Publications

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2019
Cakmak, S, Hebbern C, Vanos J, Crouse DL, Tjepkema M.  2019.  Exposure to traffic and mortality risk in the 1991-2011 Canadian Census Health and Environment Cohort (CanCHEC). Environment International. 124:16-24.   10.1016/j.envint.2018.12.045   AbstractWebsite

There is evidence that local traffic density and living near major roads can adversely affect health outcomes. We aimed to assess the relationship between local road length, proximity to primary highways, and cause-specific mortality in the 1991 Canadian Census Health and Environment Cohort (CanCHEC). In this long-term study of 2.6 million people, based on completion of the long-form census in 1991 and followed until 2011, we used annual residential addresses to determine the total length of local roads within 200m of postal code representative points and the postal code's distance to primary highways. The association between exposure to traffic and cause-specific non-accidental mortality was estimated using Cox proportional hazards models, adjusting for individual covariates and contextual factors, including census division-level proportion in high school, the percentage of recent immigrants, and neighborhood income. We performed sensitivity analyses, including adjustment for exposure to PM2.5, NO2, or O-3, restricting to subjects in core urban areas, and spatial variation by climatic zone. The hazard ratio (HR) for all non-accidental mortality associated with an interquartile increase in length of local roads was 1.05 (95% CI 1.04, 1.05), while for an interquartile range increase in proximity to primary highways, the HR was 1.03 (95% CI 1.02, 1.04). HRs by traffic quartile increased with increasing lengths of local roads, as well as with closer proximity to primary highways, for all mortality causes. The associations were stronger within subjects' resident in urban core areas, attenuated by adjustment for PM2.5, and HRs showed limited spatial variation by climatic zone. In the CanCHEC cohort, exposure to higher road density and proximity to major traffic roads was associated with increased mortality risk from cerebrovascular and cardiovascular disease, ischemic heart disease, COPD, respiratory disease, and lung cancer, with unclear results for diabetes.

Vanos, JK, Kosaka E, Iida A, Yokohari M, Middel A, Scott-Fleming J, Brown RD.  2019.  Planning for spectator thermal comfort and health in the face of extreme heat: The Tokyo 2020 Olympic marathons. Science of the Total Environment. 657:904-917.   10.1016/j.scitotenv.2018.11.447   AbstractWebsite

The 2020 Olympic Games marathon will be run through the streets of Tokyo on the mornings of August 2nd and 9th, a time of year that is typically hot, sunny, and humid. Few studies have assessed the potential impact of extreme heat along the marathon course to understand the multiple factors (e.g., radiation, wind flow) affecting human thermal comfort (TC) as influenced by urban design and vegetation. The current research establishes a baseline of microclimate conditions and scenarios to estimate the projected TC along the marathon route for spectators. Mobile microclimate data (air and surface temperatures, solar radiation, humidity, wind speed) were collected along the marathon course over 15 periods in the summer of 2016 and aligned with sky view factors (SVF). Human energy budget modeling was applied to provide spatially-explicit heat budget and TC information along the route. Conditions are expected to create the most discomfort along open, sun-exposed locations, with similar to 50% of the area along the second half of the course resulting in 'Hot' (budget > 200 W m(-2)) or 'Very hot' (budget > 295 W m(-2)) conditions. The heat strain index frequently rises above 80% in these locations, with high humidity and low wind flow exacerbating discomfort. Buildings and trees producing a low SVF over roads and sidewalks protect spectators from the morning radiant heat, but such locations should be balanced with wind flow to optimize comfort. The modeling and spatial information can aid in preparing for and mitigating heat stress during the Olympics. Potential solutions can be implemented in collaboration with local organizers and government. This 'research through design' strategy can aid in preparing for and mitigating heat illness during the Olympics. Knowledge gained can be extended to other areas of Tokyo to reduce urban heat, and further provide targeted guidance for effective environmental cooling techniques for human health. (C) 2018 Elsevier B.V. All rights reserved.

2017
Grundstein, A, Knox JA, Vanos J, Cooper ER, Casa DJ.  2017.  American football and fatal exertional heat stroke: a case study of Korey Stringer. International Journal of Biometeorology. 61:1471-1480.   10.1007/s00484-017-1324-2   AbstractWebsite

On August 1, 2001, Korey Stringer, a Pro Bowl offensive tackle for the Minnesota Vikings, became the first and to date the only professional American football player to die from exertional heat stroke (EHS). The death helped raise awareness of the dangers of exertional heat illnesses in athletes and prompted the development of heat safety policies at the professional, collegiate, and interscholastic levels. Despite the public awareness of this death, no published study has examined in detail the circumstances surrounding Stringer's fatal EHS. Using the well-documented details of the case, our study shows that Stringer's fatal EHS was the result of a combination of physiological limitations, organizational and treatment failings, and extreme environmental conditions. The COMfort FormulA (COMFA) energy budget model was used to assess the relative importance of several extrinsic factors on Stringer's EHS, including weather conditions, clothing insulation, and activity levels. We found that Stringer's high-intensity training in relation to the oppressive environmental conditions was the most prominent factor in producing dangerous, uncompensable heat stress conditions and that the full football uniform played a smaller role in influencing Stringer's energy budget. The extreme energy budget levels that led to the fatal EHS would have been avoided according to our modeling through a combination of reduced intensity and lower clothing insulation. Finally, a long delay in providing medical treatment made the EHS fatal. These results highlight the importance of modern heat safety guidelines that provide controls on extrinsic factors, such as the adjustment of duration and intensity of training along with protective equipment modifications based on environmental conditions and the presence of an emergency action plan focused on rapid recognition and immediate on-site aggressive cooling of EHS cases.