Health Risks of Radon and Other Internally Deposited Alpha-Emitters BEIR IV (1988) / Chapter Skim
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IV Epidemiological Studies of Persons Exposed to Radon Progeny
IV Epidemiological Studies of Persons Exposed to Radon Progeny
Pages 445-488
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From page 445... ...
These 9 miners were among 19 miners in Joachimsthal who died during 1929-1930. Formal epidemiological studies of the Schneeberg and Joachimsthal miners were not carried out, but published reports documented that about 50% of the miners eventually died from lung cancer.53 Peller44 calculated lung-cancer 445
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From page 446... ...
In 1944, Lorenz30 argued that radon alone could not be the cause of lung cancer and proposed that genetic susceptibility to lung cancer might be unusually high in the miners. However, during the 1950s and 1960s, as the biological basis of respiratory carcinogenesis became better understood and additional mining groups were studied, it came to be accepted that inhaled radon progeny were the cause of lung cancer in the Schneeberg and Joachimsthal miners and other exposed minerS.26~33,53 After World War II, several new epidemiological studies were initiated to determine the safety of exposure to radon progeny in mines.
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From page 447... ...
Many of the miners worked in other types of hard-rock mines before becoming uranium miners. For exposures to radon daughters in the hard-rock mines, WL values were based on calendar year: 1.0 WL for years before 1935, 0.5 WL for 1935-1939, and 0.3 WL for years 1940 and later.33 The arithmetic average of the individual WL measurements made within a mine in a given calendar year was assigned to the mine for that year.
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From page 448... ...
Comment Reference 1959 2,666 6/3 Increase not statistically significant 2 1959 907 5/1.1a Cohort members with at least 3 yr of experience 2 1962 3,656 15/4.2a Includes 1,156 workers with surface, open-pit, or occasional under ground work, respectively, through 1960 65 1963 3,415 22/5.7b Response increases with cumulative BALM 66 1967 3,414 62/10.06 Excess lung cancer in all exposure categories from < 120 WLM to 3,720 WLM 32 1968 3,366 70/11.7b Most comprehensive report 33 1974 3,366 144/29.8b Response increases with cumulative VVLM in all smoking groups 4 1977 3,362 185/38.4C WLM not considered in analysis 67 ap < 0.05.
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From page 449... ...
In fact, WLM totals were calculated solely from measurements on only 10.3% of the white miners. For 36.1%0 of the white miners, some type of estimation was involved in the calculation of all WLM values; for the remainder, some WLM estimates were based on WL values derived by one of the estimation procedures.33 In reports published to date, the WLM estimates have extended through September 1969.
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From page 450... ...
Most published reports are based on analysis with a modified life-table approach, which is a conventional method for longitudinal studies that compares observed with expected numbers of deaths by cause. More recently, several investigators have applied modeling techniques to the data.23~24 34~69 In cohort analyses based on an external referent population, expected numbers of deaths were calculated with mortality rates for the western states where the mines were or with the rates for all U.S.
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From page 451... ...
are age- and calendar-year-adjusted ratios of observed to expected deaths, ranged from approximately 4 to 6, without an obvious temporal trend. In several reports, the investigators used stratified analysis to examine the exposure-response relationship of lung-cancer mortality with cumulative WLM by calculating standardized mortality ratios within strata of increasing WLM 3 4,32,33,66 In one report,32 the mortality rates were standardized for cigarette smoking; in another,4 they were stratified by cumulative WLM and smoking.
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From page 452... ...
On a multiplicative scale for assessing the effects of exposures on lung-cancer risk, smoking and radondaughter exposure had statistically significant ejects, but a cross-product term of the two exposures was not statistically significant. These analyses were limited, however, to examination of only the exponential form of the relative risk.
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From page 453... ...
In New Mexico during 1969-1977, for example, the average annual lung-cancer mortality rate in American Indian males was 8.6/100,000, whereas the rate for non-Hispanic white males was 60.8/100,000.5° Lungcancer mortality rates for black males have generally been equal to or higher than rates for white males. Two other reports have addressed lung-cancer risks in American Indians employed in the Colorado Plateau mines.
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bp < 0.01. the 64 matched controls had been uranium miners.
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From page 455... ...
The success of this approach for identifying lung-cancer cases is not established, and the number of persons lost to follow-up is not given in the 1976 report by Sevc et al.56 Except for a paper on skin cancer, health eRects other than lung cancer have not been reported. In analyses of this cohort, observed lung-cancer mortality was compared with that expected on the basis of age- and calendar-period-specific rates of the male population in Czechoslovakia.
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From page 456... ...
However, person-years at risk were counted from the first date underground, rather than from the date of eligibility, so expected deaths were slightly overestimated. Cigarette smoking was not assessed for all cohort members individually, but results of studies on a random group of 700 miners indicated that about 70%0 of the uranium miners were smokers.
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From page 457... ...
ONTARIO URANIUM MINERS A retrospective cohort study of Ontario miners37~39 engaged in various types of mining included a subcohort of uranium miners who met the following criteria: . received a miner's physical examination required annually by the company any time in 1955-1977 (uranium mining began in 1955 in Ontario)
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From page 458... ...
1_ 1 1 1 1 1 1 600 800 0 200 400 14.0 CUMULATED EXPOSURE (WLM) FIGURE IV-1 Relation between additional lung-cancer frequency and cumulative radiation exposure in three groups of Czechoslovakian uranium miners by mean duration of exposure.
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From page 459... ...
Adjustment was made for deviations from normal working hours in a mine, considered to be 2,000 h/yr. No estimates of WL were made for prior gold-mining experience, but persons with such experience were analyzed separately, because Ontario gold miners were at increased risk of lung cancer.40 It should be noted that the committee's analysis of the Ontario miners, described in Annex 2A, excluded miners with previous gold-mining experience.
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~ 1 1 1 1 _ ~ ~ r I I 1 1 1 1 1 1 1 1 0 200 400 600 800 GROUP C GROUP B GROUP A CUMULATED EXPOSURE (WLM) FIGURE IV-2 Relation between additional lung-cancer frequency and cumulative radiation exposure in three groups of Czechoslovakian uranium miners by time course of exposure accumulation (see text)
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From page 461... ...
Among uranium miners without any gold-mining experience, Muller et al.38 found that observed to expected ratios for lung-cancer deaths increased across the six categories of cumulative WLM (Table IV-9. When the upper estimated exposures were used, the first definite excess occurred at a cumulative WLM of 10~170 (mean, 130)
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From page 462... ...
462 o Ct ;^ ._ ~ V o S: o ._ Cal 5._ ._ S" ._ Ct ~ o o ~ _ ~ o ~ US ~ a, TO EM ~ .
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From page 463... ...
Muller, M.D., 1986. TABLE IV-9 Observed and Expected Lung-Cancer Deaths by Cumulative WLM among Ontario Uranium Miners with No Gold-Mining Experiencea M C I ti No.
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The WLM values for Beaverlodge uranium miners were calculated by Eldorado Resources Ltd., which operated the mine. Different approaches were used for 1966 and earlier years and for 1967 and later years.
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From page 465... ...
Exposure within each category was represented by the mean cumulative WLM, and PYAR was used for weighting. The addition of a quadratic term did not significantly improve the fit of the linear model to the data.
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From page 466... ...
FRENCH URANIUM MINERS Tirmarche et al.64 carried out a retrospective cohort study of all men who began underground uranium mining during 1947-1972 in any of 12 French mines and worked a minimum of 3 months. For 19471955, WLM values were based on a few radon measurements, ventilation conditions, ore characteristics, and working methods.
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From page 468... ...
The authors reported government estimates of 25 WLM and 15 WLM, respectively, annually for the two mines. CHINESE TIN MINERS Tin has been mined in the Yunnan region of China for centuries,62 and the miners in this region are known to have arsenic and radon-daughter exposures.
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From page 469... ...
, but apparently without adjustment for age, sex, calendar period, or smoking. In addition to radon daughters, exposure to arsenic was considered to play an etiological role in the lung-cancer excess.
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From page 470... ...
Death certificates, histological-cytological reports, and, chest x rays were cross-checked to confirm the cases. The little available information on relative risks was based on a crude cohort study that calculated expected deaths using the age distribution of the workers in one of the mines in 1975.
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From page 471... ...
The authors found that latency periods decreased for men first exposed when older and for men exposed during the earlier years, when exposures were presumably higher. SWEDISH IRON MINERS: MALMBERGET A retrospective cohort mortality study by Radford and Renard48 included miners from two iron mines fin Malmberget and Koskoskulle)
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From page 472... ...
The WLM values for this analysis were those calculated by Radford and Renard.48 As described in their 1984 report, radon dissolved in water was assumed to be a major source of radon daughters in the mines. Comparison of radon measurements in water taken in 1915 with data from 1972 and 1975 indicated constant radon concentrations in groundwater.
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From page 473... ...
Information on cigarette smoking was not reported for all cohort members individually, but only for a sample of the responses to a 19721973 survey of active miners and surface workers and from a 1977 survey of pensioners in the study cohort. In addition, smoking histories were obtained for each lung-cancer death.
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From page 474... ...
Of the mining groups exposed to radon daughters, this cohort offers one of the longer follow-up experiences. Over 41% of the cohort (532/1,294)
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From page 475... ...
versus 4.5 expected based on the cause-specific distribution of deaths among all other residents of Kiruna and versus 4.2 based on the cause-specific distribution of deaths among the entire Swedish male population in 1951-1966. Analyses were not presented on dose-response relationships, latency, or interaction of cigarette smoking and exposure to radon daughters.
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From page 476... ...
A separate analysis in the same report of the effect of cigarette smokingi5 added cases through 1980, but included only persons who had been underground miners. A new set of controls (individually matched for age, sex, and year of death)
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From page 477... ...
Radon daughters were sampled with conventional glass-fiber filters and analyzed by the Kusnetz method. In March 1972, exposures were limited by regulation to an annual average of 30 psi/liter.
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From page 478... ...
Workers involved in the mining and the processing of the ore might be exposed to radon and radon daughters. Two retrospective cohort studies of mortality in Florida phosphate workers have been conducted recently; each was performed because of concern raised by apparent clusters of lung cancer.
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From page 479... ...
at Risk Observed Expected Ratio 0 4,622 0 1.73 0 1-38 1,343 3 0.50 6.0 40-158 1,312 4 0.58 6.9 160-238 147 2 0.07 28.6 ~ 240 169 3 0.08 37.5 aBased on data from Solli et al.60 Stayner et al.6i conducted a study of 3,199 workers employed at a phosphate fertilizer plant. Seven samples were taken for radon progeny; the range was 0.00~.02 WL.
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From page 480... ...
Both descriptive and analytical approaches have been used to examine the association between radondaughter exposure in the home and lung cancer. Techniques for estimating lifetime exposure of people to radon daughters from indoor air are not yet available, and surrogates based on residence type or a few limited measurements have been used in the analytical studies.
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From page 481... ...
Most of the dwellings were monitored for radon daughters during 3 months of summer and 1 month of winter. The dwellings were also classified on the basis of structural characteristics, as in the earlier study by Axelson et al.,8 and cigarette-smoking information was obtained from next of kin.
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From page 482... ...
482 ~5 Cal of en Cal to o x = o Ct ~ o o As C~)
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From page 484... ...
1976. Re piratory disea e mortality among uranium miners.
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From page 485... ...
1952. An Interim Report of a Health Study of the Uranium Mines and Mills by the Federal Security Agency, Public Health Service, Division of Occupational Health, and the Colorado State Department of Public Health.
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From page 486... ...
1979. An exposuretime-response model for lung cancer mortality in uranium miners—effects of radiation exposure, age and cigarette smoking.
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From page 487... ...
uranium mines past and present. In Aseesement of the Scientific Basis for Existing Federal Limitations on Radiation Exposure to Underground Uranium Miners, Appendix F
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From page 488... ...
1981. Mortality follow-up through 1977 of the white underground uranium miners cohort examined by the United States Public Health Service.
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