Background: The “infodemic” accompanying the SARS-CoV-2 virus pandemic has the potential to increase avoidable spread as well as engagement in risky health behaviors. Although social media platforms, such as YouTube, can be an inexpensive and effective method of sharing accurate health information, inaccurate and misleading information shared on YouTube can be dangerous for viewers. The confusing nature of data and claims surrounding the benefits of vitamin D, particularly in the prevention or cure of COVID-19, influences both viewers and the general “immune boosting” commercial interest. Objective: The aim of this study was to ascertain how information on vitamin D and COVID-19 was presented on YouTube in 2020. Methods: YouTube video results for the search terms “COVID,” “coronavirus,” and “vitamin D” were collected and analyzed for content themes and deemed useful or misleading based on the accuracy or inaccuracy of the content. Qualitative content analysis and simple statistical analysis were used to determine the prevalence and frequency of concerning content, such as confusing correlation with causation regarding vitamin D benefits. Results: In total, 77 videos with a combined 10,225,763 views (at the time of data collection) were included in the analysis, with over three-quarters of them containing misleading content about COVID-19 and vitamin D. In addition, 45 (58%) of the 77 videos confused the relationship between vitamin D and COVID-19, with 46 (85%) of 54 videos stating that vitamin D has preventative or curative abilities. The major contributors to these videos were medical professionals with YouTube accounts. Vitamin D recommendations that do not align with the current literature were frequently suggested, including taking supplementation higher than the recommended safe dosage or seeking intentional solar UV radiation exposure. Conclusions: The spread of misinformation is particularly alarming when spread by medical professionals, and existing data suggesting vitamin D has immune-boosting abilities can add to viewer confusion or mistrust in health information. Further, the suggestions made in the videos may increase the risks of other poor health outcomes, such as skin cancer from solar UV radiation.

Ionising radiation is a human carcinogen, but the evidence is less clear that exposure to low-dose ionising radiation (LDIR) increases the risk of adverse cardiovascular outcomes. We synthesised the literature of chronic occupational exposure to LDIR and cardiovascular disease, particularly for ischaemic heart disease (IHD).The literature search was conducted using three databases including studies published between 1990 and 2022. A quality assessment of the studies was completed using the Office of Health and Assessment and Translation Risk of Bias Rating Tool. We conducted meta-analyses for IHD mortality using random effects models using measures of excess relative risk per sievert (ERR/Sv) obtained from internal cohort comparisons, as well as with standardised mortality ratios (SMRs) from external cohort comparisons.We identified 2189 articles, and of these, 26 provided data on IHD and were retained. Most studies were classified as having a ‘moderate’ level of risk of bias. Fourteen and 10 studies reporting external radiation doses were included in meta-analyses using SMR and ERR/Sv, respectively. The meta-summary SMR was 0.81 (95% CI 0.74 to 0.89) with evidence of reduced risk but high heterogeneity across studies. For internal cohort measures, the summary ERR/Sv for a lagged exposure of 10 years was 0.10 (95% CI 0.01 to 0.20) with low heterogeneity. The subgroup analysis by lagged exposure time showed the strongest association were for the 15 and 20 years lag.Our findings suggest that occupational exposure to LDIR increases the risk IHD mortality and highlight the relevance of internal cohort comparisons.

Background: Misinformation, defined as a claim that is false or misleading, considers information that is both shared with the intention of causing harm, and information that is false with no ill intent. Early attempts to downplay the risk of monkeypox (mpox) by singling out men who have sex with men (MSM) may have had the ill effect of stigmatising this group in discussions online. The aim of this study was to evaluate themes present on Instagram related to the 2022 mpox outbreak under #monkeypox. Specifically, this study sought to determine if the pervasive narratives surrounding the coronavirus disease 2019 (COVID-19) pandemic, particularly related to government mistrust and conspiracy, were penetrating discussions about mpox. Methods: A total of 255 posts under #monkeypox (the top 85 posts per day, every 10 days in July 2022) were collected on Instagram. A content analysis approach, which seeks to quantify themes present, was utilised to evaluate themes present in posts under #monkeypox. Results: Contrary to previous research investigating public health misinformation online, the majority of posts under #monkeypox were categorised as accurate information (85.9%). Moreover, a surprising number of posts were classified as anti-misinformation (32.9%), whereby users actively worked to debunk false information being shared online related to mpox. Conclusions: We hypothesise that early labelling of the disease as one that strictly affects online MSM communities has resulted in the digital community coming together to fact-check and debunk misinformation under #monkeypox on Instagram.

Background. In Canada, understanding the demographic and job-related factors influencing the prevalence of new workers and their exposure to potential carcinogens is crucial for improving workplace safety and guiding policy interventions. Methods. Logistic regression was performed on the 2017 Labour Force Survey (LFS), to estimate the likelihood of being a new worker based on age, industry, occupation, season, and immigration status. Participants were categorized by sector and occupation using the North American Industry Classification System (NAICS) 2017 Version 1.0 and National Occupational Classification (NOC) system 2016 Version 1.0. Finally, an exposures-per-worker metric was used to highlight the hazardous exposures new workers encounter in their jobs and industries. Results. Individuals younger than 25 years had 3.24 times the odds of being new workers compared to those in the 25–39 age group (adjusted odds ratios (OR) = 3.24, 95% confidence interval (95% CI) = 3.18, 3.31). Recent immigrants (less than 10 years in the country) were more likely to be new workers than those with Canadian citizenship (OR 1.36, 95% CI: 1.32, 1.41). The total workforce exposures-per-worker metric using CAREX Canada data was 0.56. By occupation, new workers were the most overrepresented in jobs in natural resources and agriculture (20.5% new workers), where they also experienced a high exposures-per-worker metric (1.57). Conclusions. Younger workers (under 25 years) and recent immigrants who had arrived 10 or fewer years prior were more likely to be new workers, and were overrepresented in jobs with more frequent hazardous exposures (Construction, Agriculture, and Trades).

Outdoor artificial light at night (ALAN) may increase breast cancer risk by suppressing melatonin secretion, an effect influenced by light intensity and wavelength. We evaluated the association of multiple ALAN measures with breast cancer risk. We pooled data from two cohort studies (baseline: 2009-2016; n = 24,793 female participants, 674 breast cancer cases). ALAN exposures at residential addresses were estimated using images taken from the International Space Station (2011-2013; ∼30-meter spatial resolution). Measures included average visual radiance (i.e., brightness), average melatonin suppression index (MSI), which quantifies the extent to which light suppresses melatonin, and their product (average impact MSI). Cox proportional hazards regression, adjusted for breast cancer risk factors and built environment features, was used to generate hazard ratios with 95 % confidence intervals (CI) for the associations between ALAN and breast cancer incidence. We also explored associations with breast cancer subtypes (invasive ductal, luminal A, postmenopausal) and among participants self-reporting light entering their rooms while sleeping. No statistically significant associations were observed in the overall study population. Among women reporting light entering their rooms, statistically significant associations of average impact MSI with breast cancer risk, overall and across each subtype, were observed. For example, those in the highest versus lowest tertile of average impact MSI had a 1.53-fold increased hazard of overall breast cancer (95 % CI: 1.18-1.98). Our findings suggest that outdoor ALAN is associated with increased risk of breast cancer and that both intensity and wavelength of light should be considered when evaluating ALAN exposures.