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Assessment and management of residential radon health risks: a report from the health Canada radon workshop.

https://arctichealth.org/en/permalink/ahliterature169838
Source
J Toxicol Environ Health A. 2006 Apr;69(7):735-58
Publication Type
Conference/Meeting Material
Article
Date
Apr-2006
Author
Bliss L Tracy
Daniel Krewski
Jing Chen
Jan M Zielinski
Kevin P Brand
Dorothy Meyerhof
Author Affiliation
Radiation Protection Bureau, Health Canada, Ottawa, Ontario.
Source
J Toxicol Environ Health A. 2006 Apr;69(7):735-58
Date
Apr-2006
Language
English
Publication Type
Conference/Meeting Material
Article
Keywords
Air Pollutants, Radioactive - adverse effects
Air Pollution, Indoor - adverse effects
Canada
Carcinogens, Environmental - adverse effects
Environmental Exposure - adverse effects
Housing
Humans
Lung Neoplasms - etiology
Neoplasms, Radiation-Induced - etiology
Radon - adverse effects
Risk assessment
Abstract
Epidemiologic studies of uranium miners and other underground miners have consistently shown miners exposed to high levels of radon to be at increased risk of lung cancer. More recently, concern has arisen about lung cancer risks among people exposed to lower levels of radon in homes. The current Canadian guideline for residential radon exposure was set in 1988 at 800 Bq/m(3). Because of the accumulation of a considerable body of new scientific evidence on radon lung cancer risks since that time, Health Canada sponsored a workshop to review the current state-of-the-science on radon health risks. The specific objectives of the workshop were (1) to collect and assess scientific information relevant to setting national radon policy in Canada, and (2) to gather information on social, political, and operational considerations in setting national policy. The workshop, held on 3-4 March 2004, was attended by 38 invited scientists, regulators, and other stakeholders from Canada and the United States. The presentations on the first day dealt primarily with scientific issues. The combined analysis of North American residential radon and lung cancer studies was reviewed. The analysis confirmed a small but detectable increase in lung cancer risk at residential exposure levels. Current estimates suggest that radon in homes is responsible for approximately 10% of all lung cancer deaths in Canada, making radon the second leading cause of lung cancer after tobacco smoking. This was followed by a perspective from an UNSCEAR (United Nations Scientific Committee on the Effects of Atomic Radiation) working group on radon. There were two presentations on occupational exposures to radon and two presentations considered the possibility of radon as a causative factor for cardiovascular disease and for cancer in other organs besides the lung. The possible contribution of environmental tobacco smoke to lung cancers in nonsmokers was also considered. Areas for future research were identified. The second day was devoted to policy and operational issues. The presentations began with a perspective from the U.S. Environmental Protection Agency, followed by a history of radon policy development in Canada. Subsequent presentations dealt with the cost-effectiveness of radon mitigation, Canadian building codes and radon, and a summary of radon standards from around the world. Provincial representatives and a private consultant were given opportunities to present their viewpoints. A number of strategies for reducing residential radon exposure in Canada were recognized, including testing and mitigation of existing homes (on either a widespread or targeted basis) and changing the building code to require that radon mitigation devices be installed at the time a new home is constructed. The various elements of a comprehensive national radon policy were set forth.
PubMed ID
16608836 View in PubMed
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Canadian National Dose Registry of radiation workers: overview of research from 1951 through 2007.

https://arctichealth.org/en/permalink/ahliterature152521
Source
Int J Occup Med Environ Health. 2008;21(4):269-75
Publication Type
Article
Date
2008
Author
Jan M Zielinski
Natalia S Shilnikova
Daniel Krewski
Author Affiliation
Health Environments and Consumer Safety Branch, Health Canada, Tunney's Pasture, Ottawa, Ontario, Canada. jan_zielinski@hc-sc.gc.ca
Source
Int J Occup Med Environ Health. 2008;21(4):269-75
Date
2008
Language
English
Publication Type
Article
Keywords
Canada - epidemiology
Humans
Incidence
Neoplasms, Radiation-Induced - epidemiology
Occupational Diseases - epidemiology - etiology
Occupational Exposure
Radiation Injuries - epidemiology
Radiometry
Registries
Abstract
The National Dose Registry (NDR) of Canada is a unique resource for a direct estimation of the potential health risks associated with low doses of ionizing radiation. This is the largest national occupational radiation exposure database, comprising records for about 600,000 nuclear, industrial, medical and dental workers. An analysis of the NDR data based on a cohort of about 200,000 workers first exposed before 1984 and followed through 1987 and 1988 for mortality and cancer incidence, respectively, revealed that the mortality from most causes of death considered was lower than that in the general population, which is typical of occupational cohorts. Although the same was also observed for cancer incidence, there was a significant increase in the incidence of thyroid cancer and melanoma which, however, was not clearly related to radiation exposure. A significant dose-response was found for mortality from all causes, all cancers, lung cancer, cardiovascular diseases, accidents, for incidence of all cancers, cancers of the rectum and lung, leukaemia, all cancers except lung, and all cancers except leukaemia. In addition, in male workers, a significant dose-response was found for the incidence of colon, pancreatic, and testicular cancers. The estimates of cancer risks (mortality and incidence) were higher than those in most other occupational cohorts and in the studies on atomic bomb survivors. The biologically based dose-response models used to describe lung cancer incidence in the NDR showed that for a protracted exposure to low radiation doses there was a significant radiation effect on the promotion and malignant conversion, but not on the initiation stage of carcinogenesis. This stands in contrast to the findings for high-dose acute exposures in A-bomb survivors, where the initiation and possibly promotion were found to be affected by radiation exposure. Evidence of an inverse dose-rate effect (i.e. an increase in the risk with a protraction of a given cumulative dose) was found in the NDR cohort.
PubMed ID
19228574 View in PubMed
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Decreases in occupational exposure to ionizing radiation among Canadian dental workers.

https://arctichealth.org/en/permalink/ahliterature176619
Source
J Can Dent Assoc. 2005 Jan;71(1):29-33
Publication Type
Article
Date
Jan-2005
Author
Jan M Zielinski
Michael J Garner
Daniel Krewski
J Patrick Ashmore
Pierre R Band
Martha E Fair
Huixa Jiang
Ernest G Letourneau
Robert Semenciw
Willem N Sont
Author Affiliation
Healthy Environments and Consumer Safety Branch, Health Canada, Ottawa, Ontario.
Source
J Can Dent Assoc. 2005 Jan;71(1):29-33
Date
Jan-2005
Language
English
Publication Type
Article
Keywords
Adult
Canada - epidemiology
Cause of Death
Cohort Studies
Dental Staff
Female
Humans
Incidence
Male
Middle Aged
Neoplasms, Radiation-Induced - epidemiology - etiology - mortality
Occupational Exposure - adverse effects
Radiation Dosage
Radiography, Dental - adverse effects
Abstract
To describe doses of ionizing radiation and their possible associations with mortality rates and cancer incidence among Canadian dental workers.
The National Dose Registry (NDR) of Canada was used to assess occupational dose of ionizing radiation received by dental workers. The NDR cohort includes 42,175 people classified as dental workers. Subjects in the NDR were linked to both the Canadian Mortality Database and the Canadian Cancer Database to ascertain cause of death and cancer incidence, respectively.
The cohort consisted of 9,051 male and 33,124 female dental workers. A total of 656 incident cases of cancer and 558 deaths were observed. The standardized mortality ratio associated with all-cause mortality was 0.53 (90% confidence interval [CI] 0.49-0.57). The incidence of cancer among dental workers was lower than that for the Canadian population for all cancers except melanoma of the skin (for melanoma, the standardized incidence ratio was 1.46 [90% CI 1.14-1.85]). Occupational doses of ionizing radiation among dentists and dental workers have decreased markedly since the 1950s.
Dental workers receive very low doses of ionizing radiation, and these doses do not appear to be associated with any increase in cancer incidence; the increased incidence of melanoma is more likely related to other risk factors such as exposure to ultraviolet radiation from sunlight.
PubMed ID
15649338 View in PubMed
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The effect of censoring on cancer risk estimates based on the Canadian National Dose Registry of occupational radiation exposure.

https://arctichealth.org/en/permalink/ahliterature177015
Source
J Expo Anal Environ Epidemiol. 2005 Sep;15(5):398-406
Publication Type
Article
Date
Sep-2005
Author
Hwashin Shin
Timothy Ramsay
Daniel Krewski
Jan M Zielinski
Author Affiliation
R. Samuel McLaughlin Centre for Population Health Risk Assessment, Ottawa, ON, Canada.
Source
J Expo Anal Environ Epidemiol. 2005 Sep;15(5):398-406
Date
Sep-2005
Language
English
Publication Type
Article
Keywords
Canada - epidemiology
Cohort Studies
Confounding Factors (Epidemiology)
Humans
Models, Statistical
Neoplasms, Radiation-Induced - epidemiology - etiology
Occupational Exposure
Radiation Injuries - epidemiology - etiology
Radiation, Ionizing
Radiometry
Registries - standards - statistics & numerical data
Risk assessment
Abstract
Cohort studies represent an important epidemiological tool for exploring the potential adverse health effects of low-dose exposure to ionizing radiation in the workplace. Analyses of data from the National Dose Registry of Canada have suggested that occupational radiation exposure leads to increased risk of several specific types of cancer, as well as increased overall risk of cancer. An important aspect of such studies is the censoring in recorded exposures induced by dosimetry detection limits. Such a censoring effect can lead to significant underestimation of cumulative doses which, in turn, can result in overestimation of the excess cancer risk associated with occupational radiation exposure. In this article, we present analytic results, supported by a simulation study, on the magnitude of overestimation of risk based on the additive relative risk model used in the analysis of the NDR data that can occur due to censoring. Our results indicate that overestimation of risk is modest, being less than 20% in all situations considered here. Because censoring also results in ovestimation of the precision of the risk estimates, the significance levels of Wald-type statistical tests for increased risk based on the ratio of the estimate to its standard error are virtually unaffected by censoring. These results suggest that although the application of the additive excess relative risk model in the presence of censoring may lead to some overestimation of risk, the model does not lead to invalid conclusions regarding the association between occupational radiation exposure and cancer risk based on data from the NDR.
PubMed ID
15592443 View in PubMed
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Health outcomes of low-dose ionizing radiation exposure among medical workers: a cohort study of the Canadian national dose registry of radiation workers.

https://arctichealth.org/en/permalink/ahliterature150149
Source
Int J Occup Med Environ Health. 2009;22(2):149-56
Publication Type
Article
Date
2009
Author
Jan M Zielinski
Michael J Garner
Pierre R Band
Daniel Krewski
Natalia S Shilnikova
Huixia Jiang
Patrick J Ashmore
Willem N Sont
Martha E Fair
Ernest G Letourneau
Robert Semenciw
Author Affiliation
Healthy Environments and Consumer Safety Branch, Health Canada, Ottawa, Ontario, Canada. jan_zielinski@hc-sc.gc.ca
Source
Int J Occup Med Environ Health. 2009;22(2):149-56
Date
2009
Language
English
Publication Type
Article
Keywords
Adult
Canada - epidemiology
Cohort Studies
Female
Health Personnel
Humans
Incidence
Male
Neoplasms, Radiation-Induced - epidemiology - mortality
Occupational Exposure - adverse effects
Radiation Dosage
Radiation Injuries - epidemiology - mortality
Radiation, Ionizing
Registries
Risk assessment
Abstract
Medical workers can be exposed to low-dose ionizing radiation from various sources. The potential cancer risks associated with ionizing radiation exposure have been derived from cohort studies of Japanese atomic bomb survivors who had experienced acute, high-level exposure. Since such extrapolations are subject to uncertainty, direct information is needed on the risk associated with chronic low-dose occupational exposure to ionizing radiation.
To determine the occupational doses of ionizing radiation and examine possible associations with mortality rates and cancer incidence in a cohort of medical workers deriving from the National Dose Registry of Canada (NDR) over the period of 1951-1987.
Standardized mortality and incidence ratios (SMR and SIR, respectively) were ascertained by linking NDR data for a cohort of 67 562 medical workers (23 580 males and 43 982 females) with the data maintained by the Canadian Mortality, and Cancer Incidence databases. Dosimetry information was obtained from the National Dosimetry Services.
During the follow-up period, 1309 incident cases of cancer (509 in males, 800 in females) and 1325 deaths (823 in males, 502 in females) were observed. Mortality from cancer and non-cancer causes was generally below expected as compared to the general Canadian population. Thyroid cancer incidence was significantly elevated both among males and females, with a combined SIR of 1.74 and 90% CI: 1.40-2.10.
The findings confirm previous reports on an increased risk of the thyroid cancer among medical workers occupationally exposed to ionizing radiation. Over the last 50 years, radiation protection measures have been effective in reducing radiation exposures of medical workers to the current very low levels.
PubMed ID
19546093 View in PubMed
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Low dose ionizing radiation exposure and cardiovascular disease mortality: cohort study based on Canadian national dose registry of radiation workers.

https://arctichealth.org/en/permalink/ahliterature151801
Source
Int J Occup Med Environ Health. 2009;22(1):27-33
Publication Type
Article
Date
2009
Author
Jan M Zielinski
Patrick J Ashmore
Pierre R Band
Huixia Jiang
Natalia S Shilnikova
Valerie K Tait
Daniel Krewski
Author Affiliation
Healthy Environments and Consumer Safety Branch, Health Canada, Ottawa, Ontario, Canada. jan_zielinski@hc-sc.gc.ca
Source
Int J Occup Med Environ Health. 2009;22(1):27-33
Date
2009
Language
English
Publication Type
Article
Keywords
Adult
Canada
Cardiovascular Diseases - mortality
Cohort Studies
Female
Humans
Male
Middle Aged
Occupational Diseases - mortality
Occupational Exposure - adverse effects
Radiation Dosage
Radiation Injuries - mortality
Radiation, Ionizing
Registries - statistics & numerical data
Risk assessment
Sex Factors
Abstract
The purpose of our study was to assess the risk of cardiovascular disease (CVD) mortality in a Canadian cohort of 337 397 individuals (169 256 men and 168 141 women) occupationally exposed to ionizing radiation and included in the National Dose Registry (NDR) of Canada.
Exposure to high doses of ionizing radiation, such as those received during radiotherapy, leads to increased risk of cardiovascular diseases. The emerging evidence of excess risk of CVDs after exposure to doses well below those previously considered as safe warrants epidemiological studies of populations exposed to low levels of ionizing radiation. In the present study, the cohort consisted of employees at nuclear power stations (nuclear workers) as well as medical, dental and industrial workers. The mean whole body radiation dose was 8.6 mSv for men and 1.2 mSv for women.
During the study period (1951-1995), as many as 3 533 deaths from cardiovascular diseases have been identified (3 018 among men and 515 among women). In the cohort, CVD mortality was significantly lower than in the general population of Canada. The cohort showed a significant dose response both among men and women. Risk estimates of CVD mortality in the NDR cohort, when expressed as excess relative risk per unit dose, were higher than those in most other occupational cohorts and higher than in the studies of Japanese atomic bomb survivors.
The study has demonstrated a strong positive association between radiation dose and the risk of CVD mortality. Caution needs to be exercised when interpreting these results, due to the potential bias introduced by dosimetry uncertainties, the possible record linkage errors, and especially by the lack of adjustment for non-radiation risk factors.
PubMed ID
19329385 View in PubMed
Less detail

Residential radon in Canada: an uncertainty analysis of population and individual lung cancer risk.

https://arctichealth.org/en/permalink/ahliterature174933
Source
Risk Anal. 2005 Apr;25(2):253-69
Publication Type
Article
Date
Apr-2005
Author
Kevin P Brand
Jan M Zielinski
Daniel Krewski
Author Affiliation
McLauglin Centre for Population Health Risk Assessment, Institute of Population Health, University of Ottawa, Ottawa, Ontario, Canada. kbrand@uottawa.ca
Source
Risk Anal. 2005 Apr;25(2):253-69
Date
Apr-2005
Language
English
Publication Type
Article
Keywords
Age Factors
Air Pollutants, Radioactive
Air pollution, indoor
Air Pollution, Radioactive
Canada
Environmental Exposure
Housing
Humans
Life tables
Lung - radiation effects
Lung Neoplasms - epidemiology - etiology - mortality
Models, Statistical
Models, Theoretical
Neoplasms, Radiation-Induced - epidemiology
Radon
Risk
Risk assessment
Sensitivity and specificity
Sex Factors
Smoking
Time Factors
Uncertainty
Abstract
Following a comprehensive evaluation of the health risks of radon, the U.S. National Research Council (US-NRC) concluded that the radon inside the homes of U.S. residents is an important cause of lung cancer. To assess lung cancer risks associated with radon exposure in Canadian homes, we apply the new (US-NRC) techniques, tailoring assumptions to the Canadian context. A two-dimensional uncertainty analysis is used to provide both population-based (population attributable risk, PAR; excess lifetime risk ratio, ELRR; and life-years lost, LYL) and individual-based (ELRR and LYL) estimates. Our primary results obtained for the Canadian population reveal mean estimates for ELRR, PAR, and LYL are 0.08, 8%, and 0.10 years, respectively. Results are also available and stratified by smoking status (ever versus never). Conveniently, the three indices (ELRR, PAR, and LYL) reveal similar output uncertainty (geometric standard deviation, GSD approximately 1.3), and in the case of ELRR and LYL, comparable variability and uncertainty combined (GSD approximately 4.2). Simplifying relationships are identified between ELRR, LYL, PAR, and the age-specific excess rate ratio (ERR), which suggest a way to scale results from one population to another. This insight is applied in scaling our baseline results to obtain gender-specific estimates, as well as in simplifying and illuminating sensitivity analysis.
PubMed ID
15876202 View in PubMed
Less detail

Uranium in drinking water: renal effects of long-term ingestion by an aboriginal community.

https://arctichealth.org/en/permalink/ahliterature146722
Source
Arch Environ Occup Health. 2009;64(4):228-41
Publication Type
Article
Date
2009
Author
Maria L Limson Zamora
Jan M Zielinski
Gerry B Moodie
Renato A F Falcomer
Wendy C Hunt
Kevin Capello
Author Affiliation
Radiation Protection Bureau, Health Canada, Ottawa, Canada. maria.zamora@rogers.com
Source
Arch Environ Occup Health. 2009;64(4):228-41
Date
2009
Language
English
Publication Type
Article
Keywords
Adolescent
Adult
Biological Markers - urine
Environmental Exposure - adverse effects - analysis
Female
Humans
Indians, North American
Kidney Diseases - chemically induced
Kidney Function Tests
Male
Middle Aged
Quebec
Time
Uranium - analysis - toxicity - urine
Urinalysis
Water Pollutants, Radioactive - analysis - toxicity
Water Supply - analysis
Young Adult
Abstract
The authors conducted a study of an aboriginal community to determine if kidney func-tion had been affected by the chronic ingestion of uranium in drinking water from the community's drilled wells. Uranium concentrations in drinking water varied from
PubMed ID
20007119 View in PubMed
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8 records – page 1 of 1.