There isn’t a lot of good news about fracking lately. Another train with volatile fracked crude oil from North Dakota’s Bakken Shale exploded in Lynchburg, Virginia igniting a ball of fire on the surface of the James River. Accidents involving these “bomb trains” are becoming commonplace. So are recent studies indicating serious health risks from fracking and reports linking fracking to earthquakes.

With all that press you may have missed another cause for alarm: radiation risks. The oil and gas-drilling boom, aided by the practice of fracking, has unleashed some potentially scary radioactive stuff into our environment.

Fracking involves injecting large quantities (sometimes millions of gallons) of water, sand, and chemicals at high pressure deep underground to break apart shale and release trapped hydrocarbons like oil and gas. But the process can also bring to the surface water that is laced with naturally-occurring radioactive materials that were underground. In small, dispersed quantities low-level radiation is not life threatening, but what happens when those quantities start increasing in the environment, and getting into the water we drink, the fish we eat, and the soil in which our food grows?

Scientists are trying to figure that out. But it’s a difficult process to track since fracking isn’t regulated under most federal environmental laws like the Safe Drinking Water Act and the Clean Water Act. That means industry is charge of policing itself a lot of the time.

Another problem is that it’s really hard to keep track of all the stuff that may become tainted by radioactive materials in the drilling process. Millions of gallons of soupy wastewater that flow back from wells after drilling and fracking can end up in a number of places. Sometimes the wastewater is simply left in lined or unlined pits to either evaporate or sink back into the ground. Other times it is sent to water treatment plants and eventually released back into rivers and streams. At times it is simply spilled or illegally dumped. It also ends up contaminating drilling mud (a more solid waste from the process), storage tanks, and equipment.

“Radionuclides in these wastes are primarily radium-226, radium-228, and radon gas,” reports the Environmental Protection Agency. “The radon is released to the atmosphere, while the produced water and mud containing radium are placed in ponds or pits for evaporation, reuse, or recovery.”

The fact that drilling for oil or gas increases radiation is not news. Avner Vengosh, a professor of geochemistry at Duke University told Bloomberg News that we’ve know that since the 1970s, but the pace and intensity of drilling now, combined with the huge amount of wastewater, is taking the issue to a new level of concern. “We are actually building up a legacy of radioactivity in hundreds of points where people have had leaks or spills around the country,” he said.

Vengosh was part of team of researchers that turned up some troubling findings in Pennsylvania, ground zero for hydraulic fracturing in the Marcellus Shale. Their study, published in the peer-reviewed journal Environmental Science & Technology, took samples over a two-year period from Blacklick Creek just below the discharge from the Josephine Brine Treatment Facility, which accepted water from drilling operations. They found that radium levels of wastewater from fracking operations had been reduced in treatment by about 90 percent, but what was coming out of the plant still exceeded upstream levels by 200 times.

“Such elevated levels of radioactivity are above regulated levels and would normally be seen at licensed radioactive disposal facilities, according to the scientists at Duke University's Nicholas school of the environment in North Carolina,” reported Felicity Carus for the Guardian.

The biggest threat is the bioaccumulation of radium. Small quantities can build up in the environment, eventually posing a health hazard (especially if it ends up in food we eat).

It also means that even if you don’t have a drilling rig in your backyard or even your neighborhood, you may still face some risks. As Carus wrote:

From January to June 2013, the 4,197 unconventional gas wells in Pennsylvania reported 3.5m barrels of fluid waste and 10.7m barrels of "produced" fluid. Most of that waste is disposed of within Pennsylvania, but some of it is also went to other states, such as Ohio and New York despite its moratorium on shale gas exploration. In July, a treatment company in New York state pleaded guilty to falsifying more than 3,000 water tests.

The Duke study came just two years after the New York Times did an exhaustive search of thousands of government and industry documents to try and assess how risky radioactive wastewater from fracking may be.

“The documents reveal that the wastewater, which is sometimes hauled to sewage plants not designed to treat it and then discharged into rivers that supply drinking water, contains radioactivity at levels higher than previously known, and far higher than the level that federal regulators say is safe for these treatment plants to handle,” Ian Urbina wrote for the Times.

“The Times also found never-reported studies by the EPA and a confidential study by the drilling industry that all concluded that radioactivity in drilling waste cannot be fully diluted in rivers and other waterways.” They found that 116 wells produced wastewater with levels more than 100 times higher than safe drinking water standards, and 15 wells were more than 1,000 times above the limit.

“The radioactivity in the wastewater is not necessarily dangerous to people who are near it. It can be blocked by thin barriers, including skin, so exposure is generally harmless,” wrote Urbina. “Rather, E.P.A. and industry researchers say, the bigger danger of radioactive wastewater is its potential to contaminate drinking water or enter the food chain through fish or farming. Once radium enters a person’s body, by eating, drinking or breathing, it can cause cancer and other health problems, many federal studies show.”

The Duke study and the Times’ research both focused on Pennsylvania, but the Marcellus region is not the only experiencing problems with radioactive waste. In February, an abandoned building in Noonan, North Dakota was found to contain bags of illegally dumped “filter socks” which are used by the industry to filter liquids during oil production. The radiation level from the material wasn’t high enough to be a health hazard unless people ventured into the building but it signals a growing problem for boomtowns, the likes of which have emerged across North Dakota’s Bakken shale. It’s not the first time this kind of waste has been dumped — and the booming Bakken is producing around 27 tons of filter socks a day, by one estimate.

And the problem persists across the country.

“While it’s unclear how much drilling waste is produced nationally, state totals are rising. West Virginia landfills accepted 721,000 tons of drilling debris in 2013, a figure that doesn’t include loads rejected because they topped radiation limits,” wrote Alex Nussbaum for Bloomberg. “The per-month tonnage more than tripled from July 2012, when records were first kept, through last December. In Pennsylvania, epicenter of the Marcellus boom, the oil and gas industry sent 1.3 million tons to landfills last year.” Are those facilities equipped to monitor and handle radioactive waste?

North Dakota is attempting to cope with the problem by creating new regulations requiring industry to store these contaminated filter socks on site in special containers until they can be moved to a “certified dump.” But, Rebecca Leber writes for Think Progress, “North Dakota has no facilities to process this level of radioactive waste. According to the Wall Street Journal, the closest facilities are hundreds of miles away in states like Idaho, Colorado, Utah, and Montana.”

So the problem is not solved, it’s simply passed from one state to the next — increasing the area that may be affected and the number of people. Meanwhile the grand experiment of fracking’s effects on human health continues.