Road noise can expand waistlines, cause strokes and heart disease
Researchers at the London School of Hygiene & Tropical Medicine in partnership with Imperial College London and King's College London have found that long-term exposure to moderately loud or very loud traffic sounds during the daytime — the kind you'd experience after months to years of city dwelling — contributed to the risk of a shorter life expectancy.
"In this study, we observed that the risk of death from any cause was increased by 4% in areas with noise level over 60 decibels when compared to quieter areas," said study co-author Jaana Halonen. "Risk of death from ischemic heart disease was also increased by 3% in adults and 4% in the elderly in areas with daytime noise levels of 55-60 decibels, when compared to areas with noise levels under 55 decibels."
The researchers believe this happens because traffic noise can cause spikes in blood pressure and increased levels of stress hormones such as cortisol and noradrenaline, which can increase stress and sleep problems.
And all of these factors can raise your risk of cardiovascular conditions.
A new study by Swedish researchers, published in the journal Occupational & Environmental Medicine, found that being immersed on a daily basis in road noise — as well as noise from a nearby airport or rail station — can widen your waistline. Sixty-two percent of subjects regularly exposed to 45 decibels or higher of road, airport or rail noise had a 25% to 50% larger waist measurement than those not exposed to this noise. The researchers also found that road, airport and rail noises increase the body's production of the stress hormone cortisol, which affects metabolism.
Ongoing research by Danish scientist Mette Sorensen indicates that people 65 or older who live in high road noise areas were 27% more likely to suffer a stroke; what's more, Sorensen believes her results could indicate that up to 19% of all stroke cases could be due in whole or part to traffic noise. The damage is cumulative — the longer you live near the noise, the higher your stroke risk. Interestingly too, Sorensen found the main factor contributing to these strokes is Type 2 diabetes. Her findings indicate this is because road noise lowers one's ability to get quality sleep, which causes decreased glucose tolerance.
So is it time to move?
Keep the research in perspective, experts say. Individual responses to road noise is not universal.
"For some people, daily exposure to road noise may not be so stressful — these people can habituate to that stress effect much better than others," says Dr. Emeran Mayer, professor and director of the Oppenheimer Family Center for Neurobiology of Stress at UCLA. "Their brains may be more resilient in that way. Other people, especially those whose genetic makeup may predispose them to obesity, for example, may experience health problems due to road noise stress."
Source: Los Angeles Magazine www.lamag.com