Chronic disease prevalence in women and air pollution — A 30-year longitudinal cohort study
Introduction
The adverse health effects associated with exposure to ambient air pollution, particularly traffic-related pollution, have been well established. In recent years, there has been extensive literature suggesting an increased risk in the incidence and mortality of several chronic diseases in association with long-term exposure to air pollutants. The biological plausibility is that air pollutants may promote inflammation, oxidative stress and endothelial dysfunction that may contribute to the development of chronic conditions such as cardiovascular disease, hypertension and diabetes (Brook et al., 2004, Coogan et al., 2012, Johnson and Parker, 2009, Kramer et al., 2010, Pearson et al., 2010, Puett et al., 2011, EPA, 2008, EPA, 2009, EPA, 2013). In addition, air pollution has also been linked to the worsening of diseases of the pulmonary system, including asthma and chronic obstructive pulmonary disease (COPD) (To et al., 2013a, To et al., 2013b). Older adults living with a chronic condition such as hypertension, asthma and COPD may be at higher risk of having their conditions aggravated by exposure to air pollution.
A few population-based studies have quantified the association of air pollution exposure and incidence of chronic disease. For example, using data from Ontario, Canada, Chen et al., 2013, Chen et al., 2014 reported significantly elevated hazard ratios of incident hypertension and diabetes (HR = 1.13, 95% confidence interval: 1.05–1.22 and HR = 1.11; 95% CI: 1.02, 1.21, respectively) per 10-μg/m3 increase of PM2.5. Coogan et al. (2012) studied a cohort of 4204 women who lived in Los Angeles from 1995 to 2005 and reported elevated incidence rate ratios for hypertension and diabetes per unit (10 μg/m3) increase in fine particulate matter (PM2.5). Puett et al. (2011) used data from the final two years of a 23-year follow-up of the Nurses' Health Study and reported a statistically significant relative risk of type 2 diabetes per unit (4 μg/m3) increase of PM2.5. Johnson and Parker (2009) conducted cross-sectional analyses using the National Health Interview Survey data and reported statistically significant increased odds of self-reported prevalent hypertension associated with PM2.5.
In this study, we used a large population-based cohort of women with over 30 years of follow-up data to quantify the prevalence risks of cardiovascular conditions, cancers, diabetes and respiratory diseases in association with PM2.5 exposure. Since these conditions and diseases are chronic (i.e., with a relatively long duration), measures of disease prevalence would better characterize the burden of illness than incidence. A better understanding of the long-term risks of exposure to air pollution on these major chronic conditions will enable the development of new strategies to protect individuals at risk and reduce detrimental effects of air pollution on health as a whole.
Section snippets
Study population
The Canadian National Breast Screening Study (CNBSS) included 89,835 women between the ages of 40 and 59 recruited between 1980 and 1985 (Miller et al., 1992, Miller et al., 1996). The CNBSS was a randomized controlled trial of screening for breast cancer with the original objective of determining whether screening contributed to lower breast cancer mortality, as well as answering questions about what ages to screen and frequency of screening. Detailed risk factor data were collected using
Results
Table 1 shows the demographic characteristics of the ONBSS population. The study population consisted of 29,549 women with valid health card number for data linkage, which represented 92.4% of the total ONBSS cohort. Approximately 79% of these women were still alive at the end of the study (March 31, 2013) with a mean age of 77.3 years (± 6.3). The majority of the women were Canadian born (72.6%), married (81.1%), had at least completed high school education (81.4%) and were in the workforce
Discussion
To date, this is one of the largest longitudinal cohort studies examining the impact of air quality on the prevalence of major cardiovascular conditions, cancer, diabetes and respiratory diseases in women. This study estimated significant elevated prevalence per unit increase in PM2.5 for nine out of the ten chronic diseases studied.
The ONBSS study population consisted of nearly 30,000 women who were recruited for the CNBSS in the 1980s when they were between 40 and 59 years of age. The majority
Role of funding source
Funding for this study is provided by a research contract with Health Canada (Contract Reference #: 4500306095). Neither Health Canada nor ICES had any role in study design, analysis, interpretation of data, or writing of the report. The opinions, results and conclusions presented in this report are those of the authors and are independent from the funding sources. No endorsement by Health Canada or ICES is intended or should be inferred.
Contributors
TT and PV initiated and designed the study, interpreted findings and drafted the manuscript. JZ conducted all statistical analysis. JS, LF, CG and DW conducted a search of the literature, summarized relevant study findings and reviewed the manuscript. JS, HC, PV, SW, CW and ABM interpreted findings, reviewed and commented on drafts. All authors have seen and approved the final version.
Conflicts of interest
We declare that we have no conflicts of interest.
Acknowledgments
Data were provided by the CNBSS and ICES.
References (27)
- et al.
Long-term air pollution exposure and diabetes in a population-based Swiss cohort
Environ. Int.
(2014) - et al.
Air pollution exposure and self-reported cardiovascular disease
Environ. Res.
(2009) - et al.
Cumulative exposure to particulate matter air pollution and long-term post-myocardial infarction outcomes
Prev. Med.
(2013) - et al.
Air pollution and cardiovascular disease: a statement for healthcare professionals from the Expert Panel on Population and Prevention Science of the American Heart Association
Circulation
(2004) - et al.
Long-term fine particulate matter exposure and mortality from diabetes in Canada
Diabetes Care
(2013) - et al.
Risk of incident diabetes in relation to long-term exposure to fine particulate matter in Ontario, Canada
Environ. Health Perspect.
(2013) - et al.
Spatial association between ambient fine particulate matter and incident hypertension
Circulation
(2014) - et al.
Air pollution and incidence of hypertension and diabetes mellitus in black women living in Los Angeles
Circ. Res.
(2012) - et al.
Risk of nonaccidental and cardiovascular mortality in relation to long-term exposure to low concentrations of fine particulate matter: a Canadian national-level cohort study
Environ. Health Perspect.
(2012) Integrated Science Assessment for Oxides of Nitrogen — Health Criteria (Final Report)
(2008)
Integrated Science Assessment for Particulate Matter (Final Report)
Integrated Science Assessment of Ozone and Related Photochemical Oxidants (Final Report)
Overdiagnosis due to breast cancer screening: updated estimates of the Helsinki Service Study in Finland
Br. J. Cancer
Cited by (87)
Long-term PM<inf>2.5</inf> exposure and early-onset diabetes: Does BMI link this risk?
2024, Science of the Total EnvironmentAir pollution exposure and heart failure: A systematic review and meta-analysis
2023, Science of the Total EnvironmentLong-term residential exposure to source-specific particulate matter and incidence of diabetes mellitus — A cohort study in northern Sweden
2023, Environmental ResearchCitation Excerpt :A Canadian study comprising five population-based health surveys and satellite-derived PM2.5 concentrations, showed an 11% risk increase for DM per 10 μg/m3 in a setting with lower average exposure (Chen et al., 2013). Another Canadian cohort study, the Canadian National Breast Screening Study (CNBSS), demonstrated a 28% risk increase per 10 μg/m3 PM2.5 (To et al., 2015). Considering studies from Asia, a Chinese cohort of elderly in Hong Kong, a setting with a higher range of exposure, found an association between PM2.5 and a 55% risk increase of DM per 10 μg/m3 (Qiu et al., 2018).
How long-term air pollution and its metal constituents affect type 2 diabetes mellitus prevalence? Results from Wuhan Chronic Disease Cohort
2022, Environmental ResearchCitation Excerpt :Also, the elderly are more likely to have underlying medical conditions such as respiratory disease and cardiovascular disease, which may worsen the impact of persistent air pollution on oxidative stress and vasoconstriction (Ben-Shlomo and Kuh, 2002; Strain and Paldánius, 2018). Another possible reason is that compared with the young, older people are more frequently exposed to ambient air pollution because of outdoor activity (To et al., 2015). Interestingly, our study further indicated that different levels of income earners were unequally affected by PM2.5, PM10, and NO2.