Excess noise exposure in the workplace is an important occupational health issue, according to research published by the University of British Columbia.

The report was published in the Oct. 6 online edition ofOccupational and Environmental Medicine.

For the study, data was collected on 6,307 people aged 20 and older who took part in the U.S. National Health and Nutrition Examination Survey between 1999 and 2004.

The association between a noisy work environment and heart disease was particularly strong in those under 50 years of age, who were three to four times more likely to have angina or coronary artery disease or to have had a heart attack, according to the research results. Men and smokers in this age group were also at higher risk.

Diastolic blood pressure (the second number in a blood pressure reading) was higher than normal, a condition linked to serious heart problems, the researchers stated.

Employees exposed to loud noise at work were twice as likely to have a higher-than-normal diastolic blood pressure, a phenomenon known as isolated diastolic hypertension, the researchers found.

The authors speculated that stress caused by loud noise could resemble that sparked by sudden, strong emotion, which over time can lead chemical messengers to constrict blood flow through the coronary arteries.