1
|
Pappin AJ, Charman N, Egyed M, Blagden P, Duhamel A, Miville J, Popadic I, Manseau PM, Marcotte G, Mashayekhi R, Racine J, Rittmaster R, Edwards B, Kipusi W, Smith-Doiron M. Attribution of fine particulate matter and ozone health impacts in Canada to domestic and US emission sources. Sci Total Environ 2024; 909:168529. [PMID: 37963524 DOI: 10.1016/j.scitotenv.2023.168529] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Revised: 11/03/2023] [Accepted: 11/10/2023] [Indexed: 11/16/2023]
Abstract
Exposure to ambient air pollution is associated with a wide range of adverse health effects such as respiratory symptoms, cardiovascular events, and premature mortality. Canada and the United States (US) have worked collaboratively for decades to address transboundary air pollution and its impacts across their shared border. To inform transboundary air quality considerations, we conducted modelling to attribute health impacts from ambient PM2.5 and O3 exposure in Canada to Canadian and US emission sources. We employed emissions, chemical transport, and health impacts modelling for 2015, 2025, and 2035 using a brute-force modelling approach whereby anthropogenic domestic and US emissions were reduced separately by 20 % or 100 %, and the resulting changes in health impacts were estimated across Canada. We find that transboundary PM2.5 and O3 related health impacts vary widely by region, with >80 % of impacts occurring in Central Canada, and most health impacts occurring within 200-300 km of the Canada-US border. The relative contribution of US sources to O3 in Canada is larger than for PM2.5, yet we find that the health impacts from transboundary PM2.5 exceeded those from transboundary O3. Nationally, we estimate that roughly one in five PM2.5 deaths in Canada is attributable to US sources (2000 deaths in 2015) and more than one in two O3 deaths are attributable to US sources (roughly 800 to 1200 deaths in 2015). We project health impacts from domestic and US sources to increase from 2025 to 2035 in Canada. Our results suggest that there are substantial benefits to be gained by domestic and international strategies to reduce PM2.5 in the Canada-US transboundary region.
Collapse
Affiliation(s)
- Amanda J Pappin
- Water and Air Quality Bureau, Safe Environments Directorate, Health Canada, Canada.
| | - Nick Charman
- Water and Air Quality Bureau, Safe Environments Directorate, Health Canada, Canada
| | - Marika Egyed
- Water and Air Quality Bureau, Safe Environments Directorate, Health Canada, Canada
| | - Phil Blagden
- Water and Air Quality Bureau, Safe Environments Directorate, Health Canada, Canada
| | - Annie Duhamel
- Air Quality Policy-Issue Response Section, Meteorological Service of Canada, Environment and Climate Change Canada, Canada
| | - Jessica Miville
- Air Quality Policy-Issue Response Section, Meteorological Service of Canada, Environment and Climate Change Canada, Canada
| | - Ivana Popadic
- Air Quality Policy-Issue Response Section, Meteorological Service of Canada, Environment and Climate Change Canada, Canada
| | - Patrick M Manseau
- Air Quality Policy-Issue Response Section, Meteorological Service of Canada, Environment and Climate Change Canada, Canada
| | - Guillaume Marcotte
- Air Quality Policy-Issue Response Section, Meteorological Service of Canada, Environment and Climate Change Canada, Canada
| | - Rabab Mashayekhi
- Air Quality Policy-Issue Response Section, Meteorological Service of Canada, Environment and Climate Change Canada, Canada
| | - Jacinthe Racine
- Canadian Centre for Climate Services, Environment and Climate Change Canada, Canada
| | - Robyn Rittmaster
- Risk Management Bureau, Safe Environments Directorate, Health Canada, Canada
| | - Betty Edwards
- Risk Management Bureau, Safe Environments Directorate, Health Canada, Canada
| | - Wambui Kipusi
- Risk Management Bureau, Safe Environments Directorate, Health Canada, Canada
| | - Marc Smith-Doiron
- Environmental Health Science and Research Bureau, Healthy Environments and Consumer Products Safety Branch, Health Canada, Canada
| |
Collapse
|
2
|
Weichenthal S, Pinault L, Christidis T, Burnett RT, Brook JR, Chu Y, Crouse DL, Erickson AC, Hystad P, Li C, Martin RV, Meng J, Pappin AJ, Tjepkema M, van Donkelaar A, Weagle CL, Brauer M. How low can you go? Air pollution affects mortality at very low levels. Sci Adv 2022; 8:eabo3381. [PMID: 36170354 PMCID: PMC9519036 DOI: 10.1126/sciadv.abo3381] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Accepted: 08/11/2022] [Indexed: 05/29/2023]
Abstract
The World Health Organization (WHO) recently released new guidelines for outdoor fine particulate air pollution (PM2.5) recommending an annual average concentration of 5 μg/m3. Yet, our understanding of the concentration-response relationship between outdoor PM2.5 and mortality in this range of near-background concentrations remains incomplete. To address this uncertainty, we conducted a population-based cohort study of 7.1 million adults in one of the world's lowest exposure environments. Our findings reveal a supralinear concentration-response relationship between outdoor PM2.5 and mortality at very low (<5 μg/m3) concentrations. Our updated global concentration-response function incorporating this new information suggests an additional 1.5 million deaths globally attributable to outdoor PM2.5 annually compared to previous estimates. The global health benefits of meeting the new WHO guideline for outdoor PM2.5 are greater than previously assumed and indicate a need for continued reductions in outdoor air pollution around the world.
Collapse
Affiliation(s)
- Scott Weichenthal
- McGill University, Montreal, QC, Canada
- Health Canada, Ottawa, ON, Canada
| | | | | | - Richard T. Burnett
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, USA
| | | | - Yen Chu
- University of British Columbia, Vancouver, BC, Canada
| | | | | | | | - Chi Li
- Dalhousie University, Halifax, NS, Canada
| | - Randall V. Martin
- Dalhousie University, Halifax, NS, Canada
- Washington University, Saint Louis, WA, USA
| | - Jun Meng
- Washington University, Saint Louis, WA, USA
- Air Quality Research Division, Environment and Climate Change Canada, Toronto, ON, Canada
| | | | | | - Aaron van Donkelaar
- Dalhousie University, Halifax, NS, Canada
- Washington University, Saint Louis, WA, USA
| | | | - Michael Brauer
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, USA
- University of British Columbia, Vancouver, BC, Canada
| |
Collapse
|
3
|
Brauer M, Brook JR, Christidis T, Chu Y, Crouse DL, Erickson A, Hystad P, Li C, Martin RV, Meng J, Pappin AJ, Pinault LL, Tjepkema M, van Donkelaar A, Weagle C, Weichenthal S, Burnett RT. Mortality-Air Pollution Associations in Low Exposure Environments (MAPLE): Phase 2. Res Rep Health Eff Inst 2022; 2022:1-91. [PMID: 36224709 PMCID: PMC9556709] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023] Open
Abstract
INTRODUCTION Mortality is associated with long-term exposure to fine particulate matter (particulate matter ≤2.5 μm in aerodynamic diameter; PM2.5), although the magnitude and form of these associations remain poorly understood at lower concentrations. Knowledge gaps include the shape of concentration-response curves and the lowest levels of exposure at which increased risks are evident and the occurrence and extent of associations with specific causes of death. Here, we applied improved estimates of exposure to ambient PM2.5 to national population-based cohorts in Canada, including a stacked cohort of 7.1 million people who responded to census year 1991, 1996, or 2001. The characterization of the shape of the concentration-response relationship for nonaccidental mortality and several specific causes of death at low levels of exposure was the focus of the Mortality-Air Pollution Associations in Low Exposure Environments (MAPLE) Phase 1 report. In the Phase 1 report we reported that associations between outdoor PM2.5 concentrations and nonaccidental mortality were attenuated with the addition of ozone (O3) or a measure of gaseous pollutant oxidant capacity (Ox), which was estimated from O3 and nitrogen dioxide (NO2) concentrations. This was motivated by our interests in understanding both the effects air pollutant mixtures may have on mortality and also the role of O3 as a copollutant that shares common sources and precursor emissions with those of PM2.5. In this Phase 2 report, we further explore the sensitivity of these associations with O3 and Ox, evaluate sensitivity to other factors, such as regional variation, and present ambient PM2.5 concentration-response relationships for specific causes of death. METHODS PM2.5 concentrations were estimated at 1 km2 spatial resolution across North America using remote sensing of aerosol optical depth (AOD) combined with chemical transport model (GEOS-Chem) simulations of the AOD:surface PM2.5 mass concentration relationship, land use information, and ground monitoring. These estimates were informed and further refined with collocated measurements of PM2.5 and AOD, including targeted measurements in areas of low PM2.5 concentrations collected at five locations across Canada. Ground measurements of PM2.5 and total suspended particulate matter (TSP) mass concentrations from 1981 to 1999 were used to backcast remote-sensing-based estimates over that same time period, resulting in modeled annual surfaces from 1981 to 2016. Annual exposures to PM2.5 were then estimated for subjects in several national population-based Canadian cohorts using residential histories derived from annual postal code entries in income tax files. These cohorts included three census-based cohorts: the 1991 Canadian Census Health and Environment Cohort (CanCHEC; 2.5 million respondents), the 1996 CanCHEC (3 million respondents), the 2001 CanCHEC (3 million respondents), and a Stacked CanCHEC where duplicate records of respondents were excluded (Stacked CanCHEC; 7.1 million respondents). The Canadian Community Health Survey (CCHS) mortality cohort (mCCHS), derived from several pooled cycles of the CCHS (540,900 respondents), included additional individual information about health behaviors. Follow-up periods were completed to the end of 2016 for all cohorts. Cox proportional hazard ratios (HRs) were estimated for nonaccidental and other major causes of death using a 10-year moving average exposure and 1-year lag. All models were stratified by age, sex, immigrant status, and where appropriate, census year or survey cycle. Models were further adjusted for income adequacy quintile, visible minority status, Indigenous identity, educational attainment, labor-force status, marital status, occupation, and ecological covariates of community size, airshed, urban form, and four dimensions of the Canadian Marginalization Index (Can-Marg; instability, deprivation, dependency, and ethnic concentration). The mCCHS analyses were also adjusted for individual-level measures of smoking, alcohol consumption, fruit and vegetable consumption, body mass index (BMI), and exercise behavior. In addition to linear models, the shape of the concentration-response function was investigated using restricted cubic splines (RCS). The number of knots were selected by minimizing the Bayesian Information Criterion (BIC). Two additional models were used to examine the association between nonaccidental mortality and PM2.5. The first is the standard threshold model defined by a transformation of concentration equaling zero if the concentration was less than a specific threshold value and concentration minus the threshold value for concentrations above the threshold. The second additional model was an extension of the Shape Constrained Health Impact Function (SCHIF), the eSCHIF, which converts RCS predictions into functions potentially more suitable for use in health impact assessments. Given the RCS parameter estimates and their covariance matrix, 1,000 realizations of the RCS were simulated at concentrations from the minimum to the maximum concentration, by increments of 0.1 μg/m3. An eSCHIF was then fit to each of these RCS realizations. Thus, 1,000 eSCHIF predictions and uncertainty intervals were determined at each concentration within the total range. Sensitivity analyses were conducted to examine associations between PM2.5 and mortality when in the presence of, or stratified by tertile of, O3 or Ox. Additionally, associations between PM2.5 and mortality were assessed for sensitivity to lower concentration thresholds, where person-years below a threshold value were assigned the mean exposure within that group. We also examined the sensitivity of the shape of the nonaccidental mortality-PM2.5 association to removal of person-years at or above 12 μg/m3 (the current U.S. National Ambient Air Quality Standard) and 10 μg/m3 (the current Canadian and former [2005] World Health Organization [WHO] guideline, and current WHO Interim Target-4). Finally, differences in the shapes of PM2.5-mortality associations were assessed across broad geographic regions (airsheds) within Canada. RESULTS The refined PM2.5 exposure estimates demonstrated improved performance relative to estimates applied previously and in the MAPLE Phase 1 report, with slightly reduced errors, including at lower ranges of concentrations (e.g., for PM2.5 <10 μg/m3). Positive associations between outdoor PM2.5 concentrations and nonaccidental mortality were consistently observed in all cohorts. In the Stacked CanCHEC analyses (1.3 million deaths), each 10-μg/m3 increase in outdoor PM2.5 concentration corresponded to an HR of 1.084 (95% confidence interval [CI]: 1.073 to 1.096) for nonaccidental mortality. For an interquartile range (IQR) increase in PM2.5 mass concentration of 4.16 μg/m3 and for a mean annual nonaccidental death rate of 92.8 per 10,000 persons (over the 1991-2016 period for cohort participants ages 25-90), this HR corresponds to an additional 31.62 deaths per 100,000 people, which is equivalent to an additional 7,848 deaths per year in Canada, based on the 2016 population. In RCS models, mean HR predictions increased from the minimum concentration of 2.5 μg/m3 to 4.5 μg/m3, flattened from 4.5 μg/m3 to 8.0 μg/m3, then increased for concentrations above 8.0 μg/m3. The threshold model results reflected this pattern with -2 log-likelihood values being equal at 2.5 μg/m3 and 8.0 μg/m3. However, mean threshold model predictions monotonically increased over the concentration range with the lower 95% CI equal to one from 2.5 μg/m3 to 8.0 μg/m3. The RCS model was a superior predictor compared with any of the threshold models, including the linear model. In the mCCHS cohort analyses inclusion of behavioral covariates did not substantially change the results for both linear and nonlinear models. We examined the sensitivity of the shape of the nonaccidental mortality-PM2.5 association to removal of person-years at or above the current U.S. and Canadian standards of 12 μg/m3 and 10 μg/m3, respectively. In the full cohort and in both restricted cohorts, a steep increase was observed from the minimum concentration of 2.5 μg/m3 to 5 μg/m3. For the full cohort and the <12 μg/m3 cohort the relationship flattened over the 5 to 9 μg/m3 range and then increased above 9 μg/m3. A similar increase was observed for the <10 μg/m3 cohort followed by a clear decline in the magnitude of predictions over the 5 to 9 μg/m3 range and an increase above 9 μg/m3. Together these results suggest that a positive association exists for concentrations >9 μg/m3 with indications of adverse effects on mortality at concentrations as low as 2.5 μg/m3. Among the other causes of death examined, PM2.5 exposures were consistently associated with an increased hazard of mortality due to ischemic heart disease, respiratory disease, cardiovascular disease, and diabetes across all cohorts. Associations were observed in the Stacked CanCHEC but not in all other cohorts for cerebrovascular disease, pneumonia, and chronic obstructive pulmonary disease (COPD) mortality. No significant associations were observed between mortality and exposure to PM2.5 for heart failure, lung cancer, and kidney failure. In sensitivity analyses, the addition of O3 and Ox attenuated associations between PM2.5 and mortality. When analyses were stratified by tertiles of copollutants, associations between PM2.5 and mortality were only observed in the highest tertile of O3 or Ox. Across broad regions of Canada, linear HR estimates and the shape of the eSCHIF varied substantially, possibly reflecting underlying differences in air pollutant mixtures not characterized by PM2.5 mass concentrations or the included gaseous pollutants. Sensitivity analyses to assess regional variation in population characteristics and access to healthcare indicated that the observed regional differences in concentration-mortality relationships, specifically the flattening of the concentration-mortality relationship over the 5 to 9 μg/m3 range, was not likely related to variation in the makeup of the cohort or its access to healthcare, lending support to the potential role of spatially varying air pollutant mixtures not sufficiently characterized by PM2.5 mass concentrations. CONCLUSIONS In several large, national Canadian cohorts, including a cohort of 7.1 million unique census respondents, associations were observed between exposure to PM2.5 with nonaccidental mortality and several specific causes of death. Associations with nonaccidental mortality were observed using the eSCHIF methodology at concentrations as low as 2.5 μg/m3, and there was no clear evidence in the observed data of a lower threshold, below which PM2.5 was not associated with nonaccidental mortality.
Collapse
Affiliation(s)
- M Brauer
- The University of British Columbia, Vancouver, British Columbia, Canada
- Institute for Health Metrics and Evaluation, University of Washington, Seattle, Washington
| | - J R Brook
- University of Toronto, Toronto, Ontario, Canada
| | - T Christidis
- Health Analysis Division, Statistics Canada, Ottawa, Ontario, Canada
| | - Y Chu
- The University of British Columbia, Vancouver, British Columbia, Canada
| | - D L Crouse
- University of New Brunswick, Fredericton, New Brunswick, Canada
| | - A Erickson
- The University of British Columbia, Vancouver, British Columbia, Canada
| | - P Hystad
- Oregon State University, Corvallis, Oregon
| | - C Li
- Dalhousie University, Halifax, Nova Scotia, Canada
| | - R V Martin
- Dalhousie University, Halifax, Nova Scotia, Canada
- Washington University, Saint Louis, Missouri
- Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts
| | - J Meng
- Dalhousie University, Halifax, Nova Scotia, Canada
| | - A J Pappin
- Health Analysis Division, Statistics Canada, Ottawa, Ontario, Canada
| | - L L Pinault
- Health Analysis Division, Statistics Canada, Ottawa, Ontario, Canada
| | - M Tjepkema
- Health Analysis Division, Statistics Canada, Ottawa, Ontario, Canada
| | | | - C Weagle
- Dalhousie University, Halifax, Nova Scotia, Canada
| | | | - R T Burnett
- Population Studies Division, Health Canada, Ottawa, Ontario, Canada
| |
Collapse
|
4
|
Zhao S, Russell MG, Hakami A, Capps SL, Turner MD, Henze DK, Percell PB, Resler J, Shen H, Russell AG, Nenes A, Pappin AJ, Napelenok SL, Bash JO, Fahey KM, Carmichael GR, Stanier CO, Chai T. A multiphase CMAQ version 5.0 adjoint. Geosci Model Dev 2020; 13:2925-2944. [PMID: 33343831 PMCID: PMC7745733 DOI: 10.5194/gmd-13-2925-2020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
We present the development of a multiphase adjoint for the Community Multiscale Air Quality (CMAQ) model, a widely used chemical transport model. The adjoint model provides location- and time-specific gradients that can be used in various applications such as backward sensitivity analysis, source attribution, optimal pollution control, data assimilation, and inverse modeling. The science processes of the CMAQ model include gas-phase chemistry, aerosol dynamics and thermodynamics, cloud chemistry and dynamics, diffusion, and advection. Discrete adjoints are implemented for all the science processes, with an additional continuous adjoint for advection. The development of discrete adjoints is assisted with algorithmic differentiation (AD) tools. Particularly, the Kinetic PreProcessor (KPP) is implemented for gas-phase and aqueous chemistry, and two different automatic differentiation tools are used for other processes such as clouds, aerosols, diffusion, and advection. The continuous adjoint of advection is developed manually. For adjoint validation, the brute-force or finite-difference method (FDM) is implemented process by process with box- or column-model simulations. Due to the inherent limitations of the FDM caused by numerical round-off errors, the complex variable method (CVM) is adopted where necessary. The adjoint model often shows better agreement with the CVM than with the FDM. The adjoints of all science processes compare favorably with the FDM and CVM. In an example application of the full multiphase adjoint model, we provide the first estimates of how emissions of particulate matter (PM2.5) affect public health across the US.
Collapse
Affiliation(s)
- Shunliu Zhao
- Department of Civil and Environmental Engineering, Carleton University, Ottawa, ON K1S 5B6, Canada
| | - Matthew G. Russell
- Department of Civil and Environmental Engineering, Carleton University, Ottawa, ON K1S 5B6, Canada
| | - Amir Hakami
- Department of Civil and Environmental Engineering, Carleton University, Ottawa, ON K1S 5B6, Canada
| | - Shannon L. Capps
- Civil, Architectural, and Environmental Engineering, Drexel University, Philadelphia, PA 19104, USA
| | | | - Daven K. Henze
- Mechanical Engineering Department, University of Colorado, Boulder, CO 80309, USA
| | - Peter B. Percell
- Department of Earth & Atmospheric Sciences, University of Houston, Houston, TX 77204, USA
| | - Jaroslav Resler
- Institute of Computer Science of the Czech Academy of Sciences, Prague, 182 07, Czech Republic
| | - Huizhong Shen
- School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, GA 30331, USA
| | - Armistead G. Russell
- School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, GA 30331, USA
| | - Athanasios Nenes
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA 30331, USA
- School of Architecture, Civil & Environmental Engineering, École polytechnique fédérale de Lausanne, 1015, Lausanne, Switzerland
- Institute for Chemical Engineering Sciences, Foundation for Research and Technology Hellas, Patras, 26504, Greece
| | - Amanda J. Pappin
- Air Health Effects Division, Health Canada, Ottawa, ON K1A 0K9, Canada
| | - Sergey L. Napelenok
- Atmospheric & Environmental Systems Modeling Division, U.S. EPA, Research Triangle Park, NC 27711, USA
| | - Jesse O. Bash
- Atmospheric & Environmental Systems Modeling Division, U.S. EPA, Research Triangle Park, NC 27711, USA
| | - Kathleen M. Fahey
- Atmospheric & Environmental Systems Modeling Division, U.S. EPA, Research Triangle Park, NC 27711, USA
| | - Gregory R. Carmichael
- Department of Chemical and Biochemical Engineering, University of Iowa, Iowa City, IA 52242, USA
| | - Charles O. Stanier
- Department of Chemical and Biochemical Engineering, University of Iowa, Iowa City, IA 52242, USA
| | - Tianfeng Chai
- College of Computer, Mathematical, and Natural Sciences, University of Maryland, College Park, MD 20742, USA
| |
Collapse
|
5
|
Brauer M, Brook JR, Christidis T, Chu Y, Crouse DL, Erickson A, Hystad P, Li C, Martin RV, Meng J, Pappin AJ, Pinault LL, Tjepkema M, van Donkelaar A, Weichenthal S, Burnett RT. Mortality-Air Pollution Associations in Low-Exposure Environments (MAPLE): Phase 1. Res Rep Health Eff Inst 2019; 2019:1-87. [PMID: 31909580 PMCID: PMC7334864] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023] Open
Abstract
INTRODUCTION Fine particulate matter (particulate matter ≤2.5 μm in aerodynamic diameter, or PM2.5) is associated with mortality, but the lower range of relevant concentrations is unknown. Novel satellite-derived estimates of outdoor PM2.5 concentrations were applied to several large population-based cohorts, and the shape of the relationship with nonaccidental mortality was characterized, with emphasis on the low concentrations (<12 μg/m3) observed throughout Canada. METHODS Annual satellite-derived estimates of outdoor PM2.5 concentrations were developed at 1-km2 spatial resolution across Canada for 2000-2016 and backcasted to 1981 using remote sensing, chemical transport models, and ground monitoring data. Targeted ground-based measurements were conducted to measure the relationship between columnar aerosol optical depth (AOD) and ground-level PM2.5. Both existing and targeted ground-based measurements were analyzed to develop improved exposure data sets for subsequent epidemiological analyses. Residential histories derived from annual tax records were used to estimate PM2.5 exposures for subjects whose ages ranged from 25 to 90 years. About 8.5 million were from three Canadian Census Health and Environment Cohort (CanCHEC) analytic files and another 540,900 were Canadian Community Health Survey (CCHS) participants. Mortality was linked through the year 2016. Hazard ratios (HR) were estimated with Cox Proportional Hazard models using a 3-year moving average exposure with a 1-year lag, with the year of follow-up as the time axis. All models were stratified by 5-year age groups, sex, and immigrant status. Covariates were based on directed acyclical graphs (DAG), and included contextual variables (airshed, community size, neighborhood dependence, neighborhood deprivation, ethnic concentration, neighborhood instability, and urban form). A second model was examined including the DAG-based covariates as well as all subject-level risk factors (income, education, marital status, indigenous identity, employment status, occupational class, and visible minority status) available in each cohort. Additional subject-level behavioral covariates (fruit and vegetable consumption, leisure exercise frequency, alcohol consumption, smoking, and body mass index [BMI]) were included in the CCHS analysis. Sensitivity analyses evaluated adjustment for covariates and gaseous copollutants (nitrogen dioxide [NO2] and ozone [O3]), as well as exposure time windows and spatial scales. Estimates were evaluated across strata of age, sex, and immigrant status. The shape of the PM2.5-mortality association was examined by first fitting restricted cubic splines (RCS) with a large number of knots and then fitting the shape-constrained health impact function (SCHIF) to the RCS predictions and their standard errors (SE). This method provides graphical results indicating the RCS predictions, as a nonparametric means of characterizing the concentration-response relationship in detail and the resulting mean SCHIF and accompanying uncertainty as a parametric summary. Sensitivity analyses were conducted in the CCHS cohort to evaluate the potential influence of unmeasured covariates on air pollution risk estimates. Specifically, survival models with all available risk factors were fit and compared with models that omitted covariates not available in the CanCHEC cohorts. In addition, the PM2.5 risk estimate in the CanCHEC cohort was indirectly adjusted for multiple individual-level risk factors by estimating the association between PM2.5 and these covariates within the CCHS. RESULTS Satellite-derived PM2.5 estimates were low and highly correlated with ground monitors. HR estimates (per 10-μg/m3 increase in PM2.5) were similar for the 1991 (1.041, 95% confidence interval [CI]: 1.016-1.066) and 1996 (1.041, 1.024-1.059) CanCHEC cohorts with a larger estimate observed for the 2001 cohort (1.084, 1.060-1.108). The pooled cohort HR estimate was 1.053 (1.041-1.065). In the CCHS an analogous model indicated a HR of 1.13 (95% CI: 1.06-1.21), which was reduced slightly with the addition of behavioral covariates (1.11, 1.04-1.18). In each of the CanCHEC cohorts, the RCS increased rapidly over lower concentrations, slightly declining between the 25th and 75th percentiles and then increasing beyond the 75th percentile. The steepness of the increase in the RCS over lower concentrations diminished as the cohort start date increased. The SCHIFs displayed a supralinear association in each of the three CanCHEC cohorts and in the CCHS cohort. In sensitivity analyses conducted with the 2001 CanCHEC, longer moving averages (1, 3, and 8 years) and smaller spatial scales (1 km2 vs. 10 km2) of exposure assignment resulted in larger associations between PM2.5 and mortality. In both the CCHS and CanCHEC analyses, the relationship between nonaccidental mortality and PM2.5 was attenuated when O3 or a weighted measure of oxidant gases was included in models. In the CCHS analysis, but not in CanCHEC, PM2.5 HRs were also attenuated by the inclusion of NO2. Application of the indirect adjustment and comparisons within the CCHS analysis suggests that missing data on behavioral risk factors for mortality had little impact on the magnitude of PM2.5-mortality associations. While immigrants displayed improved overall survival compared with those born in Canada, their sensitivity to PM2.5 was similar to or larger than that for nonimmigrants, with differences between immigrants and nonimmigrants decreasing in the more recent cohorts. CONCLUSIONS In several large population-based cohorts exposed to low levels of air pollution, consistent associations were observed between PM2.5 and nonaccidental mortality for concentrations as low as 5 μg/m3. This relationship was supralinear with no apparent threshold or sublinear association.
Collapse
Affiliation(s)
- M Brauer
- University of British Columbia, Vancouver, British Columbia, Canada
| | - J R Brook
- University of Toronto, Toronto, Ontario, Canada
| | - T Christidis
- Health Analysis Division, Statistics Canada, Ottawa, Ontario, Canada
| | - Y Chu
- University of British Columbia, Vancouver, British Columbia, Canada
| | - D L Crouse
- University of New Brunswick, Fredericton, New Brunswick, Canada
- New Brunswick Institute for Research, Data, and Training, Fredericton, New Brunswick, Canada
| | - A Erickson
- University of British Columbia, Vancouver, British Columbia, Canada
| | - P Hystad
- Oregon State University, Corvallis, Oregon, U.S.A
| | - C Li
- Dalhousie University, Halifax, Nova Scotia, Canada
| | - R V Martin
- Dalhousie University, Halifax, Nova Scotia, Canada
- Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts, U.S.A
| | - J Meng
- Dalhousie University, Halifax, Nova Scotia, Canada
| | - A J Pappin
- Health Analysis Division, Statistics Canada, Ottawa, Ontario, Canada
| | - L L Pinault
- Health Analysis Division, Statistics Canada, Ottawa, Ontario, Canada
| | - M Tjepkema
- Health Analysis Division, Statistics Canada, Ottawa, Ontario, Canada
| | | | | | - R T Burnett
- Population Studies Division, Health Canada, Ottawa, Ontario, Canada
| |
Collapse
|
6
|
Christidis T, Erickson AC, Pappin AJ, Crouse DL, Pinault LL, Weichenthal SA, Brook JR, van Donkelaar A, Hystad P, Martin RV, Tjepkema M, Burnett RT, Brauer M. Low concentrations of fine particle air pollution and mortality in the Canadian Community Health Survey cohort. Environ Health 2019; 18:84. [PMID: 31601202 PMCID: PMC6785886 DOI: 10.1186/s12940-019-0518-y] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Accepted: 08/13/2019] [Indexed: 05/07/2023]
Abstract
BACKGROUND Approximately 2.9 million deaths are attributed to ambient fine particle air pollution around the world each year (PM2.5). In general, cohort studies of mortality and outdoor PM2.5 concentrations have limited information on individuals exposed to low levels of PM2.5 as well as covariates such as smoking behaviours, alcohol consumption, and diet which may confound relationships with mortality. This study provides an updated and extended analysis of the Canadian Community Health Survey-Mortality cohort: a population-based cohort with detailed PM2.5 exposure data and information on a number of important individual-level behavioural risk factors. We also used this rich dataset to provide insight into the shape of the concentration-response curve for mortality at low levels of PM2.5. METHODS Respondents to the Canadian Community Health Survey from 2000 to 2012 were linked by postal code history from 1981 to 2016 to high resolution PM2.5 exposure estimates, and mortality incidence to 2016. Cox proportional hazard models were used to estimate the relationship between non-accidental mortality and ambient PM2.5 concentrations (measured as a three-year average with a one-year lag) adjusted for socio-economic, behavioural, and time-varying contextual covariates. RESULTS In total, 50,700 deaths from non-accidental causes occurred in the cohort over the follow-up period. Annual average ambient PM2.5 concentrations were low (i.e. 5.9 μg/m3, s.d. 2.0) and each 10 μg/m3 increase in exposure was associated with an increase in non-accidental mortality (HR = 1.11; 95% CI 1.04-1.18). Adjustment for behavioural covariates did not materially change this relationship. We estimated a supra-linear concentration-response curve extending to concentrations below 2 μg/m3 using a shape constrained health impact function. Mortality risks associated with exposure to PM2.5 were increased for males, those under age 65, and non-immigrants. Hazard ratios for PM2.5 and mortality were attenuated when gaseous pollutants were included in models. CONCLUSIONS Outdoor PM2.5 concentrations were associated with non-accidental mortality and adjusting for individual-level behavioural covariates did not materially change this relationship. The concentration-response curve was supra-linear with increased mortality risks extending to low outdoor PM2.5 concentrations.
Collapse
Affiliation(s)
- Tanya Christidis
- Health Analysis Division, Statistics Canada, 100 Tunney’s Pasture Driveway, Ottawa, Ontario K1A 0T6 Canada
| | - Anders C. Erickson
- School of Population and Public Health, The University of British Columbia, 2206 East Mall, Vancouver, British Columbia V6T 1Z3 Canada
| | - Amanda J. Pappin
- Health Analysis Division, Statistics Canada, 100 Tunney’s Pasture Driveway, Ottawa, Ontario K1A 0T6 Canada
- Safe Environments Directorate, Health Canada, 269 Laurier Avenue West, Ottawa, Ontario K1A 0K9 Canada
| | - Daniel L. Crouse
- Department of Sociology, University of New Brunswick, PO Box 4400, Fredericton, New Brunswick E3B 5A3 Canada
| | - Lauren L. Pinault
- Health Analysis Division, Statistics Canada, 100 Tunney’s Pasture Driveway, Ottawa, Ontario K1A 0T6 Canada
| | - Scott A. Weichenthal
- Department of Epidemiology, Biostatistics & Occupational Health, McGill University, 1110 Pine Ave West, Montreal, Quebec H3A 1A3 Canada
- Air Health Science Division, Health Canada, 269 Laurier Avenue West, Ottawa, Ontario K1A 0K0 Canada
| | - Jeffrey R. Brook
- Dalla Lana School of Public Health, University of Toronto, 155 College Street, Toronto, Ontario M5T 1P8 Canada
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, 223 College St., Toronto, ON M5T 1R4 Canada
| | - Aaron van Donkelaar
- Department of Physics and Atmospheric Science, Dalhousie University, 6310 Coburg Road, PO Box 15000, Halifax, NS B3H 4R2 Canada
- Department of Energy, Environmental & Chemical Engineering, Washington University in St. Louis, St. Louis, Missouri 63130 USA
| | - Perry Hystad
- College of Public Health and Human Sciences, Oregon State University, 2520 SW Campus Way, Corvallis, Oregon 97331 USA
| | - Randall V. Martin
- Department of Physics and Atmospheric Science, Dalhousie University, 6310 Coburg Road, PO Box 15000, Halifax, NS B3H 4R2 Canada
- Harvard-Smithsonian Center for Astrophysics, 60 Garden St, Cambridge, MA 02138 USA
- Department of Energy, Environmental & Chemical Engineering, Washington University in St. Louis, St. Louis, Missouri 63130 USA
| | - Michael Tjepkema
- Health Analysis Division, Statistics Canada, 100 Tunney’s Pasture Driveway, Ottawa, Ontario K1A 0T6 Canada
| | - Richard T. Burnett
- Population Studies Division, Health Canada, 50 Columbine Driveway, Ottawa, Ontario K1A 0K9 Canada
| | - Michael Brauer
- School of Population and Public Health, The University of British Columbia, 2206 East Mall, Vancouver, British Columbia V6T 1Z3 Canada
| |
Collapse
|
7
|
Pappin AJ, Christidis T, Pinault LL, Crouse DL, Brook JR, Erickson A, Hystad P, Li C, Martin RV, Meng J, Weichenthal S, van Donkelaar A, Tjepkema M, Brauer M, Burnett RT. Examining the Shape of the Association between Low Levels of Fine Particulate Matter and Mortality across Three Cycles of the Canadian Census Health and Environment Cohort. Environ Health Perspect 2019; 127:107008. [PMID: 31638837 PMCID: PMC6867181 DOI: 10.1289/ehp5204] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 09/18/2019] [Accepted: 09/18/2019] [Indexed: 05/19/2023]
Abstract
BACKGROUND Ambient fine particulate air pollution with aerodynamic diameter ≤2.5 μm (PM2.5) is an important contributor to the global burden of disease. Information on the shape of the concentration-response relationship at low concentrations is critical for estimating this burden, setting air quality standards, and in benefits assessments. OBJECTIVES We examined the concentration-response relationship between PM2.5 and nonaccidental mortality in three Canadian Census Health and Environment Cohorts (CanCHECs) based on the 1991, 1996, and 2001 census cycles linked to mobility and mortality data. METHODS Census respondents were linked with death records through 2016, resulting in 8.5 million adults, 150 million years of follow-up, and 1.5 million deaths. Using annual mailing address, we assigned time-varying contextual variables and 3-y moving-average ambient PM2.5 at a 1×1 km spatial resolution from 1988 to 2015. We ran Cox proportional hazards models for PM2.5 adjusted for eight subject-level indicators of socioeconomic status, seven contextual covariates, ozone, nitrogen dioxide, and combined oxidative potential. We used three statistical methods to examine the shape of the concentration-response relationship between PM2.5 and nonaccidental mortality. RESULTS The mean 3-y annual average estimate of PM2.5 exposure ranged from 6.7 to 8.0 μg/m3 over the three cohorts. We estimated a hazard ratio (HR) of 1.053 [95% confidence interval (CI): 1.041, 1.065] per 10-μg/m3 change in PM2.5 after pooling the three cohort-specific hazard ratios, with some variation between cohorts (1.041 for the 1991 and 1996 cohorts and 1.084 for the 2001 cohort). We observed a supralinear association in all three cohorts. The lower bound of the 95% CIs exceeded unity for all concentrations in the 1991 cohort, for concentrations above 2 μg/m3 in the 1996 cohort, and above 5 μg/m3 in the 2001 cohort. DISCUSSION In a very large population-based cohort with up to 25 y of follow-up, PM2.5 was associated with nonaccidental mortality at concentrations as low as 5 μg/m3. https://doi.org/10.1289/EHP5204.
Collapse
Affiliation(s)
- Amanda J Pappin
- Health Analysis Division, Statistics Canada, Ottawa, Ontario, Canada
| | - Tanya Christidis
- Health Analysis Division, Statistics Canada, Ottawa, Ontario, Canada
| | - Lauren L Pinault
- Health Analysis Division, Statistics Canada, Ottawa, Ontario, Canada
| | - Dan L Crouse
- Department of Sociology, University of New Brunswick, Fredericton, New Brunswick, Canada
- New Brunswick Institute for Research, Data, and Training, Fredericton, New Brunswick, Canada
| | - Jeffrey R Brook
- Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada
| | - Anders Erickson
- School of Population and Public Health, University of British Columbia, Vancouver, British Columbia, Canada
| | - Perry Hystad
- College of Public Health and Human Sciences, Oregon State University, Corvallis, Oregon, USA
| | - Chi Li
- Department of Physics and Atmospheric Science, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Randall V Martin
- Department of Physics and Atmospheric Science, Dalhousie University, Halifax, Nova Scotia, Canada
- Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts, USA
- Department of Energy, Environmental & Chemical Engineering, Washington University in St. Louis, St. Louis, Missouri, United States
| | - Jun Meng
- Department of Physics and Atmospheric Science, Dalhousie University, Halifax, Nova Scotia, Canada
- Department of Energy, Environmental & Chemical Engineering, Washington University in St. Louis, St. Louis, Missouri, United States
| | - Scott Weichenthal
- Department of Epidemiology, Biostatistics & Occupational Health, McGill University, Montreal, Quebec, Canada
- Air Health Science Division, Health Canada, Ottawa, Ontario, Canada
| | - Aaron van Donkelaar
- Department of Physics and Atmospheric Science, Dalhousie University, Halifax, Nova Scotia, Canada
- Department of Energy, Environmental & Chemical Engineering, Washington University in St. Louis, St. Louis, Missouri, United States
| | - Michael Tjepkema
- Health Analysis Division, Statistics Canada, Ottawa, Ontario, Canada
| | - Michael Brauer
- School of Population and Public Health, University of British Columbia, Vancouver, British Columbia, Canada
| | | |
Collapse
|
8
|
Pappin AJ, Mesbah SM, Hakami A, Schott S. Response to Comment on "Diminishing Returns or Compounding Benefits of Air Pollution Control? The Case of NO(x) and Ozone". Environ Sci Technol 2016; 50:502-503. [PMID: 26683230 DOI: 10.1021/acs.est.5b05889] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Affiliation(s)
- Amanda J Pappin
- Department of Civil and Environmental Engineering, Carleton University , Ottawa, Ontario, Canada K1S 5B6
| | - S Morteza Mesbah
- Department of Civil and Environmental Engineering, Carleton University , Ottawa, Ontario, Canada K1S 5B6
| | - Amir Hakami
- Department of Civil and Environmental Engineering, Carleton University , Ottawa, Ontario, Canada K1S 5B6
| | - Stephan Schott
- School of Public Policy and Administration, Carleton University , Ottawa, Ontario, Canada K1S 5B6
| |
Collapse
|
9
|
Pappin AJ, Hakami A. Attainment vs exposure: ozone metric responses to source-specific NOx controls using adjoint sensitivity analysis. Environ Sci Technol 2013; 47:13519-13527. [PMID: 24143935 DOI: 10.1021/es4024145] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
We establish linkages between sources of NOx emissions and two types of national ozone metrics in Canada and the U.S. using the adjoint of an air quality model. We define an attainment-based metric using probabilistic design values (PDVs) exceeding 65 ppb to represent polluted regions and define an exposure-based metric as the premature mortality count related to short-term ozone exposure, both in Canada and the U.S. Our results reveal differences in both temporally averaged and day-specific influences of NOx emission controls across source locations. We find NOx emission reductions in California and the eastern U.S. to be most effective for reducing attainment- and exposure-based metrics, amounting to a total reduction of 6500 ppb in PDVs and 613 deaths/season nationally from a 10% reduction in NOx emissions from those source locations. While source controls in the remainder of the western U.S. are beneficial at reducing nonattainment, these reductions are less influential on ozone mortality. We also find that while exposure-based metrics are sensitive to daily emission reductions, much of the reduction in PDVs arises from controlling emissions on only a fraction of simulation days. We further illustrate the dependency of adjoint estimates of emission influences on the choice of averaging period as a follow-up to previous work.
Collapse
Affiliation(s)
- Amanda J Pappin
- Department of Civil and Environmental Engineering, Carleton University , 1125 Colonel By Drive, Ottawa, ON, Canada K1S 5B6
| | | |
Collapse
|
10
|
Ingram MD, Pappin AJ, Delalande F, Poupard D, Terzulli G. Development of electrochemical capacitors incorporating processable polymer gel electrolytes. Electrochim Acta 1998. [DOI: 10.1016/s0013-4686(97)10060-3] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
11
|
Dawson IM, Pappin AJ, Peck CJ, Sammes PG. Pyrazine chemistry. Part 14. On the preparation and oxygenation of pyrazines and some reactions of the product peroxides. ACTA ACUST UNITED AC 1989. [DOI: 10.1039/p19890000453] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
12
|
Baulch DL, Griffiths JF, Pappin AJ, Sykes AF. Third-body interactions in the oscillatory oxidation of hydrogen in a well stirred flow reactor. ACTA ACUST UNITED AC 1988. [DOI: 10.1039/f19888401575] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|