Journal Article

Long-Term Exposure to Constituents of Fine Particulate Air Pollution and Mortality: Results from the California Teachers Study

Hertz, Andrew, Garcia, Cynthia, Ostro, Bart, Lipsett, Michael, Bernstein, Leslie, Reynolds, Peggy, Goldberg, Debbie, Henderson, Katherine D.

2010

Overview

Background: Several studies have reported associations between long-term exposure to ambient fine particulate matter (PM) and cardiovascular mortality. However, the health impacts of long-term exposure to specific constituents of ${\\rm PM}_{2.5}$ (PM with aerodynamic diameter ≤ 2.5 μm) have not been explored. Methods: We used data from the California Teachers Study, a prospective cohort of active and former female public school professionals. We developed estimates of long-term exposures to ${\\rm PM}_{2.5}$ and several of its constituents, including elemental carbon, organic carbon (OC), sulfates, nitrates, iron, potassium, silicon, and zinc. Monthly averages of exposure were created using pollution data from June 2002 through July 2007. We included participants whose residential addresses were within 8 and 30 km of a monitor collecting ${\\rm PM}_{2.5}$ constituent data. Hazard ratios (HRs) were estimated for long-term exposure for mortality from all nontraumatic causes, cardiopulmonary disease, ischemic heart disease (IHD), and pulmonary disease. Results: Approximately 45,000 women with 2,600 deaths lived within 30 km of a monitor. We observed associations of all-cause, cardiopulmonary, and IHD mortality with ${\\rm PM}_{2.5}$ mass and each of its measured constituents, and between pulmonary mortality and several constituents. For example, for cardiopulmonary mortality, HRs for interquartile ranges of ${\\rm PM}_{2.5}$, OC, and sulfates were 1.55 [95% confidence interval (CI), 1.43-1.69], 1.80 (95% CI, 1.68-1.93), and 1.79 (95% CI, 1.58-2.03), respectively. Subsequent analyses indicated that, of the constituents analyzed, OC and sulfates had the strongest associations with all four outcomes. Conclusions: Long-term exposures to ${\\rm PM}_{2.5}$ and several of its constituents were associated with increased risks of all-cause and cardiopulmonary mortality in this cohort. Constituents derived from combustion of fossil fuel (including diesel), as well as those of crustal origin, were associated with some of the greatest risks. These results provide additional evidence that reduction of ambient ${\\rm PM}_{2.5}$ may provide significant public health benefits.

• Publisher: National Institute of Environmental Health Sciences,US Department of Health and Human Services
• Subject: Adult / Aged / Aged, 80 and over / Air / Air pollution / Biological and medical sciences / California / Carbon / Cardiovascular diseases / Cardiovascular Diseases - chemically induced / Cardiovascular Diseases - epidemiology / Cardiovascular Diseases - etiology / Cardiovascular Diseases - mortality / Chemical hazards / Cohort Studies / Environment. Living conditions / Environmental agencies / Environmental aspects / Environmental Exposure - adverse effects / Environmental Exposure - analysis / Environmental health / Environmental pollutants toxicology / Epidemiology / Exposure / Faculty / Female / Health aspects / Humans / Lung Diseases - chemically induced / Lung Diseases - epidemiology / Lung Diseases - etiology / Lung Diseases - mortality / Medical sciences / Metals / Middle Aged / Mortality / Myocardial ischemia / Nitrates / Organic carbon / Organic Chemicals / Particle Size / Particulate matter / Particulate Matter - adverse effects / Particulate Matter - chemistry / Pollutants / Public health / Public health. Hygiene / Public health. Hygiene-occupational medicine / Risk Factors / Smoke / Sulfates / Time Factors / Toxicology / United States / Young Adult