Fracking, assailed for its environmental cost while its made the U.S. the world’s top oil producer, is being investigated as a possible cause in the surge of young people hit by a rare cancer in Pennsylvania.

Pennsylvania is funding research into finding if there’s a link between fracking and rising cases of Ewing sarcoma in the state’s southwest. In four counties, 31 people were diagnosed with the disease from 2006 through 2017, a 40% increase from the prior 11-year period, the Wall Street Journal reported, citing state cancer data.

Fracking, breaking underground rock to make oil and natural gas easier to extract, has contributed to the production of more than seven billion barrels of oil and 600 trillion cubic feet of natural gas over the past 70 years, according to the Independent Petroleum Association of America. The process is criticized for contaminating groundwater supplies and harming the environment. England halted fracking in November, and several U.S. states, including New York, ban the practice. Some Democratic U.S. presidential candidates have called for a ban.

While there is no known environmental cause for Ewing sarcoma, Pennsylvania wants to see if there is a connection, Rachel Levine, the state’s secretary of health, told the WSJ.

“The biggest challenge is that a correlation doesn’t necessarily prove causation,” she said.

While the state’s three main oil-and-gas industry associations told the Wall Street Journal that they support the research, the U.S. Chamber of Commerce warned that an end to fracking would have harmful effects on the state’s economy.

A ban would lead to the loss of more than 600,000 jobs in Pennsylvania between 2021 and 2025, and reduce the state’s gross domestic product by $261 billion over the same period, according to a study released this week by the chamber’s Global Energy Institute. 

Pennsylvania plans to spend $3.9 million to do the research into the Ewing sarcoma cases. A second study will look at potential associations between fracking and oil industry in the region and conditions such as asthma, headaches and preterm births.

  • Ewing sarcoma, a cancerous tumor that occurs in bones or soft tissues, hits about three in one million children, or about 250 kids in the U.S., each year. The cause is unknown and there are no clear risk factors.