidemiological studies in six groups of miners, who work in U mines, Fe mines and shale clay mines. A significant excess of lung cancer was proved in exposure categories below 50 WLM, the first significant excess of lung cancer rate was found in the sixth year following the start of exposure, and a significant difference between the observed and expected rate was found in miners even before the fortieth year of age. The mean attributable annual cancer risk after about 30 y of observation in the whole study was approximately 20.0 and in persons starting exposure after 30 y of age the risk was approximately 30.0 per year per 1 WLM per 10(6) persons. The dose-effect relationship and the attributable lung cancer risk per 1 WLM were significantly influenced by the age at the first exposure by total accumulated exposure and by the character of the accumulation of exposure. The observed effects of smoking and exposure to alpha radiation from Rn daughters were nearly additive. The lung cancer risk per 1 WLM at low levels of exposure (not including the contribution from natural sources in the living environment) in U as well as Fe mines indicated a certain elevation compared with the risk at higher accumulated exposure.

Topics: Adult; Aged; Bismuth; Carcinoma, Small Cell; Carcinoma, Squamous Cell; Czechoslovakia; Humans; Iron; Lead; Longitudinal Studies; Lung Neoplasms; Middle Aged; Mining; Neoplasms, Radiation-Induced; Polonium; Prospective Studies; Radon Daughters; Uranium

The alpha-activity on the bronchial airways has been calculated for 222Rn daughter exposures producing observable excess bronchogenic lung cancer in underground miners. The activity distribution of aerosol particles with attached 222Rn daughters on the bronchial tree is truly diffuse because of the short half-life of the daughters and the large number of particles in the ambient aerosol. From the bronchial airway activity and the minor epidemiology, it can be shown that it requires, on average, 4 X 10(9) stem cells in bronchial epithelium to be hit in order to produce an observed lung cancer. For very high 222Rn daughter exposures of miners, multiply hit cells are highly probable; yet the lung cancer response is lower per unit exposure at high exposures than for mining exposures--near those sustained in the environment probably due to stem cell death. A knowledge of the number of multiply hit cells in miners permits some infererences to be made about the effectiveness of particulate versus diffusely distributed alpha emitters in the lung, namely, that particulates should not be significantly more effective in lung cancer induction than a diffuse distribution.

Topics: Air Pollution, Radioactive; Alpha Particles; Bismuth; Bronchi; Carcinoma, Bronchogenic; Humans; Lead; Lung Neoplasms; Mining; Neoplasms, Radiation-Induced; Polonium; Radon Daughters

Topics: Adult; Age Factors; Air Pollutants; Air Pollutants, Radioactive; Bismuth; Female; Humans; Lead; Life Expectancy; Lung Neoplasms; Male; Mining; Models, Biological; Neoplasms, Radiation-Induced; Polonium; Radiation Dosage; Radiation Protection; Radon Daughters; Risk; Sex Factors; Smoking; Time Factors

Topics: Bismuth; Housing; Humans; Lead; Lung Neoplasms; Neoplasms, Radiation-Induced; Polonium; Radon Daughters; Risk Factors

The National Institute for Occupational Safety and Health (NIOSH) has recently updated the vital status of the U.S. cohort of U miners through the end of 1982. This represents 69 additional lung cancer deaths since the last published follow-up through 1977. This more recent data was used to generate quantitative risk estimates of lung cancer after exposure to Rn daughters. Relative risks were estimated through use of the Cox proportional hazards model with an internal referent group. Results indicated that the exposure-response relationship was a slightly convex curve, predicting excess relative risks between 0.9 and 1.4 per 100 working level months (WLM) in the lower cumulative exposure range. Other findings of interest include a significant exposure-rate effect with low exposure rates more harmful per unit of cumulative exposure (WLM). Two temporal effects which modify relative risk estimates were also found. Relative risk increased with age at initial exposure to underground U mining. However, relative risk of lung cancer fell dramatically in the years following cessation of exposure.

Topics: Bismuth; Humans; Lead; Lung Neoplasms; Mining; Neoplasms, Radiation-Induced; Occupational Diseases; Polonium; Radon Daughters; Risk; Smoking; United States; Uranium

Topics: Bismuth; Carcinoma, Bronchogenic; Humans; Lead; Lung Neoplasms; Neoplasms, Radiation-Induced; Polonium; Radon Daughters; Smoking

Topics: Bismuth; Housing; Humans; Lead; Lung Neoplasms; Neoplasms, Radiation-Induced; Polonium; Radon; Radon Daughters; Risk; United States

This paper presents clinical, experimental, and epidemiologic evidence to help explain the rapidly increasing incidence of primary lung cancer, with recently observed reversal in leading cell type from squamous cell to adenocarcinoma. It postulates that this may be due to changes in modern cigarettes, with or without filters, which allow inhalation of increased amounts of radioactive lead and polonium and decreased amounts of benzopyrene. This hypothesis is based upon measurements of increased concentrations of radioactive polonium in the lungs of cigarette smokers, in modern tobaccos grown since 1950, and in high-phosphate fertilizers used for tobacco farming in industrialized countries. Critical support for this thesis is based upon experimental animal studies in which lung cancers that resemble adenocarcinomas are induced with as little as 15 rads of radioactive polonium, equal to one fifth the dosage inhaled by cigarette smokers who average two packs a day during a 25-year period.

Topics: Adenocarcinoma; Alpha Particles; Animals; Benzopyrenes; Carcinoma, Squamous Cell; Cricetinae; Female; Fertilizers; Humans; Lead; Lung; Lung Neoplasms; Male; Neoplasms, Radiation-Induced; Nicotiana; Plants, Toxic; Polonium; Smoking; Tobacco Smoke Pollution

The radioactive noble gas radon, a member of the natural decay chains of uranium and thorium, enters the indoor environment in regionally highly diverging amounts. Subsoil of dwellings, building materials and drinking water are the main sources. In Switzerland and in many other countries, exposure of the lung tissue to the short lived radon decay products is the most important component of the radiation dose of the general public. Annual doses in areas with crystalline rock of high uranium content may reach the limits set up for occupational exposure. However, a clear link between cumulative exposure to radon daughters and elevation of the lung cancer incidence exists only for underground miners. The majority of human epidemiological studies point to a linear dose effect relationship. The indoor radon levels are determined by geology, building materials and techniques, climate and behaviour of the occupants. Experiences from Scandinavia and the Northern parts of America clearly indicate the possibility of cost-efficient remedial measures to reduce indoor radon levels.

Topics: Air Pollution, Radioactive; Bismuth; Housing; Humans; Lead; Lung Neoplasms; Neoplasms, Radiation-Induced; Polonium; Radiation Dosage; Radiation Monitoring; Radon; Radon Daughters; Risk; Switzerland; Water Pollution, Radioactive

Topics: Bismuth; Connecticut; Female; Geological Phenomena; Geology; Housing; Humans; Lead; Lung Neoplasms; Male; Neoplasms, Radiation-Induced; New Jersey; New York; Pennsylvania; Polonium; Radon Daughters

The principal hazard associated with exposure to Rn progeny is lung cancer. However, most lung cancer is caused by smoking, which raises a dual problem of deriving Rn-progeny cancer risk estimates from miner populations who, in large part, are smokers and applying these estimates to the general population whose lung cancer risk, in large part, is determined by smoking habits. We examine current risk estimates for Rn-progeny-induced lung cancer using a cohort life table methodology. Estimates of lifetime probability of dying of lung cancer, average loss in life expectancy due to premature lung cancer death, and loss in life expectancy per premature lung cancer death are calculated for the general population for 1969 and 1978, nonsmokers, and smokers. These calculations demonstrate that such risk estimates are affected by smoking, and by trends in smoking habits, in several ways. Major smoking-related factors in this interaction are the proportion of smokers in the mining population used to derive lung cancer risk estimates, the proportion of smokers in the "general" population, and the assumed interaction (additive or multiplicative) between lung cancer risk, Rn-progeny exposure, and smoking history. At this time the data are not sufficient to recommend one particular modeling approach. However, our evaluation demonstrates that broad statements about Rn-progeny lung cancer risk such as "x cancers/10(6) person working level month," while informative, are incomplete without further specification. Any risk assessment must clearly state the population assumed to be at risk and the risk model assumed to be operating. Finally, the caveats appropriate to these assumptions should also be enunciated.

Topics: Adult; Aged; Bismuth; Female; Humans; Lead; Lung Neoplasms; Male; Middle Aged; Mining; Neoplasms, Radiation-Induced; Occupational Diseases; Polonium; Radon; Radon Daughters; Risk; Smoking; Uranium

Topics: Air Pollutants; Air Pollutants, Radioactive; Bismuth; Environmental Exposure; Female; Humans; Lead; Lung Neoplasms; Male; Mining; Neoplasms, Radiation-Induced; Occupational Diseases; Polonium; Radon Daughters; Sweden

Data on five mining populations exposed to Rn progeny have been used to estimate the lifetime risk of lung cancer resulting from occupational and environmental exposure under current standards. Slopes of dose-response relations for lung cancer show a tendency to decrease with increasing dose. Our best estimate of curvilinearity is given by raising dose to the power 0.92 +/- 0.07, but the improvement in fit beyond simple linearity is not significant. On the other hand, the addition of a cell-killing term significantly improves the fit of the linear model. In any event, linear extrapolation is unlikely to underestimate the excess risk at low doses by more than a factor of 1.5. However, these inferences about curvilinearity are highly subject to error from the choice of reference populations, dosimetry, and latency. Under the linear-cell-killing model, our best estimate of excess relative risk is 2.28 +/- 0.35 per 100 working level month (WLM) (a doubling dose of 44 WLM). Attributable risks in these five studies range from 3.4-17.8 per 10(6) person-yr WLM-1. Risks from Rn progeny appear to interact with age and smoking in a form intermediate between additive and multiplicative. The "relative risk" model is therefore preferable for projecting lifetime risks, but life-table projections are described for a wide variety of assumptions. Our best estimate of the effect of a 50-yr occupational exposure to 4 WLM yr-1 is 130 excess lung cancer deaths per 1000 persons (0.65 per 1000 person-WLM), with a range from 60-250 per 1000. Similar calculations for lifetime exposure to an additional 0.02 working level (WL) beyond normal background produces an estimate of 20 excess lung cancers per 1000 persons.

Topics: Adolescent; Adult; Aged; Bismuth; Child; Humans; Lead; Lung Neoplasms; Middle Aged; Mining; Neoplasms, Radiation-Induced; Occupational Diseases; Polonium; Radon Daughters; Risk; Smoking

Topics: Adult; Aged; Air Pollutants; Air Pollutants, Radioactive; Bismuth; Child; Female; Humans; Lead; Lead Poisoning; Lung Neoplasms; Male; Neoplasms, Radiation-Induced; Polonium; Radon Daughters

Topics: Bismuth; Dose-Response Relationship, Drug; Humans; Lead; Lung; Lung Neoplasms; Neoplasms, Radiation-Induced; Polonium; Radon Daughters; Risk; Thorium Dioxide

The effect of dose rate on the induction of lung cancer in Syrian hamsters by 5.3 MeV alpha particles was examined by varying the number of weekly intratracheal instillations of carrier-free 210Po. By this technique, most of the radiation dose to the lungs was delivered over intervals ranging from 10 to 120 days. Protraction of exposure over 120 days was slightly more carcinogenic at lower total lung doses (24 rad), but slightly less carcinogenic at higher doses (240 rad), than exposure limited to a 10-day interval. No synergism was observed between very low radiation exposures (2.4 rad) and simultaneously administered benzo[a]pyrene. The carcinogenic effect of a single intratracheal instillation of 210Po in isotonic saline was markedly enhanced by subsequent weekly instillations of 0.2 ml of saline alone, emphasizing the importance of noncarcinogenic secondary factors in the expression of radiation-induced lung cancer.

Topics: Alpha Particles; Animals; Cricetinae; Dose-Response Relationship, Radiation; Lung Neoplasms; Male; Mesocricetus; Neoplasms, Radiation-Induced; Polonium

Topics: Bismuth; Carcinoma, Small Cell; Humans; Lead; Lung Neoplasms; Male; Mining; Neoplasms, Radiation-Induced; Occupational Diseases; Polonium; Radon Daughters

In a retrospective study, we investigated lung-cancer mortality from 1951 to 1976 in 1415 Swedish iron miners exposed to short-lived radioactive daughters of radon gas at concentrations leading to annual doses close to the currently accepted occupational limit. Fifty deaths from lung cancer were observed, as compared with 12.8 expected; expected rates were determined by a smoking-specific analysis based on data from a random sample of the Swedish male population. Among nonsmokers 18 deaths were observed, as compared with 1.8 expected; among current smokers and recent exsmokers 32 deaths were observed and 11.0 were expected. The effects of smoking and exposure to alpha radiation from radon daughters were nearly additive. Comparison of lung-cancer risk coefficients from this study and from other cohort studies of underground miners showed good agreement. Exposure to radon daughters is a major medical problem is underground metal mining, but our results also indicate that exposure to radon daughters at home accounts for an appreciable number of cases of lung cancer in the general population.

Topics: Adult; Aged; Bismuth; Environmental Exposure; Humans; Iron; Lead; Lung Neoplasms; Male; Middle Aged; Mining; Neoplasms, Radiation-Induced; Occupational Diseases; Polonium; Radon Daughters; Risk; Smoking; Sweden; Time Factors

Topics: Bismuth; Environmental Exposure; Humans; Lead; Lung Neoplasms; Male; Mining; Neoplasms, Radiation-Induced; Occupational Diseases; Polonium; Radon Daughters; Risk

Topics: Bismuth; Humans; Lead; Lung Neoplasms; Mining; Neoplasms, Radiation-Induced; Polonium; Radon Daughters; Uranium

A high mortality from lung cancer among miners was reported from Central Europe already in the 19th century. In the 60s and 70s several reports have indicated an increased lung cancer mortality among uranium miners and other metal-miners, e.g. in the US, UK, France and Sweden, but also among fluorspar miners in Canada. The cause is supposed to be the decay products of radon as emanating from the rocks, i.e. the alpha-radiation from short-lived radon daughters. Radon and radon daughter exposure in dwellings have more recently attracted interest as a potential hazard to the general population, especially since radon daughter concentrations seem to have increased due to more effective insulation for energy saving. In many Swedish houses the radon daughter exposures amount to levels similar to that of mines. Some epidemiological evaluations of the relationship between lung cancer and exposure to radon daughters, i.e. residency in stone houses versus wooden houses (with and without consideration of the contribution of radon from the ground underneath the houses), seem to indicate a risk also to the general population and, moreover, the risk of smoking seems to be several times greater in stone houses than in wooden houses, the latter usually having less radon daughters on the average.

Topics: Adult; Aged; Air; Air Pollutants; Air Pollutants, Radioactive; Bismuth; Female; Housing; Humans; Lead; Lung Neoplasms; Male; Middle Aged; Mining; Polonium; Radon Daughters; Risk; Smoking; Sweden

Epidemiological investigations concerning lung cancer mortality of miners in radioactive underground climate have clearly resulted that the alpha-radiation of radon daughters emerging from the geological formations represent the causative factor for the accumulation of these lung cancers. The same radionuclides are also important as components of the natural radiation exposure, above all in houses built with radium containing material. Estimations of the risk referring to this form of natural radiation exposure allow rough calculation of its role for lung cancer incidence in GDR. Accordingly about 10%, in men 5% and 50% in females, of the cases of lung cancer may be caused by the natural inhalative radiation exposure. Natural radioactivity by coal and coal ashes as well by tobacco smoke are shortly outlined in their additional significance. The measures of radiation protection legal in GDR to limit inhalative exposure, above all in buildings, by supervision and selection of building material are described.

Topics: Air Pollutants, Radioactive; Bismuth; Construction Materials; Environmental Exposure; Environmental Pollution; Female; Germany, East; Humans; Lead; Lung Neoplasms; Male; Neoplasms, Radiation-Induced; Polonium; Radioisotopes; Radon Daughters; Respiratory System; Risk; Sex Factors

Radon exposures to U.S. uranium miners under present conditions average about 1.3 WLM per year approximately or equal to 60 WLM per full working lifetime. This is intermediate between (a) the lowest exposures for which there have been excess lung cancers reported among U.S. miners (120-240 WLM) and (b) average environmental radon exposures (16 WLM), so models based on these two situations are used to estimate expected effects on present uranium miners. In Model A, the loss of life expectancy is 45 days, the SMR (standardized mortality ratio) for lung cancer is 1.10, and the SMR for all causes between ages 18 and 65 is 1.013. In Model B these are 10 days, 1.03 and 1.002 respectively. It is shown that the radon exposures to miners are similar to those to millions of Americans from environmental exposure, and that miner health risks are comparable to those of other radiation workers. Their lung cancer risk from radon is 7-50 times less than their job-related accident mortality risk, and represents 0.7-4% of their total risk in mining. Miners suffer from many diseases with SMR very much larger than that for radon-induced lung cancer, and there are many other occupations and industries with far higher SMR for lung cancer than that from radon exposure to miners.

Topics: Adult; Aged; Air Pollution, Radioactive; Bismuth; Humans; Lead; Lung Neoplasms; Maximum Allowable Concentration; Middle Aged; Mining; Neoplasms, Radiation-Induced; Polonium; Radon Daughters; Risk; United States; Uranium

Lung dose calculations for inhaled radon decay products presented in part I have revealed that mean basal cell doses are significantly dependent on various personal and environmental factors. Whereas these macroscopic dosimetric methods have been applied with great success to radiation protection problems, the interpretation of radiobiological effects, such as lung cancer incidence, needs some refinement of these methods. Energy deposition at the microscopic level as the physical input quantity and radiation carcinogenesis as the biological endpoint are by nature stochastic processes. Therefore, a microdosimetric model was developed taking into consideration the randomness of physical and biological parameters involved, Part II of the paper presents results on specific energy distributions in lung cells, demonstrating that single event density distributions together with the number of cells receiving single hits represent more appropriate parameters than mean radiation doses.

Topics: Alpha Particles; Animals; Bismuth; Humans; Lead; Lung Neoplasms; Neoplasms, Radiation-Induced; Polonium; Radiation Dosage; Radon Daughters; Rats; Rats, Inbred Strains; Respiration; Risk

Lung cancer induction is commonly regarded as the most important somatic risk arising from the inhalation of radon and its decay products. Relating carcinogenesis to radiation exposure needs a detailed knowledge of the cellular dose distribution in the human respiratory tract. Different dosimetric models have been developed for the determination of cellular doses, particularly for the basal cells of the bronchial epithelium which are considered as the critical cells for lung cancer induction. Part 1 of the paper describes the influence of various environmental as well as anatomical and physiological factors on the resulting dose. Significant inter- as well as intra-subject variabilities of structural components of the human lung, respiration characteristics and clearance mechanisms demonstrate the necessity of applying stochastic models in lung dosimetry.

Topics: Adolescent; Adult; Bismuth; Child; Child, Preschool; Cilia; Cocarcinogenesis; Humans; Humidity; Lead; Lung Neoplasms; Neoplasms, Radiation-Induced; Polonium; Radiation Dosage; Radon Daughters; Respiration; Risk

The alpha dose from 222Rn daughters per unit exposure (rad per WLM or rad per year per pCi 222Rn/m3) to basal cells in bronchial epithelium in a five-lobed human male lung is calculated. These factors are then derived for women, children and infants by scaling the dimensions of the male lung. The 222Rn daughter characteristics chosen are those typical of environmental atmospheres. Both active and resting breathing patterns are utilized in the calculations to yield the overall dose per unit exposure in typical population exposures.

Topics: Adult; Air Pollutants; Air Pollutants, Radioactive; Bismuth; Child; Female; Humans; Infant; Lead; Lung; Lung Neoplasms; Male; Models, Biological; Neoplasms, Radiation-Induced; Polonium; Radiation Dosage; Radon Daughters; Respiration

Dose calculations for inhaled radon decay products presented in Part I (Ho79) have revealed that the doses to tracheobronchial and pulmonary compartments of the ICRP lung model are significantly dependent on age. From a consideration of the nonuniform dose distribution within the tracheobronchial region, doses are now calculated for the bronchial epithelium basal cells which are commonly regarded as the critical target for the induction of lung cancer. For the simulation of deposition and clearance mechanisms a refined mathematical model for postnatal growth of the human respiratory tract was developed on the basis of the Weibel model A. A reference atmosphere of 1 pCi/l for each nuclide with a mean respiratory minute volume, corresponding to a mean physical activity, was used to determine doses for the basal cells in different generations of the tracheobronchial tree as functions of age. The results obtained show again a strong dependence on age. In general a continuous decrease of dose with increasing age can be seen, with distinct differences between the various generations. If, however, the physical activity distribution and the ratio for the decay products as already defined in Part I are used, maximum dose values appear again in all generations at the age of about six years. Application of data on the relative risk of the induction of various malignancies versus age, taken from the BEIR report, results in even more pronounced dose maxima with a significantly higher radiation risk for children between birth and ten years of life of about one order of magnitude as compared to adults.

Topics: Adolescent; Adult; Bismuth; Child; Child, Preschool; Humans; Infant; Infant, Newborn; Lead; Lung; Lung Neoplasms; Models, Biological; Neoplasms, Radiation-Induced; Polonium; Radiation Dosage; Radon Daughters; Risk

The role of cellular proliferation in a two-stage model of carcinogenesis in the hamster lung was investigated. Syrian golden hamsters were treated intratracheally with either one instillation of 0.2 microCi of 210Po (Po-0 group), seven weekly instillations of BP (0-BP group), or 0.2 microCi 210Po followed 15 weeks later by either seven instillations of 0.9% NaCl solution (Po-Sal group) or seven instillations of BP (Po-BP group). All BP instillations were 3 mg each of BP:ferric oxide (1:1, w/w) carrier particles). Serial sacrifices were performed for up to 85 weeks. Two hr before sacrifice, each animal was given i.p. injections of 200 microCi of [3H]thymidine. Glycol methacrylate section autoradiographs (1 micrometer) were prepared. Labeling indices in the alveolar region, labeling of terminal bronchiolar cells, and morphological changes were examined. Equal numbers of Po-Sal and Po-BP animals developed lung tumors. No tumors were found in Po-0 or 0-BP animals. Tumor development was preceded by the appearance of hyperplastic areas of bronchiolar-type cells in the alveolar region and by changes in morphology of bronchiolar cells. Labeling indices in the alveolar region of the treated groups were slightly increased relative to untreated controls. Labeling of terminal bronchiolar cells was highest in the Po-BP and 0-BP groups and was associated with much inflammation. A single 0.9% NaCl solution instillation also increased proliferation of bronchiolar cells. We conclude that 0.9% NaCl solution instillations may potentiate carcinogenesis in the hamster lung by acting as a nonspecific stimulus to proliferation; in addition, we conclude that not all hyperplasia progresses on to form lung tumors in the Po-BP and Po-Sal groups.

Topics: Animals; Benzopyrenes; Cell Division; Cricetinae; Epithelium; Ferric Compounds; Hyperplasia; Lung; Lung Neoplasms; Male; Mesocricetus; Neoplasms, Experimental; Polonium; Sodium Chloride

Tobaccos from countries with high and low incidences of lung cancer were analyzed. Tobacco concentrations of polonium-210 were similar in cigarettes from high- and low-incidence countries, as were levels of cigarette smoke tar and nicotine. Tobaccos from low-incidence countries had significantly lower Alternaria spore counts. Mean selenium concentrations of tobaccos from the high-incidence countries (0.16 +/- 0.05 micrograms/g) were significantly lower than those of tobaccos from the low-incidence countries (0.49 +/- 0.22 micrograms/g).

Topics: Alternaria; Colombia; Female; Humans; Lung Neoplasms; Male; Mexico; Mitosporic Fungi; Nicotiana; Nicotine; Plants, Toxic; Polonium; Selenium; Smoke; Sweden; Tars; United Kingdom; United States

The present series of experiments was carried out in order to see what role pre-existing localized fibrosis plays in carcinogenesis of the lung. Hemorrhagic infarction was produced in the lung of 180 male Wistar rats by injecting 0.05 ml of hexachlorotetrafluorobutane into the tail vein. This resulted in localized fibrosis in the lung 3 months later. One hundred and fiften rats were alive 3 months after administration of the chemical. Of these animals, 30 were given no further treatment (control). The remaining 85 rats were given intratracheal instillation of 0.2 microCi of polonium-210 once a week, a total of 15 times. It was subsequently found that lung carcinoma was induced in close proximity to the localized pulmonary fibrosis in 3 of 26 rats (11.5%) during the period from completion of the 15 weekly administrations of polonium-210 until the end of this experiment (21 months after the 1st instillation of polonium-210). Polonium-210 was found to be deposited in the fibrous thickening of the alveolus around the subpleural fibrotic lesion, bronchial epithelium, and peribronchial lymph apparati at the initial period of administration of polonium-210, but during the period of pulmonary carcinogenesis, it was deposited in the localized fibrotic lesion in the lung and in a few cancer cells. This suggests that polonium-210 deposited in the pulmonary fibrotic lesion remains there over a long period of time, indicating a reduced clearance ability at this site.

Topics: Adenocarcinoma; Adenocarcinoma, Papillary; Animals; Carcinoma, Squamous Cell; Hyperplasia; Lung Neoplasms; Male; Neoplasms, Experimental; Neoplasms, Radiation-Induced; Polonium; Pulmonary Fibrosis; Rats

Topics: Alpha Particles; Animals; Cricetinae; Lung; Lung Neoplasms; Mesocricetus; Methods; Microspheres; Neoplasms, Radiation-Induced; Plutonium; Polonium; Promethium; Radiation Dosage

Topics: Adenocarcinoma; Alpha Particles; Animals; Cricetinae; Disease Models, Animal; Dose-Response Relationship, Radiation; Lung Neoplasms; Male; Mesocricetus; Neoplasms, Experimental; Neoplasms, Radiation-Induced; Polonium; Radiation Dosage

The pathogenesis of 210Po-induced tumors in the peripheral lung of Syrian golden hamsters has been studied in a serial sacrifice experiment utilizing both plastic (glycol methacrylate) and routine paraffin embedding procedures for lung sections. A rapid progression from hyperplasia of bronchiolar-type cells that appear in the alveolar region to malignant tumors was documented. Tumors began appearing as early as 15 weeks after the first intratracheal instillation of 210Po.

Topics: Adenocarcinoma; Animals; Carcinoma, Squamous Cell; Cricetinae; Hyperplasia; Lung Neoplasms; Male; Mesocricetus; Neoplasms, Experimental; Neoplasms, Radiation-Induced; Polonium; Precancerous Conditions; Time Factors

Benzo(a)pyrene and 210Po were administered both simultaneously and sequentially by intratracheal instillations to Syrian golden hamsters in experiments designed to identify any synergistic interactions between these carcinogens. Their effects were additive after simultaneous administration. A significant synergistic interaction between the two agents appeared to occur when benzo(a)pyrene exposure followed 4 months after 210Po exposure. Most of this effect could be ascribed, however, to a potentiating effect of subsequent 0.9% NaCl solution instillations on 210Po carcinogenesis. These results emphasize the fact that seemingly innocuous stimuli may significantly potentiate lung carcinogenesis. The implications of these findings in terms of the interactions between alpha-radiation and cigarette smoke in human populations are discussed.

Topics: Adenocarcinoma; Alpha Particles; Animals; Benzopyrenes; Carcinoma, Squamous Cell; Cocarcinogenesis; Cricetinae; Humans; Lung Neoplasms; Male; Mesocricetus; Neoplasms, Experimental; Neoplasms, Radiation-Induced; Polonium; Smoking; Sodium Chloride; Solutions

Topics: Alpha Particles; Animals; Carcinoma; Carcinoma, Squamous Cell; Cricetinae; Disease Models, Animal; Female; Lung Neoplasms; Lymphoma; Mesocricetus; Neoplasm Metastasis; Neoplasms, Radiation-Induced; Polonium; Tracheal Neoplasms

Topics: Animals; Benzopyrenes; Cell Line; Cheek; Cricetinae; Glycosaminoglycans; Histocytochemistry; Lung Neoplasms; Microscopy, Electron; Neoplasms, Experimental; Neoplasms, Radiation-Induced; Polonium

Topics: Acid Phosphatase; Alkaline Phosphatase; Animals; Cricetinae; Histocytochemistry; L-Lactate Dehydrogenase; Lung; Lung Neoplasms; Malate Dehydrogenase; Male; Neoplasms, Radiation-Induced; Polonium; Succinate Dehydrogenase

Topics: Animals; Cell Transformation, Neoplastic; Cricetinae; Glycoproteins; Histocytochemistry; Lung Neoplasms; Male; Mesocricetus; Microscopy, Electron; Neoplasms, Experimental; Neoplasms, Radiation-Induced; Polonium

Topics: Adult; Bismuth; Czechoslovakia; Environmental Exposure; Humans; Lead; Lung Neoplasms; Male; Mining; Neoplasms, Radiation-Induced; Occupational Diseases; Polonium; Radioisotopes; Radon; Risk; Time Factors; Uranium

Lung cancers have been induced in 9 to 53 percent of hamsters given multiple intratracheal instillations of polonium-210 in amounts yielding lifetime exposures of 15 to 300 rads to the lungs. Cigarette smokers have previously been estimated to receive 20 rads to areas of the bronchial epithelium from deposited polonium-210. This finding thus supports the hypothesis that alpha radiation resulting from the polonium-210 or lead-210 present in cigarette smoke may be a significant causative factor in human lung cancer.

Topics: Adenocarcinoma; Alpha Particles; Animals; Carcinoma, Squamous Cell; Cricetinae; Disease Models, Animal; Humans; Lead; Lung Neoplasms; Neoplasms, Experimental; Neoplasms, Radiation-Induced; Nicotiana; Plants, Toxic; Plutonium; Polonium; Radiation Dosage; Radioisotopes; Smoke; Smoking

Several cell lines designated HLAC were derived from primary lung carcinomas induced in Syrian hamsters by polonium-210 or benzo[a]pyrene. Primary tumor nodules were initially transplanted into cheek pouches, and the tumors that grew were passed into tissue culture and into the cheek pouches of other hamsters for continued in vivo passage. By serial passage and cloning, cell lines were isolated with plating efficiencies of 20-50% in vitro and 10-25% when cultured directly from solid tumors. These cells formed adenocarcinomas in vivo. The radiosensitivities in vitro of HLAC-4 and HLAC-14 varied; observed D0 (the inverse of the slope of the exponential portion of the survival curve) values were 80 and 155 rads, respectively; n (the dose at which the exponential portion of the survival curve extrapolates to 100% survival) values were approximately 1.8. Survival curves obtained following in situ irradiation of 4- to 5-mm3 HLAC-4 tumors showed a D0 of 80 rads and an n of 7. Morphology and growth characteristics of two HLAC cell lines in vivo and in vitro were described.

Topics: Adenocarcinoma; Animals; Benzopyrenes; Cell Division; Cell Line; Cricetinae; Dose-Response Relationship, Radiation; Lung Neoplasms; Male; Neoplasm Transplantation; Neoplasms, Experimental; Neoplasms, Radiation-Induced; Polonium; Transplantation, Homologous

Topics: Alpha Particles; Animals; Barium; Cerium Radioisotopes; Cricetinae; Dose-Response Relationship, Radiation; Electrons; Lung; Lung Neoplasms; Neoplasms, Experimental; Neoplasms, Radiation-Induced; Plutonium; Polonium; Protons; Radiation Dosage; Radiation Protection; Radioisotopes; Rats; Skin Neoplasms

Topics: Acrylic Resins; Aldehydes; Animals; Autoradiography; Bronchi; Cricetinae; Evaluation Studies as Topic; Glutaral; Glycols; Lung; Lung Neoplasms; Macrophages; Male; Medical Laboratory Science; Neoplasms, Radiation-Induced; Polonium; Staining and Labeling; Tissue Preservation

Topics: Adenocarcinoma; Animals; Benzopyrenes; Bronchial Neoplasms; Carcinogens; Carcinoma; Carcinoma, Squamous Cell; Cricetinae; Dose-Response Relationship, Drug; Dose-Response Relationship, Radiation; Female; Hyperplasia; Intubation, Intratracheal; Lung Neoplasms; Male; Neoplasms, Experimental; Neoplasms, Radiation-Induced; Papilloma; Polonium; Respiratory Tract Neoplasms; Time Factors; Tracheal Neoplasms

Topics: Adenocarcinoma; Animals; Autoradiography; Benzopyrenes; Carcinoma, Squamous Cell; Cricetinae; Freeze Drying; Intubation, Intratracheal; Iron; Lung; Lung Neoplasms; Male; Microscopy, Fluorescence; Microscopy, Ultraviolet; Neoplasms, Experimental; Neoplasms, Radiation-Induced; Polonium; Time Factors

Topics: Bismuth; Humans; Lead; Lung; Lung Neoplasms; Mining; Neoplasms, Radiation-Induced; Occupational Diseases; Polonium; Sweden; Time Factors

Topics: Aged; Bismuth; Bronchial Neoplasms; Dust; Gases; Humans; Lead Poisoning; Lung Neoplasms; Male; Middle Aged; Mining; Occupational Diseases; Polonium; Radon; Silver; Zinc

Topics: Lung Neoplasms; Nicotiana; Plants, Toxic; Polonium; Radon

Topics: Carcinogens; Cardiovascular Diseases; Cardiovascular System; Free Radicals; Humans; Lung Neoplasms; Neoplasms, Radiation-Induced; Polonium; Pulmonary Emphysema; Radioisotopes; Smoking

Topics: Bismuth; Chemical Phenomena; Chemistry; Humans; Lead; Lung Neoplasms; Nicotiana; Plants, Toxic; Polonium; Radium; Smoking

Topics: Lung Neoplasms; Polonium; Smoking

Topics: Air Pollution, Radioactive; Australia; Carcinogens; Humans; Lung Neoplasms; Neoplasms, Radiation-Induced; New Zealand; Nicotiana; Plants, Toxic; Polonium; Smoking

Concentrations of the alpha-particle-emitting radioactive element polonium was measured in various pulmonary tissues of smokers and nonsmokers in order to determine 1) whether this radiation exposure is associated with the development of bronchial cancer in smokers; and 2) how smoke is absorbed and excreted in human lungs. Lung specimens from 25 current cigarette smokers, 2 current pipe smokers, 1 former cigarette smoker, and 8 nonsmokers ere analyzed. The average concentration of polonium in the peripheral parenchyma of current smokers was .0074 picocurie/gm and in nonsmokers was .0016. For smokers, the average concentration was doubled in more centrally located parenchyma and was greater in the upper than in the lower lobes. Polonium concentrations correlated with daily cigarette consumption but not with total cigarettes smoked. The concentrations in peribronchial lymph nodes of smokers were also higher than in nonsmokers. These values show no correlation with total or daily cigarette consumption. Polonium concentration was similiar in bronchial wall parenchyma as in lung parenchyma but was greater in bronchial epithelium than in parenchymal or lymph nodes. The patterns of distribution of polonium throughout the lung suggest that most inhaled smoke particles are rapidly cleared from the lung, and polonium is primarily cleared by mucus sheet. Since the highest local concentrations of polonium were found in bronchial epithelium from segmental bifurcations, leading to a high cumulative local radiation dose, polonium may be implicated in the initiation of bronchial cancer in humans.

Topics: Bronchi; Humans; In Vitro Techniques; Lung; Lung Neoplasms; Lymph Nodes; Polonium; Radiometry; Smoking

Polonium-210, which emits alpha particles, is a natural contaminant of tobacco. For an individual smoking two packages of cigarettes a day, the radiation dose to bronchial epithelium from Po(210) inhaled in cigarette smoke probably is at least seven times that from background sources, and in localized areas may be up to 1000 rem or more in 25 years. Radiation from this source may, therefore, be significant in the genesis of bronchial cancer in smokers.

Topics: Humans; Lung Neoplasms; Neoplasms; Neoplasms, Radiation-Induced; Nicotiana; Polonium; Radiation Dosage; Smoke; Smoking; Toxicology

Topics: Carcinogens; Humans; Lung Neoplasms; Neoplasms; Neoplasms, Radiation-Induced; Polonium; Smoking

Topics: Gastrointestinal Neoplasms; Humans; Incidence; Lung Neoplasms; Neoplasms; Nicotiana; Polonium; Radiation Injuries; Smoking; Toxicology; Vehicle Emissions

Topics: Carcinogens; Humans; Lung Neoplasms; Polonium; Smoking; Toxicology