More than 100 environmental groups and over 800 concerned citizens sent a letter on Monday urging Pennsylvania Gov. Tom Wolf to investigate the link between fracking and growing cancer diagnoses, citing recent reports of rare forms of childhood cancer emerging in counties located near fossil fuel development projects.

The letter (pdf), which calls on Wolf to suspend drilling permits until a thorough investigation is conducted, comes after the Pittsburgh Post-Gazette documented nearly 70 cases of childhood and young adult cancer diagnoses in rural Pennsylvania counties.

"This is a public health crisis that requires immediate and significant action," reads the letter, which was signed by local and national environmental leaders, including 350.org founder Bill McKibben and Concerned Health Professionals of New York co-founder Dr. Sandra Steingraber.

"Obviously, this high number of cancer cases among children in four counties in southwest Pennsylvania over the last eleven years is not only heartbreaking but extremely unusual," the letter states. "Scientific evidence about the harmful toxic chemicals used in gas drilling and fracking activities strongly suggest a connection. Many of the chemicals used in these activities are known carcinogens."

NEW: Over 100 organizations & 800 individuals sign letter calling on Pennsylvania @GovernorTomWolf to investigate links between fracking and childhood cancer & suspend all new drilling permits. #BanFracking https://t.co/c9bHI7fPap SCROLL TO CONTINUE WITH CONTENT Never Miss a Beat. Get our best delivered to your inbox.





— Food & Water Watch (@foodandwater) June 17, 2019

In its series on the public health effects of fracking in rural Pennsylvania counties, the Post-Gazette found 27 cases of the rare bone cancer Ewing sarcoma since 2008. The newspaper also documented more than a dozen children and young adult deaths from cancer during this period.

Emily Wurth, organizing co-director of Food & Water Watch, said in a statement that the Post-Gazette's reporting confirms that "fracking presents clear threats to our drinking water, our air quality, and to the health and safety of residents in these sacrifice zones."

"But this investigative reporting points to an even more serious and heartbreaking toll on Pennsylvanians," Wurth said. "Governor Wolf must take immediate action to protect the health and safety of his state."