The National Institute for Occupational Safety and Health (NIOSH) is preparing to send questionnaires to hundreds of onshore oil and gas (O&G) extraction workers in three states next year, part of a three-year study designed to make the industry safer.

NIOSH, part of the Centers for Disease Control and Prevention (CDC), said the goals of its study are to determine the causes of motor vehicle crashes, injuries and illnesses among O&G extraction workers, to identify the safety and health needs of the workers, and to address workers’ concerns.

In a public notice of the study, published last July in the Federal Register, NIOSH noted that most O&G extraction workers do not belong to a union.

“The results of this study will guide the development of evidence-based and priority interventions and future research in the O&G extraction industry that will improve the safety and health of O&G workers,” the agency said.

NIOSH said it plans to approach 625 workers in three states: North Dakota, Texas and an undisclosed state in the Appalachian Basin. The agency said it needs 500 responses for the study and anticipates the response rate will be 80%, hence the need to approach 625 workers.

According to NIOSH, the questionnaires will be given at temporary housing, or “man camps,” used by O&G workers, as well as at training centers, equipment and trucking yards, wells sites and community centers in oilfield towns. For the first part of the questionnaire, about 313 workers will be screened per year, for two years, to determine whether they are eligible for the rest of the survey. The screening process will take about five minutes.

The agency said it expects that up to 63 workers per year, or 20% of the screened workers, will be eligible for the rest of the survey but will decline to participate. Those workers will then be asked to complete a brief, six-question questionnaire that will also take about five minutes.

NIOSH said the remaining 250 workers per year deemed eligible will be asked to participate in three survey modules, with the topics of general issues, well site work and closing questions. The agency said it should take respondents 40-50 minutes to complete all three modules, depending on whether they use a tablet computer or used a hard copy of the survey.

Workers who drive will be asked questions from a fourth module covering motor vehicles. NIOSH said that part of the survey is expected to take respondents 10-20 minutes, again depending on whether they use a tablet or hard copy.

CDC spokeswoman Nura Sadeghpour told NGI on Tuesday that researchers are planning to begin administering the surveys at the end of 2016.

According to the Occupational Safety & Health Administration (OSHA), 823 O&G workers were killed on the job between 2003 and 2010. OSHA added that census data from the Bureau of Labor Statistics shows the fatality rate among O&G workers on site is seven times greater than the rate for all U.S. industries. The most common causes for fatalities are vehicle accidents; explosions and fires; falls; confined spaces; chemical exposures; and struck-by, caught-in and caught-between incidents.

Reid Porter, spokesman for the American Petroleum Institute, told NGI on Tuesday that the organization backed the initiative.

“NIOSH is an important partner in our ongoing efforts to preserve safety in the workplace, and we support research efforts that will contribute to the mission of continuous improvement, even as the industry creates thousands of new American jobs,” Porter said.