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.
October 2 | 2017
/in Paper of the Week /by Eleanor SettonAssociation 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.
Does Living in Greener Areas and Near Water Affect Mortality? | October 10 | 2017 | VIDEO AVAILABLE
/in Webinars /by Eleanor SettonOctober 10, 2017
9am – 10am pacific | 12 noon – 1pm eastern
Hear the latest results based on an analysis of the Canadian Census Health and Environment Cohort, from Dr. Dan Crouse and Adele Balram, University of New Brunswick.
Dan L Crouse is a Research Associate in the Department of Sociology at UNB. He is trained in both epidemiology and geography, and has led and been involved in many studies examining the impacts of exposure to air pollution on adverse health outcomes, including risk of mortality, adverse birth outcomes, and incidence of cancer. He lead the first Canadian Census Health and Environment Cohort (CanCHEC) study to examine associations between mortality and long-term exposures to fine particulate matter, which was published in 2012, and has published several other studies with CanCHEC since then.
Adele Balram is a Database Analyst with the New Brunswick Institute for Research, Data, and Training. She holds a Bachelor of Science degree in Biology from the University of New Brunswick and a Master of Public Health from Memorial University in Newfoundland. Adele has several years’ experience in public health, including working as an epidemiologist on environmental and community health issues across New Brunswick.
Both Dr. Crouse and Ms. Balram are supported by the Maritime SPOR Support Unit (MSSU), which receives financial support from the Canadian Institutes of Health Research (CIHR), the Nova Scotia Department of Health and Wellness, the New Brunswick Department of Health, the Nova Scotia Health Research Foundation (NSHRF), and the New Brunswick Health Research Foundation (NBHRF).
Lead author and CANUE Director Dan Crouse talks about his recent paper on Radio Canada. http://www.rcinet.ca/en/2017/
September 25 | 2017
/in Paper of the Week /by Eleanor SettonExposure 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.
September 18 | 2017
/in Paper of the Week /by Eleanor SettonEstimated Changes in Life Expectancy and Adult Mortality Resulting from Declining PM2.5 Exposures in the Contiguous United States: 1980–2010
Neal Fann, Sun-Young Kim, Casey Olives, and Lianne Sheppard.
Environ Health Perspect. 2017; Vol 125, Issue 9. https://doi.org/10.1289/EHP507
ABSTRACT
Background: PM2.5 precursor emissions have declined over the course of several decades, following the implementation of local, state, and federal air quality policies. Estimating the corresponding change in population exposure and PM2.5-attributable risk of death prior to the year 2000 is made difficult by the lack of PM2.5 monitoring data.
Objectives: We used a new technique to estimate historical PM2.5 concentrations, and estimated the effects of changes in PM2.5 population exposures on mortality in adults (age ≥30 y), and on life expectancy at birth, in the contiguous United States during 1980–2010.
Methods: We estimated annual mean county-level PM2.5 concentrations in 1980, 1990, 2000, and 2010 using universal kriging incorporating geographic variables. County-level death rates and national life tables for each year were obtained from the U.S. Census and Centers for Disease Control and Prevention. We used log-linear and nonlinear concentration–response coefficients from previous studies to estimate changes in the numbers of deaths and in life years and life expectancy at birth, attributable to changes in PM2.5.
Results: Between 1980 and 2010, population-weighted PM2.5 exposures fell by about half, and the estimated number of excess deaths declined by about a third. The States of California, Virginia, New Jersey, and Georgia had some of the largest estimated reductions in PM2.5-attributable deaths. Relative to a counterfactual population with exposures held constant at 1980 levels, we estimated that people born in 2050 would experience an ∼1-y increase in life expectancy at birth, and that there would be a cumulative gain of 4.4 million life years among adults ≥30 y of age.
Conclusions: Our estimates suggest that declines in PM2.5 exposures between 1980 and 2010 have benefitted public health.
CANUE Health Data Holders Survey
/in Reports /by Eleanor SettonUnderstanding technical, procedural and functional needs of major health data holders.
In May and June of 2017, representatives of 22 health data platforms were interviewed to gain a better understanding of how best to format and transfer CANUE data for integration and analysis.
CANUE Health Data Holder Survey
September 11 | 2017
/in Paper of the Week /by Eleanor SettonBeyond the Normalized Difference Vegetation Index (NDVI): Developing a Natural Space Index for population-level health research.
Rugel EJ, Henderson SB, Carpiano RM, Brauer M.
Environ Res. 2017 Aug 29; 159:474-483. doi: 10.1016/j.envres.2017.08.033
Abstract
BACKGROUND:
Natural spaces can provide psychological benefits to individuals, but population-level epidemiologic studies have produced conflicting results. Refining current exposure-assessment methods is necessary to advance our understanding of population health and to guide the design of health-promoting urban forms.
OBJECTIVES:
The aim of this study was to develop a comprehensive Natural Space Index that robustly models potential exposure based on the presence, form, accessibility, and quality of multiple forms of greenspace (e.g., parks and street trees) and bluespace (e.g., oceans and lakes).
MATERIAL AND METHODS:
The index was developed for greater Vancouver, Canada. Greenness presence was derived from remote sensing (NDVI/EVI); forms were extracted from municipal and private databases; and accessibility was based on restrictions such as private ownership. Quality appraisals were conducted for 200 randomly sampled parks using the Public Open Space Desktop Appraisal Tool (POSDAT). Integrating these measures in GIS, exposure was assessed for 60,242 postal codes using 100- to 1,600-m buffers based on hypothesized pathways to mental health. A single index was then derived using principal component analysis (PCA).
RESULTS:
Comparing NDVI with alternate approaches for assessing natural space resulted in widely divergent results, with quintile rankings shifting for 22-88% of postal codes, depending on the measure. Overall park quality was fairly low (mean of 15 on a scale of 0-45), with no significant difference seen by neighborhood-level household income. The final PCA identified three main sets of variables, with the first two components explaining 68% of the total variance. The first component was dominated by the percentages of public and private greenspace and bluespace and public greenspace within 250m, while the second component was driven by lack of access to bluespace within 1 km.
CONCLUSIONS:
Many current approaches to modeling natural space may misclassify exposures and have limited specificity. The Natural Space Index represents a novel approach at a regional scale with application to urban planning and policy-making.
September 5 | 2017
/in Paper of the Week /by Eleanor SettonAssociations of Pregnancy Outcomes and PM2.5 in a National Canadian Study
Stieb DM, Chen L, Beckerman BS, Jerrett M, Crouse DL, Omariba DW, Peters PA, van Donkelaar A, Martin RV, Burnett RT, Gilbert NL, Tjepkema M, Liu S, Dugandzic RM.
Environ Health Perspect. 2016 Feb;124(2):243-9. doi: 10.1289/ehp.1408995
ABSTRACT
Background
Numerous studies have examined associations between air pollution and pregnancy outcomes, but most have been restricted to urban populations living near monitors.
Objectives
We examined the association between pregnancy outcomes and fine particulate matter in a large national study including urban and rural areas.
Methods
Analyses were based on approximately 3 million singleton live births in Canada between 1999 and 2008. Exposures to PM2.5(particles of median aerodynamic diameter ≤ 2.5 μm) were assigned by mapping the mother’s postal code to a monthly surface based on a national land use regression model that incorporated observations from fixed-site monitoring stations and satellite-derived estimates of PM2.5. Generalized estimating equations were used to examine the association between PM2.5 and preterm birth (gestational age < 37 weeks), term low birth weight (< 2,500 g), small for gestational age (SGA; < 10th percentile of birth weight for gestational age), and term birth weight, adjusting for individual covariates and neighborhood socioeconomic status (SES).
Results
In fully adjusted models, a 10-μg/m3 increase in PM2.5 over the entire pregnancy was associated with SGA (odds ratio = 1.04; 95% CI 1.01, 1.07) and reduced term birth weight (–20.5 g; 95% CI –24.7, –16.4). Associations varied across subgroups based on maternal place of birth and period (1999–2003 vs. 2004–2008).
Conclusions
This study, based on approximately 3 million births across Canada and employing PM2.5 estimates from a national spatiotemporal model, provides further evidence linking PM2.5 and pregnancy outcomes.
Navigating the Data Merge | September 20 | 26 | 28 |2017 | PRESENTATION NOW AVAILABLE
/in Webinars /by Eleanor Setton9am – 10:30am pacific | 12 noon – 1:30pm eastern
Do you manage a cohort, health survey, or administrative health database? Please join us for an overview of our upcoming urban environmental exposure data release, and a discussion of logistics for receiving and merging our data with yours.
We will be giving the same overview on September 20th, 26th and 28th to accommodate as many of you as possible. Just choose the most convenient date!
Read the recently completed CANUE Health Data Holder Survey, identifying opportunities and issues for data merging.
AGENDA
Introduction of CANUE team
Overview of data sets
themes (air pollution, greenness,etc.)
format
documentation
conditions for use
Data delivery and merging
planned delivery dates
push and pull model
ad hoc requests
CANUE tool development
unique exposure combinations tool
temporal aggregation tool
spatial aggregation tool
Q/A and discussion
New Opportunities for Weather and Health Research | September 21 | 2017 | VIDEOS NOW AVAILABLE
/in Webinars /by Eleanor SettonEnvironment Canada is currently working on the 2.5 km High Resolution Deterministic Prediction system (HRDPS), expected to become operational next year.
This webinar-style meeting will highlight some of the health databases that CANUE researchers typically use, and provide an overview of these new weather/climate datasets. The overall objective of the meeting is to explore the utility of HRDPS data sets for conducting health research, and identify which health databases might be of most interest, as a first step in working together to advance our research agendas.
AGENDA
Presentation: CANUE
Overview of cohorts/health databases and opportunities for weather/climate research
Presentation: Environment Canada
HRDPS model/outputs, reanalysis opportunities
Discussion
Priorities for data development/linkage
August 28 | 2017
/in Paper of the Week /by Eleanor SettonOutdoor Light at Night and Breast Cancer Incidence in the Nurses’ Health Study II
Peter James, Kimberly A. Bertrand, Jaime E. Hart, Eva S. Schernhammer, Rulla M. Tamimi, and Francine Laden
Environmental Health Perspectives, August 2017, Volume 125 Issue 8, https://doi.org/10.1289/EHP935
BACKGROUND:
Animal and epidemiologic studies suggest that exposure to light at night (LAN) may disrupt circadian patterns and decrease nocturnal secretion of melatonin, which may disturb estrogen regulation, leading to increased breast cancer risk.
OBJECTIVES:
We examined the association between residential outdoor LAN and breast cancer incidence using data from the nationwide U.S.-based Nurses’ Health Study II cohort.
METHODS:
We followed 109,672 women from 1989 through 2013. Cumulative LAN exposure was estimated using time-varying satellite data for a composite of persistent nighttime illumination at ∼1 km2 scale for each residence during follow-up. Incident invasive breast cancer cases were confirmed by medical record review. We used Cox proportional hazard models to calculate hazard ratios (HRs) and 95% confidence intervals (CIs), adjusting for anthropometric, reproductive, lifestyle, and socioeconomic risk factors.
RESULTS:
Over 2,187,425 person-years, we identified 3,549 incident breast cancer cases. Based on a fully adjusted model, the estimated HR for incident breast cancer with an interquartile range (IQR) (31.6 nW/cm2/sr) increase in cumulative average outdoor LAN was 1.05 (95% CI: 1.00, 1.11). An association between LAN and breast cancer appeared to be limited to women who were premenopausal at the time of a case [HR=1.07 (95% CI: 1.01, 1.14) based on 1,973 cases vs. HR=1.00 (95% CI: 0.91, 1.09) based on 1,172 cases in postmenopausal women; p-interaction=0.08]. The LAN–breast cancer association was observed only in past and current smokers at the end of follow-up [HR=1.00 (95% CI: 0.94, 1.07) based on 2,215 cases in never smokers; HR=1.10 (95% CI: 1.01, 1.19) based on 1,034 cases in past smokers vs. HR=1.21 (95% CI: 1.07, 1.37) for 300 cases in current smokers; p-interaction=0.08].
CONCLUSIONS:
Although further work is required to confirm our results and to clarify potential mechanisms, our findings suggest that exposure to residential outdoor light at night may contribute to invasive breast cancer risk.