Coal ash contains radioactive contaminants: U.S. study

http://pubs.acs.org/doi/10.1021/acs.est.5b01978

Radium has 33 known isotopes, with mass numbers from 202 to 234: all of them are radioactive.[8] Four of these – 223Ra (half-life 11.4 days), 224Ra (3.64 days), 226Ra (1600 years), and 228Ra (5.75 years) – occur naturally in the decay chains of primordial thorium-232, uranium-235, and uranium-238 (223Ra from uranium-235, 226Ra from uranium-238, and the other two from thorium-232). These isotopes nevertheless still have half-lives too short to be primordial radionuclides and only exist in nature from these decay chains.[9] Together with the artificial 225Ra (15 d), these are the five most stable isotopes of radium.[9] All other known radium isotopes have half-lives under two hours, and the majority have half-lives under a minute

Hasn't this been accepted knowledge for years and not something that they "found" just recently?

Coal Ash is a hazardous, toxic waste. Coal tar is the foundation of German chemistry that for the last 140 years produced poison gas, plastics, pesticides, PCB's, dioxins, halons - the entire poisonous mess that causes cancer and disrupts hormone and genetic regulation in every species of life.

Huh, no wonder I've been hearing those stupid ads on the radio by coal companies that we need to use more coal (with an environmentally consideration for "cleaner burning" coal") for energy stability. This folks is just how stupid these fossil fuel companies believe the majority of American's to be. Sad thing is they might be right...

were up to five times higher than in normal soil

So is that significant or not? I quick read on Wikipedia suggests that the radioactivity of natural soil can vary by more than five times.

@albateo

There's controversy over what constitues a 'safe' level of background radiation. Experts don’t agree because experts can’t scientifically observe if there is an effect on a human due to exposure to radiation at low doses. Why can’t they observe whether there is an effect or not? Because if there is an effect at the doses we are interested in for protecting the public and the worker, it is so small it can’t be conclusively seen in scientific studies. The fact that there is disagreement provides some comfort that the effect can’t be very large or it would be conclusively seen.

-Hasn't this been accepted knowledge for years and not something that they "found" just recently?

Absolutely, and oil/gas has the same radium and other issues that coal has. Many of these "impurities" are sold as "petroleum distillates."

http://blogs.scientificamerican.com/plugged-in/duke-study-finds-radium-and-elevated-salinity-in-treated-oil-and-gas-wastewater-highlights-need-for-revised-water-quality-regulations/