Both fine-particle air pollution and noise pollution may increase a person's risk of developing cardiovascular disease, according to German researchers who have conducted a large population study, in which both factors were considered simultaneously.
"Many studies have looked at air pollution, while others have looked at noise pollution," said study leader Barbara Hoffmann, MD, MPH, a professor of environmental epidemiology at the IUF Leibniz Research Institute for Environmental Medicine in Germany. "This study looked at both at the same time and found that each form of pollution was independently associated with subclinical atherosclerosis."
The research will be presented at ATS 2013.
"This study is important because it says that both air pollution and noise pollution represent important health problems," said Dr. Philip Harber, a professor of public health at the University of Arizona who was not involved in the research. "In the past, some air pollution studies have been dismissed because critics said it was probably the noise pollution that caused the harm, and vice versa. Now we know that people who live near highways, for instance, are being harmed by air pollution and by noise pollution."
Using data from the Heinz Nixdorf Recall study, an ongoing population study from three neighboring cities in the Ruhr region of Germany, Dr. Hoffmann and her colleagues assessed the long-term exposure to fine particulate matter with an aerodynamic diameter <2.5 µm (PM2.5) and long-term exposure to traffic noise in 4238 study participants (mean age 60 years, 49.9% male).
The exposure to air pollutants was calculated using the EURopean Air Pollution Disperson, or EURAD, model. Exposure to traffic noise was calculated using European Union models of outdoor traffic noise levels. These levels were quantified as weighted 24-hour mean exposure (Lden) and nighttime exposure (Lnight).
To determine the association of the two variables with cardiovascular risk, the researchers looked at thoracic aortic calcification (TAC), a measure of subclinical atherosclerosis.
TAC was quantified using non-contrast enhanced electron beam computed tomography. Using multiple linear regression, the researchers controlled for other cardiovascular risk factors, including age, gender, education, unemployment, smoking status and history, exposure to second-hand smoke, physical activity, alcohol use and body mass index.