High blood pressure and high cholesterol — two risk factors for heart disease — are more common among workers exposed to loud noise in their workplaces, according to a recent study from the Centers for Disease Control and Prevention (CDC).

The findings, which were published in the American Journal of Industrial Medicine, add to growing concerns that the health hazards from noise exposure go beyond an increased risk of hearing loss.

Indeed, other research has suggested that loud noise triggers a stress response that, over time, can have a harmful effect on the body’s blood vessels and lead to an increased risk of heart disease.

About 22 million workers are affected by loud noise each year, making it one of the most common workplace hazards in the United States. Noise is considered hazardous, according to the CDC, when it reaches a level of 85 decibels or higher — a level at which a person would have to raise his or her voice to speak with someone three feet away. 

“Reducing workplace noise levels is critical not just for hearing loss prevention — it may also impact blood pressure and cholesterol,” said Dr. John Howard, director of the CDC’s National Institute for Occupational Safety and Health (NIOSH), in a released statement.

“Worksite health and wellness programs that include screenings for high blood pressure and cholesterol should also target noise-exposed workers,” he added 

Linking noise to health problems

For the current study, NIOSH researchers analyzed data from a representative sample of almost 23,000 U.S. workers who participated in the 2014 National Health Interview Survey. That year’s survey was chosen because it was the most recent one that included questions about occupational noise and hearing problems.

The researchers specifically looked at how many of the workers were regularly exposed to loud noise, how many had hearing problems, and how many had high blood pressure or high cholesterol. Here are the key findings from the analysis:

• About 25 percent of the workers had a history of on-the-job exposure to potentially damaging levels of noise, and about 14 percent of them had been exposed to such levels of noise during the previous year.
• About 12 percent of the workers had a hearing loss. The researchers estimated that 58 percent of those cases could be attributed to the workers’ exposure to excessive workplace-related noise.
• About 24 percent of the workers had high blood pressure, and about 28 percent had high cholesterol. The researchers estimated that 14 percent of the high blood pressure cases and 9 percent of the high cholesterol ones could be attributed to occupational noise.

The industries with the highest exposure to potentially damaging noise were mining (61 percent of workers were exposed), construction (54 percent) and manufacturing (47 percent). The occupations with the highest exposure were production (55 percent) construction and extraction (54 Percent) and installation, maintenance and repair (54 percent).

The importance of prevention

This study is observational, which means it does not prove a link between job-related noise exposure and high blood pressure and high cholesterol. Also, the data on noise exposure came from the workers’ own reports, which might have been inaccurate.

Still, as the study’s authors point out, this isn’t the first research to find evidence of an association between occupational noise and risk factors for heart disease. And if there is a causal relationship, the impact across all workers could be significant.

The study estimates that 5.3 million cases of hearing loss, 1.7 million cases of high blood pressure and 1.2 cases of high cholesterol among American workers could potentially be prevented if workplace noise was reduced to safer levels.

“It is important that workers be screened regularly for these conditions in the workplace or through a healthcare provider, so interventions can occur,” said Liz Masterson, a NIOSH researcher and one of the study’s co-authors, in a released statement. “As these conditions are more common among noise-exposed workers, they could especially benefit from these screenings.” 

Of course, it would also help if all employers took steps — as required by current safety regulations — to reduce their workers’ exposure to hazardous noise. According to the U.S. Department of Labor, U.S. businesses paid more than $1.5 million in fines last year for failing to protect their workers from loud noise.

FMI: The study can be read in full on the website for the American Journal of Industrial Medicine.