Long-term associations of sector-specific air pollution mixtures with mortality in Canada.

Previous studies often focus on individual air pollutants rather than their mixtures or specific sources. To assess associations between mixtures of fine particulate matter (PM), sulfur dioxide (SO), nitrogen dioxide (NO), and ozone (O) from various industrial and residential sources and mortality from ischemic heart disease (IHD), cardiovascular disease (CVD), and non-accidental causes. The 2006 Canadian Census Health and Environment Cohort (CanCHEC) was linked to the Canadian Vital Statistics Database included 3,019,125 adults with 36,112,640 person-years of follow-up.

Understanding mortality differentials of Black adults in Canada.

Background: It is not clear whether the increased mortality pattern observed in a prior analysis of the Canadian Census Health and Environment Cohorts for HIV/AIDS, diabetes, prostate cancer, and uterine cancer among Black adults is reflected in incident hospitalization (a marker of severity) or the diagnosis of these diseases, nor is it clear whether disparities exist regarding early screening and survivability.

Methods: To understand the paths that contribute to differential mortality patterns, standard Cox proportional hazard models were used to assess the incidence risk of diagnosis (uterine and prostate cancer) and incident hospitalization (HIV and diabetes) among 161,520 Black adults, compared with 6,866,070 White adults. Competing risk regression was used to evaluate the cumulative risk of death for the four disease outcomes since diagnosis or hospitalization.

Epidemiological studies likely need to consider PM composition even if total outdoor PM mass concentration is the exposure of interest.

Background: Outdoor fine particulate air pollution, <2.5 µm (PM) mass concentrations can be constructed through many different combinations of chemical components that have varying levels of toxicity. This poses a challenge for studies interested in estimating the health effects of total outdoor PM (i.

Long-Term Exposure to Low-Level and Mortality: Investigation of Heterogeneity by Harmonizing Analyses in Large Cohort Studies in Canada, United States, and Europe.

Background: Studies across the globe generally reported increased mortality risks associated with particulate matter with aerodynamic diameter () exposure with large heterogeneity in the magnitude of reported associations and the shape of concentration-response functions (CRFs). We aimed to evaluate the impact of key study design factors (including confounders, applied exposure model, population age, and outcome definition) on effect estimates by harmonizing analyses on three previously published large studies in Canada [Mortality-Air Pollution Associations in Low Exposure Environments (MAPLE), 1991-2016], the United States (Medicare, 2000-2016), and Europe [Effects of Low-Level Air Pollution: A Study in Europe (ELAPSE), 2000-2016] as much as possible.

Methods: We harmonized the study populations to individuals years of age, applied the same satellite-derived exposure estimates, and selected the same sets of potential confounders and the same outcome.

Inequality in the Distribution of Air Pollution Attributable Mortality Within Canadian Cities.

Recent studies have identified inequality in the distribution of air pollution attributable health impacts, but to our knowledge this has not been examined in Canadian cities. We evaluated the extent and sources of inequality in air pollution attributable mortality at the census tract (CT) level in seven of Canada's largest cities. We first regressed fine particulate matter (PM) and nitrogen dioxide (NO) attributable mortality against the neighborhood (CT) level prevalence of age 65 and older, low income, low educational attainment, and identification as an Indigenous (First Nations, Métis, Inuit) or Black person, accounting for spatial autocorrelation.

Mortality inequalities of Black adults in Canada.

Background: Mortality rates in Canada have been shown to vary by population group (e.g., Indigenous peoples, immigrants) and social economic status (e.

Long-term exposure to wildfires and cancer incidence in Canada: a population-based observational cohort study.

Background: Wildfires emit many carcinogenic pollutants that contaminate air, water, terrestrial, and indoor environments. However, little is known about the relationship between exposure to wildfires and cancer risk. We aimed to assess the associations between residential exposure to wildfires and the incidence of several cancer outcomes (lung cancer, brain cancer, non-Hodgkin lymphoma, multiple myeloma, and leukaemia) in Canada.

Neighbourhood walkability and mortality: Findings from a 15-year follow-up of a nationally representative cohort of Canadian adults in urban areas.

Background: Using a nationally representative cohort of Canadian adults, we assessed associations between neighbourhood walkability and cause-specific mortality and investigated whether they differed by socioeconomic status.

Methods: The study population was drawn from the 2001 Canadian Census Health and Environment Cohort, which contains individual-level data from a random sample of 20% of Canadian households mandated to complete the long-form census. We included those aged ≥ 25 years at baseline who lived in urban and suburban areas.

The influence of outdoor PM concentration at workplace on nonaccidental mortality estimates in a Canadian census-based cohort.

Background: Associations between mortality and exposure to ambient air pollution are usually explored using concentrations of residential outdoor fine particulate matter (PM) to estimate individual exposure. Such studies all have an important limitation in that they do not capture data on individual mobility throughout the day to areas where concentrations may be substantially different, leading to possible exposure misclassification. We examine the possible role of outdoor PM concentrations at work for a large population-based mortality cohort.

Ethnocultural and socioeconomic disparities in exposure to residential greenness within urban Canada.

Background: Residential greenness has been associated with health benefits, such as lower risk of mortality, cardiovascular disease, obesity, adverse birth outcomes and asthma and better psychological health. However, the variation in greenness across socioeconomic and demographic characteristics in urban areas of Canada has not been well documented.

Data And Methods: Respondents to the 2016 Census long-form questionnaire were assigned estimates of exposure to residential greenness based on the mean Normalized Difference Vegetation Index (NDVI) (from 2012 or the most recent year available) within a 500 m buffer around their home, based on postal code.

Residential greenness and indicators of stress and mental well-being in a Canadian national-level survey.

Background: Residential proximity to greenness in urban areas has been shown to confer a number of health benefits, including improved mental health. We investigated whether greenness was associated with self-reported stress, distress, and mental health among adult participants of multiple cycles of a national Canadian health survey, and whether these associations varied by sex, age, income, and neighbourhood characteristics.

Methods: Our study population included 397,900 participants of the Canadian Community Health Survey, 18 years of age or older, who lived in census metropolitan areas between 2000 and 2015.

Self-rated stress, distress, mental health, and health as modifiers of the association between long-term exposure to ambient pollutants and mortality.

Background: Individual and neighbourhood-scale socioeconomic characteristics modify associations between exposure to air pollution and mortality. The role of stress, which may integrate effects of social and environmental exposures on health, is unknown. We examined whether an individual's perspective on their own well-being, as assessed using self-rated measures of stress and health, modifies the pollutant-mortality relationship.

The association between ambient air pollution concentrations and psychological distress.

Background: A growing number of epidemiological studies have linked air pollution exposure to psychological conditions. Laboratory studies indicate that air pollutants can activate the neuroendocrine stress axis and modulate stress hormone levels, which could contribute to the development or exacerbation of psychological distress. The present study examined the spatial associations between air pollutants (fine particulate matter [PM], nitrogen dioxide [NO] and ground-level ozone [O]) and psychological distress among subjects in the most populous provinces in Canada.

Disease assimilation: The mortality impacts of fine particulate matter on immigrants to Canada.

Background: Immigrants make up 20% of the Canadian population; however, little is known about the mortality impacts of fine particulate matter (PM) air pollution on immigrants compared with non-immigrants, or about how impacts may change with duration in Canada.

Data And Methods: This study used the 2001 Canadian Census Health and Environment Cohort, a longitudinal cohort of 3.5 million individuals, of which 764,000 were classified as immigrants (foreign-born).

Cohort profile: The Canadian Census Health and Environment Cohorts (CanCHECs).

The Canadian Census Health and Environment Cohorts (CanCHECs) are population-based linked datasets of the household population at the time of census collection. The CanCHECs combine data from respondents to the long-form census or the National Household Survey between 1991 and 2011 with administrative health data (e.g.

Within-city Spatial Variations in Ambient Ultrafine Particle Concentrations and Incident Brain Tumors in Adults.

Background: Ambient ultrafine particles (UFPs, <0.1 µm) can reach the human brain, but to our knowledge, epidemiologic studies have yet to evaluate the relation between UFPs and incident brain tumors.

Methods: We conducted a cohort study of within-city spatial variations in ambient UFPs across Montreal and Toronto, Canada, among 1.

Evaluating the Sensitivity of PM2.5-Mortality Associations to the Spatial and Temporal Scale of Exposure Assessment.

Background: The temporal and spatial scales of exposure assessment may influence observed associations between fine particulate air pollution (PM2.5) and mortality, but few studies have systematically examined this question.

Methods: We followed 2.

Examining the Shape of the Association between Low Levels of Fine Particulate Matter and Mortality across Three Cycles of the Canadian Census Health and Environment Cohort.

Background: Ambient fine particulate air pollution with aerodynamic diameter () is an important contributor to the global burden of disease. Information on the shape of the concentration-response relationship at low concentrations is critical for estimating this burden, setting air quality standards, and in benefits assessments.

Objectives: We examined the concentration-response relationship between and nonaccidental mortality in three Canadian Census Health and Environment Cohorts (CanCHECs) based on the 1991, 1996, and 2001 census cycles linked to mobility and mortality data.

Low concentrations of fine particle air pollution and mortality in the Canadian Community Health Survey cohort.

Background: Approximately 2.9 million deaths are attributed to ambient fine particle air pollution around the world each year (PM). In general, cohort studies of mortality and outdoor PM concentrations have limited information on individuals exposed to low levels of PM as well as covariates such as smoking behaviours, alcohol consumption, and diet which may confound relationships with mortality.

An examination of the associations between walkable neighbourhoods and obesity and self-rated health in Canadians.

Background: Two-thirds of Canadian adults and one-third of Canadian children and youth are overweight or obese. There is increased interest in identifying features of the built environment-such as walkability-that facilitate lifestyle habits associated with reduced obesity and improved health. The purpose of this study is to examine how the associations between walkability and both obesity and self-rated health vary by age in Canadians using a new walkability dataset.

The association between walkable neighbourhoods and physical activity across the lifespan.

Background: Walkability is positively associated with physical activity in adults. Walkability is more consistently associated with walking for transportation than recreational walking. The purpose of this study is to examine how the association between walkable neighbourhoods and physical activity varies by age and type of physical activity using a new Canadian walkability database.

Evaluation of a method to indirectly adjust for unmeasured covariates in the association between fine particulate matter and mortality.

Background: Indirect adjustment via partitioned regression is a promising technique to control for unmeasured confounding in large epidemiological studies. The method uses a representative ancillary dataset to estimate the association between variables missing in a primary dataset with the complete set of variables of the ancillary dataset to produce an adjusted risk estimate for the variable in question. The objective of this paper is threefold: 1) evaluate the method for non-linear survival models, 2) formalize an empirical process to evaluate the suitability of the required ancillary matching dataset, and 3) test modifications to the method to incorporate time-varying exposure data, and proportional weighting of datasets.

Diabetes Status and Susceptibility to the Effects of PM2.5 Exposure on Cardiovascular Mortality in a National Canadian Cohort.

Background: Diabetes is infrequently coded as the primary cause of death but may contribute to cardiovascular disease (CVD) mortality in response to fine particulate matter (PM2.5) exposure. We analyzed all contributing causes of death to examine susceptibility of diabetics to CVD mortality from long-term exposure.

Evidence for the benefits of food chain interventions on E. coli O157:H7/NM prevalence in retail ground beef and human disease incidence: A success story.

Objectives: Human infection with Escherichia coli O157:H7/NM has historically been associated with consumption of undercooked ground beef. The purpose of this paper is to investigate the correlation of the decline in E. coli O157:H7/NM infections in Canada with the introduction of control efforts in ground beef by industry.