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Research Rounds – Volume 4, Issue 6, December 2018

NIOSH Research Rounds is a monthly bulletin of selected research conducted by researchers at NIOSH and NIOSH-funded researchers at other institutions.
Volume 4, Number 6 (December 2018)

Inside NIOSH:
Noise-related Health Risk Varies by Industry and Occupation

Oil industry worker looking out on a plant.

A NIOSH study found that high blood pressure and high cholesterol are more common among workers exposed to loud noise at work. Photo from Getty Images.

High blood pressure and high cholesterol are more common among workers exposed to loud noise at work, according to a NIOSH study published in the American Journal of Industrial Medicine.

Researchers at NIOSH also found that a quarter of U.S. workers–an estimated 41 million people–reported a history of noise exposure at work.

Loud Noise Linked to Heart Disease               

High blood pressure and high LDL cholesterol are key risk factors for heart disease, the leading cause of death for both men and women. Loud noise is one of the most common workplace hazards in the United States affecting about 22 million workers each year.

NIOSH researchers analyzed data from the 2014 National Health Interview Survey to estimate the prevalence of occupational noise exposure, hearing difficulty and heart conditions within U.S. industries and occupations. They also looked at the association between workplace noise exposure and heart disease. The analysis showed several key findings:

  • Twenty-five percent of current workers had a history of work-related noise exposure; 14 percent were exposed in the last year.
  • Twelve percent of current workers had hearing difficulty, 24 percent had high blood pressure and 28 percent had high cholesterol. Of these cases 58 percent, 14 percent, and 9 percent, respectively, can be attributed to occupational noise exposure.
  • Industries with the highest prevalence of occupational noise exposure were mining (61%), construction (51%), and manufacturing (47%).
  • Occupations with the highest prevalence of occupational noise exposure were production (55%); construction and extraction (54%); and installation, maintenance, and repair (54%).
NIOSH Research Rounds is Brought to You By:
  • John Howard, M.D., Director
  • Christina Spring, Editor in Chief
  • Anne Blank, Managing Editor
  • Donjanea Williams, Contributing Editor
  • Sarah Mitchell, Contributing Editor
  • Jeanette Novakovic, Copy Editor
  • Glenn Doyle, Technical Lead
  • Tonya White, Technical Support

Nonfatal Injuries Remain High Among Firefighters

firefighters silhouettes on fire background

Strains and sprains, and other nonfatal injuries frequently occur among firefighters, highlighting the need for additional prevention research. Photo from Getty Images.

Firefighters continue to experience frequent nonfatal injuries, especially strains and sprains, according to a NIOSH study of injuries treated in U.S. emergency departments published in the American Journal of Preventive Medicine.

Firefighting is an undeniably dangerous job where work can often lead to injury and death. Previous studies have investigated firefighter injuries, but these studies have been limited to individual departments, small groups of departments, or subsets within the firefighter workforce (e.g., wildland firefighter). The NIOSH study used a nationally representative sample of emergency departments to further our understanding of nonfatal injuries among firefighters.

Investigators looked at nonfatal injuries to firefighters, from 2003 through 2014, identified in the National Electronic Injury Surveillance System occupational supplement (NEISS-Work). Administered by the U.S. Consumer Product Safety Commission, NEISS-Work compiles work-related injury information from a representative sample of 67 emergency departments in the United States. To calculate average annual rates, labor force estimates for firefighters were obtained from the National Fire Protection Association.

In the years studied, approximately 351,800 firefighters received treatment in an emergency department for a nonfatal injury. This number translates to 260 injuries for every 10,000 firefighters, overall, including career and volunteer workers. Among career firefighters only, however, the annual rate jumped to 699, while volunteer workers had a rate of 39 injuries per 10,000 firefighters.

These findings highlight the importance of additional research and prevention needs in the areas of lifting techniques and body posture and movements. The next step for NIOSH is to use NEISS-Work to conduct follow-back surveys of injured firefighters to gather more details about their injuries and exposures. The information will be used to determine common injuries and exposures, assist in identifying subsets of the firefighting population who are at most risk for occupational injuries and exposures, and identify circumstances and activities that put firefighters at risk. These incident and circumstance details collected directly from firefighters are critical to better understanding and addressing health and safety challenges of this workforce.

More information is available:

Outside NIOSH:
Poor Sleep Can Impair Workplace Safety Practices

The NIOSH Total Worker Health® Program looks for ways organizations can improve worker health and well-being, on and off the job. One aspect of home that overlaps into work is sleep. Healthy sleep is essential for worker safety and well-being, especially for work, such as construction, that requires following many safety procedures. Knowing how lack of sleep affects safety behaviors, as well as how to design effective organizational-level interventions, can improve worker health and safety.

To investigate this further, a NIOSH-supported study at the Oregon Health Sciences University Healthy Workforce Center, in Portland, looked at the relationship between self-reported sleep and lapses in attention, memory, and action at work that impact safety. Researchers referred to these lapses as cognitive, or thought, failures. Sleep behavior included quantity, or duration, and quality, which is the feeling of being rested, and the ability to fall asleep and stay asleep. To better understand how these factors relate, the study looked at workers’ sleep quantity and quality and workplace safety behaviors, including participation in safety procedures, as well as reports of minor injuries, such as cuts, bruises, or sprains requiring first aid or no treatment, that did not require workers to miss work.

The study used information from three surveys conducted in 2012-2013, completed by more than 318 construction workers at two public works agencies at the beginning of the study, and repeated 6 months and 12 months later. Results suggest that workers with more insomnia symptoms are less likely to follow required and voluntary safety behaviors and are at higher risk for minor workplace injuries due to cognitive failures. The researchers defined insomnia as taking 30-plus minutes to fall asleep or waking in the middle of the night or early morning. In addition, workers who reported not feeling well-rested upon waking on average also reported that they were less likely to follow safety procedures.

These results indicate that organizations can improve safety with tools to reduce insomnia symptoms and improve sleep. The study was recently published by the Journal of Occupational Health Psychology.

The next steps for the researchers include studying how to reduce workers’ insomnia symptoms, improving their ability to fall and stay asleep, and how sleep influences day-to-day safety behavior and more serious workplace injuries.

More information is available:

Computer Model Estimates Chemical Exposure Years after Deepwater Horizon Oil Spill

After Deepwater Horizon, response workers manually removed tar balls from the beach sand at Destin, Florida, during 12-hour night shifts. Photo by Aaron Sussell, CDCNIOSH.

After Deepwater Horizon, response workers manually removed tar balls from the beach sand at Destin, Florida, during 12-hour night shifts. Photo by Aaron Sussell, CDC/NIOSH.

More than 8 years ago, one of the largest oil spills in U.S. history killed 11 oil rig workers and dumped more than 3 million barrels of oil into the Gulf of Mexico. Cleanup efforts have continued since April 2010, when the Deepwater Horizon oil rig exploded and sank. The Gulf oil spill affected hundreds of miles of coastline, and researchers are now working to understand the full extent of the chemical exposures to the thousands of workers who were cleaning this area.

While researchers have chemical measurements for some locations at the time of the oil spill, many locations were not tested. Measurements for the entire coastline will allow researchers to fully understand the risk the chemicals pose to workers; for this reason, it is important to estimate measurements for previously untested locations. But after more than 8 years, the question is how?

The answer may be through a statistical method called “kriging,” which combines geographic information with known values in a computer model to estimate unknown values. In a NIOSH-funded study at the University of California, Los Angeles (UCLA), researchers applied a form of this method, called “Bayesian coastline kriging,” to estimate chemical exposures along the entire Gulf Coast during the 2010 oil spill. Bayesian predictions rely upon past knowledge to make reasonable estimates about what might occur.

First, researchers validated their approach by creating three computer test models, using Bayesian coastline kriging with simulated, or computer-generated, information for the Gulf Coast. Then, using real geographic information for the Gulf Coast, the researchers plotted the coastline and combined this information with the results of 60 actual air samples from an onsite study at the time of the oil spill. The National Institute of Environmental Health Sciences collected air samples from Waveland Beach, Mississippi between September and December 2010 as part of the Gulf Long-term Follow-up Study.

Next, the UCLA researchers developed a computer model, estimating the chemical levels for areas that lacked real-time measurements from the time of the oil spill. To test the accuracy of these estimates, they then compared them to the results of other statistical methods. Compared to the other statistical methods, Bayesian coastline kriging more accurately estimated chemical exposures along the entire Gulf Coast, according to a recent paper published in the Annals of Work Exposures and Health.

According to the researchers, these findings show that this method can help estimate past chemical exposures from the oil spill along the coastline. In turn, these exposure estimates could uncover potential health effects related to the oil spill. However, they caution that the study focused only on chemical exposure among workers involved in cleanup efforts, not among people living in affected coastal communities. Accordingly, the researchers now are considering expanding the project to include chemical measurements in these communities.

More information is available:


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