Pennsylvania children living near fracking sites at birth are two to three times more likely to be diagnosed with leukemia during early childhood than those who did not live near such facilities, a new study has found.
The study, published in Environmental Health Perspectives on Wednesday, explored the connection between the development of cancer and proximity to such unconventional oil and gas development - also known as hydraulic fracturing, or "fracking."
Scientists have previously reported on potential threats to residents posed by fracking, such as air pollution from vehicle emissions and construction, as well as water contamination from the drilling process or wastewater spills, according to the authors.
In addition, hundreds of chemicals - some with known or suspected cancer links - have reportedly been used in the water injection process that occurs during fracking, they added.
Yet data on the association between fracking and childhood cancer remains scarce, the researchers observed.
"Unconventional oil and gas development can both use and release chemicals that have been linked to cancer," senior author Nicole Deziel, an associate professor of epidemiology at the Yale School of Public Health, said in a statement.
As a result, Deziel continued, the possibility that children living near such sites are "exposed to these chemical carcinogens is a major public health concern."
Deziel and her team conducted a registry-based survey - an observational study that comes from patient registries - of 405 Pennsylvania children aged 2-7, who were diagnosed with acute lymphoblastic leukemia between 2009 and 2017, according to the study.
The survey also included 2,080 control subjects matched on birth year.
Acute lymphoblastic leukemia (ALL) is the most common form of childhood leukemia. Although long-term survival rates are high, patients may end up at higher risk of other health problems, developmental challenges and psychological issues, the researchers said.
The authors probed the link between in-utero exposure and childhood leukemia diagnosis in two different exposure windows: a so-called "primary window" of three months preconception to one year prior to diagnosis and a "perinatal window" of preconception to birth.
Ultimately, they found that children with at least one fracking well within 2 kilometers (1.24 miles) of their birth residence during the primary window had 1.98 times the odds of developing ALL in comparison to those with no such wells.
Meanwhile, children with at least one fracking well within 2 kilometers of their birth residence during the perinatal window were 2.8 times more likely to develop ALL than their peers who had no wells nearby.
These results demonstrate that exposure to fracking sites "may be an important risk factor for ALL, particularly for children exposed in utero," first author Cassandra Clark, a postdoctoral associate at the Yale Cancer Center, said in a statement.
Clark and her colleagues also determined that drinking water could play an important role in exposing children to oil and gas-related chemicals.
Going forward, the researchers said they hope their findings will help inform public policy, including the regulation of "setback distances" - the required minimum distances between private residences and fracking wells.
Setback distances are under debate across the U.S., with some communities calling for these measures to be extended to more than 305 meters (1,000 feet) or as far as 1,000 meters (3,281 feet), according to the authors.
In Pennsylvania, where the study occurred, the allowable setback distance is 152 meters (500 feet).
"We hope that studies like ours are taken into account in the ongoing policy discussion," she added.
For the latest news, weather, sports, and streaming video, head to The Hill.