PURPOSE:  Reduce health problems for miners resulting from workplace stress by examining the relationship between workplace stress in the underground coal mining industry and the salivary cortisol response to awakening (SCRA).

RESEARCH SUMMARY:  Workplace stress has been linked to increased risks for cardiovascular disease, depression, and musculoskeletal disorders. The mechanisms by which stress affects health are not established, but research suggests that they may involve maladaptive changes in the hypothalamic-pituitary-adrenal (HPA) axis, the physiological system responsible for regulating the stress response.

This study will evaluate one measure of HPA axis function, the salivary cortisol response to awakening (SCRA), for use as a potential biomarker for workplace stressors in underground coal mine workers. The SCRA will be assessed by measuring cortisol levels in a series of saliva samples obtained by subjects during the first hour after they wake in the morning. The SCRA is reported to be a reliable marker of the function of the HPA axis. Although the SCRA has been used in studies of workplace stressors, research to date has been limited by 1) small sample sizes; 2) measurement error due to subjects’ failure to obtain samples at the specific times required in the protocol; 3) measurement error due to the use of immunoassays with insufficient specificity for cortisol; and 4) inadequate assessment or control of confounding factors, including light exposure, time of awakening, duration of sleep, body mass index (BMI), and alcohol intake. This project will collect measurements of the SCRA using a much larger group of subjects (target of 400) than previous research. A sample of subjects will be monitored for compliance with the saliva sampling protocol, using an electronic monitoring device that was developed for monitoring compliance with taking medications. Human Subjects Review Board and Office of Management and Budget approval for the project has been received. It is anticipated that annual safety refresher training classes for miners will be attended by NIOSH personnel to solicit participation from miners. One such trip has been completed and an initial set of samples collected.

Successful project completion will result in: the development of a biomarker for chronic workplace stress, which can be used to screen workers under chronic stress and identify those at high risk of developing adverse health outcomes, and the development of a training module on workplace stress which can be used by mine trainers to teach miners about the effects of stress and what they can do to reduce stress.