August 13 | 2018

Comparing the Normalized Difference Vegetation Index with the Google Street View Measure of Vegetation to Assess Associations between Greenness, Walkability, Recreational Physical Activity, and Health in Ottawa, Canada

Paul J. Villeneuve, Renate L. Ysseldyk, Ariel Root, Sarah Ambrose, Jason DiMuzio, Neerija Kumar, Monica Shehata, Min Xi, Evan Seed, Xiaojiang Li, Mahdi Shooshtari, and Daniel Rainham.

Int. J. Environ. Res. Public Health 201815(8),1719;


The manner in which features of the built environment, such as walkability and greenness, impact participation in recreational activities and health are complex. We analyzed survey data provided by 282 Ottawa adults in 2016. The survey collected information on participation in recreational physical activities by season, and whether these activities were performed within participants’ neighbourhoods. The SF-12 instrument was used to characterize their overall mental and physical health. Measures of active living environment, and the satellite derived Normalized Difference Vegetation Index (NDVI) and Google Street View (GSV) greenness indices were assigned to participants’ residential addresses. Logistic regression and least squares regression were used to characterize associations between these measures and recreational physical activity, and self-reported health. The NDVI was not associated with participation in recreational activities in either the winter or summer, or physical or mental health. In contrast, the GSV was positively associated with participation in recreational activities during the summer. Specifically, those in the highest quartile spent, on average, 5.4 more hours weekly on recreational physical activities relative to those in the lowest quartile (p = 0.01). Active living environments were associated with increased utilitarian walking, and reduced reliance on use of motor vehicles. Our findings provide support for the hypothesis that neighbourhood greenness may play an important role in promoting participation in recreational physical activity during the summer.

August 7 | 2018

Effect of Greening Vacant Land on Mental Health of Community-Dwelling Adults  A Cluster Randomized Trial

Eugenia C. South, MD, MS; Bernadette C. Hohl, PhD; Michelle C. Kondo, PhD; John M. MacDonald, PhD; Charles C. Branas, PhD.

JAMA Network Open. 2018;1(3):e180298.doi:10.1001/jamanetworkopen.2018.0298

And Invited Commentary doi:10.1001/jamanetworkopen.2018.0299


Importance Neighborhood physical conditions have been associated with mental illness and may partially explain persistent socioeconomic disparities in the prevalence of poor mental health.

Objective To evaluate whether interventions to green vacant urban land can improve self-reported mental health.

Design, Setting, and Participants This citywide cluster randomized trial examined 442 community-dwelling sampled adults living in Philadelphia, Pennsylvania, within 110 vacant lot clusters randomly assigned to 3 study groups. Participants were followed up for 18 months preintervention and postintervention. This trial was conducted from October 1, 2011, to November 30, 2014. Data were analyzed from July 1, 2015, to April 16, 2017.

Interventions  The greening intervention involved removing trash, grading the land, planting new grass and a small number of trees, installing a low wooden perimeter fence, and performing regular monthly maintenance. The trash cleanup intervention involved removal of trash, limited grass mowing where possible, and regular monthly maintenance. The control group received no intervention.

Main Outcomes and Measures Self-reported mental health measured by the Kessler-6 Psychological Distress Scale and the components of this scale.

Results  A total of 110 clusters containing 541 vacant lots were enrolled in the trial and randomly allocated to the following 1 of 3 study groups: the greening intervention (37 clusters [33.6%]), the trash cleanup intervention (36 clusters [32.7%]), or no intervention (37 clusters [33.6%]). Of the 442 participants, the mean (SD) age was 44.6 (15.1) years, 264 (59.7%) were female, and 194 (43.9%) had a family income less than $25 000. A total of 342 participants (77.4%) had follow-up data and were included in the analysis. Of these, 117 (34.2%) received the greening intervention, 107 (31.3%) the trash cleanup intervention, and 118 (34.5%) no intervention. Intention-to-treat analysis of the greening intervention compared with no intervention demonstrated a significant decrease in participants who were feeling depressed (−41.5%; 95% CI, −63.6% to −5.9%; P = .03) and worthless (−50.9%; 95% CI, −74.7% to −4.7%; P = .04), as well as a nonsignificant reduction in overall self-reported poor mental health (−62.8%; 95% CI, −86.2% to 0.4%; P = .051). For participants living in neighborhoods below the poverty line, the greening intervention demonstrated a significant decrease in feeling depressed (−68.7%; 95% CI, −86.5% to −27.5%; P = .007). Intention-to-treat analysis of those living near the trash cleanup intervention compared with no intervention showed no significant changes in self-reported poor mental health.

Conclusions and Relevance Among community-dwelling adults, self-reported feelings of depression and worthlessness were significantly decreased, and self-reported poor mental health was nonsignificantly reduced for those living near greened vacant land. The treatment of blighted physical environments, particularly in resource-limited urban settings, can be an important treatment for mental health problems alongside other patient-level treatments.

July 30 | 2018

Associations between Living Near Water and Risk of Mortality among Urban Canadians.

Crouse DL, Balram A, Hystad P, Pinault L, van den Bosch M, Chen H, Rainham D, Thomson EM, Close CH, van Donkelaar A, Martin RV, Ménard R, Robichaud A, Villeneuve PJ.

Environ Health Perspect. 2018 Jul 24;126(7):077008. eCollection 2018 Jul.


BACKGROUND: Increasing evidence suggests that residential exposures to natural environments, such as green spaces, are associated with many health benefits. Only a single study has examined the potential link between living near water and mortality.

OBJECTIVE: We sought to examine whether residential proximity to large, natural water features (e.g., lakes, rivers, coasts, “blue space”) was associated with cause-specific mortality.

METHODS: Our study is based on a population-based cohort of nonimmigrant adults living in the 30 largest Canadian cities [i.e., the 2001 Canadian Census Health and Environment Cohort) (CanCHEC)]. Subjects were drawn from the mandatory 2001 Statistics Canada long-form census, who were linked to the Canadian mortality database and to annual income-tax filings, through 2011. We estimated associations between living within of blue space and deaths from several common causes of death. We adjusted models for many personal and contextual covariates, as well as for exposures to residential greenness and ambient air pollution.

RESULTS: Our cohort included approximately 1.3 million subjects at baseline, 106,180 of whom died from nonaccidental causes during follow-up. We found significant, reduced risks of mortality in the range of 12-17% associated with living within of water in comparison with living farther away, among all causes of death examined, except with external/accidental causes. Protective effects were found to be higher among women and all older adults than among other subjects, and protective effects were found to be highest against deaths from stroke and respiratory-related causes.

CONCLUSIONS: Our findings suggest that living near blue spaces in urban areas has important benefits to health, but further work is needed to better understand the drivers of this association.

July 23 | 2018

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

Matz CJ, Stieb DM, Egyed M, Brion O, Johnson M. 

Air Qual Atmos Health. 2018;11(2):209-220. DOI: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.

July 16 | 2018

Environmental Determinants of Insufficient Sleep and Sleep Disorders: Implications for Population Health.

Johnson DA, Billings ME, Hale L.

Curr Epidemiol Rep. 2018 Jun;5(2):61-69. DOI:10.1007/s40471-018-0139-y .



Sleep is important for overall health and well-being. Insufficient sleep and sleep disorders are highly prevalent among adults and children and therefore a public health burden, particularly because poor sleep is associated with adverse health outcomes. Emerging evidence has demonstrated that environmental factors at the household- and neighborhood-level can alter healthy sleep. This paper will (1) review recent literature on the environmental determinants of sleep among adults as well as children and adolescents; and (2) discuss the opportunities and challenges for advancing research on the environment and sleep.


Epidemiologic research has shown that social features of environments, family, social cohesion, safety, noise, and neighborhood disorder can shape and/or impact sleep patterns; and physical features such as light, noise, traffic, pollution, and walkability can also influence sleep and is related to sleep disorders among adults and children. Prior research has mainly measured one aspect of the environment, relied on self-reported sleep, which does not correlate well with objective measures, and investigated cross-sectional associations. Although most studies are conducted among non-Hispanic white populations, there is growing evidence that indicates that minority populations are particularly vulnerable to the effects of the environment on insufficient sleep and sleep disorders.


There is clear evidence that environmental factors are associated with insufficient sleep and sleep disorders. However, more research is warranted to evaluate how and which environmental factors contribute to sleep health. Interventions that target changes in the environment to promote healthy sleep should be developed, tested, and evaluated as a possible pathway for ameliorating sleep health disparities and subsequently health disparities.

July 9 | 2018

Long-term exposure to air pollution and the incidence of multiple sclerosis: A population-based cohort study.

Bai L, Burnett RT, Kwong JC, Hystad P, van Donkelaar A, Brook JR, Tu K, Copes R, Goldberg MS, Martin RV, Murray BJ, Kopp A, Chen H.

Environ Res. 2018 Jun 22;166:437-443.  [Epub ahead of print] DOI:10.1016/j.envres.2018.06.003



Evidence of the adverse neurological effects of exposure to ambient air pollution is emerging, but little is known about its effect on the development of multiple sclerosis (MS), the most common autoimmune disease of the central nervous system.


To investigate the associations between MS incidence and long-term exposures to fine particles (PM2.5), nitrogen dioxide (NO2), and ozone (O3) METHODS: We conducted a population-based cohort study to investigate the associations between long-term exposures to PM2.5, NO2, and O3 and the incidence of MS. Our study population included all Canadian-born residents aged 20-40 years who lived in the province of Ontario, Canada from 2001 to 2013. Incident MS was ascertained from a validated registry. We assigned estimates of annual concentrations of these pollutants to the residential postal codes of subjects for each year during the 13 years of follow-up. We estimated hazard ratios (HRs) and 95% confidence intervals (CIs) for each pollutant separately using random-effects Cox proportional hazards models. We conducted various sensitivity analyses, such as lagging exposure up to 5 years and adjusting for access to neurological care, annual average temperature, and population density.


Between 2001 and 2013, we identified 6203 incident cases of MS. The adjusted HR of incident MS was 0.96 (95% CI: 0.86-1.07) for PM2.5, 0.91(95% CI: 0.81-1.02) for NO2, and 1.09 (95% CI: 0.98-1.23) for O3. These results were robust to various sensitivity analyses conducted.


In this large population-based cohort, we did not observe significant associations between MS incidence and long-term exposures to PM2.5, NO2, and O3 in adults in Ontario, 2001-2013.

June 25 | 2018

The Association of Long-Term Exposure to Particulate Matter Air Pollution with Brain MRI Findings: The ARIC Study

Melinda C. Power, Archana P. Lamichhane, Duanping Liao, Xiaohui Xu, Clifford R. Jack Jr., Rebecca F. Gottesman, Thomas Mosley, James D. Stewart, Jeff D. Yanosky, and Eric A. Whitsel

Environ Health Perspect; February 2018 Vol 126 Issue 2.


BACKGROUND: Increasing evidence links higher particulate matter (PM) air pollution exposure to late-life cognitive impairment. However, few studies have considered associations between direct estimates of long-term past exposures and brain MRI findings indicative of neurodegeneration or cerebrovascular disease.

OBJECTIVE: Our objective was to quantify the association between brain MRI findings and PM exposures approximately 5 to 20 y prior to MRI in the Atherosclerosis Risk in Communities (ARIC) study.

METHODS: ARIC is based in four U.S. sites: Washington County, Maryland; Minneapolis suburbs, Minnesota; Forsyth County, North Carolina; and Jackson, Mississippi. A subset of ARIC participants underwent 3T brain MRI in 2011–2013 (n=1,753). We estimated mean exposures to PM with an aerodynamic diameter less than 10 or 2.5μm (PM10 and PM2.5) in 1990–1998, 1999–2007, and 1990–2007 at the residential addresses of eligible participants with MRI data. We estimated site-specific associations between PM and brain MRI findings and used random-effect, inverse variance–weighted meta-analysis to combine them.

RESULTS: In pooled analyses, higher mean PM2.5 and PM10 exposure in all time periods were associated with smaller deep-gray brain volumes, but not other MRI markers. Higher PM2.5 exposures were consistently associated with smaller total and regional brain volumes in Minnesota, but not elsewhere.

CONCLUSIONS: Long-term past PM exposure in was not associated with markers of cerebrovascular disease. Higher long-term past PM exposures were associated with smaller deep-gray volumes overall, and higher PM2.5 exposures were associated with smaller brain volumes in the Minnesota site. Further work is needed to understand the sources of heterogeneity across sites.

June 11 | 2018

Do green neighbourhoods promote urban health justice?

Isabelle Anguelovski, Helen Cole, James Connolly, Margarita Triguero-Mas

The Lancet, Public Health. Vol 3, No. 6, e270 June 2018


For the past 30 years, a search for social and health justice has shaped many cities in North America and Europe. Residents of these cities have mobilised to address the effects of neighbourhood disinvestment, pollution, harmful land uses, and low-quality green spaces on health. In cities such as Leipzig or Barcelona, these movements have transformed neighbourhoods. However, while green amenities are important selling points for attracting high-income populations, the resulting increased property values shape a new conundrum, embodied in the exclusion and displacement associated with so-called green gentrification

June 4 | 2018

Healthy cities: key to a healthy future in China

William Summerskill, Helena Hui Wang, Richard Horton

The Lancet, Vol 391, No. 10135, p2086–2087, 26 May 2018 DOI:


By 2030, up to one in eight people will live in a city in China. As urbanisation accelerates around the world, and particularly in Asia, the pivotal role of cities to influence the health of their inhabitants has never been greater. Hence, the UN Sustainable Development Goal 11 is to make cities inclusive, safe, resilient, and sustainable.


May 21 | 2018

Kernel Density Estimation as a Measure of Environmental Exposure Related to Insulin Resistance in Breast Cancer Survivors

Marta M. Jankowska, Loki Natarajan, Suneeta Godbole, Kristin Meseck, Dorothy D. Sears, Ruth E. Patterson and Jacqueline Kerr

Cancer Epidemiol Biomarkers Prev; 26(7); 1078–84. Published July 2017

DOI: 10.1158/1055-9965.EPI-16-0927



Environmental factors may influence breast cancer; however, most studies have measured environmental exposure in neighborhoods around home residences (static exposure). We hypothesize that tracking environmental exposures over time and space (dynamic exposure) is key to assessing total exposure. This study compares breast cancer survivors’ exposure to walkable and recreation-promoting environments using dynamic Global Positioning System (GPS) and static home-based measures of exposure in relation to insulin resistance.


GPS data from 249 breast cancer survivors living in San Diego County were collected for one week along with fasting blood draw. Exposure to recreation spaces and walkability was measured for each woman’s home address within an 800 m buffer (static), and using a kernel density weight of GPS tracks (dynamic). Participants’ exposure estimates were related to insulin resistance (using the homeostatic model assessment of insulin resistance, HOMA-IR) controlled by age and body mass index (BMI) in linear regression models.


The dynamic measurement method resulted in greater variability in built environment exposure values than did the static method. Regression results showed no association between HOMA-IR and home-based, static measures of walkability and recreation area exposure. GPS-based dynamic measures of both walkability and recreation area were significantly associated with lower HOMA-IR (P < 0.05).


Dynamic exposure measurements may provide important evidence for community- and individual-level interventions that can address cancer risk inequities arising from environments wherein breast cancer survivors live and engage.

Impact: This is the first study to compare associations of dynamic versus static built environment exposure measures with insulin outcomes in breast cancer survivors.