February 12 | 2018

Effect of air quality alerts on human health: a regression discontinuity analysis in Toronto, Canada

Hong Chen, PhD, Qiongsi Li, MMath, Jay S Kaufman, PhD, Jun Wang, MSc, Ray Copes, MD, Yushan Su, PhD, Tarik Benmarhnia, PhD

The Lancet Planetary Health, Volume 2, No. 1, e19–e26, January 2018  DOI: https://doi.org/10.1016/S2542-5196(17)30185-7



Ambient air pollution is a major health risk globally. To reduce adverse health effects on days when air pollution is high, government agencies worldwide have implemented air quality alert programmes. Despite their widespread use, little is known about whether these programmes produce any observable public-health benefits. We assessed the effectiveness of such programmes using a quasi-experimental approach.


We assembled a population-based cohort comprising all individuals who resided in the city of Toronto (Ontario, Canada) from 2003 to 2012 (about 2·6 million people). We ascertained seven health outcomes known to be affected by short-term elevation of air pollution, using provincial health administrative databases. These health outcomes were cardiovascular-related mortality, respiratory-related mortality, and hospital admissions or emergency-department visits for acute myocardial infarction, heart failure, stroke, asthma, and chronic obstructive pulmonary disease (COPD). We applied a regression discontinuity design to assess the effectiveness of an intervention (ie, the air quality alert programme). To quantify the effect of the air quality alert programme, we estimated for each outcome both the absolute rate difference and the rate ratio attributable to programme eligibility (by intention-to-treat analysis) and the alerts themselves (by two-stage regression approach), respectively.


Between Jan 1, 2003, and Dec 31, 2012, on average between three and 27 daily cardiovascular or respiratory events were reported in Toronto (depending on the outcome). Alert announcements reduced asthma-related emergency-department visits by 4·73 cases per 1 000 000 people per day (95% CI 0·55–9·38), or in relative terms by 25% (95% CI 1–47). Programme eligibility also led to 2·05 (95% CI 0·07–4·00) fewer daily emergency-department visits for asthma. We did not detect a significant reduction in any other health outcome as a result of alert announcements or programme eligibility. However, a non-significant trend was noted towards decreased asthma-related and COPD-related admissions.


In this population-based cohort, the air quality alert programme was related to some reductions in respiratory morbidity, but not any other health outcome examined. This finding suggests that issuing air quality alerts alone has a limited effect on public health and that implementing enforced public actions to reduce air pollution on high pollution days could be warranted. Together with accumulating evidence of substantial burden from long-term air pollution exposure, this study underscores the need for further strengthening of global efforts that can lead to long-term improvement of overall air quality.


Public Health Ontario, Canadian Institutes for Health Research.

February 5 | 2018

Evaluating street view exposure measures of visible green space for health research.

Larkin AHystad P.

J Expo Sci Environ Epidemiol. 2018 Jan 19. doi: 10.1038/s41370-018-0017-1. [Epub ahead of print]


Urban green space, or natural environments, are associated with multiple physical and mental health outcomes. Several proposed pathways of action for these benefits (e.g., stress reduction and attention restoration) require visual perception of green space; however, existing green space exposure measures commonly used in epidemiological studies do not capture street-scale exposures. We downloaded 254 Google Street View (GSV) panorama images from Portland, Oregon and calculated percent of green in each image, called Green View Index (GVI). For these locations we also calculated satellite-based normalized difference vegetation index (NDVI), % tree cover, % green space, % street tree buffering, distance to parks, and several neighborhood socio-economic variables. Correlations between the GVI and other green space measures were low (-0.02 to 0.50), suggesting GSV-based measures captured unique information about green space exposures. We further developed a GVI:NDVI ratio, which was associated with the amount of vertical green space in an image. The GVI and GVI:NDVI ratio were weakly related to neighborhood socioeconomic status and are therefore less susceptible to confounding in health studies compared to other green space measures. GSV measures captured unique characteristics of the green space environment and offer a new approach to examine green space and health associations in epidemiological research.

January 29 | 2018

Human Health Risk Assessment for Gasoline Exhaust

Prepared by: Fuels Assessment Section Water and Air Quality Bureau Healthy Environments and Consumer Safety Branch Health Canada November 2017


Excerpt from Executive Summary

Gasoline, or spark ignition, engines are used throughout Canada, representing 92% of on-road vehicles and 87% of off-road engines or equipment. It is reasonable to assume that exposure to gasoline engine exhaust (GE) is nearly ubiquitous, particularly for Canadians living in urban areas or in close proximity to a major roadway: it is estimated that approximately 2 million people live within 50 m of a major road in Canada. GE is a highly variable and complex mixture of particulate and gaseous pollutants, the composition of which depends on numerous factors, including fuel quality, engine and pollution control technologies, vehicle operating conditions and ambient temperature. GE is an important source of criteria air contaminants (CACs) associated with adverse effects on human health, including fine particulate matter (PM2.5), ground-level ozone (O3), nitrogen dioxide (NO2), volatile organic compounds (VOCs) and carbon monoxide (CO). In addition, GE constituents include air toxics that are recognized internationally as carcinogens, such as benzene and polycyclic aromatic hydrocarbons (PAHs).

Gasoline fuel, vehicles and engines are subject to multiple federal regulations that have successfully reduced air pollutant emissions from gasoline mobile sources, representing a major success in the management of air quality in Canada and the protection of human health. However, given the number of vehicles and engines in use, the age structure of the in-use fleets, and the vehicle kilometres travelled by Canadians, gasoline engines remain a key source of air pollution. The adverse health effects of individual pollutants in GE or produced secondarily in the atmosphere from primary GE emissions (e.g. PM2.5, O3, NO2, benzene and PAHs), are well characterized in the scientific literature and include increased risk of cardiorespiratory mortality and morbidity and of cancer, among other outcomes.

This report is a comprehensive review and analysis of the potential adverse health effects associated with gasoline fuel use in Canada. Two distinct approaches are used. Part A provides an evaluation of scientific studies that have examined the health effects associated with exposure to GE as a mixture. Studies on the health effects of individual GE constituents, such as PM2.5 and benzene, were not considered, as these substances have been extensively reviewed by Health Canada elsewhere. Part B provides a quantitative assessment of the contribution of on-road and off-road gasoline mobile source emissions to individual air pollutant concentrations in Canada and the population health impacts associated with that incremental contribution. The health impact analysis in Part B, which is based on well-established quantitative estimates of risk of adverse health impacts associated with incremental changes in air concentrations of individual pollutants, is complementary to the traditional risk assessment approach presented in Part A.

January 15 | 2018

The Canadian Urban Environmental Health Research Consortium – a protocol for building a national environmental exposure data platform for integrated analyses of urban form and health

Jeffrey R. Brook, Eleanor M. Setton, Evan Seed, Mahdi Shooshtari, Dany Doiron and CANUE – The Canadian Urban Environmental Health Research Consortium

BMC Public Health BMC series https://doi.org/10.1186/s12889-017-5001-5 Published: 8 January 2018



Multiple external environmental exposures related to residential location and urban form including, air pollutants, noise, greenness, and walkability have been linked to health impacts or benefits. The Canadian Urban Environmental Health Research Consortium (CANUE) was established to facilitate the linkage of extensive geospatial exposure data to existing Canadian cohorts and administrative health data holdings. We hypothesize that this linkage will enable investigators to test a variety of their own hypotheses related to the interdependent associations of built environment features with diverse health outcomes encompassed by the cohorts and administrative data.

January 8 | 2018

Respiratory and cardiovascular responses to walking down a traffic-polluted road compared with walking in a traffic-free area in participants aged 60 years and older with chronic lung or heart disease and age-matched healthy controls: a randomised, crossover study

Rudy Sinharay, MBBS, Jicheng Gong, PhD, Benjamin Barratt, PhD, Pamela Ohman-Strickland, PhD, Sabine Ernst, MD, Prof Frank Kelly, PhD, Prof Junfeng (Jim) Zhang, PhD, Prof Peter Collins, MD, Prof Paul Cullinan, MD, Prof Kian Fan Chung, DSc

Co-first authors contributed equally

The Lancet.  DOI: http://dx.doi.org/10.1016/S0140-6736(17)32643-0 Published: 05 December 2017


Long-term exposure to pollution can lead to an increase in the rate of decline of lung function, especially in older individuals and in those with chronic obstructive pulmonary disease (COPD), whereas shorter-term exposure at higher pollution levels has been implicated in causing excess deaths from ischaemic heart disease and exacerbations of COPD. We aimed to assess the effects on respiratory and cardiovascular responses of walking down a busy street with high levels of pollution compared with walking in a traffic-free area with lower pollution levels in older adults.

January 1 | 2018

Evaluation of daily time spent in transportation and traffic-influenced microenvironments by urban Canadians

Carlyn J. Matz ,David M. Stieb, Marika Egyed, Orly Brion, Markey Johnson

Air Quality, Atmosphere & Health pp 1–12|  First Online: 30 November 2017 https://doi.org/10.1007/s11869-017-0532-6


Exposure to traffic and traffic-related air pollution is associated with a wide array of health effects. Time spent in a vehicle, in active transportation, along roadsides, and in close proximity to traffic can substantially contribute to daily exposure to air pollutants. For this study, we evaluated daily time spent in transportation and traffic-influenced microenvironments by urban Canadians using the Canadian Human Activity Pattern Survey (CHAPS) 2 results. Approximately 4–7% of daily time was spent in on- or near-road locations, mainly associated with being in a vehicle and smaller contributions from active transportation. Indoor microenvironments can be impacted by traffic emissions, especially when located near major roadways. Over 60% of the target population reported living within one block of a roadway with moderate to heavy traffic, which was variable with income level and city, and confirmed based on elevated NO2 exposure estimated using land use regression. Furthermore, over 55% of the target population ≤ 18 years reported attending a school or daycare in close proximity to moderate to heavy traffic, and little variation was observed based on income or city. The results underline the importance of traffic emissions as a major source of exposure in Canadian urban centers, given the time spent in traffic-influenced microenvironments.

December 18 | 2017

The Lancet Commissions

The Lancet Commission on pollution and health

The Lancet Commission on pollution and health Philip J Landrigan, Richard Fuller, Nereus J R Acosta, Olusoji Adeyi, Robert Arnold, Niladri (Nil) Basu, Abdoulaye Bibi Baldé, Roberto Bertollini, Stephan Bose-O’Reilly, Jo Ivey Boufford, Patrick N Breysse, Thomas Chiles, Chulabhorn Mahidol, Awa M Coll-Seck, Maureen L Cropper, Julius Fobil, Valentin Fuster, Michael Greenstone, Andy Haines, David Hanrahan, David Hunter, Mukesh Khare, Alan Krupnick, Bruce Lanphear, Bindu Lohani, Keith Martin, Karen V Mathiasen, Maureen A McTeer, Christopher J L Murray, Johanita D Ndahimananjara, Frederica Perera, Janez Potočnik, Alexander S Preker, Jairam Ramesh, Johan Rockström, Carlos Salinas, Leona D Samson, Karti Sandilya, Peter D Sly, Kirk R Smith, Achim Steiner, Richard B Stewart, William A Suk, Onno C P van Schayck, Gautam N Yadama, Kandeh Yumkella, Ma Zhong

Published: 19 October 2017  DOI: http://dx.doi.org/10.1016/S0140-6736(17)32345-0

Pollution is the largest environmental cause of disease and premature death in the world today. Diseases caused by pollution were responsible for an estimated 9 million premature deaths in 2015—16% of all deaths worldwide—three times more deaths than from AIDS, tuberculosis, and malaria combined and 15 times more than from all wars and other forms of violence. In the most severely affected countries, pollution-related disease is responsible for more than one death in four.

December 11 | 2017

The Chief Public Health Officer’s Report on the State of Public Health in Canada 2017 – Designing Healthy Living

The Chief Public Health Officer’s Report on the State of Public Health in Canada 2017 – Designing Healthy Living

A message from Canada’s Chief Public Health Officer

Without being aware of it, our neighbourhoods and how they are built influence how healthy we are.

I chose designing healthy living as the topic for my first report as Canada’s Chief Public Health Officer because of the tremendous potential that changing our built environment has for helping Canadians live healthier lives.

Chronic diseases like diabetes, cancer and cardiovascular disease are the leading causes of death in Canada. It is alarming that in 2011, almost 2.7 million or 1 in 10 Canadians 20 years and older were living with diabetes. Rising rates of type II diabetes can be considered a red flag for poor health as they are associated with higher rates of other diseases and conditions and linked to an unhealthy diet, low physical activity and higher rates of overweight and obesity. Rates of type II diabetes and other chronic diseases in Canada could be reduced by seamlessly integrating healthy living into our daily lives which can be achieved, in part, by designing and redesigning our communities.

Improving public health and preventing disease through changes to our environment is a well-founded concept. For example, infectious disease rates in the last century were reduced not just through scientific innovation and vaccination, but also through infrastructure planning by improving sanitation and addressing overcrowding in residential neighbourhoods.

This report answers many questions but also raises several others. We need better information if we are to measure the health impacts of community design to incorporate evidence-based strategies into community planning. This report will raise awareness among Canadians about the unique aspects of their communities that they could take advantage of to improve their health. It will also encourage more dialogue across the many disciplines involved in community planning and health promotion so that neighbourhood design considers and promotes physical activity, healthy diets and mental wellness.

Dr. Theresa Tam
Chief Public Health Officer of Canada


December 4 | 2017

Heat and pregnancy-related emergencies: Risk of placental abruption during hot weather.

He S1Kosatsky T2Smargiassi A3Bilodeau-Bertrand M4Auger N5.

Environ Int. 2017 Nov 13. pii: S0160-4120(17)31686-0  DOI:10.1016/j.envint.2017.11.004



Outdoor heat increases the risk of preterm birth and stillbirth, but the association with placental abruption has not been studied. Placental abruption is a medical emergency associated with major morbidity and mortality in pregnancy. We determined the relationship between ambient temperature and risk of placental abruption in warm seasons.


We performed a case-crossover analysis of 17,172 women whose pregnancies were complicated by placental abruption in Quebec, Canada from May to October 1989-2012. The main exposure measure was the maximum temperature reached during the week before abruption. We computed odds ratios (OR) and 95% confidence intervals (CI) for the association of temperature with placental abruption, adjusted for humidity and public holidays. We assessed whether associations were stronger preterm or at term, or varied with maternal age, parity, comorbidity and socioeconomic status.


Compared with 15°C, a maximum weekly temperature of 30°C was associated with 1.07 times the odds of abruption (95% CI 0.99-1.16). When the timing of abruption was examined, the associations were significantly stronger at term (OR 1.12, 95% CI 1.02-1.24) than preterm (OR 0.96, 95% CI 0.83-1.10). Relationships were more prominent at term for women who were younger than 35years old, nulliparous or socioeconomically disadvantaged, but did not vary with comorbidity. Associations were stronger within 1 and 5days of abruption. Temperature was not associated with preterm abruption regardless of maternal characteristics.


Elevated temperatures in warm seasons may increase the risk of abruption in women whose pregnancies are near or at term. Pregnant women may be more sensitive to heat and should consider preventive measures such as air conditioning and hydration during hot weather.

Noise Exposure and Cardiovascular Disease Onset | January 10 | 2018 | VIDEO AVAILABLE

January 10|2018

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



Environmental noise has been linked to a number of health effects including annoyance, sleep disturbance and cardiovascular diseases (CVD). In this seminar, we will present the current evidence on the association between environmental noise and onset of CVD. We will also present preliminary assessments of associations between noise and CVD in Quebec. These assessments are based on population cohorts created with linked medico-administrative health data and recent noise models. We will also present gaps that remain on the relationship between environmental noise and the onset of CVD.

Audrey Smargiassi is an Associate Professor at the Department of Environmental and Occupational Health at the School of Public Health and a researcher at the Public Health Research Institute at the University of Montreal.

Larisa Ines Yankoty is a PhD Candidate in Public Health, Epidemiology at the School of Public Health at the University of Montreal.