Evaluation of the impact of the European Code against Cancer on awareness and attitudes towards cancer prevention at the population and health promoters' levels.

INTRODUCTION: The European Code against Cancer (ECAC) informs the public on steps to take to reduce their cancer risk. Despite over three decades of promotion, no systematic evaluation of its impact has yet been carried out. This study aimed to address the gap in knowledge regarding the impact of the ECAC. METHODS: An online survey targeting adults in the general population was conducted and analysed by age, gender, and country, both descriptive and mutually adjusted in logistic regression analyses. Additionally, semi-structured interviews with health promotion professionals from not-for-profit organisations in Europe were conducted and a qualitative thematic analysis was carried out for each interview. RESULTS: 8171 people from eight European countries responded to the survey. Although 70 % of respondents were aware of cancer prevention guidance, a low percentage of participants had previously heard about the ECAC (2% in UK to 21 % in Hungary and Poland). Females were more likely to make lifestyle changes to reduce their risk of cancer (odds ratio = 1.17; 95 % confidence interval: 1.05-1.29). Twenty-eight online semi-structured interviews with professionals were conducted covering 25 countries. Regional variation in the methods and target groups of the promotion and dissemination of the ECAC was reported. CONCLUSION: Whilst familiarity with the ECAC in the general public is low, professionals frequently use it as a basis for informing population-level actions. Future editions should be accompanied by a systematic evaluation of the ECAC investigating the impact upon society.

Comparison of Two Information Sources for Cause-of-Death Follow-up in the Russian Federation: The Asbest Chrysotile Cohort Study.

BACKGROUND: The Asbest chrysotile cohort was set up in Asbest town, Sverdlovsk oblast, Russian Federation, among the current and former workforce of the world's largest operating chrysotile mine and its processing mills, to investigate cancer risk in relation to occupational exposure to chrysotile. OBJECTIVES: The cohort of 35,837 people was followed-up for mortality using cause-of-death information from official death certificates issued by the Civil Act Registration Office (ZAGS) of Sverdlovsk oblast from 1976 to 2015. Data were also retrieved from the electronic cause-of-death registry of the Medical Information Analytical Centre (MIAC) of Sverdlovsk oblast, which was launched in 1990 and operates independently of ZAGS. The objectives were to compare the completeness of record linkage (RL) with ZAGS and with MIAC, and to compare the agreement of cause-of-death information obtained from ZAGS and from MIAC, with a focus on malignant neoplasms. METHODS: RL completeness of identifying cohort members in ZAGS and in MIAC was compared for the period 1990 to 2015. In the next step, for the comparison of the retrieved cause-of-death information, 5,463 deaths (1,009 from cancer) were used that were registered in 2002 to 2015, when causes of death were coded using International Statistical Classification of Diseases and Related Health Problems, 10th revision (ICD-10) nomenclature by MIAC. For ZAGS, original cause-of-death text from the death certificates was obtained and then coded according to ICD-10 by the International Agency for Research on Cancer/World Health Organization (IARC/WHO). Agreement was evaluated at various levels of detail, and reasons for any disagreements between the MIAC and the IARC/WHO ICD-10-coded cancer diagnosis were systematically explored. RESULTS: A total of 10,886 deaths were obtained from all avenues of follow-up for the period 1990 to 2015 in the cohort; 10,816 (99.4%) of these were found in ZAGS. This percentage was 88.3% if only automated deterministic RL was used and 99.4% when deterministic RL was complemented with manual searches of cohort members. Comparison of the cause-of-death information showed agreement of 97.9% at the ICD-10 main group level between ZAGS (coded by IARC/WHO) and MIAC. Of 1,009 cancer deaths, 679 (67.3%) cases had identical coding, 258 (25.6%) cases corresponded at the three-character ICD-10 level, 36 (3.6%) had codes that were within the same anatomical or morphological cluster, and for only 36 (3.6%) cases were major discrepancies identified. Altogether, the agreement between IARC/WHO coding of cause-of-death information from ZAGS and MIAC coding of malignant neoplasms was therefore 96.4%. CONCLUSIONS: RL completeness and agreement of cause-of-death information obtained from ZAGS and from MIAC were both very high. This is reassuring for the quality of cancer mortality follow-up of the Asbest chrysotile cohort. For future epidemiological studies in the Russian Federation, ZAGS appears to be a reliable information source for mortality follow-up, if the automated RL is complemented with manual searches of cohort members. MIAC is a good resource for prospective studies.

Prospective case-series analysis of haematological malignancies in goldmining areas in South Africa.

BACKGROUND: South Africa (SA) has a long history of goldmining that has resulted in locally high levels of environmental contamination from uranium and its decay products (radium-226 and radon-222) from the mine tailings. Populations living around mine tailings of the Witwatersrand goldfields may be exposed through various pathways, raising concern about potential health risks associated with haematological malignancies (HMs), for which evidence is inconclusive. OBJECTIVES: We designed a prospective case-series study of HMs at Chris Hani Baragwanath Academic Hospital (CHBAH), Johannesburg, the major public hospital in the area, to describe demographic and clinical characteristics, lifetime residential history and potential environmental uranium exposure pathways. METHODS: All patients, male and female, aged ≥18 years and newly diagnosed with any form of leukaemia, lymphoma or myeloma at the CHBAH Haematology Unit in 2014 and 2015 were considered for inclusion in the study. Information on uranium exposure pathways and lifetime residential history was recorded from interviewer-administered questionnaires. These characteristics were described overall and according to subtypes of HM. RESULTS: Of 556 patients with HMs diagnosed in 2014 and 2015 at CHBAH, 189 patients aged 18 - 90 years were interviewed, mainly with non-Hodgkin's lymphoma (NHL) (37.6%), leukaemia (32.8%) and Hodgkin's lymphoma (HL) (13.8%). HIV status was positive for 39.2% of the patients, mostly with NHL and HL. Potential environmental uranium exposure pathways were identified. Working on goldmines was reported by 12 patients (6.3%). Consumption of soil (geophagia) was a habit of 51 patients (27.0%), particularly during pregnancy. Drinking water was mainly piped water (76.6% in childhood and 97.9% in adulthood). Animal products and vegetables were most frequently obtained from stores (82.0% and 68.7%, respectively, in childhood and 96.3% and 83.6% in adulthood). Patients were referred to CHBAH by government clinic doctors (44.4%), referral hospitals (24.3%) and private doctors (20.1%). Most participants had been born and lived in Gauteng Province and Soweto (94.7% and 58.2%, respectively), and reported two lifetime places of residence on average and living at their current residence for ≥20 years (49.2%). CONCLUSIONS: We identified potential environmental uranium exposure pathways (occupational, lifestyle related and domestic) among patients with HMs that could have resulted in increased uranium exposure. HIV is common among patients with HMs. Together with the results from a previous retrospective case series of HMs at CHBAH (2004 - 2013), our findings suggest that further research on environmental uranium exposure in mining areas and HM risk in residents is warranted.

Retrospective case-series analysis of haematological malignancies in goldmining areas of South Africa.

BACKGROUND: South Africa (SA)'s high levels of environmental contamination of mine tailings from uranium and its decay products, coupled with remarkably short distances between mine tailings and residential areas, raise concern about whether there is an association between environmental uranium exposure and risk of cancer, including haematological malignancies. OBJECTIVES: We reviewed information on cases from the central hospital offering cancer diagnostics and treatment in a major mining area of SA to describe their basic clinical and demographic characteristics, as part of assessing whether a cancer epidemiological study in this area would be feasible. METHODS: Basic clinical, demographic and residential information on patients with haematological malignancy diagnosed between 2004 and 2013 was collected retrospectively from the patient files at Chris Hani Baragwanath Academic Hospital in Soweto, Johannesburg. RESULTS: In total, 1 880 patients aged 18 - 94 years were identified. Referral from distant provinces was not uncommon, but >80% lived within 50 km of the hospital. Non-Hodgkin's lymphoma accounted for 44% of the haematological malignancies, followed by leukaemia with 26%. HIV status was known for 93% of the patients, of whom 47% were HIV-positive. CONCLUSIONS: Caution is required when interpreting spatial distributions of patients, given inaccuracies in residential addresses and referral patterns to the hospital, and with HIV and other infections probable important confounders. Our study therefore shows that active case recruitment is required for accurate assessment of residential information. However, some findings on spatial distributions in the study warrant the continuation of efforts to develop a study protocol to investigate the possible link between uranium exposure in mining areas and haematological malignancies in residents. Disproportionately high incidence rates of haematological malignancies observed in specific districts would be relevant for further investigation.

International cancer seminars: a focus on esophageal squamous cell carcinoma.

The International Agency for Research on Cancer (IARC) and the US National Cancer Institute (NCI) have initiated a series of cancer-focused seminars [Scelo G, Hofmann JN, Banks RE et al. International cancer seminars: a focus on kidney cancer. Ann Oncol 2016; 27(8): 1382-1385]. In this, the second seminar, IARC and NCI convened a workshop in order to examine the state of the current science on esophageal squamous cell carcinoma etiology, genetics, early detection, treatment, and palliation, was reviewed to identify the most critical open research questions. The results of these discussions were summarized by formulating a series of 'difficult questions', which should inform and prioritize future research efforts.

Cancer Incidence after In Utero Exposure to Ionizing Radiation in Techa River Residents.

Health effects of in utero exposure to ionizing radiation, especially among adults, are still unclear. The aim of this study was to analyze cancer risk in a cohort of subjects exposed in utero due to releases of nuclear waste into the Techa River in the Southern Urals, taking into account additional postnatal exposure. Analysis for solid cancer was based on 242 cases among 10,482 cohort members, accumulating 381,948 person-years at risk, with follow-up from 1956-2009, while analysis for hematological malignancies was based on 26 cases among 11,070 persons, with 423,502 person-years at risk, with follow-up from 1953-2009. Mean doses accumulated in soft tissues and in red bone marrow during the prenatal period were 4 mGy and 30 mGy, respectively. Additional respective mean postnatal doses received by cohort members were 11 and 84 mGy. Poisson regression analysis was used to estimate the excess relative risk (ERR) of cancer incidence related to in utero and postnatal doses. No association was observed for in utero exposure with solid cancer risk [ERR per 10 mGy: -0.007; 95% confidence interval (CI): <-0.107; 0.148] or with hematological malignancy risk (ERR/10 mGy: -0.011; 95% CI: <-0.015; 0.099). However, ERR of solid cancer increased significantly with increasing postnatal dose (ERR/10 mGy: 0.11; 95% CI: 0.04; 0.22). The very wide confidence intervals in these ERR results are similar to those of studies performed on the LSS cohort and the offspring of the Mayak Female Worker Cohort, as well as case-control studies of effects after in utero medical exposure. There were limitations of this study, with decreased statistical power, due to the low prenatal doses received by most of the cohort members, the small number of cancer cases and the absence of cohort members over the age of 59 years (living cohort members had reached 49-59 years of age). Further aging of the cohort and extension of the follow-up period will enhance the statistical power of this study in the future. There is a shortage of cohort studies reporting on the effects of prenatal radiation exposure, as well as information on chronic exposure during the prenatal period. Therefore, further research of this unique cohort will be a useful addition to the published literature on this subject, and a valuable means of elucidating the long-term effects of low-dose radiation exposure in the fetus.

Informing etiologic research priorities for squamous cell esophageal cancer in Africa: A review of setting-specific exposures to known and putative risk factors.

Esophageal squamous cell carcinoma (ESCC) is one of the most common cancers in most Eastern and Southern African countries, but its etiology has been understudied to date. To inform its research agenda, we undertook a review to identify, of the ESCC risk factors which have been established or strongly suggested worldwide, those with a high prevalence or high exposure levels in any ESCC-affected African setting and the sources thereof. We found that for almost all ESCC risk factors known to date, including tobacco, alcohol, hot beverage consumption, nitrosamines and both inhaled and ingested PAHs, there is evidence of population groups with raised exposures, the sources of which vary greatly between cultures across the ESCC corridor. Research encompassing these risk factors is warranted and is likely to identify primary prevention strategies.

Risk of Hematologic Malignancies in the Offspring of Female Workers of the Mayak Nuclear Facility in the Southern Urals, Russian Federation.

Long-term effects of in utero exposure to ionizing radiation remain poorly quantified in humans. In this study, the risk of hematologic malignancies was investigated in offspring of female workers of the Mayak Production Association, a large Russian nuclear facility. Excess relative risks (ERR) for exposure to gamma radiation and plutonium were estimated in a cohort of 8,466 offspring who were born between January 1, 1948 and December 31, 1988 and followed until 2009. An unstable linear ERR of 1.12 (95% CI 0.11-3.44) per 100 mGy gamma exposure in utero was estimated based on 32 incident hematologic malignancies in 277,002 person-years under risk. The ERR was increased in the dose category 20-79 mGy gamma exposure in utero (1.75, 95% CI 0.04; 5.63), while the other dose categories showed decreased or unstable estimates. Leukemia showed an ERR of 1.76 (95% CI 0.01-8.33) per 100 mGy based on 13 cases. There was no consistent association with plutonium exposure. While an increased risk of hematologic malignancies after gamma exposure in utero was suggested, the small numbers prevented more definitive conclusions.

Environmental carcinogen exposure and lifestyle factors affecting cancer risk in Qatar: findings from a qualitative review.

To meet the country's health goals for 2011-2016, a qualitative review of exposure to risk factors for cancer in Qatar was conducted in 2013. The review included exposure to environmental agents carcinogenic to humans (International Agency for Research on Cancer classification), as well as lifestyle factors known to affect cancer risk. Information from all available sources was assembled and reviewed. The levels of particulate matter reported in Qatar were in the upper range of ambient air pollutants reported internationally, and may influence the country's future lung cancer burden. The limited data on occupational exposure suggests that the greatest risks for workers in the construction industry are likely to be from environmental dust and related air pollutants. The greatest cancer risks for Qatari nationals may be lifestyle factors, particularly obesity, physical inactivity and tobacco use. Extended monitoring of the composition of and human exposure to air pollutants is recommended.

Risk of solid cancer in the offspring of female workers of the Mayak nuclear facility in the Southern Urals, Russian Federation.

Studies of cancer risk following in utero exposure to ionizing radiation are limited in number, particularly for adult-onset cancers, and the evidence is unclear. In the present study, the risk of solid cancer incidence following in utero radiation exposure is examined among 8466 offspring of female nuclear workers at one of the largest nuclear facilities (Mayak Production Association) in the Russian Federation. Poisson regression methods were used to estimate excess relative risks (ERRs) per Gray (Gy). Mother's uterine gamma dose served as a surrogate for fetal gamma dose. During 277,002 person-years of follow-up (1948-2009), there were 177 first primary solid cancers excluding non-melanoma skin cancers. Estimated in utero gamma and plutonium doses exceeded zero for 41 and 23 % of offspring, respectively. Of the 177 solid cancers, 66 occurred among individuals with some in utero exposure to gamma radiation and 53 among those with estimated plutonium exposures. There was no indication of a statistically significantly increased risk of solid cancer incidence from in utero gamma exposure (linear ERR/Gy -1.0; upper 95 % confidence limit 0.5). This result was unchanged after accounting for subsequent occupational exposure. Plutonium doses were estimated but were too low to obtain meaningful risk estimates. Thus, in this cohort in utero radiation exposure was not associated with solid cancer risk. This is consistent with an earlier report of mortality in the cohort, but is based on twice as many cases and less susceptible to biases inherent in mortality analyses. Given the relatively young age of the cohort with respect to cancer, continued follow-up should be done as the number of cancer cases increases.

Comparison of mortality in Asbest city and the Sverdlovsk region in the Russian Federation: 1997-2010.

BACKGROUND: The Sverdlovsk region of the Russian Federation is characterised by its abundance of natural resources and industries. Located in this region, Asbest city is situated next to one of the largest open-pit chrysotile asbestos mines currently operational; many city residents are employed in activities related to mining and processing of chrysotile. We compared mortality rates from 1997 to 2010 in Asbest city to the remaining Sverdlovsk region, with additional analyses conducted for site-specific cancer mortality. METHODS: Population and mortality data for Asbest city and Sverdlovsk region were used to estimate crude and age-specific rates by gender for the entire period and for each calendar year. Age-standardized mortality rates were also calculated for the adult population (20+) and Poisson regression was used to estimate standardized mortality ratios, overall and by gender. RESULTS: During the period of 1997 to 2010, there were similar mortality rates overall in Asbest and the Sverdlovsk region. However, there were higher rates of cancer mortality (18 % males; 21 % females) and digestive diseases (21 % males; 40 % females) in Asbest and lower rates of unknown/ill-defined in Asbest (60 % males; 47 % females). Circulatory disease mortality was slightly lower in Asbest. Cancer mortality was higher for men in Asbest from oesophageal, urinary tract and lung cancers compared to the Sverdlovsk region. In women, cancer mortality was higher for women in Asbest from stomach, colon, lung and breast cancers compared to the Sverdlovsk region. CONCLUSIONS: This large population-based analysis indicates interesting differences but studies with individual exposure information are needed to understand the underlying factors.

Qat Chewing and Risk of Potentially Malignant and Malignant Oral Disorders: A Systematic Review.

BACKGROUND: Qat (also known as Khat, Kat and Miraa) is a green-leaved plant (Catha edulis). It is a shrub indigenous to Yemen and certain parts of eastern Africa. Chewing the leaves, which have sympathomimetic and euphoric effects, has been documented in many countries and increased with worldwide migration. The effect of long-term chewing Qat on the oral cavity is unknown. OBJECTIVE: A systematic review was performed to identify any associations between Qat chewing and the occurrence of potentially malignant and malignant oral disorders. METHODS: Medline and the Web of Science were searched for articles published before May 2014 without limits with regard to publication date and language. RESULTS: From a total of 890 papers identified, 17 English papers reported potentially malignant or malignant oral disorders and Qat chewing. One additional paper in Arabic language was identified from reviewing the list of references of eligible papers. It was found that exposure to Qat may be associated with potentially malignant and malignant oral disorders, but methodological issues, such as inadequate study design, sample size, selection of study subjects, clinical evaluations of outcome and limited adjustment for confounders, limit the strength of the evidence base in this area. CONCLUSION: The association between Qat chewing and potentially malignant and malignant oral disorders remains debatable and requires further investigations.

Methods for Ensuring High Quality of Coding of Cause of Death. The Mortality Register to Follow Southern Urals Populations Exposed to Radiation.

BACKGROUND: To follow up populations exposed to several radiation accidents in the Southern Urals, a cause-of-death registry was established at the Urals Center capturing deaths in the Chelyabinsk, Kurgan and Sverdlovsk region since 1950. OBJECTIVES: When registering deaths over such a long time period, quality measures need to be in place to maintain quality and reduce the impact of individual coders as well as quality changes in death certificates. METHODS: To ensure the uniformity of coding, a method for semi-automatic coding was developed, which is described here. Briefly, the method is based on a dynamic thesaurus, database-supported coding and parallel coding by two different individuals. RESULTS: A comparison of the proposed method for organizing the coding process with the common procedure of coding showed good agreement, with, at the end of the coding process, 70 - 90% agreement for the three-digit ICD -9 rubrics. CONCLUSIONS: The semi-automatic method ensures a sufficiently high quality of coding by at the same time providing an opportunity to reduce the labor intensity inherent in the creation of large-volume cause-of-death registries.

A framework for estimating radiation-related cancer risks in Japan from the 2011 Fukushima nuclear accident.

We present here a methodology for health risk assessment adopted by the World Health Organization that provides a framework for estimating risks from the Fukushima nuclear accident after the March 11, 2011 Japanese major earthquake and tsunami. Substantial attention has been given to the possible health risks associated with human exposure to radiation from damaged reactors at the Fukushima Daiichi nuclear power station. Cumulative doses were estimated and applied for each post-accident year of life, based on a reference level of exposure during the first year after the earthquake. A lifetime cumulative dose of twice the first year dose was estimated for the primary radionuclide contaminants ((134)Cs and (137)Cs) and are based on Chernobyl data, relative abundances of cesium isotopes, and cleanup efforts. Risks for particularly radiosensitive cancer sites (leukemia, thyroid and breast cancer), as well as the combined risk for all solid cancers were considered. The male and female cumulative risks of cancer incidence attributed to radiation doses from the accident, for those exposed at various ages, were estimated in terms of the lifetime attributable risk (LAR). Calculations of LAR were based on recent Japanese population statistics for cancer incidence and current radiation risk models from the Life Span Study of Japanese A-bomb survivors. Cancer risks over an initial period of 15 years after first exposure were also considered. LAR results were also given as a percentage of the lifetime baseline risk (i.e., the cancer risk in the absence of radiation exposure from the accident). The LAR results were based on either a reference first year dose (10 mGy) or a reference lifetime dose (20 mGy) so that risk assessment may be applied for relocated and non-relocated members of the public, as well as for adult male emergency workers. The results show that the major contribution to LAR from the reference lifetime dose comes from the first year dose. For a dose of 10 mGy in the first year and continuing exposure, the lifetime radiation-related cancer risks based on lifetime dose (which are highest for children under 5 years of age at initial exposure), are small, and much smaller than the lifetime baseline cancer risks. For example, after initial exposure at age 1 year, the lifetime excess radiation risk and baseline risk of all solid cancers in females were estimated to be 0.7 · 10(-2) and 29.0 · 10(-2), respectively. The 15 year risks based on the lifetime reference dose are very small. However, for initial exposure in childhood, the 15 year risks based on the lifetime reference dose are up to 33 and 88% as large as the 15 year baseline risks for leukemia and thyroid cancer, respectively. The results may be scaled to particular dose estimates after consideration of caveats. One caveat is related to the lack of epidemiological evidence defining risks at low doses, because the predicted risks come from cancer risk models fitted to a wide dose range (0-4 Gy), which assume that the solid cancer and leukemia lifetime risks for doses less than about 0.5 Gy and 0.2 Gy, respectively, are proportional to organ/tissue doses: this is unlikely to seriously underestimate risks, but may overestimate risks. This WHO-HRA framework may be used to update the risk estimates, when new population health statistics data, dosimetry information and radiation risk models become available.

Atopic conditions and brain tumor risk in children and adolescents--an international case-control study (CEFALO).

BACKGROUND: A number of epidemiological studies indicate an inverse association between atopy and brain tumors in adults, particularly gliomas. We investigated the association between atopic disorders and intracranial brain tumors in children and adolescents, using international collaborative CEFALO data. PATIENTS AND METHODS: CEFALO is a population-based case-control study conducted in Denmark, Norway, Sweden, and Switzerland, including all children and adolescents in the age range 7-19 years diagnosed with a primary brain tumor between 2004 and 2008. Two controls per case were randomly selected from population registers matched on age, sex, and geographic region. Information about atopic conditions and potential confounders was collected through personal interviews. RESULTS: In total, 352 cases (83%) and 646 controls (71%) participated in the study. For all brain tumors combined, there was no association between ever having had an atopic disorder and brain tumor risk [odds ratio 1.03; 95% confidence interval (CI) 0.70-1.34]. The OR was 0.76 (95% CI 0.53-1.11) for a current atopic condition (in the year before diagnosis) and 1.22 (95% CI 0.86-1.74) for an atopic condition in the past. Similar results were observed for glioma. CONCLUSIONS: There was no association between atopic conditions and risk of all brain tumors combined or of glioma in particular. Stratification on current or past atopic conditions suggested the possibility of reverse causality, but may also the result of random variation because of small numbers in subgroups. In addition, an ongoing tumor treatment may affect the manifestation of atopic conditions, which could possibly affect recall when reporting about a history of atopic diseases. Only a few studies on atopic conditions and pediatric brain tumors are currently available, and the evidence is conflicting.

Patterns of exposure to infectious diseases and social contacts in early life and risk of brain tumours in children and adolescents: an International Case-Control Study (CEFALO).

BACKGROUND: Infectious diseases and social contacts in early life have been proposed to modulate brain tumour risk during late childhood and adolescence. METHODS: CEFALO is an interview-based case-control study in Denmark, Norway, Sweden and Switzerland, including children and adolescents aged 7-19 years with primary intracranial brain tumours diagnosed between 2004 and 2008 and matched population controls. RESULTS: The study included 352 cases (participation rate: 83%) and 646 controls (71%). There was no association with various measures of social contacts: daycare attendance, number of childhours at daycare, attending baby groups, birth order or living with other children. Cases of glioma and embryonal tumours had more frequent sick days with infections in the first 6 years of life compared with controls. In 7-19 year olds with 4+ monthly sick day, the respective odds ratios were 2.93 (95% confidence interval: 1.57-5.50) and 4.21 (95% confidence interval: 1.24-14.30). INTERPRETATION: There was little support for the hypothesis that social contacts influence childhood and adolescent brain tumour risk. The association between reported sick days due to infections and risk of glioma and embryonal tumour may reflect involvement of immune functions, recall bias or inverse causality and deserve further attention.

A retrospective cohort study of cancer mortality in employees of a Russian chrysotile asbestos mine and mills: study rationale and key features.

Chrysotile, a serpentine asbestos fibre, is the only type of asbestos produced and consumed in the world today. It is an established human carcinogen. We have begun fieldwork on a retrospective cohort study of employees of one of the world's largest chrysotile mine and mills, situated in Asbest, Russia. The primary aim of the study is to better characterize and quantify the risk of cancer mortality in terms of (i) the dose-response relationship of exposure with risk; (ii) the range of cancer sites affected, including female-specific cancers; and (iii) effects of duration of exposure and latency periods. This information will expand our understanding of the scale of the impending cancer burden due to chrysotile, including if chrysotile use ceased worldwide forthwith. Herein we describe the scientific rationale for conducting this study and the main features of its study design.

Extremely low-frequency magnetic fields and survival from childhood acute lymphoblastic leukemia: an international follow-up study.

A previous US study reported poorer survival in children with acute lymphoblastic leukemia (ALL) exposed to extremely low-frequency magnetic fields (ELF-MF) above 0.3 µT, but based on small numbers. Data from 3073 cases of childhood ALL were pooled from prospective studies conducted in Canada, Denmark, Germany, Japan, UK and US to determine death or relapse up to 10 years from diagnosis. Adjusting for known prognostic factors, we calculated hazard ratios (HRs) and 95% confidence intervals (CI) for overall survival and event-free survival for ELF-MF exposure categories and by 0.1 µT increases. The HRs by 0.1 µT increases were 1.00 (CI, 0.93-1.07) for event-free survival analysis and 1.04 (CI, 0.97-1.11) for overall survival. ALL cases exposed to >0.3 µT did not have a poorer event-free survival (HR=0.76; CI, 0.44-1.33) or overall survival (HR=0.96; CI, 0.49-1.89). HRs varied little by subtype of ALL. In conclusion, ELF-MF exposure has no impact on the survival probability or risk of relapse in children with ALL.

Mayak workers study cohort. An inter-institutional comparison of causes of death in the cause-of-death register of Ozyorsk in the Russian Federation.

BACKGROUND: The cause-of-death register at the Southern Urals Biophysics Institute (SUBI), Ozyorsk, Russia, was established to document the number and causes of deaths in the Mayak workers cohort, which includes all persons (N = 22,377) employed at Mayak nuclear facility between 1948 and 1982. Most workers were occupationally exposed to high doses of ionizing radiation and have been shown to have increased risks of various chronic diseases including cancer. OBJECTIVES: To investigate the quality of cause of death coding in the SUBI register. METHODS: A random sample of 246 deaths (~1% of the total) was coded independently at the SUBI and the Danish Cancer Society using the International Classification of Diseases 9 (ICD-9). Proportions of matching codes were calculated. RESULTS: Overall, 233 deaths (95%) were identically classified using the ICD-9 main category matching. Excluding mismatches that were considered to be incorrectly coded during validation, the validity of the register increased to 98%. Using the specific ICD-9 first three-digit matching, 182 deaths were identically coded (74%) and the respective validity of the register was 85%. There were also some non-resolvable discrepancies demonstrating limitations of assigning one code for each death or using language-adapted ICD-9 version. CONCLUSIONS: This validation study was an important quality check of a register used for mortality follow-up in a highly influential epidemiological study on radiation-related health effects. The results of the inter-institutional comparison were generally favourable; however, since the comparison revealed individual mismatches and some systematically differing coding practices, it is essential to repeat it on a regular basis in order to maintain a high quality.