Radiation Overexposures Linked to Tx Oil/Gas Rig Count

Research prompts action by Texas Radiation Advisory Board to improve safety

Presentation of results of a 30-year study of radiation overexposures and Texas oil and gas exploration activities led to action by the Texas Radiation Advisory Board (TRAB) to help prevent future job-related exposures.

Robert Emery, Dr.P.H.

During the Feb. 26 meeting of the TRAB in Austin, Robert Emery, Dr.P.H., assistant vice president for safety, health, environment and risk management at The University of Texas Health Science Center at Houston, made the presentation.

The research, conducted by the UT School of Public Health at Houston in cooperation with the Texas Department of State Health Services, describes a significant relationship between upswings in excessive radiation exposures and growth surges in the number of active oil and gas rigs in the state.

"We intend to send an advisory to the regulated community that may also be shared with other states and programs - and a precautionary statement should be made to the public and potentially affected industry sectors," said TRAB Chair Michael S. Ford.

Devices emitting radiation are commonly used to detect the presence of oil and gas in the subsurface, and to examine the quality of welds during fabrication. Allowable limits for exposure to radiation are set by the Radiation Control Section of the Texas Department of State Health Services.

Work-related overexposure to radioactivity may increase the risk of developing certain types of cancers. At high enough levels, overexposures cause skin burns, gastrointestinal effects, central nervous system problems, or even death.

The current standard for unacceptable overexposure is any total dose over 5 rem per year.

"Radiation sources are invaluable tools in the industry, and when handled appropriately, are quite safe - but, if mishandled, workers can receive excessive radiation doses," said Emery, lead investigator for the study.

Researchers looked at data collected by the Department of State Health Services radiation regulatory programs from 1970 to 2000. During this 30-year span, the number of licenses issued for using radioactive materials in Texas increased. The number of reported overexposure events also increased - until 1982, when there was a steady decline. The overall trend of overexposures was found statistically to be closely related to the number of active oil and gas rigs (known as "rig count").

Emery, who also is associate professor of occupational health at the School of Public Health, reported to the TRAB that, as the Texas rig count rises, the number of potentially dangerous radiation overexposures also could go up.

"The department has greatly benefited from its relationship with Dr. Emery, as his research findings have served to help us improve our regulatory program by better analysis of trends. The study by Dr. Emery and his colleagues is resulting in the creation of a advisory notice to the industry so that, collectively, we can work together to prevent such events in the future," said Radiation Program Officer Richard A. Ratliff, Division of Regulatory Services, Department of State Health Services.

The study has been accepted for publication in an upcoming issue of the Health Physics Journal.

By David R. Bates, Public Affairs