Technologically Enhanced Naturally Occurring Radioactive Materials on Oil and Gas Sites
Author: Don Garvey, CIH, CSP, CHMM
Occupational Health & Safety (June 2014)
Read the full article: http://ohsonline.com/Articles/2014/06/01/Technologically-Enhanced-Naturally-Occurring-Radioactive-Materials-on-Oil-and-Gas-Sites.aspx?Page=1
Excerpt
The National Institute for Occupational Safety and Health (NIOSH) has identified several potential occupational health risks on oil and gas well sites. These include noise, silica, hydrocarbons, and also ionizing radiation hazards in the form of technologically enhanced naturally occurring radioactive materials (TENORM).
The ANSI/HPS N13.53-2009 standard Control and Release of Technologically Enhanced Naturally Occurring Radioactive Material (TENORM) defines it as "naturally occurring radioactive material disturbed or altered from natural settings or present in a technologically enhanced state due to past or present human activities and practices, which may result in a relative increase in radionuclide concentrations, radiation exposures and risks to the public, and threat to the accessible environment above background radiation levels." Oil and gas well drilling, with subsequent produced water, muds, and other wastes, can "disturb" these materials and release them to the above-ground environment. While radioactive materials are not necessarily present in the soils at every well or drilling site, some areas of the country, such as Texas and the Gulf Coast states, are more likely to contain radioactive material. California, Utah. Wyoming and Colorado typically have much lower levels. It is estimated that approximately 30 percent of oil and gas wells produce TENORM, with amounts varying greatly from well to well.
The primary radioactive materials in oil and gas drilling wastes are typically radium and radon gas. 2,8 Radium radioactively decays to radon gas--an odorless, tasteless, noble gas that is relatively non-reactive chemically. Radon then quickly decays (half life approximately four days) to produce radon decay products (radon daughters or radon progeny). The decay of both radium and radon releases ionizing radiation in the form of alpha particle radiation. Unlike radon gas, the radon progeny are solids that typically adhere to atmospheric dust and aerosols. These particles can be inhaled and lodge in the lower reaches of the lungs. Subsequent decay of these progeny can expose the lung tissue to alpha radiation. Exposure to radon gas and its progeny in indoor air has been linked to lung cancer.