As noted in the book, Heal and Protect: A Nuclear World, one of the environmental sources for radiation results from oil and gas operations, especially frac’ing (hydraulic fracturing). These operations bring to the surface large amounts of naturally occurring radioactive materials (NORM) in the produced water used to hydraulically fracture the rock containing hydrocarbons. This has been shown to increase levels of all heavy-metal contaminants in local soils and waters, especially documented in the Marcellus Shale formation (also the Utica Shale formation) in the Eastern Great Lakes region of the U.S, affecting large areas of Pennsylvania, New York, West Virginia, and Ohio.

These operations have shown to increase the amount of radium-226 and -228, which are both toxic and damaging radioisotopes, in soils and waters around these oil and gas operations. Radium releases both alpha particles and gamma rays. It has a specific activity of 1 curie per gram (0.99), which makes it one of the most active emitters of alpha particles (the curie was originally defined based on activity of radium-226). Roughly a fifth of the ingested radium-226 will migrate into the bloodstream and move into the bones leading to cancers and other health issues.

This latest report from Duke University researchers shows the same trend in the Bakken Shale formation in North Dakota:

Environmental Science and Technology Journal, Brine Spills Associated with Unconventional Oil Development in North Carolina, April 2016

From the report:

In addition to high salinity, OGW often contains a number of toxic trace elements and naturally occurring radioactive materials (NORM) in elevated concentrations that can be threatening to local water quality if released to the environment. Previous studies have shown contamination of local surface water resources from unconventional oil and gas development due to the release of OGW to the environment in the form of (1) effluents to local streams and rivers following inadequate treatment by water treatment facilities,(2) dust suppressants and deicing agents,(3) leaks and spills. The release of OGW to the environment has been linked to salt, trace metal, and NORM contamination of local surface water, shallow groundwater, and stream sediments.

Produced waters can have elevated levels of naturally occurring radioactive materials (NORM), primarily the long-lived radium isotopes 228Ra (t1/2= 5.75 years) and 226Ra (t1/2=1600years). Bakken produced and flowback waters analyzed in this study were found to have total Ra activities (228Ra +226Ra) up to 64 Bq/L and an average 228Ra/226Ra activity ratio of 0.45.

We conclude that the impact of the high NORM in the Bakken brines will be reflected in accumulation of Ra in soil…