Air pollution exposure and self-reported cardiovascular disease☆
Introduction
The health effects of air pollution exposure are of interest to policy makers and scientists. In an effort to monitor air quality, the US Environmental Protection Agency (EPA) currently measures six criteria pollutants (nitrogen dioxide, sulfur dioxide, carbon monoxide, lead, ozone, and particulate matter—PM) for regulatory purposes (US Environmental Protection Agency, 2007a, US Environmental Protection Agency, 2007b). Much of the recent interest in air pollution has centered on particulate matter, which is a composite of other types of pollution ranging from solid to liquid particles emitted from various sources. This study focuses on the effects of PM with an aerodynamic diameter of less than or equal to 2.5 μm (PM2.5), which is sometimes referred to as “fine particles” (US Environmental Protection Agency, 2007a, US Environmental Protection Agency, 2007b). Fine PM remains suspended in the air longer and has been shown to have different associations with health than larger PM (Le Tertre et al., 2002; Samet et al., 2000; Schulz et al., 2005).
Associations between short-term exposure to PM2.5 and acute mortality (Le Tertre et al., 2002; Goldberg et al., 2003; Pope et al., 2006; Toren et al., 2007), hospital admissions for cardiac morbidity (Dominici et al., 2006; Tonne et al., 2007), and other cardiovascular markers, such as blood pressure (Urch et al., 2005), arrhythmia (Rich et al., 2005), and heart rate variability (Adar et al., 2007; Park et al., 2005) have been documented in several studies. Other studies have examined these outcomes as being associated with other specific air pollutants or traffic exposure (Gehring et al., 2006; Hoek et al., 2002).
Fewer studies have explored the health effects of long-term exposure to PM2.5 or other air pollutants. Some of these long-term exposure studies attempt to assess the temporal variability in pollution exposure through “natural experiments” such as the 13-month closure of a Utah Valley steel mill that was associated with a reduction in hospitalizations for cardiovascular events (Pope, 1996). A ban on sulfur-containing fuels was associated with a reduction in cardiovascular health problems in Hong Kong (Hedley et al., 2002). In the Southwestern United States, an 8-month strike at a copper smelter was associated with a large drop in sulfate PM and a slight reduction in hospitalizations (Pope et al., 2007).
In the United States, the Harvard Six Cities study, a long-term cohort study, showed that cardiovascular mortality due to an increase in pollution exposure remained after controlling for smoking and other individual factors (Dockery et al., 1993). The American Cancer Society (ACS) prospective cohort study on pollution exposure and mortality from 1982 to 1998 found that increases in PM2.5 were associated with cardiopulmonary mortality and lung cancer mortality (Pope III et al., 1995, Pope et al., 2002). A later analysis of women using data from the Women's Health Initiative (WHI; Miller et al., 2007) found similar results for mortality as well as increased non-fatal cardiac events. Cohort studies from Europe have also documented increased cardiovascular mortality with increased exposure to ambient air pollution (Nafstad et al., 2004) and increased exposure to traffic-related air pollution (Gehring et al., 2006; Rosenlund et al., 2008). For example, Hoek et al. (2002) found that cardiopulmonary mortality was associated with the distance a resident lived from a major road.
Other studies have examined the association between long-term exposure to air pollution and cardiovascular morbidities (Balluz et al., 2007; Rosenlund et al., 2008). Residential traffic studies have shown increases in acute myocardial infarction (Tonne et al., 2007) and clinical coronary heart disease (Hoffmann et al., 2006) among adults living close to major roadways. The increased long-term and short-term mortality associated with exposure to air pollution could be due to the exacerbation of underlying morbidities (Brook, 2005). With approximately 29% of American adults aged 18 years or older being hypertensive and 12% of adults reporting heart disease (NCHS, 2007), increasing our understanding of the possible effects of exposure to air pollution on cardiovascular morbidities could have implications for many people.
The aim of this study is to examine the associations between exposure to PM2.5 and two self-reported cardiovascular outcomes, hypertension, and heart disease, using a large nation-wide survey. Specifically, the objectives are to: (1) determine if there are relationships between PM2.5 exposure and self-reported rates of hypertension and heart disease, (2) determine whether there are factors that affect the associations between PM2.5 exposure and cardiovascular outcomes, and (3) determine if associations differ among subgroups defined by demographic or health-related factors.
Section snippets
National Health Interview Survey
This analysis is based on 1999–2005 data collected from the National Center for Health Statistics (NCHS) National Health Interview Survey (NHIS) and the EPA Air Quality System (AQS) database. The NHIS is a nationally representative health survey of the United States’ non-institutionalized civilian population (NCHS, NHIS, 2007). Data for the NHIS are collected from approximately 35,000 households annually, comprising nearly 100,000 people. One adult is randomly selected from each family to
Study subjects
Among sample adults that matched our study criteria, 25% (weighted percent) reported being told they had hypertension and 11.9% (weighted percent) reported heart disease (Table 1). The majority of the respondents were non-Hispanic white and between the ages of 30 and 49. High pollution levels were distributed evenly across most variables with a few exceptions. For example, more non-Hispanic black and Hispanic adults lived in areas with higher exposure values than non-Hispanic white adults (P
Discussion
We found that a 10 μg/m3 increase of PM2.5 was associated with a slight increase in self-reported adverse cardiovascular outcomes. After adjusting for the potentially confounding effects of smoking and health insurance, PM2.5 continued to be significantly associated with adverse cardiovascular outcomes. Associations were similar after adjustment for BMI and diabetes. Sensitivity analysis using different monitor radii to calculate pollution exposure led to results similar to those of our main
Conclusion
Studies of the relationship between diseases and long-term exposure to air pollution in the United States have been relatively few. Better exposure measures are being developed for local areas describing the pollution exposure levels within urban areas that may reduce exposure misclassification (Finkelstein et al., 2005). Developing nation-wide exposure measures to complement the large ongoing national surveys will help us understand associations and monitor trends. The findings from this
References (60)
- et al.
Cardiorespiratory and all-cause mortality after restrictions on sulphur content of fuel in Hong Kong: an intervention study
Lancet
(2002) - et al.
Association between mortality and indicators of traffic-related air pollution in the Netherlands: a cohort study
Lancet
(2002) - et al.
The influence of psychological and social factors on accuracy of self-reported blood pressure
Journal of Clinical Epidemiology
(1997) - et al.
Validity of a self-reported history of doctor-diagnosed angina
Journal of Clinical Epidemiology
(1999) - et al.
The riskscape and the color line examining the role of segregation in environmental health disparities
Environmental Research
(2006) - et al.
Air pollution and acute respiratory morbidity: an observational study of multiple pollutants
Environmental Research
(1989) The effects of pollution on work loss and morbidity
Journal of Environmental Economics and Management
(1983)- et al.
Focused exposures to airborne traffic particles and heart rate variability in the elderly
Epidemiology
(2007) - Balluz, L., Wen, X., Town, M., 2007. Ischemic heart disease and ambient air pollution of particulate matter 2.5 in 51...
You are what you breathe: evidence linking air pollution and blood pressure
Current Hypertension Reports
(2005)
Metabolic syndrome and inflammatory responses to long-term particulate air pollutants
Environmental Health Perspectives
Recall bias in epidemiologic studies
Journal of Clinical Epidemiology
Does income inequality modify the association between air pollution and health?
Environmental Research
Access to care as a predictor of patients’ knowledge of cardiovascular diseases
Journal of the National Medical Association
An association between air pollution and mortality in six US cities
New England Journal of Medicine
Racial/ethnic inequities in continuity and site of care: location, location, location
Health Services Research
Fine particulate air pollution and hospital admission for cardiovascular and respiratory diseases
Journal of the American Medical Association
Environmental inequality and circulatory disease mortality gradients
Journal of Epidemiology and Community Health
Relation between income, air pollution and mortality: a cohort study
Canadian Medical Association Journal
Socioeconomic status, particulate air pollution, and daily mortality: differential exposure or differential susceptibility
American Journal of Industrial Medicine
Long-term exposure to ambient air pollution and cardiopulmonary mortality in women
Epidemiology
Population disparities in asthma
Annual Review of Public Health
A review of time-series studies used to evaluate the short-term effects of air pollution on human health
Environmental Health Perspectives
Time series analysis of air pollution and mortality effects by cause, age and socioeconomic status
Journal of Epidemiology and Community Health
The burden of air pollution impacts among racial minorities
Environmental Health Perspectives
Residence close to high traffic and prevalence of coronary heart disease
European Heart Journal
Modeling the intraurban variability of ambient traffic pollution in Toronto, Canada
Journal of Toxicology and Environmental Health
Spatial analysis of air pollution and mortality in Los Angeles
Epidemiology
How active are older Americans?
Preventing Chronic Disease
Short-term effects of particulate air pollution on cardiovascular diseases in eight European cities
Journal of Epidemiology Community Health
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2021, Science of the Total EnvironmentCitation Excerpt :Finally, a total of 46 articles (57 studies) (Fuks et al., 2014; Braziene et al., 2020; Huang et al., 2019; Adar et al., 2018; Bai et al., 2018; Honda et al., 2018; Shamy et al., 2018; Xie et al., 2018; Zhang et al., 2018; Curto et al., 2019; Howell et al., 2019; Klompmaker et al., 2019; Lee et al., 2019; Li et al., 2019; Rammah et al., 2019; Weaver et al., 2019; Wu et al., 2019; Yang et al., 2019; Zhang et al., 2019; Arku et al., 2020; Li et al., 2020; Wu et al., 2020; Yan et al., 2020; Yu et al., 2020; Zhang et al., 2020; Lin et al., 2017; Liu et al., 2017; Chan et al., 2008; Johnson and Parker, 2009; Oudin et al., 2011; Coogan et al., 2012; Sorensen et al., 2012; Dong et al., 2013; Chen et al., 2014; Dong et al., 2014; Levinsson et al., 2014; Chan et al., 2015; Chen et al., 2015; Lazarevic et al., 2015; Coogan et al., 2016; Lee et al., 2016; Zhang et al., 2016; Coogan et al., 2017; Honda et al., 2017; Requia et al., 2017; Wallwork et al., 2017) met the inclusion criteria and were included in the meta-analysis for the long-term effect of ambient air pollution on hypertension risk, including 1 study of ultrafine particles, 3 of PM1, 1 of PM1–2.5, 39 of PM2.5, 24 of PM10, 16 of PM2.5–10, 28 of NO2, 17 of NOX, 5 of SO2, 5 of O3, and 2 of CO (Fig. 1, Table 1). A total of 53 studies (Fuks et al., 2014; Braziene et al., 2020; Huang et al., 2019; Adar et al., 2018; Bai et al., 2018; Shamy et al., 2018; Weaver et al., 2019; Wu et al., 2019; Yang et al., 2019; Zhang et al., 2019; Arku et al., 2020; Li et al., 2020; Wu et al., 2020; Yan et al., 2020; Yu et al., 2020; Zhang et al., 2020; Hu et al., 2020; Lin et al., 2017; Liu et al., 2017; Kim, 2004; Stroup et al., 2000; Stang, 2010; Moola et al., 2020; DerSimonian and Laird, 2015; Higgins et al., 2003a; Higgins et al., 2003b; Begg and Mazumdar, 1994; Chan et al., 2008; Johnson and Parker, 2009; Oudin et al., 2011; Coogan et al., 2012; Dong et al., 2013; Chen et al., 2014; Dong et al., 2014; Levinsson et al., 2014; Chan et al., 2015; Chen et al., 2015; Lazarevic et al., 2015; Coogan et al., 2016; Lee et al., 2016; Zhang et al., 2016; Coogan et al., 2017; Honda et al., 2017; Requia et al., 2017) investigated the long-term effect of air pollution on hypertension risk in adults, but only 4 (Zhang et al., 2019; Wu et al., 2020; Zhang et al., 2020; Dong et al., 2014) in children. The article by Fuks et al. (2014) included multiple studies which were treated as separate studies.
Long-Term Air Pollution and Blood Pressure in an African American Cohort: the Jackson Heart Study
2021, American Journal of Preventive Medicine
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Disclaimer: The findings and conclusions in this paper are those of the authors and do not necessarily represent the views of the National Center for Health Statistics, Centers for Disease Control and Prevention.