Extreme Heat, Forest Fires and the Role of the Built Environment | October 7th | 2021


This summer, record-breaking hot temperatures in British Columbia were met with a higher-than-average number of wildfires across the province. Extremely hot days caused by climate change are expected to lead to longer wildfire seasons which will burn larger areas, and public health officials will need to adapt their existing advice for prolonged smoky periods.

This webinar will:

  • Review trends and population health impacts of extreme heat and forest fires
  • Explain how the built environment can contribute to and protect against extreme heat and wildfire smoke exposure in cities
  • Explore local and national policy options to reduce harmful effects of extreme heat and wildfire smoke exposure

About the presenter:

Sarah Henderson is a Scientific Director in Environmental Health Services at BCCDC. She is also an Associate Professor in the UBC School of Population & Public Health.

Dr. Henderson leads a program of applied research and surveillance to support evidence-based policy for the province. This role requires her to be a generalist rather than a specialist and her work spans a wide range of topics, including air pollution from all provincially relevant sources (wildfire smoke, residential woodsmoke, industry, road dust, shipping, and vehicles), extreme weather events, radon gas, food safety, water quality, and exposures managed by the Drug and Poison Information Centre (DPIC). All of her work integrates large environmental datasets with large human health dataset from multiple sources, and she views data science as a key competency in environmental health.


Check out the Panel presentations, Discussion and Data Teams videos!



Environment and Health : Data 101 Seminar Series: February 26th | 2021 | 10am pacific | 1pm eastern




December 14 | 2020

Longitudinal impact of changes in the residential built environment on physical activity: findings from the ENABLE London cohort study.

Christelle ClaryDaniel LewisElizabeth LimbClaire M NightingaleBina RamAngie S PageAshley R CooperAnne Ellaway, Billie Giles-Corti, Peter H WhincupAlicja R RudnickaDerek G CookChristopher G OwenSteven Cummins.

Int J Behav Nutr Phys Act. 2020 Aug 1;17(1):96. doi: 10.1186/s12966-020-01003-9.


Background: Previous research has reported associations between features of the residential built environment and physical activity but these studies have mainly been cross-sectional, limiting inference. This paper examines whether changes in a range of residential built environment features are associated with changes in measures of physical activity in adults. It also explores whether observed effects are moderated by socio-economic status.

Methods: Data from the Examining Neighbourhood Activity in Built Living Environments in London (ENABLE London) study were used. A cohort of 1278 adults seeking to move into social, intermediate, and market-rent East Village accommodation was recruited in 2013-2015, and followed up after 2 years. Accelerometer-derived steps (primary outcome), and GIS-derived measures of residential walkability, park proximity and public transport accessibility were obtained both at baseline and follow-up. Daily steps at follow-up were regressed on daily steps at baseline, change in built environment exposures and confounding variables using multilevel linear regression to assess if changes in neighbourhood walkability, park proximity and public transport accessibility were associated with changes in daily steps. We also explored whether observed effects were moderated by housing tenure as a marker of socio-economic status.

Results: Between baseline and follow-up, participants experienced a 1.4 unit (95%CI 1.2,1.6) increase in neighbourhood walkability; a 270 m (95%CI 232,307) decrease in distance to their nearest park; and a 0.7 point (95% CI 0.6,0.9) increase in accessibility to public transport. A 1 s.d. increase in neighbourhood walkability was associated with an increase of 302 (95%CI 110,494) daily steps. A 1 s.d. increase in accessibility to public transport was not associated with any change in steps overall, but was associated with a decrease in daily steps amongst social housing seekers (- 295 steps (95%CI – 595, 3), and an increase in daily steps for market-rent housing seekers (410 95%CI -191, 1010) (P-value for effect modification = 0.03).

Conclusion: Targeted changes in the residential built environment may result in increases in physical activity levels. However, the effect of improved accessibility to public transport may not be equitable, showing greater benefit to the more advantaged.

November 25 | 2020

Association of the Built Environment With Childhood Psychosocial Stress.

Meredith FranklinXiaozhe YinRob McConnellScott Fruin.

JAMA Netw Open, 2020 Oct 1;3(10):e2017634. doi: 10.1001/jamanetworkopen.2020.17634.


Importance: Emerging research suggests that factors associated with the built environment, including artificial light, air pollution, and noise, may adversely affect children’s mental health, while living near green space may reduce stress. Little is known about the combined roles of these factors on children’s stress.

Objective: To investigate associations between components of the built environment with personal and home characteristics in a large cohort of children who were assessed for perceived stress.

Design, setting, and participants: In this cohort study, a total of 2290 Southern California Children’s Health Study participants residing in 8 densely populated urban communities responded to detailed questionnaires. Exposures of artificial light at night (ALAN) derived from satellite observations, near-roadway air pollution (NRP) determined from a dispersion model, noise estimated from the US Traffic Noise Model, and green space from satellite observations of the enhanced vegetation index were linked to each participant’s geocoded residence.

Main outcomes and measures: Children’s stress was assessed at ages 13 to 14 years and 15 to 16 years using the 4-item Perceived Stress Scale (PSS-4), scaled from 0 to 16, with higher scores indicating greater perceived stress. Measurements were conducted in 2010 and 2012, and data were analyzed from February 6 to August 24, 2019. Multivariate mixed-effects models were used to examine multiple exposures; modification and mediation analyses were also conducted.

Results: Among the 2290 children in this study, 1149 were girls (50%); mean (SD) age was 13.5 (0.6) years. Girls had significantly higher perceived stress measured by PSS-4 (mean [SD] score, 5.7 [3.4]) than boys (4.9 [3.2]). With increasing age (from 13.5 [0.6] to 15.3 [0.6] years), the mean PSS-4 score rose from 5.6 (3.3) to 6.0 (3.4) in girls but decreased for boys from 5.0 (3.2) to 4.7 (3.1). Multivariate mixed-effects models examining multiple exposures indicated that exposure to secondhand smoke in the home was associated with a 0.85 (95% CI, 0.46-1.24) increase in the PSS-4 score. Of the factors related to the physical environment, an interquartile range (IQR) increase in ALAN was associated with a 0.57 (95% CI, 0.05-1.09) unit increase in the PSS-4 score together with a 0.16 score increase per IQR increase of near-roadway air pollution (95% CI, 0.02-0.30) and a -0.24 score decrease per IQR increase of the enhanced vegetation index (95% CI, -0.45 to -0.04). Income modified the ALAN effect size estimate; participants in households earning less than $48 000 per year had significantly greater stress per IQR increase in ALAN. Sleep duration partially mediated the associations between stress and both enhanced vegetation index (17%) and ALAN (18%).

Conclusions and relevance: In this cohort study, children’s exposure to smoke at home in addition to residential exposure to ALAN and near-roadway air pollution were associated with increased perceived stress among young adolescent children. These associations appeared to be partially mitigated by more residential green space. The findings may support the promotion of increased residential green spaces to reduce pollution associated with the built environment, with possible mental health benefits for children.