Health Canada (HC; French: Santé Canada, SC)[NB 1] is the department of the Government of Canada responsible for national health policy. The department itself is also responsible for numerous federal health-related agencies, including the Canadian Food Inspection Agency (CFIA) and the Public Health Agency of Canada (PHAC), among others. These organizations help to ensure compliance with federal law in a variety of healthcare, agricultural, and pharmaceutical activities. This responsibility also involves extensive collaboration with various other federal- and provincial-level organizations in order to ensure the safety of food, health, and pharmaceutical products—including the regulation of health research and pharmaceutical manufacturing/testing facilities.The department is responsible to Parliament through the minister of health—presently Jean-Yves Duclos—as part of the federal health portfolio. The minister is assisted by the associate minister of health, and minister of mental health and addictions—presently Carolyn Bennett. The deputy minister of health, the senior most civil servant within the department, is responsible for the day-to-day leadership and operations of the department and reports directly to the minister. Originally created as the "Department of Health" in 1919—in the wake of the Spanish flu crisis—what is known as Health Canada today was formed in 1993 from the former Health and Welfare Canada department (established in 1944), which split into two separate units; the other department being Human Resources and Labour Canada.
The health effects of high and moderate doses of ionizing radiation are recognized, but the impacts at lower doses are less clear. Medical workers represent the largest occupational group exposed to radiation. Herein, we examine mortality patterns in a Canadian cohort of medical workers, sex differences in risk, and trends in exposure over time. Annual whole-body effective doses for 301,740 medical workers between 1951 and 2018 were obtained from the Canadian National Dose Registry. Dose trends were characterised by job class and sex. Underlying cause of death was ascertained using linkage to mortality data through 2020. Standardized mortality ratios (SMRs) were estimated to compared the risk of mortality among 124,180 workers with with a lifetime cumulative dose > 0 mSv to the Canadian general population. Internal cohort comparisons incorporated person-time and events among unexposed workers. Poisson regression was used for internal cohort comparisons to explore healthy worker bias. The mean annual radiation dose among workers declined from 0.56 mSv during 1948–1977 to 0.09 mSv in 2000–2018. Compared to the general Canadian population, all-cause mortality was lower for both men (SMR = 0.54, 95
Detection of N-nitrosamines (NA) in pharmaceuticals became a point of interest due to the mutagenic and carcinogenic potential of some compounds of this class, and their identification as nitrosated forms of marketed drugs, otherwise known as NA Drug Substance-Related Impurities (NDSRIs). The Ames test is used to assess the mutagenic potential of drug impurities, including NAs. Concerns over the sensitivity of the Ames test, as recommended in Organization for Economic Co-operation and Development Test Guideline 471, in predicting the rodent carcinogenic potential of NAs has prompted optimization of several test parameters used for detecting the mutagenicity of NAs (e.g. methods used for metabolic activation and the selection of tester strains). In order to discuss optimal Ames test conditions for the evaluation of NAs, including NDSRIs, the Office of New Drugs in the US Food and Drug Administration's Center for Drug Evaluation and Research and the Health and Environmental Sciences Institute's Genetic Toxicology Technical Committee co-organized and co-sponsored a workshop entitled "Nitrosamines: Ames Data Review and Method Development Workshop". The workshop featured five sessions addressing charge questions pertinent to the Ames test conditions and performance through the presentation of data and panel discussions. This report outlines the key takeaway points from the workshop.
Variability drives the organization and behavior of complex systems, including the human brain. Understanding the variability of brain signals is thus necessary to broaden our window into brain function and behavior. Few empirical investigations of macroscale brain signal variability have been undertaken, given the difficulty in separating biological sources of variance from artefactual noise. Here, we characterize the temporal variability of the most predominant macroscale brain signal, the fMRI BOLD signal, and systematically investigate its statistical, topographical, and neurobiological properties. We contrast fMRI acquisition protocols, and integrate across histology, microstructure, transcriptomics, neurotransmitter receptor and metabolic data, fMRI static connectivity, and empirical and simulated magnetoencephalography data. We show that BOLD signal variability represents a spatially heterogeneous, central property of multi-scale multi-modal brain organization, distinct from noise. Our work establishes the biological relevance of BOLD signal variability and provides a lens on brain stochasticity across spatial and temporal scales.
In 2018, Canada legalized and regulated the production and sale of cannabis for non-medical purposes. This paper examined the prevalence of ‘higher risk’ cannabis use outcomes across Canadian provinces and territories (PTs), with rates hypothesized to be lower in Quebec and higher in the territories. Past 12-month cannabis consumers from the 2023 and 2024 cycles of the Canadian Cannabis Survey were included (n = 7238). A previous study identified 16 higher risk cannabis use outcomes. Logistic regression models tested differences in each outcome by PT (10 provinces; three territories combined) or region (Western Canada, Ontario, Quebec, Atlantic Canada, territories). Newfoundland and the territories had the highest rates of frequent cannabis use, and Alberta had the highest rate of inhalable cannabis extract use. Consumers in Quebec reported among the lowest rates of five ‘higher risk’ outcomes (including frequent cannabis use, past 12-month use of inhalable cannabis extracts, and use of extracts containing > 30
Microplastic pollution is a growing global environmental and public health concern, driven by the increasing production and use of plastics. Due to their ubiquitous presence in the environment, humans and animals may be exposed to micro- and nanoplastics via several possible routes. For micro- and nanoplastics, the development of standardized and validated methods remains an important area of progress to support human health risk assessments. In order to monitor micro/nanoplastics’ occurrence in organisms and the environment, it is necessary to develop accurate and reliable methods to quantify and characterize micro/nanoplastics from various biological and environmental matrices. In this study, an analytical, multi-platform approach was established to characterize and quantify polystyrene nanoplastics in biological samples through a combination of sample pre-concentration, asymmetric flow field-flow fractionation, ultraviolet–visible light, dynamic light scattering detectors and pyrolysis–gas chromatography–mass spectroscopy. Several digestion methods on various rodent tissues were tested and modified, and these led to the development of tissue-specific protocols to maximize yield. These digestion protocols were then combined with a new method of concentrating and retaining plastics to prevent the loss of submicron particles. For identification and quantification, known amounts of polystyrene nanoplastics were spiked into rodent tissues (intestine, kidney and liver). This was followed up by a mouse in vivo study consisting of a single dose of PS-NPs, followed by tissue collection, digestion and analysis. Polystyrene particles were detected in the liver and kidney, but not reliably in the intestinal tissues.
