December 17 | 2018

The influence of social networks and the built environment on physical inactivity: A longitudinal study of urban-dwelling adults.

Josey MJ, Moore S.

Health Place. 2018 Nov;54:62-68. Epub 2018 Sep 21. DOI: 10.1016/j.healthplace.2018.08.016



Policies targeting the built environment to increase physical activity may be ineffective without considering personal social networks. Physical activity and social network data came from the Montreal Neighborhood Networks and Healthy Aging Panel; built environment measures were from geolocation data on Montreal parks and businesses. Using multilevel logistic regression with repeated physical inactivity measures, we showed that adults with more favorable social network characteristics had lower odds of physical inactivity. Having more physical activity facilities nearby also lowered physical inactivity, but not in socially-isolated adults. Community programs that address social isolation may also benefit efforts to increase physical activity.





A memorial service will be held at the Congregation of Or Shalom, 534 Huron Street, London, Ontario. In lieu of flowers, donations can be made in memory of Professor Silverman to the Occupational and Environmental Health Trust Fund of the Dalla Lana School of Public Health (


Frances Sommerfreund Silverman was born in Shanghai, China after her physician parents fled Vienna in 1942, narrowly escaping Hilter’s tyranny. Frances lived in Wuhu, China to the age of 6 before emigrating to Canada where her family settled in Montreal.

Frances enrolled in a doctoral program in respiratory physiology at McGill University in 1968 under the late Professor David Bates, widely recognized one of the founding figures in the field of air pollution and health. After several years of study, Frances moved to Toronto to direct the Pulmonary Function Laboratory at the Gage Research Institute which was at the time, a joint Centre of the University of Toronto (Department of Medicine) and Toronto Western Hospital.

After completing her doctoral work at McGill in 1978, Frances was immediately appointed Assistant Professor in the Department of Medicine at the University of Toronto. Both then and throughout the rest of her career, Frances was proud to be one of a very small group of non-clinical appointees in an otherwise clinical Department.

Frances remained at the Gage Research Institute as an early faculty member in the fledgling discipline of Environmental Health where her research continued to focus on air contaminants, staying true to her first publication in the CMAJ in 1970 – “Problems in studies of human exposure to air pollutants”.

Over the years, her research activities expanded to include many health-relevant air contaminants that remain important today, including ozone, cigarette smoke, allergens and particulate matter arising from industry and motor vehicle emissions. Frances’s earliest work on the health consequences of ozone exposure in the 1970s was formative and continues to be cited regularly. From that and her other insights, she is widely regarded as one of the founding researchers in this area.

The health outcomes she considered also expanded beyond airways measurements to increasingly more sophisticated measures such as genetic and epigenetic markers, inflammatory mediators, and vascular measures. Elegant and highly cited work in the early 2000s by Frances and her colleagues first established a mechanistic link between air pollution exposure and acute cardiovascular events.

Frances held appointments in the Department of Medicine (Division of Respirology), the Dalla Lana School of Public Health (Division of Occupational and Environmental Health), The School of the Environment, the Faculty of Kinesiology and Physical Education, the Li Ka Shing Knowledge Institute, and the University Health Network. She was always most proud of her affiliation with the Gage Research Institute (later the Gage Occupational and Environmental Health Unit), where she served as Acting Director and a member of the Board of Directors.

Despite starting her career as a basic scientist, Frances rapidly understood that truly transformative and impactful research can only be achieved through collaboration. She focused her efforts at the poorly explored nexus that exists between the basic sciences, health sciences and engineering. There, she built a network of collaborators and developed a world-class research program to study air health effects in healthy human subjects as well as those with mild asthma, children and adolescents, and those with chronic obstructive lung disease and obesity using controlled exposure challenges. Using this approach, Frances and her group bridged a critical gap between basic laboratory science and population health, providing much essential evidence needed for policy setting in Canada and abroad in relation to a range of contaminants from environmental tobacco smoke to vehicle emissions. Her work on air contaminants continued well past her retirement in 2012, and she remained actively engaged in research and mentorship until her death. Her curiosity and enthusiasm were infectious, and her level of energy unmatched. “Not bad for an old lady,” she would often observe.

Frances was a networker before networking was a thing, she prioritized the mentorship of young scientists long before it became a trend, and had a preternatural ability to see connections and seed innovative thinking. In her final year, Frances became an advocate for the rights of the elderly to health care access, arising from her own experiences in later life as a caregiver, her deep knowledge of the health care system, her drive to help others, and her talent for building relationships. Despite retirement, she actively mentored students and kept up the schedule of an active faculty member until her last day where her final effort was to advocate tenaciously at a faculty retreat on the importance of the environment as a determinant of health.

Frances was a person of great goodness and integrity – a true Mensch in the Yiddish sense. She continually challenged all who knew her to be better and do better by example. Her spirit, her wisdom, and her generosity will be greatly missed.


Ambient Air Pollution and the Risk of Childhood-onset Inflammatory Bowel Disease | FEBRUARY 12 | 2019

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


 The incidence of inflammatory bowel disease (IBD) has risen drastically in industrialized nations, such as Canada, over the last half of the 20th century. Although the incidence rate in adults with IBD has plateaued in Canada, the incidence of IBD among Canadian children is continuing to rise. Environmental risk factors, such as air pollution may be involved in IBD development, but epidemiological studies are inconclusive.

This presentation will summarize the results from a study investigating the effects of ambient air pollution on the risk of developing pediatric-onset IBD using Ontario administrative health data. In-utero and childhood residential exposures to nitrogen dioxide (NO2), fine particulate matter (PM2.5) and ozone (O3) were evaluated in terms of their potential associations with IBD diagnosed before the age of 18. Other environmental factors, such as residential exposure to greenness as well as several maternal and individual-level factors were also considered as potential confounders and effect modifiers of these associations.

Michael Elten is currently completing a Master’s degree in Epidemiology in the School of Epidemiology and Public Health at the University of Ottawa. His research focuses on evaluating the effects of air pollution on health, with an emphasis on maternal and early-life exposures.






Interactive Mapping of Environmental Health Assessments | MARCH 19 | 2019

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

Non communicable diseases including cardiovascular disease, diabetes, and cancer are the leading causes of morbidity and mortality among populations in high income countries. The rapid increase of overweight and obesity among Canadians and its associated consequences, including hypertension and diabetes is a major public health problem, and threaten to halt the declines in cardiovascular disease deaths Canada has experienced in the past 30 years.

Knowledge gaps exist regarding the impact of the built environment in relation to individual risk factor development, and the variation of these built environments across Canada by region and rurality. In order to address these gaps in our knowledge, we convened the Canadian Alliance of Healthy Hearts and Minds – a prospective cohort of men and women recruited from existing cohorts in Canada and through recruitment of a new First Nations cohort study.

As part of the knowledge translation plan of the Canadian Alliance for Healthy Hearts and Minds project, we developed and released an on-line, interactive map of 2,074 communities across Canada that conveys the information from our community contextual health audits. In this presentation, I will describe the development of the map, and describe how to access and use the tools embedded in the map.

Russell de Souza is an Assistant Professor in the Department of Health Research Methods, Evidence, and Impact at McMaster University.  He is a registered dietitian, and his research focuses on dietary patterns, health, and how the food environment shapes food choice and risk of cardiovascular disease.

December 10 | 2018

Residential green space and pathways to term birth weight in the Canadian Healthy Infant Longitudinal Development (CHILD) Study.

Cusack L, Sbihi H, Larkin A, Chow A, Brook JR, Moraes T, Mandhane PJ, Becker AB, Azad MB, Subbarao P, Kozyrskyj A, Takaro TK, Sears MR, Turvey SE, Hystad P; CHILD Study Investigators.

Int J Health Geogr. 2018 Dec 4;17(1):43. doi: 10.1186/s12942-018-0160-x



A growing number of studies observe associations between the amount of green space around a mother’s home and positive birth outcomes; however, the robustness of this association and potential pathways of action remain unclear.


To examine associations between mother’s residential green space and term birth weight within the Canadian Healthy Infant Longitudinal Development (CHILD) study and examine specific hypothesized pathways.


We examined 2510 births located in Vancouver, Edmonton, Winnipeg, and Toronto Canada. Green space was estimated around mother’s residences during pregnancy using Landsat 30 m normalized difference vegetation index (NDVI). We examined hypothesized pathways of: (1) reduction of environmental exposure; (2) built environment features promoting physical activity; (3) psychosocial conditions; and (4) psychological influences. Linear regression was used to assess associations between green space and term birth weight adjusting first for a comprehensive set of confounding factors and then incrementally for pathway variables.


Fully adjusted models showed non-statistically significant increases in term birth weight with increasing green space. For example, a 0.1 increase in NDVI within 500 m was associated with a 21.5 g (95% CI - 4.6, 47.7) increase in term birth weight. Associations varied by city and were most robust for high-density locations. For the two largest cities (Vancouver and Toronto), we observed an increase in birth weight of 41.2 g (95% CI 7.8, 74.6) for a 0.1 increase in NDVI within 500 m. We did not observe substantial reductions in the green space effect on birth weight when adjusting for pathway variables.


Our results highlight the need to further characterize the interactions between green space, urban density and climate related factors as well as the pathways linking residential green space to birth outcomes.

December 3 | 2018

A picture tells a thousand…exposures: Opportunities and challenges of deep learning image analyses in exposure science and environmental epidemiology.

Weichenthal S, Hatzopoulou M, Brauer M. 

Environ Int. 2018 Nov 22. pii: S0160-4120(18)32200-1. [Epub ahead of print] DOI:10.1016/j.envint.2018.11.042




Artificial intelligence (AI) is revolutionizing our world, with applications ranging from medicine to engineering.


Here we discuss the promise, challenges, and probable data sources needed to apply AI in the fields of exposure science and environmental health. In particular, we focus on the use of deep convolutional neural networks to estimate environmental exposures using images and other complementary data sources such as cell phone mobility and social media information.


Characterizing the health impacts of multiple spatially-correlated exposures remains a challenge in environmental epidemiology. A shift toward integrated measures that simultaneously capture multiple aspects of the urban built environment could improve efficiency and provide important insights into how our collective environments influence population health. The widespread adoption of AI in exposure science is on the frontier. This will likely result in new ways of understanding environmental impacts on health and may allow for analyses to be efficiently scaled for broad coverage. Image-based convolutional neural networks may also offer a cost-effective means of estimating local environmental exposures in low and middle-income countries where monitoring and surveillance infrastructure is limited. However, suitable databases must first be assembled to train and evaluate these models and these novel approaches should be complemented with traditional exposure metrics.


The promise of deep learning in environmental health is great and will complement existing measurements for data-rich settings and could enhance the resolution and accuracy of estimates in data poor scenarios. Interdisciplinary partnerships will be needed to fully realize this potential.

November 26 | 2018

Association of Prenatal Exposure to Air Pollution With Autism Spectrum Disorder. 

Pagalan L, Bickford C, Weikum W, Lanphear B, Brauer M, Lanphear N, Hanley GE, Oberlander TF, Winters M. 

JAMA Pediatr. 2018 Nov 19. doi: 10.1001/jamapediatrics.2018.3101. [Epub ahead of print] 10.1001/jamapediatrics.2018.3101



IMPORTANCE: The etiology of autism spectrum disorder (ASD) is poorly understood, but prior studies suggest associations with airborne pollutants.

OBJECTIVE: To evaluate the association between prenatal exposures to airborne pollutants and ASD in a large population-based cohort.

DESIGN, SETTING, AND PARTICIPANTS: This population-based cohort encompassed nearly all births in Metro Vancouver, British Columbia, Canada, from 2004 through 2009, with follow-up through 2014. Children were diagnosed with ASD using a standardized assessment with the Autism Diagnostic Interview-Revised and Autism Diagnostic Observation Schedule. Monthly mean exposures to particulate matter with a diameter less than 2.5 µm (PM2.5), nitric oxide (NO), and nitrogen dioxide (NO2) at the maternal residence during pregnancy were estimated with temporally adjusted, high-resolution land use regression models. The association between prenatal air pollution exposures and the odds of developing ASD was evaluated using logistic regression adjusted for child sex, birth month, birth year, maternal age, maternal birthplace, and neighborhood-level urbanicity and income band. Data analysis occurred from June 2016 to May 2018.

EXPOSURES: Mean monthly concentrations of ambient PM2.5, NO, and NO2 at the maternal residence during pregnancy, calculated retrospectively using temporally adjusted, high-resolution land use regression models.

MAIN OUTCOMES AND MEASURES: Autism spectrum disorder diagnoses based on standardized assessment of the Autism Diagnostic Interview-Revised and Autism Diagnostic Observation Schedule. The hypothesis being tested was formulated during data collection.

RESULTS: In a cohort of 132 256 births, 1307 children (1.0%) were diagnosed with ASD by the age of 5 years. The final sample size for the PM2.5-adjusted model was 129 439 children, and for NO and NO2, it was 129 436 children; of these, 1276 (1.0%) were diagnosed with ASD. Adjusted odds ratios for ASD per interquartile range (IQR) were not significant for exposure to PM2.5 during pregnancy (1.04 [95% CI, 0.98-1.10] per 1.5 μg/m3 increase [IQR] in PM2.5) or NO2 (1.06 [95% CI, 0.99-1.12] per 4.8 ppb [IQR] increase in NO2) but the odds ratio was significant for NO (1.07 [95% CI, 1.01-1.13] per 10.7 ppb [IQR] increase in NO). Odds ratios for male children were 1.04 (95% CI, 0.98-1.10) for PM2.5; 1.09 (95% CI, 1.02-1.15) for NO; and 1.07 (95% CI, 1.00-1.13) for NO2. For female children, they were for 1.03 (95% CI, 0.90-1.18) for PM2.5; 0.98 (95% CI, 0.83-1.13) for NO; and 1.00 (95% CI, 0.86-1.16) for NO2.

CONCLUSIONS AND RELEVANCE: In a population-based birth cohort, we detected an association between exposure to NO and ASD but no significant association with PM2.5 and NO2.










We are getting ready to start some intensive work on developing urban form metrics from high resolution satellite and street-level imagery. We will be hosting two virtual meetings to develop a comprehensive list of metrics and applications that are high on the priority list for CANUE members. Your feedback will help us develop a work program for CANUE staff in the coming months.

We will be hosting the same meeting on Dec 4th  (9am to 10:30 am pacific) and Dec 6th (12 noon to 1:30pm pacific).

REGISTER HERE  for your preferred date.

If you are unable to attend on either date, please email with the following message: “please add me to the working group for machine learning and high resolution imagery”. You can provide feedback prior to the meetings, and we will send a summary report in early January.

November 19 | 2018

The health risks and benefits of cycling in urban environments compared with car use: health impact assessment study.

David Rojas-Rueda, Audrey de Nazelle, Marko Tainio, Mark J Nieuwenhuijsen


BMJ 2011; 343 doi:



Objective To estimate the risks and benefits to health of travel by bicycle, using a bicycle sharing scheme, compared with travel by car in an urban environment.

Design Health impact assessment study.

Setting Public bicycle sharing initiative, Bicing, in Barcelona, Spain.

Participants 181 982 Bicing subscribers.

Main outcomes measures The primary outcome measure was all cause mortality for the three domains of physical activity, air pollution (exposure to particulate matter <2.5 μm), and road traffic incidents. The secondary outcome was change in levels of carbon dioxide emissions.

Results Compared with car users the estimated annual change in mortality of the Barcelona residents using Bicing (n=181 982) was 0.03 deaths from road traffic incidents and 0.13 deaths from air pollution. As a result of physical activity, 12.46 deaths were avoided (benefit:risk ratio 77). The annual number of deaths avoided was 12.28. As a result of journeys by Bicing, annual carbon dioxide emissions were reduced by an estimated 9 062 344 kg.

Conclusions Public bicycle sharing initiatives such as Bicing in Barcelona have greater benefits than risks to health and reduce carbon dioxide emissions.


November 12 | 2018

A Web-Based Survey of Residents’ Views on Advocating with Patients for a Healthy Built Environment in Canada. 

Matthew Cruickshank and Marcus Law

International Journal of Family Medicine Volume 2014, Article ID 458184, 7 pages



Purpose. To determine family medicine residents’ perceived knowledge and attitudes towards the built environment and their responsibility for health advocacy and to identify their perceived educational needs and barriers to patient education and advocacy.

Methods. A web-based survey was conducted in Canada with University of Toronto family medicine residents. Data were analyzed descriptively.

Results. 93% agreed or strongly agreed that built environment significantly impacts health. 64% thought educating patients on built environment is effective disease prevention; 52% considered this a role of family physicians. 78% reported that advocacy for built environment is effective disease prevention; 56% perceived this to be the family physician’s role. 59% reported being knowledgeable to discuss how a patient’s environment may affect his/her health; 35% reported being knowledgeable to participate in community discussions on built environment. 78% thought education would help with integration into practice. Inadequate time (92%), knowledge (73%), and remuneration (54%) were barriers.

Conclusions. While residents perceived value in education and advocacy as disease prevention strategies and acknowledged the importance of a healthy built environment, they did not consider advocacy towards this the family physician’s role. Barrier reduction and medical education may contribute to improved advocacy, ultimately improving physical activity levels and patient health outcomes.