Paper of the Week | November 27 | 2017

Noise exposure while commuting in Toronto – a study of personal and public transportation in Toronto

Christopher M.K.L. Yao, Andrew K. Ma, Sharon L. Cushing and Vincent Y.W. Lin.

Journal of Otolaryngology – Head & Neck Surgery201746:62 https://doi.org/10.1186/s40463-017-0239-6 23 November 2017

Abstract

Background

With an increasing proportion of the population living in cities, mass transportation has been rapidly expanding to facilitate the demand, yet there is a concern that mass transit has the potential to result in excessive exposure to noise, and subsequently noise-induced hearing loss.

Methods

Noise dosimetry was used to measure time-integrated noise levels in a representative sample of the Toronto Mass Transit system (subway, streetcar, and buses) both aboard moving transit vehicles and on boarding platforms from April – August 2016. 210 measurements were conducted with multiple measurements approximating 2 min on platforms, 4 min within a vehicle in motion, and 10 min while in a car, on a bike or on foot. Descriptive statistics for each type of transportation, and measurement location (platform vs. vehicle) was computed, with measurement locations compared using 1-way analysis of variance.

Results

On average, there are 1.69 million riders per day, who are serviced by 69 subway stations, and 154 streetcar or subway routes. Average noise level was greater in the subway and bus than in the streetcar (79.8 +/− 4.0 dBA, 78.1 +/− 4.9 dBA, vs 71.5 +/−1.8 dBA, p < 0.0001). Furthermore, average noise measured on subway platforms were higher than within vehicles (80.9 +/− 3.9 dBA vs 76.8 +/− 2.6 dBA, p < 0.0001). Peak noise exposures on subway, bus and streetcar routes had an average of 109.8 +/− 4.9 dBA and range of 90.4–123.4 dBA, 112.3 +/− 6.0 dBA and 89.4–128.1 dBA, and 108.6 +/− 8.1 dBA and 103.5–125.2 dBA respectively. Peak noise exposures exceeded 115 dBA on 19.9%, 85.0%, and 20.0% of measurements in the subway, bus and streetcar respectively.

Conclusions

Although the mean average noise levels on the Toronto transit system are within the recommended level of safe noise exposure, cumulative intermittent bursts of impulse noise (peak noise exposures) particularly on bus routes have the potential to place individuals at risk for noise induced hearing

November 20 | 2017

Estimating the health benefits of planned public transit investments in Montreal.

Tétreault LF1, Eluru N2, Hatzopoulou M3, Morency P4, Plante C5, Morency C6, Reynaud F7, Shekarrizfard M3, Shamsunnahar Y2, Faghih Imani A7, Drouin L4, Pelletier A5, Goudreau S5, Tessier F5, Gauvin L8, Smargiassi A9.

Environ Res. 2017 Oct 23;160:412-419. https://doi.org/10.1016/j.envres.2017.10.025

BACKGROUND:

Since public transit infrastructure affects road traffic volumes and influences transportation mode choice, which in turn impacts health, it is important to estimate the alteration of the health burden linked with transit policies.

OBJECTIVE:

We quantified the variation in health benefits and burden between a business as usual (BAU) and a public transit (PT) scenarios in 2031 (with 8 and 19 new subway and train stations) for the greater Montreal region.

METHOD:

Using mode choice and traffic assignment models, we predicted the transportation mode choice and traffic assignment on the road network. Subsequently, we estimated the distance travelled in each municipality by mode, the minutes spent in active transportation, as well as traffic emissions. Thereafter we estimated the health burden attributed to air pollution and road traumas and the gains associated with active transportation for both the BAU and PT scenarios.

RESULTS:

We predicted a slight decrease of overall trips and kilometers travelled by car as well as an increase of active transportation for the PT in 2031 vs the BAU. Our analysis shows that new infrastructure will reduce the overall burden of transportation by 2.5 DALYs per 100,000 persons. This decrease is caused by the reduction of road traumas occurring in the inner suburbs and central Montreal region as well as gains in active transportation in the inner suburbs.

CONCLUSION:

Based on the results of our study, transportation planned public transit projects for Montreal are unlikely to reduce drastically the burden of disease attributable to road vehicles and infrastructures in the Montreal region. The impact of the planned transportation infrastructures seems to be very low and localized mainly in the areas where new public transit stations are planned.

 

November 13 | 2017

The Lancet Countdown on health and climate change: from 25 years of inaction to a global transformation for public health

Watts et al

The Lancet, DOI: http://dx.doi.org/10.1016/S0140-6736(17)32464-9

Summary

The Lancet Countdown tracks progress on health and climate change and provides an independent assessment of the health effects of climate change, the implementation of the Paris Agreement,1 and the health implications of these actions. It follows on from the work of the 2015 Lancet Commission on Health and Climate Change,2 which concluded that anthropogenic climate change threatens to undermine the past 50 years of gains in public health, and conversely, that a comprehensive response to climate change could be “the greatest global health opportunity of the 21st century”.

November 6 | 2017

The impact of urbanization and climate change on urban temperatures: a systematic review

Sarah Chapman, James E. M. Watson, Alvaro Salazar, Marcus Thatcher, Clive A. McAlpine

Landscape Ecology  October 2017, Volume 32, Issue 10, pp 1921–1935

https://link.springer.com/article/10.1007/s10980-017-0561-4

 

Abstract

Context

Cities have elevated temperatures compared to rural areas, a phenomenon known as the “urban heat island”. Higher temperatures increase the risk of heat-related mortality, which will be exacerbated by climate change.

Objectives

To examine the impact of climate change and urban growth on future urban temperatures and the potential for increased heat stress on urban residents.

Methods

We conducted a systematic review of scientific articles from Jan 2000 to May 2016.

Results

The majority (n = 49, = 86%) of studies examined climate change and the urban heat island in isolation, with few (8) considering their combined effect. Urban growth was found to have a large impact on local temperatures, in some cases by up to 5 °C in North-east USA. In some locations climate change increased the heat island, such as Chicago and Beijing, and in others decreased it, such as Paris and Brussels. When the relative impact of both factors was considered, the temperature increase associated with the urban heat island was always higher. Few studies (9) considered heat stress and its consequences for urban populations. Important contributors to urban temperatures, such as variation in urban density and anthropogenic heat release, were often excluded from studies.

Conclusions

We identify a need for an increased research focus on (1) urban growth impact on the urban heat island in climate change studies; (2) heat stress; and, (3) variation in urban density and its impacts on anthropogenic heat. Focussing on only one factor, climate change or urban growth, risks underestimating future urban temperatures and hampering adaptation.

October 30 | 2017

Healthy Cities of Tomorrow: the Case for Large Scale Built Environment-Health Studies.

Sarkar C , Webster C.

J Urban Health. 2017 Feb;94(1):4-19. DOI: 10.1007/s11524-016-0122-1

EXCERPT FROM INTRODUCTION: New scientific evidence generated over the past decade points to a significant role played by a myriad of attributes of our cities’ built environments (BE) in shaping human behaviour, health and well-being [3456]. This has resulted in a renaissance of interest in an environmentalmodel of public health, comprising interventions specific to physical and social environments [78]. We view this as similar to the wave of public health interest that gave birth to modern town planning in the mid to late twentieth century. Non-clinical environmental interventions in the form of health-specific planning and design of neighbourhoods and cities have been scientifically shown to have significant potential in playing a role in creating healthy cities of tomorrow. In addition to enabling healthier lifestyles, such interventions can produce higher cost effectiveness ratios in health service provision and can thus play a part in reducing future health expenditures [9]. The creation of healthy cities will entail a much closer integration and synergy between the disciplines of public health, epidemiology, transport planning, urban planning and design.

In the recent years several ongoing projects have emerged that aim specifically to measure health-specific components of urban environments at a large scale. The ultimate objective is to eventually link them with existing health cohorts enabling interdisciplinary collaborations and evidence generation towards creation of healthy cities. The Place, Health and Liveability project is one such national-level study aiming to create neighbourhood-level spatial measures of urban liveability across seven domains of employment, food, housing, public open space, social infrastructure, transport and walkability in Australia [10]. Algorithms measuring weighted street distance of individual dwellings to amenities and public transit have been developed to produce composite Walk Scores and Transit Scores in most US cities and some Canadian and Australian cities at the level of individual properties [11]. These are being linked with existing health cohorts to decipher associations with individual’s active travel behaviours [12]. Furthermore, there are many large scale health studies being conducted around the world, including the UK Biobank study (described in the subsequent section), 45 and Up Study in New South Wales, Australia1 (N = 250,000 participants); EpiHealth Study, Sweden2 (N = 300,000); China Kadoorie Biobank, China3 (N = 500,000); Million Death Study, India4 (N = 1,000,000) and Hong Kong FAMILY Cohort5 (N = 46,000) to name just a few. These present us (BE and urban planners and designers, epidemiologists, health economists, public health researchers and policy makers) with a well-timed opportunity to join expertise and resources for an integrated and multi-disciplinary global consortium to model and create national-level BE-health databases that can be turned into fine-tuned professional decision support and guidance systems. In the remaining part of this paper, we shall discuss some of the key issues and challenges in creation of healthy cities and ways to overcome them through interdisciplinary evidence generation on a large scale, planning and forecasting.

October 23 | 2017

A Difference-in-Differences Approach to Assess the Effect of a Heat Action Plan on Heat-Related Mortality, and Differences in Effectiveness According to Sex, Age, and Socioeconomic Status (Montreal, Quebec)

Benmarhnia T, Bailey Z, Kaiser D, Auger N, King N, Kaufman J.

Environ Health Perspect. 2016.  124:1694–1699; http://dx.doi.org/10.1289/EHP203

Abstract

Background: The impact of heat waves on mortality and health inequalities is well documented. Very few studies have assessed the effectiveness of heat action plans (HAPs) on health, and none has used quasi-experimental methods to estimate causal effects of such programs.

Objectives: We developed a quasi-experimental method to estimate the causal effects associated with HAPs that allows the identification of heterogeneity across subpopulations, and to apply this method specifically to the case of the Montreal (Quebec, Canada) HAP.

Methods: A difference-in-differences approach was undertaken using Montreal death registry data for the summers of 2000–2007 to assess the effectiveness of the Montreal HAP, implemented in 2004, on mortality. To study equity in the effect of HAP implementation, we assessed whether the program effects were heterogeneous across sex (male vs. female), age (≥ 65 years vs. < 65 years), and neighborhood education levels (first vs. third tertile). We conducted sensitivity analyses to assess the validity of the estimated causal effect of the HAP program.

Results: We found evidence that the HAP contributed to reducing mortality on hot days, and that the mortality reduction attributable to the program was greater for elderly people and people living in low-education neighborhoods.

Conclusion: These findings show promise for programs aimed at reducing the impact of extreme temperatures and health inequities. We propose a new quasi-experimental approach that can be easily applied to evaluate the impact of any program or intervention triggered when daily thresholds are reached.

October 16 | 2017

Urban greenness and mortality in Canada’s largest cities: a national cohort study

Dan L Crouse, Lauren Pinault, Adele Balram, Perry Hystad, Paul A Peters, Hong Chen, Aaron van Donkelaar, Randall V Martin, Richard Ménard, Alain Robichaud, Paul J Villeneuve

The Lancet Planetary Health Volume 1, Issue 7, October 2017, Pages e289-e29  DOI: http://dx.doi.org/10.1016/S2542-5196(17)30118-3

Summary

Background

Findings from published studies suggest that exposure to and interactions with green spaces are associated with improved psychological wellbeing and have cognitive, physiological, and social benefits, but few studies have examined their potential effect on the risk of mortality. We therefore undertook a national study in Canada to examine associations between urban greenness and cause-specific mortality.

Methods

We used data from a large cohort study (the 2001 Canadian Census Health and Environment Cohort [2001 CanCHEC]), which consisted of approximately 1·3 million adult (aged ≥19 years), non-immigrant, urban Canadians in 30 cities who responded to the mandatory 2001 Statistics Canada long-form census. The cohort has been linked by Statistics Canada to the Canadian mortality database and to annual income tax filings through 2011. We measured greenness with images from the moderate-resolution imaging spectroradiometer from NASA’s Aqua satellite. We assigned estimates of exposure to greenness derived from remotely sensed Normalized Difference Vegetation Index (NDVI) within both 250 m and 500 m of participants’ residences for each year during 11 years of follow-up (between 2001 and 2011). We used Cox proportional hazards models to estimate associations between residential greenness (as a continuous variable) and mortality. We estimated hazard ratios (HRs) and corresponding 95% CIs per IQR (0·15) increase in NDVI adjusted for personal (eg, education and income) and contextual covariates, including exposures to fine particulate matter, ozone, and nitrogen dioxide. We also considered effect modification by selected personal covariates (age, sex, household income adequacy quintiles, highest level of education, and marital status).

Findings

Our cohort consisted of approximately 1 265 000 individuals at baseline who contributed 11 523 770 person-years. We showed significant decreased risks of mortality in the range of 8–12% from all causes of death examined with increased greenness around participants’ residence. In the fully adjusted analyses, the risk was significantly decreased for all causes of death (non-accidental HR 0·915, 95% CI 0·905–0·924; cardiovascular plus diabetes 0·911, 0·895–0·928; cardiovascular 0·911, 0·894–0·928; ischaemic heart disease 0·904, 0·882–0·927; cerebrovascular 0·942, 0·902–0·983; and respiratory 0·899, 0·869–0·930). Greenness associations were more protective among men than women (HR 0·880, 95% CI 0·868–0·893 vs 0·955, 0·941–0·969), and among individuals with higher incomes (highest quintile 0·812, 0·791–0·834 vs lowest quintile 0·991, 0·972–1·011) and more education (degree or more 0·816, 0·791–0·842 vs did not complete high school 0·964, 0·950–0·978).

Interpretation

Increased amounts of residential greenness were associated with reduced risks of dying from several common causes of death among urban Canadians. We identified evidence of inequalities, both in terms of exposures to greenness and mortality risks, by personal socioeconomic status among individuals living in generally similar environments, and with reasonably similar access to health care and other social services. The findings support the development of policies related to creating greener and healthier cities.

October 10 | 2017

BlueHealth: a study programme protocol for mapping and quantifying the potential benefits to public health and well-being from Europe’s blue spaces.

Grellier J, White MP, Albin M, Bell S, Elliott LR, Gascón M, Gualdi S, Mancini L, Nieuwenhuijsen MJ, Sarigiannis DA, van den Bosch M, Wolf T, Wuijts S, Fleming LE.

BMJ Open. 2017 Jun 14;7(6)   http://dx.doi.org/10.1136/bmjopen-2017-016188

 

Abstract

INTRODUCTION:

Proximity and access to water have long been central to human culture and accordingly deliver countless societal benefits. Over 200 million people live on Europe’s coastline, and aquatic environments are the top recreational destination in the region. In terms of public health, interactions with ‘blue space’ (eg, coasts, rivers, lakes) are often considered solely in terms of risk (eg, drowning, microbial pollution). Exposure to blue space can, however, promote health and well-being and prevent disease, although underlying mechanisms are poorly understood.

AIMS AND METHODS:

The BlueHealth project aims to understand the relationships between exposure to blue space and health and well-being, to map and quantify the public health impacts of changes to both natural blue spaces and associated urban infrastructure in Europe, and to provide evidence-based information to policymakers on how to maximise health benefits associated with interventions in and around aquatic environments. To achieve these aims, an evidence base will be created through systematic reviews, analyses of secondary data sets and analyses of new data collected through a bespoke international survey and a wide range of community-level interventions. We will also explore how to deliver the benefits associated with blue spaces to those without direct access through the use of virtual reality. Scenarios will be developed that allow the evaluation of health impacts in plausible future societal contexts and changing environments. BlueHealth will develop key inputs into policymaking and land/water-use planning towards more salutogenic and sustainable uses of blue space, particularly in urban areas.

ETHICS AND DISSEMINATION:

Throughout the BlueHealth project, ethics review and approval are obtained for all relevant aspects of the study by the local ethics committees prior to any work being initiated and an ethics expert has been appointed to the project advisory board. So far, ethical approval has been obtained for the BlueHealth International Survey and for community-level interventions taking place in Spain, Italy and the UK. Engagement of stakeholders, including the public, involves citizens in many aspects of the project. Results of all individual studies within the BlueHealth project will be published with open access. After full anonymisation and application of any measures necessary to prevent disclosure, data generated in the project will be deposited into open data repositories of the partner institutions, in line with a formal data management plan. Other knowledge and tools developed in the project will be made available via the project website (www.bluehealth2020.eu). Project results will ultimately provide key inputs to planning and policy relating to blue space, further stimulating the integration of environmental and health considerations into decision-making, such that blue infrastructure is developed across Europe with both public health and the environment in mind.

October 2 | 2017

Association of Long-Term Exposure to Transportation Noise and Traffic-Related Air Pollution with the Incidence of Diabetes: A Prospective Cohort Study.

Clark C, Sbihi H, Tamburic L2, Brauer M, Frank LD, Davies HW.

Environ Health Perspect. 2017 Aug 31;125(8):087025.  https://doi.org/10.1289/EHP1279

Abstract

BACKGROUND:

Evidence for an association between transportation noise and cardiovascular disease has increased; however, few studies have examined metabolic outcomes such as diabetes or accounted for environmental coexposures such as air pollution, greenness, or walkability.

OBJECTIVES:

Because diabetes prevalence is increasing and may be on the causal pathway between noise and cardiovascular disease, we examined the influence of long-term residential transportation noise exposure and traffic-related air pollution on the incidence of diabetes using a population-based cohort in British Columbia, Canada.

METHODS:

We examined the influence of transportation noise exposure over a 5-y period (1994-1998) on incident diabetes cases in a population-based prospective cohort study (n=380,738) of metropolitan Vancouver (BC) residents who were 45-85 y old, with 4-y of follow-up (1999-2002). Annual average transportation noise (Lden), air pollution [black carbon, particulate matter with aerodynamic diameter <2.5μm (PM2.5), nitrogen oxides], greenness [Normalized Difference Vegetation Index (NDVI)], and neighborhood walkability at each participant’s residence were modeled. Incident diabetes cases were identified using administrative health records.

RESULTS:

Transportation noise was associated with the incidence of diabetes [interquartile range (IQR) increase, 6.8 A-weighted decibels (dBA); OR=1.08 (95% CI: 1.05, 1.10)]. This association remained after adjustment for environmental coexposures including traffic-related air pollutants, greenness, and neighborhood walkability. After adjustment for coexposure to noise, traffic-related air pollutants were not associated with the incidence of diabetes, whereas greenness was protective.

CONCLUSION:

We found a positive association between residential transportation noise and diabetes, adding to the growing body of evidence that noise pollution exposure may be independently linked to metabolic health and should be considered when developing public health interventions.

September 25 | 2017

Exposure to ambient air pollution and the incidence of dementia: A population-based cohort study.

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

Environ Int. 2017 Sep 13; 108: 271-277. https://doi.org/10.1016/j.envint.2017.08.020

Abstract

INTRODUCTION:

Emerging studies have implicated air pollution in the neurodegenerative processes. Less is known about the influence of air pollution, especially at the relatively low levels, on developing dementia. We conducted a population-based cohort study in Ontario, Canada, where the concentrations of pollutants are among the lowest in the world, to assess whether air pollution exposure is associated with incident dementia.

METHODS:

The study population comprised all Ontario residents who, on 1 April 2001, were 55-85years old, Canadian-born, and free of physician-diagnosed dementia (~2.1 million individuals). Follow-up extended until 2013. We used population-based health administrative databases with a validated algorithm to ascertain incident diagnosis of dementia as well as prevalent cases. Using satellite observations, land-use regression model, and an optimal interpolation method, we derived long-term average exposure to fine particulate matter (≤2.5μm in diameter) (PM2.5), nitrogen dioxide (NO2), and ozone (O3), respectively at the subjects’ historical residences based on a population-based registry. We used multilevel spatial random-effects Cox proportional hazards models, adjusting for individual and contextual factors, such as diabetes, brain injury, and neighborhood income. We conducted various sensitivity analyses, such as lagging exposure up to 10years and considering a negative control outcome for which no (or weaker) association with air pollution is expected.

RESULTS:

We identified 257,816 incident cases of dementia in 2001-2013. We found a positive association between PM2.5 and dementia incidence, with a hazard ratio (HR) of 1.04 (95% confidence interval (CI): 1.03-1.05) for every interquartile-range increase in exposure to PM2.5. Similarly, NO2 was associated with increased incidence of dementia (HR=1.10; 95% CI: 1.08-1.12). No association was found for O3. These associations were robust to all sensitivity analyses examined. These estimates translate to 6.1% of dementia cases (or 15,813 cases) attributable to PM2.5 and NO2, based on the observed distribution of exposure relative to the lowest quartile in concentrations in this cohort.

DISCUSSION:

In this large cohort, exposure to air pollution, even at the relative low levels, was associated with higher dementia incidence.