PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “AIR POLLUTION, RADIOACTIVE”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,405 records · Page 78Linked to original sources
PubMed1990

Vertical distribution and flows of lead and natural radionuclides in the atmosphere.

Vertical distributions of radium-226, lead-210, uranium and stable lead were observed in the troposphere and lower stratosphere over Poland at several altitudes between 0 and 15 km in the period 1973-1987. Greatly increased concentrations of stable lead and radium-226 were observed at all altitudes for several years after the Fuego volcano eruption in 1974, and also after the Nevado del Ruiz eruption in 1985. The volcanic eruptions in 1980-1982 contributed to the radium-226 and uranium levels at the higher altitudes. The annual flows of radium-226, lead-210, uranium and stable lead into the global atmosphere, estimated from their long-term average contents in the 0-15 km air layer, are 2.3 x 10(14) Bq, 8.4 x 10(15) Bq, 8.3 x 10(9) g and 3.7 x 10(12) g, respectively. These estimates are similar to those based on concentrations of these nuclides in widely dispersed glaciers in both hemispheres, and on radon-222 exhalation measurements. However, they are higher than estimates based on particulate emissions. The anthropogenic contribution to the total flow of radium-226 into the global atmosphere is approximately 3.7%, for lead-210 0.25%, uranium 17% and stable lead 9.7%.

Air Pollutants↗
PubMed1991

Indoor radon measurements in the Beijing area.

Average indoor air radon concentration of 30 Bq/m3 was determined in various types of dwellings in the Beijing area using activated carbon detectors. In this study, several related factors were also investigated: radon area exhalation rates of 136 building materials and from soil surfaces; Ra-226 contents of 143 soil samples, 34 building materials and 28 coal samples; and radon concentrations in gaseous fuel, outdoor air and drinking water. The magnitude and relative importance of different sources in terms of indoor radon are discussed, compared and evaluated. The results show that the underlying soil and building materials are important sources of indoor radon. Cracks in floors or walls are major pathways for the entry of radon into houses. Measurements of the annual effective dose equivalent from radon daughters for different types of aboveground and underground buildings gave average values of 1.1 and 1.5 mSv, respectively.

Air Pollution, Indoor↗
PubMed1992

Sources of present Chernobyl-derived caesium concentrations in surface air and deposition samples.

The sources of Chernobyl-derived caesium concentrations in air and deposition samples collected from mid-1986 to the end of 1990 at Munich-Neuherberg, Germany, were investigated. Local resuspension has been found to be the main source. By comparison with deposition data from other locations it is estimated that within a range from 20 Bq m-2 to 60 kBq m-2 of initially deposited 137Cs activity approximately 2% is re-deposited by the process of local resuspension in Austria, Germany, Japan and the United Kingdom, while significantly higher total resuspension is to be expected for Denmark and Finland. Stratospheric contribution to the present concentrations is shown to be negligible. This is confirmed by cross correlation analysis between the time series of 137Cs in air and precipitation before and after the Chernobyl accident and the respective time series of cosmogenic 7Be, which is an indicator of stratospheric input. Seasonal variations of caesium concentrations with maxima in the winter months were observed.

Accidents↗
PubMed1994

Cancer mortality and radiation risk evaluation for the Techa River population.

The current nominal risk coefficients for radiation induced cancer are predominantly based on the follow-up of the atomic bomb survivors, i.e. a collective of persons exposed to a short duration, high dose rate exposure. It is one of the central issues in radiation protection, whether these data are representative also for protracted, low dose rate exposures. The International Commission for Radiological Protection has postulated a dose and dose rate reduction factor in the derivation of the nominal risk coefficients; but this factor has been debated. Direct observations on populations that were subjected to prolonged low dose exposures are, therefore, of special interest, and a major contribution to the problem may result from the long term observation of the population exposed at the beginning of the 1950s as a result of massive releases of fission products by a plutonium producing facility into the Techa river in the southern Urals. The present article deals with the cancer mortality in this population during the period 1950-1982.

Adult↗
PubMed1994

Plutonium and the risk of cancer. A comparative analysis of Pu-body burdens due to releases from nuclear plants (Chelyabinsk-65, Gomel area) and global fallout.

Results of the analysis of dynamic body burdens of Pu in adult inhabitants of Chelyabinsk-65 (not occupationally exposed) and different areas of the Gomel region are presented for 1990-1991. The data are based on radiochemical analyses of Pu in human organs and tissues. Comparison with the published data on global Pu and our data for human autopsies (Ufa, Russia) revealed that estimates of Pubody burdens in Chelyabinsk-65 residents were up to 30 times higher than global levels and depended on the period of residence in town. The Pu body contents of Gomel citizens 4-5 years after the Chernobyl accident are on average 3-4 times higher than the global levels. Activity of Pu-238 in various organs constitutes 4.7-26.0% (on the average 13.5 +/- 5.0%) of the total alpha-activity of Pu-238 and Pu-239, 240. The expected number of cancers induced by incorporated plutonium is approximately the same for the two population groups despite their different sizes and does not differ from the global level by more than one order of magnitude.

Adult↗
PubMed1994

Factors effecting the morbidity in populations living in the vicinity of atomic industry plants.

In order to examine the effects of radiation, chemicals, and social factors on the incidence of different diseases in the population living in the vicinity of atomic industry facilities, the site of the Production Association 'Mayak' has been selected for detailed analyses. Diseases under study were morbidity among newborns including congenital anomalies, diseases of respiratory organs, and cancer. Using a regression model, no statistically significant correlation was found between incidence and radiation exposure.

Adult↗
PubMed1994

The gastrointestinal absorption of plutonium and americium in rats and guinea pigs after ingestion of dusts from the former nuclear weapons site at Maralinga: implications for human exposure.

The gastrointestinal absorption of plutonium and americium present in dusts from the Maralinga test sites in South Australia has been measured as an input to dose assessments. The materials studied were from three different areas, designated Taranaki (Q380II), TM100 (10/2) and N. Plume (26). The three dusts were fed to groups of rats, mixed with their normal food. The Taranaki and TM100 dusts were also fed to guinea pigs, as a suspension in water. Expressed as fractional absorption from the gastrointestinal tract (f1), the values obtained for plutonium were 2 x 10(-6) and 8 x 10(-6) for Taranaki dust in rats and guinea pigs, respectively, 3 x 10(-6) and 10(-5) for TM100 dust in rats and guinea pigs, respectively, and 2 x 10(-6) for N. Plume dust in rats. The f1 values obtained for americium were 3 x 10(-6) and 2 x 10(-5) for Taranaki dust in rats and guinea pigs, respectively, 10(-5) and 5 x 10(-5) for Taranaki dust in rats and guinea pigs, respectively, and 10(-5) for N. Plume dust in rats. On the basis of these results, rounded f1 values used in the dose assessments were 10(-5) for plutonium and 10(-4) for americium, applying to all intakes of dust. These values compare with the International Commission on Radiological Protection recommendations of 10(-3) for unspecified chemical forms of both elements, 10(-4) for plutonium nitrate and 10(-5) for plutonium oxides. The effect of changes in f1 values on doses from 239Pu and 241Am is considered.

Air Pollutants, Radioactive↗
PubMed1995

Exposure assessment needs in studies of delayed health effects.

In studies of delayed effects of environmental exposures there is a need for accurate reconstruction of exposure, to the environmental factor under study, for a large number of individuals. There is also a need for similar assessments of exposure to possible confounding factors for the same population. In general, such reconstruction is not possible but it is often possible to make an estimate of exposures as they would have likely occurred. This requires selection of populations and circumstances which allow such estimates to be made. For each environmental exposure and for each disease outcome to be evaluated it is likely that the optimum exposure assessment methodology will be different. In each case these opportunities will have to be identified, tested and validated to the extent possible. Exposures will almost always have to be assessed retrospectively, if for no other reason than that prospective designs would not yield results for long periods of time after the initiation of the study. Examples are presented for the case of residential radon progeny exposure and associated excess lung cancer, where the delay is of the order of decades, and for the case of the possible teratogenic effects associated with living in the proximity of sites in which hazardous wastes are stored. In the latter case the delay is much shorter.

Abnormalities, Drug-Induced↗
PubMed1996

The ratio of long-lived to short-lived radon-222 progeny concentrations in ground-level air.

The ratio of 210Pb air concentration to the short-lived radon (222Rn) decay products concentration at ground level was investigated at a semi-rural location 10 km north of Munich, south Germany, for a period of 11 years (1982-1992). The average ratio from 132 monthly mean values has been found to be (7.5 +/- 2.2) x 10-5 (arithmetic mean +/- S.D.). While the time series of the short-lived radon daughter concentration exhibit a distinct seasonal pattern with maxima mostly in October of each year, the course of 210Pb air concentration is characterized by high values from October through February. Consequently, high ratios of 210Pb to short-lived decay product concentration are often observed in the winter months of December-February. To study the influence of meteorological conditions on this behaviour, 210Pb and 214Pb concentrations were measured on a short-term basis with sampling intervals of 2-3 days from October 1991 to November 1992. The air concentrations obtained within those intervals were then correlated with actual meteorological parameters. On the base of this investigation the seasonal behaviour can essentially be explained by the more frequent inversion weather conditions in winter than in the summer months. At the same location, the average ratio of 210Po to 210Pb concentration in ground level air has been found to be 0.079 from 459 weekly mean values between 1976 and 1985. Hence, the corresponding average ratios of the short-lived radon daughters (EEC) to 210Pb and 210Po, were 1:7.5 x 10(-5) and l:0.6 x 10(-5), respectively.

Air Pollutants, Radioactive↗
PubMed1991

Possible association between mutant frequency in peripheral lymphocytes and domestic radon concentrations.

To investigate whether previously found geographical correlations between leukaemia incidence and exposure to radon are reflected in a detectable mutagenic effect on individuals, the frequency of mutations in the hypoxanthine guanine phosphoribosyl transferase gene (hprt) in peripheral blood T lymphocytes was measured in subjects with known domestic radon concentrations. These concentrations were measured in December, 1989, in houses in Street, Somerset, UK, by passive alpha-track radon detectors. 20 non-smoking subjects aged 36-55 years were selected from the patient list at the local health centre on the basis of the radon concentrations in their homes--the range selected varied by a factor of ten. Blood samples for preparation of T lymphocytes were taken in July, 1990. There was a significant association between the log mutant frequency and radon concentration (t = 3.47, p less than 0.01). A second analysis of a further set of radon measurements (October, 1990, to January, 1991), in both living rooms and bedrooms, and repeated mutant frequency determinations also showed a significant relation, which remained significant even after exclusion of the highest frequency and adjustment for subject's age and cloning efficiency. These data must be regarded as preliminary and further more extensive studies should be done to determine whether the observed association is causal.

Acute Disease↗
PubMed1993

Radon exposure and cancers other than lung cancer among uranium miners in West Bohemia.

Recent observations have suggested that radon in the ambient air may cause cancers at sites other than the lung, but the evidence is indirect. We have studied site-specific cancer mortality in 4320 uranium miners in West Bohemia who have been followed-up for an average of 25 years, and in whom a four-fold radon-related excess of lung cancer has already been established. For all cancers other than lung cancer the number of deaths observed was slightly greater than that expected from national rates, but the increase was not significant statistically (ratio of observed to expected deaths [O/E] = 1.11, 95% confidence interval [CI] = 0.98-1.24) and mortality did not increase with duration of employment underground or with cumulative exposure to radon. Non-lung cancer mortality was significantly raised among men who started mining work aged under 25 but the increase was not related to cumulative radon exposure. When twenty-eight individual sites and types of cancer were examined, significantly increased risks were found for cancers of the liver (O/E = 1.67) and gallbladder and extrahepatic bile ducts (O/E = 2.26). For liver cancer, mortality did not increase with duration of employment underground or with cumulative radon exposure. For cancer of the gallbladder and extrahepatic bile ducts, mortality did not increase with duration of employment, but increased with cumulative exposure to radon. Mortality from multiple myeloma, although not significantly increased overall (O/E = 1.08), increased with cumulative exposure to radon. Mortality from leukaemia was not increased overall (O/E = 0.91) and was not related to cumulative radon exposure, but did increase with increasing duration of employment in the mines. There is no evidence in these miners that a radon-rich atmosphere increases the risk of any cancer other than lung cancer. Possible exceptions are cancer of the gallbladder and extrahepatic bile ducts and multiple myeloma but further study is needed before it can be concluded that the associations found are causal.

Adult↗
PubMed1995

Inhaled radon-induced genotoxicity in Wistar rat, Syrian hamster, and Chinese hamster deep-lung fibroblasts in vivo.

This study was performed (1) to provide a comparison of the genotoxic effects of inhaled radon and radon progeny, referred to as radon in this paper, among three species of rodents: Wistar rats, Syrian hamsters, and Chinese hamsters; (2) to determine if initial chromosome damage was related to the risk of induction of lung cancer; and (3) to evaluate the tissue repair and long-term presence of cytogenetic damage in respiratory tract cells. These species were selected because Syrian hamsters are very resistant to radon induction of lung cancer and Wistar rats are sensitive; no literature is available on the in vivo effects of radon in the Chinese hamster. Exposure-response relationships were established for the rats and Syrian hamsters while the Chinese hamsters received a single exposure of radon. At 4 h (0.2 days), 15 days, and 30 days after the highest WLM exposure to radon, Wistar rats, Chinese hamsters, and Syrian hamsters were killed, and lung fibroblasts were isolated and grown in culture to determine the frequency of induced micronuclei. Animals at each level of exposure showed an increase in the frequency of micronuclei relative to that in controls (P < 0.05). The exposure-response relationship data for rats and Syrian hamsters killed 0.2 days after the end of exposure were fit to linear equations (micronuclei/1000 binucleated cells = 15.5 +/- 14.4 + 0.53 +/- 0.06 WLM and 38.3 +/- 15.1 + 0.80 +/- 0.08 WLM, respectively). For the single exposure level used (496 WLM) in Chinese hamsters killed at 0.2 days after exposure, the frequency of micronuclei/1000 binucleated cells/WLM was 1.83 +/- 0.02. A comparison of the sensitivity for induction of micronuclei/WLM illustrated that Chinese hamsters were three times more sensitive than rats. The Syrian hamsters also showed a significantly elevated response (P < 0.05) relative to rats. These data suggest that initial chromosome damage is not the major factor responsible for the high rate of radon-induced cancer in rats relative to Syrian hamsters. The frequency of micronuclei in radon-exposed rats, Syrian hamsters, and Chinese hamsters significantly decreased (P < 0.05) as a function of time after the exposure. The rate of loss of damaged cells from the lung was greatest in the Chinese hamsters, followed by Wistar rats and Syrian hamsters, respectively.(ABSTRACT TRUNCATED AT 400 WORDS)

Air Pollutants, Radioactive↗
PubMed1983

Testing of chemicals by evaluation of their distribution and degradation patterns in an environmental standard system.

Due to the EC directive 79/831 of September 18, 1979, and the German law on hazardous substances, the submission of test data on physical--chemical properties of new substances is mandatory for their registration. These data are supposed to predict in which compartments (air, water, soil, vegetation) the substance will primarily accumulate if it enters the environment. To calculate the distribution of a substance in the environment compartments, different mathematical models have been developed by several working groups, but have not yet been verified in practical experiments. During a prolonged period, the distribution of substances in the environment compartments has been investigated by experiments in an environmental standard system; design and function are explained. Distribution and degradation patterns of 12 reference substances will systematically be investigated, covering a wide spectrum in regard to their physical--chemical properties. Up to now 7 substances have been investigated under standard conditions. The distribution patterns established in these experiments are presented and compared with those obtained mathematically by use of the presently discussed stationary distribution models and values for the physical--chemical properties of the tested substances. The time alterations observed in the distribution patterns are interpreted by a kinetic model which will be part of the calculation method which is presently being developed on the basis of the obtained test values. The good consistency of distribution patterns established by experiments with those established mathematically justifies the assumption that a reliable calculation method of distribution patterns can be submitted as soon as our current work will be finished.

Air Pollutants, Radioactive↗