Persistent Workplace Noise More Than Doubles Risk of Heart Disease
A persistently noisy workplace more than doubles an employee's risk of serious heart disease, suggests research published online in Occupational and Environmental Medicine. Young male smokers seem to be particularly at risk,according to the study's findings.
The researchers base their findings on a nationally representative sample of more than 6,000 U.S. employees, aged 20 and up, who had been part of the US National Health and Nutrition Examination Survey (NHANES) between 1999 and 2004.
This study included detailed household interviews, addressing lifestyle and occupational health, medical examinations, and blood tests.
Participants were grouped into those who endured persistent loud noise at work, to the extent that it was difficult to talk at normal volume for at least three months, and those working in more comfortable surroundings.
One in five (21-percent) workers said they put up with a noisy workplace for an average of almost nine consecutive months. This group, whose average age is 40, also tended to smoke and weigh more than their peers working in quieter work environments, adding to the group's risk factors for heart disease.
Workers in persistently noisy workplaces were between two to three times as likely to have serious heart problems as their peers in quiet workplaces.
The association to heart disease was particularly strong among workers under 50, who made up more than 4,500 of the total sample. They were between three and four times as likely to have angina or coronary artery disease or to have had a heart attack.
Blood tests of these workers did not indicate particularly high levels of cholesterol or inflammatory proteins, both of which are associated with heart disease. But diastolic blood pressure, which measures the pressure of the artery walls when the heart relaxes between heartbeats, was higher than normal, a condition known as isolated diastolic hypertension, or IDH. This is an independent predictor of serious heart problems.
The findings suggest that those employees regularly exposed to loud noise at work were twice as likely to have IDH.
The authors speculate that loud noise day after day may be as strong an external stressor as sudden strong emotion or physical exertion, the effect of which is to prompt various chemical messengers to constrict blood flow through the coronary arteries.
Researchers conclude: "This study suggests that excess noise exposure in the workplace is an important occupational health issue and deserves special attention."
Source: British Medical Journal (BMJ)