May 4 | 2020

Health impact assessment of Philadelphia’s 2025 tree canopy cover goals.


Kondo MC, Mueller N, Locke DH, Roman LA, Rojas-Rueda D, Schinasi LH, Gascon M, Nieuwenhuijsen MJ.


Lancet Planet Health. 2020 Apr;4(4):e149-e157. doi: 10.1016/S2542-5196(20)30058-9




Cities across the world are undertaking ambitious projects to expand tree canopy by increasing the number of trees planted throughout public and private spaces. In epidemiological studies, greenspaces in urban environments have been associated with physical and mental health benefits for city dwellers. Greenworks Philadelphia is a plan to increase tree cover across Philadelphia (PA, USA) by the year 2025. We aimed to assess whether an increase in tree canopy or greenspace in Philadelphia could decrease mortality.


We did a greenspace health impact assessment to estimate the annual premature mortality burden for adult residents associated with projected changes in tree canopy cover in Philadelphia between 2014 and 2025. Using up-to-date exposure-response functions, we calculated the number of preventable annual premature deaths city-wide, and for areas of lower versus higher socioeconomic status, for each of three tree canopy scenarios: low, moderate and ambitious. The ambitious scenario reflected the city’s goal of 30% tree canopy cover in each of the city’s neighbourhoods; and low and moderate scenarios were based on the varying levels of plantable space across neighbourhoods.


We estimated that 403 (95% interval 298-618) premature deaths overall, including 244 (180-373) premature deaths in areas of lower socioeconomic status, could be prevented annually in Philadelphia if the city were able to meet its goal of increasing tree canopy cover to 30%.


Bringing all of Philadelphia, and particularly its poorer neighbourhoods, up to the 30% goal of tree canopy cover is not without challenge. Nevertheless, policies are warranted that value urban greening efforts as health-promoting and cost-saving measures.

April 14 | 2020

Quiet, clean, green, and active: A Navigation Guide systematic review of the impacts of spatially correlated urban exposures on a range of physical health outcomes.

Rugel EJ, Brauer M.

Environ Res. 2020 Mar 19;185:109388. [Epub ahead of print]





Recent epidemiologic analyses have considered impacts of multiple spatially correlated urban exposures, but this literature has not been systematically evaluated.


To characterize the long-term impacts of four distinct spatially correlated urban environmental exposures – traffic-related air pollution (TRAP), noise, natural spaces, and neighborhood walkability – by evaluating studies including measures of at least two such exposures in relationship to mortality, cardiovascular disease, chronic respiratory disease, allergy, type 2 diabetes, or reproductive outcomes.


Following the Navigation Guide framework, the literature was searched for studies published since 2003 and meeting predefined inclusion criteria. Identified studies were scored individually for risk of bias and all studies related to an exposure-group set were appraised for overall quality and strength of evidence.


A total of 51 individual studies (TRAP and noise: n = 29; TRAP and natural spaces: n = 10; noise and natural spaces: n = 2; TRAP, noise, and natural spaces: n = 7; TRAP, noise, natural spaces, and walkability: n = 3) were included. When TRAP and noise were considered jointly, evidence was sufficient for increased cardiovascular morbidity with higher noise exposures; sufficient for no effect of TRAP on CVD morbidity; sufficient for increased mortality with higher TRAP exposures, but limited for noise; and limited for increased adverse reproductive outcomes with higher TRAP exposures and no effect of noise. Looking at natural spaces and TRAP, there was limited evidence for lower risk of chronic respiratory disease and small increases in birthweight with greater natural space; this relationship with birthweight persisted after adjustment for noise as well. Evidence was inadequate for all other exposure groups and outcomes.


Studies that properly account for the complexity of relationships between urban form and physical health are limited but suggest that even highly correlated exposures may have distinct effects.

April 6 | 2020

Traffic-Related Air Pollution and Carotid Plaque Burden in a Canadian City With Low-Level Ambient Pollution.

Johnson M, Brook JR, Brook RD, Oiamo TH, Luginaah I, Peters PA, Spence JD.

J Am Heart Assoc. 2020 Apr 7;9(7):e013400. Epub 2020 Apr 2. DOI 10.1161/JAHA.119.013400




The association between fine particulate matter and cardiovascular disease has been convincingly demonstrated. The role of traffic-related air pollutants is less clear. To better understand the role of traffic-related air pollutants in cardiovascular disease development, we examined associations between NO2, carotid atherosclerotic plaque, and cardiometabolic disorders associated with cardiovascular disease.

Methods and Results:

Cross-sectional analyses were conducted among 2227 patients (62.9±13.8 years; 49.5% women) from the Stroke Prevention and Atherosclerosis Research Centre (SPARC) in London, Ontario, Canada. Total carotid plaque area measured by ultrasound, cardiometabolic disorders, and residential locations were provided by SPARC medical records. Long-term outdoor residential NO2 concentrations were generated by a land use regression model. Associations between NO2, total carotid plaque area, and cardiometabolic disorders were examined using multiple regression models adjusted for age, sex, smoking, and socioeconomic status. Mean NO2 was 5.4±1.6 ppb in London, Ontario. NO2 was associated with a significant increase in plaque (3.4 mm2 total carotid plaque area per 1 ppb NO2), exhibiting a linear dose-response. NO2 was also positively associated with triglycerides, total cholesterol, and the ratio of low- to high-density lipoprotein cholesterol (P<0.05). Diabetes mellitus mediated the relationship between NO2 and total carotid plaque area (P<0.05).


Our results demonstrate that even low levels of traffic-related air pollutants are linked to atherosclerotic plaque burden, an association that may be partially attributable to pollution-induced diabetes mellitus. Our findings suggest that reducing ambient concentrations in cities with NO2 below current standards would result in additional health benefits. Given the billions of people exposed to traffic emissions, our study supports the global public health significance of reducing air pollution.

March 30 | 2020

Air pollution and stunting: a missing link?

Sheela S Sinharoy, Thomas Clasen, Reynaldo Martorell.


The Lancet Global Health Comment Volume 8, Issue 4, April 2020, Pages e472-e475


Child linear growth impairment, particularly stunting, remains a global health challenge. Stunting is defined as a height-for-age Z-score more than two SDs below the WHO child growth standards reference median for age and sex. The number of children younger than 5 years who are stunted was 59 million (34%) in south Asia and 58 million (33%) in sub-Saharan Africa in 2018.1 Stunting is associated with poor child development, lower productivity and earnings in adulthood, and increased risk of chronic diseases later in life.2, 3 In this Comment, we argue that air pollution has been largely ignored as a potentially important cause of stunting, we outline a conceptual framework for how air pollution might lead to impaired linear growth in children, and we call for additional research into these mechanisms.

March 23 | 2020

Projected local rain events due to climate change and the impacts on waterborne diseases in Vancouver, British Columbia, Canada.

Bimal K. Chhetri, Eleni Galanis, Stephen Sobie, Jordan Brubacher, Robert Balshaw, Michael Otterstatter, Sunny Mak, Marcus Lem, Mark Lysyshyn, Trevor Murdock, Manon Fleury, Kirsten Zickfeld, Mark Zubel, Len Clarkson, Tim K. Takaro

Environmental Health volume 18, Article number: 116 (2019)




Climate change is increasing the number and intensity of extreme weather events in many parts of the world. Precipitation extremes have been linked to both outbreaks and sporadic cases of waterborne illness. We have previously shown a link between heavy rain and turbidity to population-level risk of sporadic cryptosporidiosis and giardiasis in a major Canadian urban population. The risk increased with 30 or more dry days in the 60 days preceding the week of extreme rain. The goal of this study was to investigate the change in cryptosporidiosis and giardiasis risk due to climate change, primarily change in extreme precipitation.


Cases of cryptosporidiosis and giardiasis were extracted from a reportable disease system (1997–2009). We used distributed lag non-linear Poisson regression models and projections of the exposure-outcome relationship to estimate future illness (2020–2099). The climate projections are derived from twelve statistically downscaled regional climate models. Relative Concentration Pathway 8.5 was used to project precipitation derived from daily gridded weather observation data (~ 6 × 10 km resolution) covering the central of three adjacent watersheds serving metropolitan Vancouver for the 2020s, 2040s, 2060s and 2080s.


Precipitation is predicted to steadily increase in these watersheds during the wet season (Oct. -Mar.) and decrease in other parts of the year up through the 2080s. More weeks with extreme rain (>90th percentile) are expected. These weeks are predicted to increase the annual rates of cryptosporidiosis and giardiasis by approximately 16% by the 2080s corresponding to an increase of 55–136 additional cases per year depending upon the climate model used. The predicted increase in the number of waterborne illness cases are during the wet months. The range in future projections compared to historical monthly case counts typically differed by 10–20% across climate models but the direction of change was consistent for all models.


If new water filtration measures had not been implemented in our study area in 2010–2015, the risk of cryptosporidiosis and giardiasis would have been expected to increase with climate change, particularly precipitation changes. In addition to the predicted increase in the frequency and intensity of extreme precipitation events, the frequency and length of wet and dry spells could also affect the risk of waterborne diseases as we observed in the historical period. These findings add to the growing evidence regarding the need to prepare water systems to manage and become resilient to climate change-related health risks.

Linked CANUE and administrative health databases: PopDataBC, MCHP and NB_IRDT | March 27th | 2020

Linked CANUE and administrative health databases: PopDataBC and MCHP

March 27th (9 am pacific | 12 noon eastern)




Linkage of CANUE exposure data with provincially managed administrative health databases offers new and exciting opportunities for environmental health research. To date, CANUE data has been linked to data held by Population Data BC (PopData), Manitoba Centre for Health Policy (MCHP), and the New Brunswick Institute for Research, Data and Training (NB-IRDT).


Kelly Sanderson is the Lead of Business and Initiatives Development at Population Data BC. She works closely with BC government and BC SUPPORT Unit partners on joint data initiatives funded by the Strategy for Patient-Oriented Research (SPOR). She joined the organization in 2009 and was previously the Data Access Unit Lead where she enjoyed working with and guiding many researchers through the Data Access Request process. Her educational background and related professional experience was in Urban Planning and Geographical Information systems so she readily appreciates the value CANUE data brings as a new PopData holding.

Charles Burchill has been an Associate Director at the Manitoba Centre for Health Policy, University of Manitoba, since 2006.  Prior to this role, he worked as a research analyst at MCHP starting in 1992.  He is actively involved with Health and Social policy-related research using Manitoba administrative health and social data.  The repository of data represents over 80 distinct programs and databases with linkable data in the areas of health, family services, justice, and education.  His graduate work was in field ecology, with the CANUE data providing an opportunity to bring his interests full circle. The CANUE data represents an important source of built environment and environmental data that can be linked through small area geographies to the overall repository.

Dr. Ted McDonald is a Professor of Economics at the University of New Brunswick in Fredericton, Academic Director of the NB Research Data Centre, Director of the NB Institute for Research, Data and Training and the New Brunswick lead for the Maritime SPOR SUPPORT Unit. He holds a Ph.D. and a Master of Commerce in Economics from the University of Melbourne. Dr. McDonald’s main areas of research include health status and labour market issues of immigrants, rural residents, minority groups and other subpopulations, as well as an ongoing program of research on the socioeconomic and demographic determinants of cancer.

Dany Doiron is a research associate in the Respiratory Epidemiology and Clinical Research Unit at the Research Institute of the McGill University Health Centre (RI-MUHC) and is CANUE’s data linkage lead. Dany holds a Masters degree in Public Policy (Simon Fraser University) and PhD in Epidemiology (University of Basel). His research explores the effects of environmental exposures on health.


March 8 | 2020

Ambient air pollution and incidence of early-onset paediatric type 1 diabetes: A retrospective population-based cohort study.

Elten M, Donelle J, Lima I, Burnett RT, Weichenthal S, Stieb DM, Hystad P, van Donkelaar A, Chen H, Paul LA, Crighton E, Martin RV, Decou ML, Luo W, Lavigne É.

Environ Res. 2020 Feb 22;184:109291.[Epub ahead of print] DOI:10.1016/j.envres.2020.109291




Studies have reported increasing incidence rates of paediatric diabetes, especially among those aged 0-5 years. Epidemiological evidence linking ambient air pollution to paediatric diabetes remains mixed.


This study investigated the association between maternal and early-life exposures to common air pollutants (NO2, PM2.5, O3, and oxidant capacity [Ox; the redox-weighted average of O3 and NO2]) and the incidence of paediatric diabetes in children up to 6 years of age.


All registered singleton births in Ontario, Ca nada occurring between April 1st, 2006 and March 31st, 2012 were included through linkage from health administrative data. Monthly exposures to NO2, PM2.5, O3, and Ox were estimated across trimesters, the entire pregnancy period and during childhood. Random effects Cox proportional hazards models were used to assess the relationships with paediatric diabetes incidence while controlling for important covariates. We also modelled the shape of concentration-response (CR) relationships.


There were 1094 children out of a cohort of 754,698 diagnosed with diabetes before the age of six. O3 exposures during the first trimester of pregnancy were associated with paediatric diabetes incidence (hazard ratio (HR) per interquartile (IQR) increase = 2.00, 95% CI: 1.04-3.86). The CR relationship between O3 during the first trimester and paediatric diabetes incidence appeared to have a risk threshold, in which there was little-to-no risk below 25 ppb of O3, while above this level risk increased sigmoidally. No other associations were observed.


O3 exposures during a critical period of development were associated with an increased risk of paediatric diabetes incidence.

February 27 | 2020

Efficient Removal of Ultrafine Particles from Diesel Exhaust by Selected Tree Species: Implications for Roadside Planting for Improving the Quality of Urban Air. 

Wang H, Maher BA, Ahmed IA, Davison B.

Environ Sci Technol. 2019 Jun 18;53(12):6906-6916. doi: 10.1021/acs.est.8b06629 Epub 2019 May 28.



Human exposure to airborne ultrafine (≪1 μm) particulate pollution may pose substantial hazards to human health, particularly in urban roadside environments where very large numbers of people are frequently exposed to vehicle-derived ultrafine particles (UFPs). For mitigation purposes, it is timely and important to quantify the deposition of traffic-derived UFPs onto leaves of selected plant species, with particularly efficient particle capture (high deposition velocity), which can be installed curbside, proximal to the emitting vehicular sources. Here, we quantify the size-resolved capture efficiency of UFPs from diesel vehicle exhaust by nine temperate-zone plant species, in wind tunnel experiments. The results show that silver birch (79% UFP removal), yew (71%), and elder (70.5%) have very high capabilities for capture of airborne UFPs. Metal concentrations and metal enrichment ratios in leaf leachates were also highest for the postexposure silver birch leaves; scanning electron microscopy showed that UFPs were concentrated along the hairs of these leaves. For all but two species, magnetic measurements demonstrated substantial increases in the concentration of magnetic particles deposited on the leaves after exposure to the exhaust particulates. Together, these new data show that leaf-deposition of UFPs is chiefly responsible for the substantial reductions in particle numbers measured downwind of the vegetation. It is critical to recognize that the deposition velocity of airborne particulate matter (PM) to leaves is species-specific and often substantially higher (∼10 to 50 times higher) than the “standard” Vd values (e.g., 0.1-0.64 cm s-1 for PM2.5) used in most modeling studies. The use of such low Vd values in models results in a major under-estimation of PM removal by roadside vegetation and thus misrepresents the efficacy of selected vegetation species in the substantial (≫20%) removal of PM. Given the potential hazard to health posed by UFPs and the removal efficiencies shown here (and by previous roadside measurements), roadside planting (maintained at or below head height) of selected species at PM “hotspots” can contribute substantially and quickly to improve in urban air quality and reductions in human exposure. These findings can contribute to the development and implementation of mitigation policies of traffic-derived PM on an international scale.

February 18 | 2020

Association of use of cleaning products with respiratory health in a Canadian birth cohort.

Jaclyn Parks, Lawrence McCandless, Christoffer Dharma, Jeffrey Brook, Stuart E. Turvey, Piush Mandhane, Allan B. Becker, Anita L. Kozyrskyj, Meghan B. Azad, Theo J. Moraes, Diana L. Lefebvre, Malcolm R. Sears, Padmaja Subbarao, James Scott and Tim K. Takaro.

CMAJ February 18, 2020 192 (7) E154-E161; DOI:



BACKGROUND: Comprehensive longitudinal studies are important for understanding the complex risk factors, pathways, exposures and interactions that lead to the development and persistence of asthma. We aimed to examine associations between use of household cleaning products in early life and childhood respiratory and allergic disease using data from the Canadian Healthy Infant Longitudinal Development (CHILD) Cohort Study.

METHODS: We summed responses from parental questionnaires that indicated the frequency of use of 26 household cleaning products in the homes of 2022 children from this birth cohort when they were 3–4 months of age to create a cumulative Frequency of Use Score (FUS). We used multivariable logistic regression models to assess whether frequent compared with less frequent use was associated with recurrent wheeze, atopy or asthma diagnosis, as defined by the questionnaire and clinical assessments at age 3 years. Data were collected between 2008 and 2015.

RESULTS: Children in homes with a higher frequency of use of cleaning products in infancy, as determined by an interquartile range increase, had higher odds of recurrent wheeze (adjusted odds ratio [OR] 1.35, 95% confidence interval [CI] 1.11–1.64), recurrent wheeze with atopy (adjusted OR 1.49, 95% CI 1.02–2.16) and asthma diagnosis (adjusted OR 1.37, 95% CI 1.09–1.70), but no increase in the odds of atopy at age 3 years (adjusted OR 1.14, 95% CI 0.96–1.35). Compared with the lowest tertile of FUS exposure, infants in the highest tertile had higher odds of acquiring asthma. Stratification of the results showed that females had higher ORs than males for all outcomes, although the p values for this sex difference did not reach statistical significance.

INTERPRETATION: Frequent use of household cleaning products in early life was associated with an increased risk for childhood wheeze and asthma but not atopy at age 3 years. Our findings add to the understanding of how early life exposures to cleaning products may be associated with the development of allergic airway disease and help to identify household behaviours as a potential area for intervention.

Environmental health research opportunities through CPTP and CANUE | February 13th | 2020

About the Speaker: Dr. Jeffrey Brook
Dr. Jeffrey Brook is CANUE’s Principal Investigator and Scientific Director. He is also an Assistant Professor at the University of Toronto’s Dalla Lana School of Public Health and Department of Chemical Engineering and Applied Chemistry. He has 25 years of experience as an Environment Canada scientist working at the science-policy interface. He is one of Canada’s leading experts in air quality, recognized at all levels of government and academically, including for his substantial contributions in air pollution health research. Dr. Brook has led scientific assessments to inform policy nationally and internationally, and advised multi-stakeholder groups shaping policy.

This webinar will provide an overview of the CANUE data and research opportunities made possible by linking CPTP’s individual lifestyle, genetic and behavioural data with CANUE’s environmental exposure metrics. This collaboration provides health researchers easy access to standardized urban environmental exposures, allowing them to tackle real-world problems related to exposures and the subsequent health outcomes. Ultimately, new knowledge enabled by the CANUE-CPTP partnership will help identify cost-effective actions that promote healthy childhood development and aging, reduce the burden of chronic disease, and minimize the impact of changing environments.

Webinar registration