Volatile organic compounds (VOCs) in indoor air and tap water samples in residences of pregnant women living in an area of unconventional natural gas operations: Findings from the EXPERIVA study.

BACKGROUND: Northeastern British Columbia (Canada) is an area of unconventional natural gas (UNG) exploitation by hydraulic fracturing, which can release several contaminants, including volatile organic compounds (VOCs). To evaluate gestational exposure to contaminants in this region, we undertook the Exposures in the Peace River Valley (EXPERIVA) study. OBJECTIVES: We aimed to: 1) measure VOCs in residential indoor air and tap water from EXPERIVA participants; 2) compare concentrations with those in the general population and explore differences related to sociodemographic and housing characteristics; and 3) determine associations between VOC concentrations and density/proximity to UNG wells. METHODS: Eighty-five pregnant women participated. Passive air samplers were analyzed for 47 VOCs, and tap water samples were analyzed for 44 VOCs. VOC concentrations were compared with those from the Canadian Health Measure Survey (CHMS). We assessed the association between different metrics of well density/proximity and indoor air and tap water VOC concentrations using multiple linear regression. RESULTS: 40 VOCs were detected in >50% of air samples, whereas only 4 VOCs were detected in >50% of water samples. We observed indoor air concentrations >95th percentile of CHMS in 10-60% of samples for several compounds (acetone, 2-methyl-2-propanol, chloroform, 1,4-dioxane, hexanal, m/p-xylene, o-xylene, styrene, decamethylcyclopentasiloxane, dodecane and decanal). Indoor air levels of chloroform and tap water levels of total trihalomethanes were higher in Indigenous participants compared to non-Indigenous participants. Indoor air levels of chloroform and acetone, and tap water levels of total trihalomethanes were positively associated with UNG wells density/proximity metrics. Indoor air BTEX (benzene, toluene, ethylbenzene, xylenes) levels were positively correlated with some well density/proximity metrics. CONCLUSION: Our results suggest higher exposure to certain VOCs in pregnant women living in an area of intense unconventional natural gas exploitation compared with the general Canadian population, and that well density/proximity is associated with increased exposure to certain VOCs.

A Population-Based Cohort Study of Respiratory Disease and Long-Term Exposure to Iron and Copper in Fine Particulate Air Pollution and Their Combined Impact on Reactive Oxygen Species Generation in Human Lungs.

Metal components in fine particulate matter (PM2.5) from nontailpipe emissions may play an important role in underlying the adverse respiratory effects of PM2.5. We investigated the associations between long-term exposure to iron (Fe) and copper (Cu) in PM2.5 and their combined impact on reactive oxygen species (ROS) generation in human lungs, and the incidence of asthma, chronic obstructive pulmonary disease (COPD), COPD mortality, pneumonia mortality, and respiratory mortality. We conducted a population-based cohort study of ∼0.8 million adults in Toronto, Canada. Land-use regression models were used to estimate the concentrations of Fe, Cu, and ROS. Outcomes were ascertained using validated health administrative databases. We found positive associations between long-term exposure to Fe, Cu, and ROS and the risks of all five respiratory outcomes. The associations were more robust for COPD, pneumonia mortality, and respiratory mortality than for asthma incidence and COPD mortality. Stronger associations were observed for ROS than for either Fe or Cu. In two-pollutant models, adjustment for nitrogen dioxide somewhat attenuated the associations while adjustment for PM2.5 had little influence. Long-term exposure to Fe and Cu in PM2.5 and estimated ROS concentration in lung fluid was associated with increased incidence of respiratory diseases, suggesting the adverse respiratory effects of nontailpipe emissions.

Long-term exposure to iron and copper in fine particulate air pollution and their combined impact on reactive oxygen species concentration in lung fluid: a population-based cohort study of cardiovascular disease incidence and mortality in Toronto, Canada.

BACKGROUND: Exposure to fine particulate (PM2.5) air pollution is associated with increased cardiovascular disease (CVD), but less is known about its specific components, such as metals originating from non-tailpipe emissions. We investigated the associations of long-term exposure to metal components [iron (Fe) and copper (Cu)] in PM2.5 with CVD incidence. METHODS: We conducted a population-based cohort study in Toronto, Canada. Exposures to Fe and Cu in PM2.5 and their combined impact on the concentration of reactive oxygen species (ROS) in lung fluid were estimated using land use regression models. Incidence of acute myocardial infarction (AMI), congestive heart failure (CHF) and CVD death was ascertained using health administrative datasets. We used mixed-effects Cox regression models to examine the associations between the exposures and health outcomes. A series of sensitivity analyses were conducted, including indirect adjustment for individual-level cardiovascular risk factors (e.g. smoking), and adjustment for PM2.5 and nitrogen dioxide (NO2). RESULTS: In single-pollutant models, we found positive associations between the three exposures and all three outcomes, with the strongest associations detected for the estimated ROS. The associations of AMI and CHF were sensitive to indirect adjustment, but remained robust for CVD death in all sensitivity analyses. In multi-pollutant models, the associations of the three exposures generally remained unaltered. Interestingly, adjustment for ROS did not substantially change the associations between PM2.5 and CVD, but attenuated the associations of NO2. CONCLUSIONS: Long-term exposure to Fe and Cu in PM2.5 and their combined impact on ROS were consistently associated with increased CVD death.

Air Pollution as a Risk Factor for Incident Chronic Obstructive Pulmonary Disease and Asthma. A 15-Year Population-based Cohort Study.

Rationale: Current evidence on the relationship between long-term exposure to air pollution and new onset of chronic lung disease is inconclusive.Objectives: To examine associations of incident chronic obstructive pulmonary disease (COPD) and adult-onset asthma with past exposure to fine particulate matter ≤ 2.5 µm in diameter (PM2.5), nitrogen dioxide (NO2), ozone (O3), and the redox-weighted average of NO2 and O3 (Ox) and characterize the concentration-response relationship.Methods: We conducted a population-based cohort study of all Ontarians, aged 35-85 years, from 2001 to 2015. A 3-year moving average of residential exposures to selected pollutants with a 1-year lag were estimated during follow-up. We used Cox proportional hazard models and Aalen additive-hazard models to quantify the pollution-disease associations and characterized the shape of these relationships using newly developed nonlinear risk models.Measurements and Main Results: Among 5.1 million adults, we identified 340,733 and 218,005 incident cases of COPD and asthma, respectively. We found positive associations of COPD with PM2.5 per interquartile-range (IQR) increase of 3.4 µg/m3 (hazard ratio, 1.07; 95% confidence interval, 1.06-1.08), NO2 per IQR increase of 13.9 ppb (1.04; 1.02-1.05), O3 per IQR increase of 6.3 ppb (1.04; 1.03-1.04), and Ox per IQR increase of 4.4 ppb (1.03; 1.03-1.03). By contrast, we did not find strong evidence linking these pollutants to adult-onset asthma. In addition, we quantified that each IQR increase in pollution exposure yielded 3.0 (2.4-3.6), 3.2 (2.0-4.3), 1.9 (1.3-2.5), and 2.3 (1.7-2.9) excess cases of COPD per 100,000 adults for PM2.5, NO2, O3, and Ox, respectively. Furthermore, most pollutant-COPD relationships exhibited supralinear shapes.Conclusions: Air pollution was associated with a higher incidence of COPD but was not associated with a higher incidence of adult-onset asthma.

Residential Greenness and Cardiovascular Disease Incidence, Readmission, and Mortality.

BACKGROUND: Living in greener areas of cities was linked to increased physical activity levels, improved mental well-being, and lowered harmful environmental exposures, all of which may affect human health. However, whether living in greener areas may be associated with lower risk of cardiovascular disease incidence, progression, and premature mortality is unclear. OBJECTIVES: We conducted a cohort study to examine the associations between residential green spaces and the incidence of acute myocardial infarction (AMI) and heart failure (HF), post-AMI and HF hospital readmissions, and mortality. METHODS: We simultaneously followed four large population-based cohorts in Ontario, Canada, including the entire adult population, adults free of AMI and HF, and survivors of AMI or HF from 2000 to 2014. We estimated residential exposure to green spaces using satellite-derived observations and ascertained health outcomes using validated disease registries. We estimated the associations using spatial random-effects Cox proportional hazards models. We conducted various sensitivity analyses, including further adjusting for property values and performing exploratory mediation analysis. RESULTS: Each interquartile range increase in residential greenness was associated with a 7% [95% confidence interval (CI): 4%, 9%] decrease in incident AMI and a 6% (95% CI: 4%, 7%) decrease in incident HF. Residential greenness was linked to a ∼10% decrease in cardiovascular mortality in both adults free of AMI and HF and the entire adult population. These associations remained consistent in sensitivity analyses and were accentuated among younger adults. Additionally, we estimated that the decreases in AMI and HF incidence associated with residential greenness explained ∼53% of the protective association between residential greenness and cardiovascular mortality. Conversely, residential greenness was not associated with any delay in readmission or mortality among AMI and HF patients. CONCLUSIONS: Living in urban areas with more green spaces was associated with improved cardiovascular health in people free of AMI and HF but not among individuals who have already developed these conditions. https://doi.org/10.1289/EHP6161.

Exposure to Road Traffic Noise and Incidence of Acute Myocardial Infarction and Congestive Heart Failure: A Population-Based Cohort Study in Toronto, Canada.

BACKGROUND: Epidemiological evidence for the association between traffic-related noise and the incidence of major cardiovascular events such as acute myocardial infarction (AMI) and congestive heart failure (CHF) is inconclusive, especially in North America. OBJECTIVES: We evaluated the associations between long-term exposure to road traffic noise and the incidence of AMI and CHF. METHODS: Our study population comprised ∼1 million people 30-100 years of age who lived in Toronto, Canada, from 2001 to 2015 and were free of AMI (referred to as the AMI cohort) or CHF (the CHF cohort) at baseline. Outcomes were ascertained from health administrative databases using validated algorithms. Annual average noise levels were estimated as the A-weighted equivalent sound pressure level over the 24-h period (LAeq24) and during nighttime (LAeqNight), respectively, using propagation modeling, and assigned to participants' annual six-digit postal code addresses during follow-up. We calculated hazard ratios (HRs) and 95% confidence intervals (CIs) for incident AMI and CHF in relation to LAeq24 and LAeqNight using random-effects Cox proportional hazards models adjusting for individual- and census tract-level covariates, including traffic-related air pollutants [e.g., ultrafine particles (UFPs) and nitrogen dioxide]. RESULTS: During follow-up, there were 37,441 AMI incident cases and 95,138 CHF incident cases. Each interquartile range change in LAeq24 was associated with an increased risk of incident AMI (HR=1.07; 95% CI: 1.06, 1.08) and CHF (HR=1.07; 95% CI: 1.06, 1.09). Similarly, LAeqNight was associated with incident AMI (HR=1.07; 95% CI: 1.05, 1.08) and CHF (HR=1.06; 95% CI: 1.05, 1.07). These results were robust to various sensitivity analyses and remained elevated after controlling for long-term exposure to UFPs and nitrogen dioxide. We found near-linear relationships between noise and the incidence of AMI and CHF with no evidence of threshold values. CONCLUSION: In this large cohort study in Toronto, Canada, chronic exposure to road traffic noise was associated with elevated risks for AMI and CHF incidence. https://doi.org/10.1289/EHP5809.

An approach to estimating the environmental burden of cancer from known and probable carcinogens: application to Ontario, Canada.

BACKGROUND: Quantifying the potential cancer cases associated with environmental carcinogen exposure can help inform efforts to improve population health. This study developed an approach to estimate the environmental burden of cancer and applied it to Ontario, Canada. The purpose was to identify environmental carcinogens with the greatest impact on cancer burden to support evidence-based decision making. METHODS: We conducted a probabilistic assessment of the environmental burden of cancer in Ontario. We selected 23 carcinogens that we defined as "environmental" (e.g., pollutants) and were relevant to the province, based on select classifications provided by the International Agency for Research on Cancer. We evaluated population exposure to the carcinogens through inhalation of indoor/outdoor air; ingestion of food, water, and dust; and exposure to radiation. We obtained or calculated concentration-response functions relating carcinogen exposure and the risk of developing cancer. Using both human health risk assessment and population attributable fraction models in a Monte Carlo simulation, we estimated the annual cancer cases associated with each environmental carcinogen, reporting the simulation summary (e.g., mean and percentiles). RESULTS: We estimated between 3540 and 6510 annual cancer cases attributable to exposure to 23 environmental carcinogens in Ontario. Three carcinogens were responsible for over 90% of the environmental burden of cancer: solar ultraviolet (UV) radiation, radon in homes, and fine particulate matter (PM2.5) in outdoor air. Eight other carcinogens had an estimated mean burden of at least 10 annual cancer cases: acrylamide, arsenic, asbestos, chromium, diesel engine exhaust particulate matter, dioxins, formaldehyde, and second-hand smoke. The remaining 12 carcinogens had an estimated mean burden of less than 10 annual cancer cases in Ontario. CONCLUSIONS: We found the environmental burden of cancer in Ontario to fall between previously estimated burdens of alcohol and tobacco use. These results allow for a comparative assessment across carcinogens and offer insights into strategies to reduce the environmental burden of cancer. Our analysis could be adopted by other jurisdictions and repeated in the future for Ontario to track progress in reducing cancer burden, assess newly classified environmental carcinogens, and identify top burden contributors.

Urban green space and the risks of dementia and stroke.

INTRODUCTION: It is unknown whether urban green space is associated with reduced risk of major neurological conditions, especially dementia and stroke. METHODS: Retrospective, population-based cohorts were created for each study outcome, including 1.7 and 4.3 million adults in Ontario, Canada for dementia and stroke, respectively. Residential green space was quantified using the satellite-derived Normalized Difference Vegetation Index. Incidence was ascertained using health administrative data with validated algorithms. Mixed-effects Cox models were used to estimate hazard ratios per interquartile range increase in green space exposure. RESULTS: Between 2001 and 2013, 219,013 individuals were diagnosed with dementia and 89,958 had a stroke. The hazard ratio per interquartile range increase in green space was 0.97 (95% CI: 0.96-0.98) for dementia and 0.96 (0.95-0.98) for stroke. Estimates remained generally consistent in sensitivity analyses. DISCUSSION: Increased exposure to urban green space was associated with reduced incidence of dementia and stroke. To our knowledge, this is the first population-based cohort study to assess these relationships.

Association Between Road Traffic Noise and Incidence of Diabetes Mellitus and Hypertension in Toronto, Canada: A Population-Based Cohort Study.

Background Exposure to road traffic noise has been linked to cardiometabolic complications, such as elevated blood pressure and glucose dysregulation. However, epidemiologic evidence linking road traffic noise to diabetes mellitus and hypertension remains scarce. We examined associations between road traffic noise and the incidence of diabetes mellitus and hypertension in Toronto, Canada. Methods and Results Using the Ontario Population Health and Environment Cohort, we conducted a retrospective, population-based cohort study of long-term residents of Toronto, aged 35 to 100 years, who were registered for provincial publicly funded health insurance, and were without a history of hypertension (n=701 174) or diabetes mellitus (n=914 607). Road traffic noise exposure levels were assessed by the equivalent continuous A-weighted sound pressure level (dBA) for the 24-hour day and the equivalent continuous A-weighted sound pressure level for the night (11 pm-7am). Noise exposures were assigned to subjects according to their annual residential postal codes during the 15-year follow-up. We used random-effect Cox proportional hazards models adjusting for personal and area-level characteristics. From 2001 to 2015, each interquartile range increase in the equivalent continuous A-weighted sound pressure level (dBA) for the 24-hour day (10.0 dBA) was associated with an 8% increase in incident diabetes mellitus (95% CI, 1.07-1.09) and a 2% increase in hypertension (95% CI, 1.01-1.03). We obtained similar estimates with the equivalent continuous A-weighted sound pressure level for the night (11 pm-7am). These results were robust to all sensitivity analyses conducted, including further adjusting for traffic-related air pollutants (ultrafine particles and nitrogen dioxide). For both hypertension and diabetes mellitus, we observed stronger associations with the equivalent continuous A-weighted sound pressure level (dBA) for the 24-hour day among women and younger adults (aged <60 years). Conclusions Long-term exposure to road traffic noise was associated with an increased incidence of diabetes mellitus and hypertension in Toronto.

Estimates of healthcare utilisation and deaths from waterborne pathogen exposure in Ontario, Canada.

Burden of disease analyses can quantify the relative impact of different exposures on population health outcomes. Gastroenteritis where the causative pathogen was not determined and respiratory illness resulting from exposure to opportunistic pathogens transmitted by water aerosols have not always been considered in waterborne burden of disease estimates. We estimated the disease burden attributable to nine enteric pathogens, unspecified pathogens leading to gastroenteritis, and three opportunistic pathogens leading primarily to respiratory illness, in Ontario, Canada (population ~14 million). Employing a burden of disease framework, we attributed a fraction of annual (year 2016) emergency department (ED) visits, hospitalisations and deaths to waterborne transmission. Attributable fractions were developed from the literature and clinical input, and unattributed disease counts were obtained using administrative data. Our Monte Carlo simulation reflected uncertainty in the inputs. The estimated mean annual attributable rates for waterborne diseases were (per 100 000 population): 69 ED visits, 12 hospitalisations and 0.52 deaths. The corresponding 5th-95th percentile estimates were (per 100 000 population): 13-158 ED visits, 5-22 hospitalisations and 0.29-0.83 deaths. The burden of disease due to unspecified pathogens dominated these rates: 99% for ED visits, 63% for hospitalisations and 40% for deaths. However, when a causative pathogen was specified, the majority of hospitalisations (83%) and deaths (97%) resulted from exposure to the opportunistic pathogens Legionella spp., non-tuberculous mycobacteria and Pseudomonas spp. The waterborne disease burden in Ontario indicates the importance of gastroenteritis not traced back to a particular pathogen and of opportunistic pathogens transmitted primarily through contact with water aerosols.

Regional variations in human chemical exposures in Canada: A case study using biomonitoring data from the Canadian Health Measures Survey for the provinces of Quebec and Ontario.

The Canadian Health Measures Survey (CHMS), an ongoing national health survey conducted in two-year cycles, collects extensive biomonitoring data that is used to assess the exposure of Canadians to environmental chemicals of concern. Combining data from multiple cycles of the CHMS allows for the calculation of robust regional estimates of chemical concentrations in blood and urine. The objective of this work was to compare biomarkers of exposure to several environmental chemicals for the provinces of Quebec and Ontario, two major CHMS regions, as well as the entire CHMS (representing Canada) minus Quebec (CMQ), and the entire CHMS minus Ontario (CMO), and to interpret differences between regions. Geometric means and 95th percentiles of blood and/or urinary concentrations of 45 environmental chemicals or their metabolites for Ontario, Quebec, CMQ, and CMO were calculated by combining the two most recent cycles of data available for a chemical (cycles 1 and 2, or cycles 2 and 3) from the first three cycles of the CHMS (2007-2013). Weighted one-way ANOVA was used to test the differences between regional estimates. After applying a Bonferonni-Holm adjustment for multiple comparisons, the following measures were significantly higher in Quebec as compared to Ontario and CMQ: blood lead, urinary lead and the urinary polyaromatic hydrocarbon (PAH) metabolites, 9-hydroxyfluorene, 1-hydroxyphenanthrene, 2- hydroxyphenanthrene and 3-hydroxyphenanthrene. In Quebec compared to CMQ only, urinary 2-hydroxfluorene, 3-hydroxyfluorene, 2-hydroxynaphthalene, and 4-hydroxyphenanthrene were higher. The concentration of urinary fluoride was significantly higher in Ontario as compared to Quebec and CMO. Blood manganese and urinary fluoride were significantly lower in Quebec compared to CMQ, and blood and urinary selenium were significantly lower in Ontario compared to CMO. Regional differences in tobacco use, age of dwellings and drinking water fluoridation are among the possible contributing factors to some of the observed differences. In conclusion, this is the first study where biomonitoring data from multiple cycles of CHMS were combined in order to generate robust estimates for subsets of the Canadian population. Such assessments can contribute to a regional-level prioritization of control measures to reduce the exposure of Canadians to chemicals in their environment.

Exposure to ambient air pollution and the incidence of lung cancer and breast cancer in the Ontario Population Health and Environment Cohort.

Lung and female breast cancers are highly prevalent worldwide. Although the association between exposure to ambient fine particulate matter (PM2.5 ) and lung cancer has been recognized, there is less evidence for associations with other common air pollutants such as nitrogen dioxide (NO2 ) and ozone (O3 ). Even less is known about potential associations between these pollutants and breast cancer. We conducted a population-based cohort study to investigate the associations of chronic exposure to PM2.5 , NO2 , O3 and redox-weighted average of NO2 and O3 (Ox ) with incident lung and breast cancer, using the Ontario Population Health and Environment Cohort (ONPHEC), which includes all long-term residents aged 35-85 years who lived in Ontario, Canada, 2001-2015. Incident lung and breast cancers were ascertained using the Ontario Cancer Registry. Annual estimates of exposures were assigned to the residential postal codes of subjects for each year during follow-up. We used Cox proportional-hazards models adjusting for personal- and neighborhood-level covariates. Our cohorts for lung and breast cancer analyses included ~4.9 million individuals and ~2.5 million women, respectively. During follow-up, 100,146 incident cases of lung cancer and 91,146 incident cases of breast cancer were diagnosed. The fully adjusted analyses showed positive associations of lung cancer incidence with PM2.5 (hazard ratio [HR] = 1.02 [95% CI: 1.01-1.05] per 5.3 µg/m3 ) and NO2 (HR = 1.05 [95% CI: 1.03-1.07] per 14 ppb). No associations with lung cancer were observed for O3 or Ox . Relationships between PM2.5 and NO2 with lung cancer exhibited a sublinear shape. We did not find compelling evidence linking air pollution to breast cancer.

The impact of air pollution on the incidence of diabetes and survival among prevalent diabetes cases.

PURPOSE: Growing evidence implicates ambient air pollutants in the development of major chronic diseases and premature mortality. However, epidemiologic evidence linking air pollution to diabetes remains inconclusive. This study sought to determine the relationships between selected air pollutants (nitrogen dioxide [NO2], fine particulate matter [PM2.5], ozone [O3], and oxidant capacity [Ox; the redox-weighted average of O3 and NO2]) and the incidence of diabetes, as well as the risk of cardiovascular or diabetes mortality among individuals with prevalent diabetes. RESEARCH DESIGN AND METHODS: We followed two cohorts, which included 4.8 million Ontario adults free of diabetes and 452,590 Ontario adults with prevalent diabetes, from 2001 to 2015. Area-level air pollution exposures were assigned to subjects' residential areas, and outcomes were ascertained using health administrative data with validated algorithms. We estimated hazard ratios for the association between each air pollutant and outcome using Cox proportional hazards models, and modelled the shape of the concentration-response relationships. RESULTS: Over the study period, 790,461 individuals were diagnosed with diabetes. Among those with prevalent diabetes, 26,653 died from diabetes and 64,773 died from cardiovascular diseases. For incident diabetes, each IQR increase in NO2 had a hazard ratio of 1.04 (95% CI: 1.03-1.05). This relationship was relatively robust to all sensitivity analyses considered, and exhibited a near-linear shape. There were also positive associations between incident diabetes and PM2.5, O3, and Ox, but these estimates were somewhat sensitive to different models considered. Among those with prevalent diabetes, almost all pollutants were associated with increased diabetes and cardiovascular mortality risk. The strongest association was observed between diabetes mortality and exposure to NO2 (HR = 1.08, 95% CI: 1.02-1.13). CONCLUSIONS: Selected air pollutants, especially NO2, were linked to an increased risk of incident diabetes, as well as risk of cardiovascular or diabetes mortality among persons with prevalent diabetes. As NO2 is frequently used as a proxy for road traffic exposures, this result may indicate that traffic-related air pollution has the strongest effect on diabetes etiology and survival after diabetes development.

Is neighbourhood walkability related to body mass index among different age groups? A cross-sectional study of Canadian urban areas.

BACKGROUND: Studies of neighbourhood walkability and body mass index (BMI) have shown mixed results, possibly due to biases from self-reported outcomes or differential effects across age groups. Our objective was to examine relationships between walkability and objectively measured BMI in various age groups, in a nationally representative population. METHODS: The study population came from the 2007-2011 Canadian Health Measures Survey, a cross-sectional survey of a nationally representative Canadian population. In our covariate-adjusted analyses, we included survey respondents aged 6-79 who were not pregnant, did not live in rural areas, were not missing data and were not thin/underweight. We used objectively measured height and weight to calculate BMI among adults aged 18-79 and zBMI among children aged 6-17. We categorised respondents into walkability quintiles based on their residential Street Smart Walk Score values. We performed linear regression to estimate differences between walkability quintiles in BMI and zBMI. We analysed adults and children overall; age subgroups 6-11, 12-17, 18-29, 30-44, 45-64 and 65-79; and sex subgroups. RESULTS: The covariate-adjusted models included 9265 respondents overall. After adjustment, differences between walkability quintiles in BMI and zBMI were small and not statistically significant, except for males aged 6-17 in the second-highest walkability quintile who had significantly lower zBMIs than those in the lowest quintile. CONCLUSION: After accounting for confounding factors, we did not find evidence of a relationship between walkability and BMI in children or adults overall, or in any age subgroup with sexes combined. However, post hoc analysis by sex suggested males aged 6-17 in more walkable areas may have lower zBMIs.

Ambient Air Pollution and the Risk of Atrial Fibrillation and Stroke: A Population-Based Cohort Study.

BACKGROUND: Although growing evidence links air pollution to stroke incidence, less is known about the effect of air pollution on atrial fibrillation (AF), an important risk factor for stroke. OBJECTIVES: We assessed the associations between air pollution and incidence of AF and stroke. We also sought to characterize the shape of pollutant-disease relationships. METHODS: The population-based cohort comprised 5,071,956 Ontario residents, age 35­85 y and without the diagnoses of both outcomes on 1 April 2001 and was followed up until 31 March 2015. AF and stroke cases were ascertained using health administrative databases with validated algorithms. Based on annual residential postal codes, we assigned 5-y running average concentrations of fine particulate matter ([Formula: see text]), nitrogen dioxide ([Formula: see text]), and ozone ([Formula: see text]) from satellite-derived data, a land-use regression model, and a fusion-based method, respectively, as well as redox-weighted averages of [Formula: see text] and [Formula: see text] ([Formula: see text]) for each year. Using Cox proportional hazards models, we estimated the hazard ratios (HRs) and 95% confidence intervals (95% CIs) of AF and stroke with each of these pollutants, adjusting for individual- and neighborhood-level variables. We used newly developed nonlinear risk models to characterize the shape of pollutant­disease relationships. RESULTS: Between 2001 and 2015, we identified 313,157 incident cases of AF and 122,545 cases of stroke. Interquartile range increments of [Formula: see text], [Formula: see text], [Formula: see text], and [Formula: see text] were associated with increases in the incidence of AF [HRs (95% CIs): 1.03 (1.01, 1.04), 1.02 (1.01, 1.03), 1.01 (1.00, 1.02), and 1.01 (1.01, 1.02), respectively] and the incidence of stroke [HRs (95% CIs): 1.05 (1.03, 1.07), 1.04 (1.01, 1.06), 1.05 (1.03, 1.06), and 1.05 (1.04, 1.06), respectively]. Associations of similar magnitude were found in various sensitivity analyses. Furthermore, we found a near-linear association for stroke with [Formula: see text], whereas [Formula: see text], [Formula: see text]-, and [Formula: see text] relationships exhibited sublinear shapes. CONCLUSIONS: Air pollution was associated with stroke and AF onset, even at very low concentrations. https://doi.org/10.1289/EHP4883.

Exposure to ambient air pollution and the incidence of congestive heart failure and acute myocardial infarction: A population-based study of 5.1 million Canadian adults living in Ontario.

Long-term exposure to ambient air pollution has been linked to cardiovascular mortality, but the associations with incidence of major cardiovascular diseases are not fully understood, especially at low concentrations. We aimed to investigate the associations between exposure to fine particulate matter (PM2.5), nitrogen dioxide (NO2), ozone (O3), redox-weighted average of NO2 and O3 (Ox) and incidence of congestive heart failure (CHF) and acute myocardial infarction (AMI). Our study population included all long-term residents aged 35-85 years who lived in Ontario, Canada, from 2001 to 2015 (~5.1 million). Incidence of CHF and AMI were ascertained from validated registries. We assigned estimates of annual concentrations of pollutants to the residential postal codes of subjects for each year during follow-up. We estimated hazard ratios (HRs) and 95% CIs for each pollutant separately using Cox proportional hazards models. We examined the shape of concentration-response associations using shape-constrained health impact functions. From 2001 to 2015, there were 422,625 and 197,628 incident cases of CHF and AMI, respectively. In the fully adjusted analyses, the HRs of CHF corresponding to each interquartile range increase in exposure were 1.05 (95% CI: 1.04-1.05) for PM2.5, 1.02 (95% CI: 1.01-1.04) for NO2, 1.03 (95% CI: 1.02-1.03) for O3, and 1.02 (95% CI: 1.02-1.03) for Ox, respectively. Similarly, exposure to PM2.5, O3, and Ox were positively associated with AMI. The concentration-response relationships were different for individual pollutant and outcome combinations (e.g., for PM2.5 the relationship was supralinear with CHF, and linear with AMI).

Evidence synthesis - Evaluating risk communication during extreme weather and climate change: a scoping review. / Synthèse des données probantes - Évaluation de la communication des risques en présence de changements climatiques et de phénomènes météorologiques extrêmes : examen de la portée.

INTRODUCTION: Communicating risk to the public continues to be a challenge for public health practitioners working in the area of climate change. We conducted a scoping literature review on the evaluation of risk communication for extreme weather and climate change to inform local public health messaging, consistent with requirements under the Ontario Public Health Standards (OPHS), which were updated in 2018 to include effective communication regarding climate change and extreme weather. METHODS: Search strategies were developed by library information specialists and used to retrieve peer-reviewed academic and grey literature from bibliographic databases (Medline, Embase, Scopus and CINAHL) and Google country specific searches, respectively. The search strategy was validated through a workshop with experts and community stakeholders, with expertise in environment, health, emergency management and risk communication. RESULTS: A total of 43 articles were included. These articles addressed issues such as: climate change (n = 22), flooding (n = 12), hurricane events (n = 5), extreme heat (n = 2), and wild fires (n = 2). Studies were predominantly from the US (n = 14), Europe (n = 6) and Canada (n = 5). CONCLUSION: To meet the OPHS 2018, public health practitioners need to engage in effective risk communication to motivate local actions that mitigate the effects of extreme weather and climate change. Based on the scoping review, risk communication efforts during short-term extreme weather events appear to be more effective than efforts to communicate risk around climate change. This distinction could highlight a unique opportunity for public health to adapt strategies commonly used for extreme weather to climate change.

A systematic review of the health impacts of occupational exposure to wildland fires.

The aim of the paper is to summarize the evidence of health impacts of occupational exposure to wildland fires. The authors searched 3 databases for relevant articles and screened the results. After full-text review, articles were included based on pre-determined criteria. The authors identified 32 relevant articles. Occupational exposure to wildland fires affects lung function in the short term and may increase the risk of hypertension in the long term. Exposure to wildland fires is also associated with post-traumatic stress symptoms. There was insufficient evidence to comment on most longer-term risks, and in particular on respiratory disease or cancer risks. Further research is required to understand whether occupational exposure to wildland fires results in clinically significant impacts on respiratory function, and to further clarify the relationship between occupational exposure and blood pressure, mental health, and cancer outcomes. Int J Occup Med Environ Health. 2019;32(2):121-40.

Screening for hand dermatitis in healthcare workers: Comparing workplace screening with dermatologist photo screening.

BACKGROUND: Healthcare workers are at increased risk for occupational contact dermatitis, owing to wet work exposure. Early detection and management improves outcomes. Although several diagnostic tools are available, none is appropriate for rapid screening. OBJECTIVES: To assess the validity and feasibility of the Hand Dermatitis Screening Tool in the acute healthcare sector. METHODS: Screening of 508 employees at three hospitals in Ontario, Canada was performed with the Hand Dermatitis Screening Tool either by an occupational health nurse (N = 225) or by self-administration (N = 283). Two occupational dermatologists rated photographs of participants' hands. RESULTS: Of the participants, 30.5% screened positive for hand dermatitis. A positive screen was associated with wet work, history of eczema, dermatitis, or other rash, and currently having a rash. Ninety-four per cent of participants reported that using the tool took <2 minutes, 99% indicated that the tool was easy to use, and 86% stated that workplace screening was very important. Workplace and dermatologist photo screening showed fair agreement. CONCLUSIONS: The prevalence of hand dermatitis and identified risk factors were consistent with the literature. These findings, along with positive feasibility results, support further testing of the tool despite only fair agreement between workplace and dermatologist screening.

Time Trends of the Incidence, Prevalence, and Mortality of Parkinsonism.

OBJECTIVES: We assessed trends in the incidence, prevalence, and post-diagnosis mortality of parkinsonism in Ontario, Canada over 18 years. We also explored the influence of a range of risk factors for brain health on the trend of incident parkinsonism. METHODS: We established an open cohort by linking population-based health administrative databases from 1996 to 2014 in Ontario. The study population comprised residents aged 20-100 years with an incident diagnosis of parkinsonism ascertained using a validated algorithm. We calculated age- and sex-standardized incidence, prevalence, and mortality of parkinsonism, stratified by young onset (20-39 years) and mid/late onset (≥40 years). We assessed trends in incidence using Poisson regression, mortality using negative binomial regression, and prevalence of parkinsonism and pre-existing conditions (e.g., head injury) using the Cochran-Armitage trend test. To better understand trends in the incidence of mid/late-onset parkinsonism, we adjusted for various pre-existing conditions in the Poisson regression model. RESULTS: From 1996 to 2014, we identified 73,129 incident cases of parkinsonism (source population of ∼10.5 million), of whom 56% were male, mean age at diagnosis was 72.6 years, and 99% had mid/late-onset parkinsonism. Over 18 years, the age- and sex-standardized incidence decreased by 13.0% for mid/late-onset parkinsonism but remained unchanged for young-onset parkinsonism. The age- and sex-standardized prevalence increased by 22.8%, while post-diagnosis mortality decreased by 5.5%. Adjustment for pre-existing conditions did not appreciably explain the declining incidence of mid/late-onset parkinsonism. CONCLUSION: Young-onset and mid/late-onset parkinsonism exhibited differing trends in incidence over 18 years in Ontario. Further research to identify other factors that may appreciably explain trends in incident parkinsonism is warranted.