Radiation
Tuesday 7 October 2025, 16.00 – 17.00 Flash
Chairs: Michelle Turner, Martha Riaño
Database on UV exposure measurements – Opportunities for prevention and epidemiological insights
Claudine Strehl (presenter)
Marc Wittlich
Abstract
Objective: Non-melanoma skin cancer (NMSC) caused by solar ultraviolet (UV) radiation is a major occupational health risk, particularly for outdoor workers. The correlation between prolonged exposure to high levels of solar UV radiation and increased incidence of NMSC has been clearly established. While there has been considerable scientific and medical debate surrounding the mechanisms of the disease, the number of affected workers, and the legal classification of NMSC as an occupational disease, comprehensive and reliable data on personal UV exposure has long been missing. Materials & Methods: To address this gap, UV exposure data has been systematically collected since 2014 using an electronic data logger dosimeter (part of the GENESIS-UV measurement system). The data collection encompassed a wide range of outdoor occupations as well as various leisure activities, creating a solid foundation for further analysis. The primary aim was to support skin cancer prevention efforts, but the data also serve as a valuable resource for ongoing epidemiological studies. Results: Over the course of the measurement campaign, approximately three billion data points were gathered across nearly 100 different occupational settings. 14 different leisure time activities were investigated. In addition to contributing to preventive measures, the collected data allow the estimation of the number of workers who are potentially at high risk of developing NMSC. To utilize this extensive dataset for occupational disease recognition and scientific research, a novel metric was developed to facilitate exposure assessment based on exposure registries. Conclusion: The GENESIS-UV project has produced a comprehensive database capturing both occupational and leisure-time UV exposure across a broad spectrum of activities. This robust dataset significantly enhances our ability to implement primary prevention strategies against occupational skin cancer. Moreover, the data are actively supporting epidemiological research aimed at identifying reliable dose-response relationships between UV radiation and NMSC development.
Daytime light exposure at work and incidence of depression among young adults: a national cohort study
Henrik Kolstad (presenter)
Lau Amdisen, Anne Vested, Jesper Medom Vestergaard, Alexander Wilhelm Gorny, Vivi Schlünssen, Alex Burdorf, Jens Peter Bonde , Esben Meulengracht Flachs, Anne Helene Garde, Susan Peters, Zara Ann Stokholm
Abstract
Objective: Depression imposes a heavy burden on the health of young adults. Disturbance of the circadian system is a key characteristic of depression. Bright light exposure during the day is the main stimulus synchronizing the circadian rhythm with that of the daily solar cycle. US and European workers spend more than 90% of their time indoor. We aimed to investigate whether outdoor levels of daytime light exposure at work prevent the onset of depression in young adult men and women. Material and methods: We conducted a cohort study of all Danish workers in the DOC-X cohort aged 19-31 years (315,381 men and 304,639 women) from January 1, 2004 through December 31, 2016 (total follow up 2,663,008 person-years). Diagnoses of depression were based on hospital contacts and prescriptions for antidepressants provided by the government health care system. Annual average daytime light exposure (lux) at work was assessed from participants’ work histories and a quantitative job exposure matrix (JEM) developed from wearable dosimeter recordings. Incidence rate ratios of depression were estimated using Poisson regression adjusting for age, family history, education, and JEM estimates of smoking and physical activity at work. Results: During follow-up, 6,441 men (2.0%) and 12,270 women (4.0%) were diagnosed with depression, corresponding to incidence rates of 4.76 and 9.77 per 1,000 person-years. Workers exposed during the previous year ≥250 lux, levels typically seen in outdoor workers, showed adjusted incidence rate ratios for depression of 0.86 (95% CI, 0.81-0.91) for men and 0.92 (95% CI, 0.87-0.97) for women, compared with workers exposed <250 lux, levels typically seen in indoor workers. Conclusion: Workers exposed to outdoor-equivalent daytime light levels had a decreased risk of depression. Integrating outdoor-equivalent daytime light exposure into workplace design and policy may prevent the onset of depression and benefit the mental well-being of many young adult workers.
Occupational exposure to ionizing radiation and cardiovascular disease mortality among nuclear power plant workers in the Canadian National Dose Registry
Brianna Frangione (presenter)
Laura A. Rodriguez Villamizar, Brianna Frangione, Tim Prendergast, Lydia Zablotska, Philippe Prince, Paul J. Villeneuve
Abstract
Objective: Findings from epidemiological studies suggest that low- to moderate ionizing radiation doses increase the risk of cardiovascular disease (CVD). However, the effects of lower doses, experienced in occupational settings, and of chronic exposures on CVD risks require further investigation. We examined the association between occupational exposure to ionizing radiation and the risk of CVD mortality among Canadian nuclear power plant (NPP) workers. Methods: We assembled a retrospective cohort of 98,735 NPP workers from the Canadian National Dose Registry employed from 1961 onwards. Mortality was ascertained via record linkage to national vital statistics data through 2020. International Classification of Disease rubrics were used to classify CVD deaths based on the underlying cause of death. Whole-body dose measurements came from workplace personal monitoring. Standardized mortality ratios (SMRs) were estimated to compare the mortality experience of the NPP workers to the age-, sex- and calendar year-specific Canadian general population. Poisson regression and linear excess relative risk (ERR) models, adjusted for attained age, sex, and calendar period, were used for internal dose-response analyses. Results: The mean whole-body lifetime accumulated exposure was 9.63mSv (SD=28.5). A total of 2,345 deaths from circulatory disease were identified during the follow-up, and of these, 1,440 and 340 were from ischemic heart disease and cerebrovascular disease, respectively. Compared to the general population, NPP workers had lower mortality rates with SMRs of 0.76 (95%CI: 0.73, 0.80), 0.78 (95%CI: 0.74, 0.82), and 0.79 (95%CI: 0.71, 0.88) for circulatory, ischemic heart disease, and cerebrovascular disease mortality, respectively. For cardiovascular disease (circulatory diseases excluding cerebrovascular disease), the ERR/100mSv was -0.16 (95%CI: -0.28, -0.04). Conclusion: Our findings suggest that contemporary levels of occupational exposure to ionizing radiation do not increase the risk of cardiovascular mortality, but our results should be interpreted cautiously due to possible biases related to uncontrolled confounding and under-ascertainment of mortality. Funding: This project was funded by Conexus Nuclear Inc.
Radon at work: Exposure levels and determinants in various Quebec workplaces
Sabrina Gravel (presenter)
Maude Pomerleau , Tony Wong , Patrick Poulin, France Labrèche
Abstract
Objective Radon is a naturally occurring lung carcinogen, which may infiltrate buildings and expose the occupants, including workers. The objective of this study is to describe radon exposure in various workplaces, to identify factors associated with exposure, and to highlight levers for preventive action. Material and Methods Workplaces of targeted sectors (e.g. municipal services, fish farming, groundwater-fed drinking water production, granite finishing) were recruited in four regions of Québec (Canada); two with a high potential for radon emissions and two with a low potential. We included workplaces with an underground or slab-on-grade work area where workers spend ≥ 4 hours per day. Information was collected on building structure, ventilation, water source, occupancy and company operations. Long-term measurements of radon (3 months) were conducted with Alpha Track AT-100 passive dosimeters, which were deployed by the research team in accordance with Health Canada’s Guide for radon measurements in public buildings. Results There were 354 radon measurements in 54 workplaces (57 buildings built between 1877 and 2021). There were on average 7 measurements (ranging from 1 to 28) per workplace. The median sampling period was 109 days (range 92-148 days). Ten buildings had all measurements below the detection limit (15 Bq/m³), and six had at least one measurement above 100 Bq/m³. The highest recorded values were above 1500 Bq/m³, in a fish hatchery. Generalized estimating equations revealed that the presence of naturally occurring radioactive material (underground water source) was the most predictive factor for higher concentrations, regardless of the geographical region. The presence of rammed earth rather than concrete foundations was also associated with higher concentrations. Conclusion Most workplaces had radon concentrations well below guidelines. Higher concentrations measured in water treatment facilities and in fish farms raise concern about occupational exposures in these workplaces, which may have been overlooked by occupational health authorities.