October 16 | 2017

Urban greenness and mortality in Canada’s largest cities: a national cohort study

Dan L Crouse, Lauren Pinault, Adele Balram, Perry Hystad, Paul A Peters, Hong Chen, Aaron van Donkelaar, Randall V Martin, Richard Ménard, Alain Robichaud, Paul J Villeneuve

The Lancet Planetary Health Volume 1, Issue 7, October 2017, Pages e289-e29  DOI: http://dx.doi.org/10.1016/S2542-5196(17)30118-3



Findings from published studies suggest that exposure to and interactions with green spaces are associated with improved psychological wellbeing and have cognitive, physiological, and social benefits, but few studies have examined their potential effect on the risk of mortality. We therefore undertook a national study in Canada to examine associations between urban greenness and cause-specific mortality.


We used data from a large cohort study (the 2001 Canadian Census Health and Environment Cohort [2001 CanCHEC]), which consisted of approximately 1·3 million adult (aged ≥19 years), non-immigrant, urban Canadians in 30 cities who responded to the mandatory 2001 Statistics Canada long-form census. The cohort has been linked by Statistics Canada to the Canadian mortality database and to annual income tax filings through 2011. We measured greenness with images from the moderate-resolution imaging spectroradiometer from NASA’s Aqua satellite. We assigned estimates of exposure to greenness derived from remotely sensed Normalized Difference Vegetation Index (NDVI) within both 250 m and 500 m of participants’ residences for each year during 11 years of follow-up (between 2001 and 2011). We used Cox proportional hazards models to estimate associations between residential greenness (as a continuous variable) and mortality. We estimated hazard ratios (HRs) and corresponding 95% CIs per IQR (0·15) increase in NDVI adjusted for personal (eg, education and income) and contextual covariates, including exposures to fine particulate matter, ozone, and nitrogen dioxide. We also considered effect modification by selected personal covariates (age, sex, household income adequacy quintiles, highest level of education, and marital status).


Our cohort consisted of approximately 1 265 000 individuals at baseline who contributed 11 523 770 person-years. We showed significant decreased risks of mortality in the range of 8–12% from all causes of death examined with increased greenness around participants’ residence. In the fully adjusted analyses, the risk was significantly decreased for all causes of death (non-accidental HR 0·915, 95% CI 0·905–0·924; cardiovascular plus diabetes 0·911, 0·895–0·928; cardiovascular 0·911, 0·894–0·928; ischaemic heart disease 0·904, 0·882–0·927; cerebrovascular 0·942, 0·902–0·983; and respiratory 0·899, 0·869–0·930). Greenness associations were more protective among men than women (HR 0·880, 95% CI 0·868–0·893 vs 0·955, 0·941–0·969), and among individuals with higher incomes (highest quintile 0·812, 0·791–0·834 vs lowest quintile 0·991, 0·972–1·011) and more education (degree or more 0·816, 0·791–0·842 vs did not complete high school 0·964, 0·950–0·978).


Increased amounts of residential greenness were associated with reduced risks of dying from several common causes of death among urban Canadians. We identified evidence of inequalities, both in terms of exposures to greenness and mortality risks, by personal socioeconomic status among individuals living in generally similar environments, and with reasonably similar access to health care and other social services. The findings support the development of policies related to creating greener and healthier cities.

October 10 | 2017

BlueHealth: a study programme protocol for mapping and quantifying the potential benefits to public health and well-being from Europe’s blue spaces.

Grellier J, White MP, Albin M, Bell S, Elliott LR, Gascón M, Gualdi S, Mancini L, Nieuwenhuijsen MJ, Sarigiannis DA, van den Bosch M, Wolf T, Wuijts S, Fleming LE.

BMJ Open. 2017 Jun 14;7(6)   http://dx.doi.org/10.1136/bmjopen-2017-016188




Proximity and access to water have long been central to human culture and accordingly deliver countless societal benefits. Over 200 million people live on Europe’s coastline, and aquatic environments are the top recreational destination in the region. In terms of public health, interactions with ‘blue space’ (eg, coasts, rivers, lakes) are often considered solely in terms of risk (eg, drowning, microbial pollution). Exposure to blue space can, however, promote health and well-being and prevent disease, although underlying mechanisms are poorly understood.


The BlueHealth project aims to understand the relationships between exposure to blue space and health and well-being, to map and quantify the public health impacts of changes to both natural blue spaces and associated urban infrastructure in Europe, and to provide evidence-based information to policymakers on how to maximise health benefits associated with interventions in and around aquatic environments. To achieve these aims, an evidence base will be created through systematic reviews, analyses of secondary data sets and analyses of new data collected through a bespoke international survey and a wide range of community-level interventions. We will also explore how to deliver the benefits associated with blue spaces to those without direct access through the use of virtual reality. Scenarios will be developed that allow the evaluation of health impacts in plausible future societal contexts and changing environments. BlueHealth will develop key inputs into policymaking and land/water-use planning towards more salutogenic and sustainable uses of blue space, particularly in urban areas.


Throughout the BlueHealth project, ethics review and approval are obtained for all relevant aspects of the study by the local ethics committees prior to any work being initiated and an ethics expert has been appointed to the project advisory board. So far, ethical approval has been obtained for the BlueHealth International Survey and for community-level interventions taking place in Spain, Italy and the UK. Engagement of stakeholders, including the public, involves citizens in many aspects of the project. Results of all individual studies within the BlueHealth project will be published with open access. After full anonymisation and application of any measures necessary to prevent disclosure, data generated in the project will be deposited into open data repositories of the partner institutions, in line with a formal data management plan. Other knowledge and tools developed in the project will be made available via the project website (www.bluehealth2020.eu). Project results will ultimately provide key inputs to planning and policy relating to blue space, further stimulating the integration of environmental and health considerations into decision-making, such that blue infrastructure is developed across Europe with both public health and the environment in mind.

October 2 | 2017

Association of Long-Term Exposure to Transportation Noise and Traffic-Related Air Pollution with the Incidence of Diabetes: A Prospective Cohort Study.

Clark C, Sbihi H, Tamburic L2, Brauer M, Frank LD, Davies HW.

Environ Health Perspect. 2017 Aug 31;125(8):087025.  https://doi.org/10.1289/EHP1279



Evidence for an association between transportation noise and cardiovascular disease has increased; however, few studies have examined metabolic outcomes such as diabetes or accounted for environmental coexposures such as air pollution, greenness, or walkability.


Because diabetes prevalence is increasing and may be on the causal pathway between noise and cardiovascular disease, we examined the influence of long-term residential transportation noise exposure and traffic-related air pollution on the incidence of diabetes using a population-based cohort in British Columbia, Canada.


We examined the influence of transportation noise exposure over a 5-y period (1994-1998) on incident diabetes cases in a population-based prospective cohort study (n=380,738) of metropolitan Vancouver (BC) residents who were 45-85 y old, with 4-y of follow-up (1999-2002). Annual average transportation noise (Lden), air pollution [black carbon, particulate matter with aerodynamic diameter <2.5μm (PM2.5), nitrogen oxides], greenness [Normalized Difference Vegetation Index (NDVI)], and neighborhood walkability at each participant’s residence were modeled. Incident diabetes cases were identified using administrative health records.


Transportation noise was associated with the incidence of diabetes [interquartile range (IQR) increase, 6.8 A-weighted decibels (dBA); OR=1.08 (95% CI: 1.05, 1.10)]. This association remained after adjustment for environmental coexposures including traffic-related air pollutants, greenness, and neighborhood walkability. After adjustment for coexposure to noise, traffic-related air pollutants were not associated with the incidence of diabetes, whereas greenness was protective.


We found a positive association between residential transportation noise and diabetes, adding to the growing body of evidence that noise pollution exposure may be independently linked to metabolic health and should be considered when developing public health interventions.

Does Living in Greener Areas and Near Water Affect Mortality? | VIDEO NOW AVAILABLE


October 10, 2017

9am – 10am pacific | 12 noon – 1pm eastern

Hear the latest results based on an analysis of the Canadian Census Health and Environment Cohort, from Dr. Dan Crouse and Adele Balram, University of New Brunswick.


Dan L Crouse is a Research Associate in the Department of Sociology at UNB. He is trained in both epidemiology and geography, and has led and been involved in many studies examining the impacts of exposure to air pollution on adverse health outcomes, including risk of mortality, adverse birth outcomes, and incidence of cancer. He lead the first Canadian Census Health and Environment Cohort (CanCHEC) study to examine associations between mortality and long-term exposures to fine particulate matter, which was published in 2012, and has published several other studies with CanCHEC since then.

Adele Balram is a Database Analyst with the New Brunswick Institute for Research, Data, and Training. She holds a Bachelor of Science degree in Biology from the University of New Brunswick and a Master of Public Health from Memorial University in Newfoundland. Adele has several years’ experience in public health, including working as an epidemiologist on environmental and community health issues across New Brunswick.

Both Dr. Crouse and Ms. Balram are supported by the Maritime SPOR Support Unit (MSSU), which receives financial support from the Canadian Institutes of Health Research (CIHR), the Nova Scotia Department of Health and Wellness, the New Brunswick Department of Health, the Nova Scotia Health Research Foundation (NSHRF), and the New Brunswick Health Research Foundation (NBHRF).

Lead author and CANUE Director Dan Crouse talks about his recent paper on Radio Canada. http://www.rcinet.ca/en/2017/10/13/new-canadian-study-suggests-that-trees-can-play-a-part-in-a-longer-life/

September 25 | 2017

Exposure to ambient air pollution and the incidence of dementia: A population-based cohort study.

Chen H, Kwong JC, Copes R, Hystad P, van Donkelaar A, Tu K, Brook JR, Goldberg MS, Martin RV, Murray BJ, Wilton AS, Kopp A, Burnett RT.

Environ Int. 2017 Sep 13; 108: 271-277. https://doi.org/10.1016/j.envint.2017.08.020



Emerging studies have implicated air pollution in the neurodegenerative processes. Less is known about the influence of air pollution, especially at the relatively low levels, on developing dementia. We conducted a population-based cohort study in Ontario, Canada, where the concentrations of pollutants are among the lowest in the world, to assess whether air pollution exposure is associated with incident dementia.


The study population comprised all Ontario residents who, on 1 April 2001, were 55-85years old, Canadian-born, and free of physician-diagnosed dementia (~2.1 million individuals). Follow-up extended until 2013. We used population-based health administrative databases with a validated algorithm to ascertain incident diagnosis of dementia as well as prevalent cases. Using satellite observations, land-use regression model, and an optimal interpolation method, we derived long-term average exposure to fine particulate matter (≤2.5μm in diameter) (PM2.5), nitrogen dioxide (NO2), and ozone (O3), respectively at the subjects’ historical residences based on a population-based registry. We used multilevel spatial random-effects Cox proportional hazards models, adjusting for individual and contextual factors, such as diabetes, brain injury, and neighborhood income. We conducted various sensitivity analyses, such as lagging exposure up to 10years and considering a negative control outcome for which no (or weaker) association with air pollution is expected.


We identified 257,816 incident cases of dementia in 2001-2013. We found a positive association between PM2.5 and dementia incidence, with a hazard ratio (HR) of 1.04 (95% confidence interval (CI): 1.03-1.05) for every interquartile-range increase in exposure to PM2.5. Similarly, NO2 was associated with increased incidence of dementia (HR=1.10; 95% CI: 1.08-1.12). No association was found for O3. These associations were robust to all sensitivity analyses examined. These estimates translate to 6.1% of dementia cases (or 15,813 cases) attributable to PM2.5 and NO2, based on the observed distribution of exposure relative to the lowest quartile in concentrations in this cohort.


In this large cohort, exposure to air pollution, even at the relative low levels, was associated with higher dementia incidence.

September 18 | 2017

Estimated Changes in Life Expectancy and Adult Mortality Resulting from Declining PM2.5 Exposures in the Contiguous United States: 1980–2010

Neal Fann, Sun-Young Kim, Casey Olives, and Lianne Sheppard.

Environ Health Perspect. 2017; Vol 125, Issue 9.  https://doi.org/10.1289/EHP507


Background: PM2.5 precursor emissions have declined over the course of several decades, following the implementation of local, state, and federal air quality policies. Estimating the corresponding change in population exposure and PM2.5-attributable risk of death prior to the year 2000 is made difficult by the lack of PM2.5 monitoring data.

Objectives: We used a new technique to estimate historical PM2.5 concentrations, and estimated the effects of changes in PM2.5 population exposures on mortality in adults (age ≥30 y), and on life expectancy at birth, in the contiguous United States during 1980–2010.

Methods: We estimated annual mean county-level PM2.5 concentrations in 1980, 1990, 2000, and 2010 using universal kriging incorporating geographic variables. County-level death rates and national life tables for each year were obtained from the U.S. Census and Centers for Disease Control and Prevention. We used log-linear and nonlinear concentration–response coefficients from previous studies to estimate changes in the numbers of deaths and in life years and life expectancy at birth, attributable to changes in PM2.5.

Results: Between 1980 and 2010, population-weighted PM2.5 exposures fell by about half, and the estimated number of excess deaths declined by about a third. The States of California, Virginia, New Jersey, and Georgia had some of the largest estimated reductions in PM2.5-attributable deaths. Relative to a counterfactual population with exposures held constant at 1980 levels, we estimated that people born in 2050 would experience an ∼1-y increase in life expectancy at birth, and that there would be a cumulative gain of 4.4 million life years among adults ≥30 y of age.

Conclusions: Our estimates suggest that declines in PM2.5 exposures between 1980 and 2010 have benefitted public health.

September 11 | 2017

Beyond the Normalized Difference Vegetation Index (NDVI): Developing a Natural Space Index for population-level health research.

Rugel EJ, Henderson SB, Carpiano RM, Brauer M.

Environ Res. 2017 Aug 29; 159:474-483. doi:  10.1016/j.envres.2017.08.033



Natural spaces can provide psychological benefits to individuals, but population-level epidemiologic studies have produced conflicting results. Refining current exposure-assessment methods is necessary to advance our understanding of population health and to guide the design of health-promoting urban forms.


The aim of this study was to develop a comprehensive Natural Space Index that robustly models potential exposure based on the presence, form, accessibility, and quality of multiple forms of greenspace (e.g., parks and street trees) and bluespace (e.g., oceans and lakes).


The index was developed for greater Vancouver, Canada. Greenness presence was derived from remote sensing (NDVI/EVI); forms were extracted from municipal and private databases; and accessibility was based on restrictions such as private ownership. Quality appraisals were conducted for 200 randomly sampled parks using the Public Open Space Desktop Appraisal Tool (POSDAT). Integrating these measures in GIS, exposure was assessed for 60,242 postal codes using 100- to 1,600-m buffers based on hypothesized pathways to mental health. A single index was then derived using principal component analysis (PCA).


Comparing NDVI with alternate approaches for assessing natural space resulted in widely divergent results, with quintile rankings shifting for 22-88% of postal codes, depending on the measure. Overall park quality was fairly low (mean of 15 on a scale of 0-45), with no significant difference seen by neighborhood-level household income. The final PCA identified three main sets of variables, with the first two components explaining 68% of the total variance. The first component was dominated by the percentages of public and private greenspace and bluespace and public greenspace within 250m, while the second component was driven by lack of access to bluespace within 1 km.


Many current approaches to modeling natural space may misclassify exposures and have limited specificity. The Natural Space Index represents a novel approach at a regional scale with application to urban planning and policy-making.

September 5 | 2017

Associations of Pregnancy Outcomes and PM2.5 in a National Canadian Study

Stieb DM, Chen L, Beckerman BS, Jerrett M, Crouse DL, Omariba DW, Peters PA, van Donkelaar A, Martin RV, Burnett RT, Gilbert NL, Tjepkema M, Liu S, Dugandzic  RM.

Environ Health Perspect. 2016 Feb;124(2):243-9. doi:  10.1289/ehp.1408995



Numerous studies have examined associations between air pollution and pregnancy outcomes, but most have been restricted to urban populations living near monitors.


We examined the association between pregnancy outcomes and fine particulate matter in a large national study including urban and rural areas.


Analyses were based on approximately 3 million singleton live births in Canada between 1999 and 2008. Exposures to PM2.5(particles of median aerodynamic diameter ≤ 2.5 μm) were assigned by mapping the mother’s postal code to a monthly surface based on a national land use regression model that incorporated observations from fixed-site monitoring stations and satellite-derived estimates of PM2.5. Generalized estimating equations were used to examine the association between PM2.5 and preterm birth (gestational age < 37 weeks), term low birth weight (< 2,500 g), small for gestational age (SGA; < 10th percentile of birth weight for gestational age), and term birth weight, adjusting for individual covariates and neighborhood socioeconomic status (SES).


In fully adjusted models, a 10-μg/m3 increase in PM2.5 over the entire pregnancy was associated with SGA (odds ratio = 1.04; 95% CI 1.01, 1.07) and reduced term birth weight (–20.5 g; 95% CI –24.7, –16.4). Associations varied across subgroups based on maternal place of birth and period (1999–2003 vs. 2004–2008).


This study, based on approximately 3 million births across Canada and employing PM2.5 estimates from a national spatiotemporal model, provides further evidence linking PM2.5 and pregnancy outcomes.

Navigating the Data Merge | September 20 | 26 | 28 |2017 | PRESENTATION NOW AVAILABLE

9am – 10:30am pacific | 12 noon – 1:30pm eastern


Do you manage a cohort, health survey, or administrative health database? Please join us for an overview of our upcoming urban environmental exposure data release, and a discussion of logistics for receiving and merging our data with yours.

We will be giving the same overview on September 20th, 26th and 28th to accommodate as many of you as possible. Just choose the most convenient date!

Read the recently completed CANUE Health Data Holder Survey, identifying opportunities and issues for data merging.


Introduction of CANUE team

Overview of data sets
themes (air pollution, greenness,etc.)
conditions for use

Data delivery and merging
planned delivery dates
push and pull model
ad hoc requests

CANUE tool development
unique exposure combinations tool
temporal aggregation tool
spatial aggregation tool

Q/A and discussion

New Opportunities for Weather and Health Research | September 21 | 2017 | VIDEOS NOW AVAILABLE


Environment Canada is currently working on the 2.5 km High Resolution Deterministic Prediction system (HRDPS), expected to become operational next year.

This webinar-style meeting will highlight some of the health databases that CANUE researchers typically use, and provide an overview of these new weather/climate datasets. The overall objective of the meeting is to explore the utility of HRDPS data sets for conducting health research, and identify which health databases might be of most interest, as a first step in working together to advance our research agendas.


Presentation: CANUE

Overview of cohorts/health databases and opportunities for weather/climate research

Presentation: Environment Canada

HRDPS model/outputs, reanalysis opportunities


Priorities for data development/linkage