Duke University scientists are known for research that raises concerns about the safety of fracking. Their newest, out Thursday, hits at one of Americans' greatest obsessions: weight gain.
The study by a pair of researchers at Duke's Nicholas School for the Environment and a professor at the University of Missouri says that exposure to industrial chemicals used in fracking overstimulates the growth of fat cells.
Duke postdoctoral research scholar Chris Kassotis said the research bears public health implications for people who live in areas where fracking takes place, potentially exposing residents to the potent chemicals on a daily basis in contaminated aquifers.
"People living in these regions may be exposed to these chemicals in the drinking water," Kassotis said. "They're trigger cells that are sitting in your body, awaiting to be recruited to become fat cells for energy storage."
This is the fifth study Kassotis and other scientists have published in peer-reviewed journals since 2015 asserting that exposing mice cells to fracking chemicals potentially damages the immune system, mammary glands, reproductive organs and lowers fertility. The industrial chemicals tested include benzene, naphthalene, phenol and toluene.
The oil-and-gas industry has characterized these studies as alarmist activism. The most consistent critic has been Energy in Depth, a research, education and public outreach campaign of the Independent Petroleum Association of America.
"Similar to previous studies by this research team, they use completely unrealistic concentrations and fail to identify exposure pathways that would expose people to fracking fluids," said Energy in Depth spokeswoman Nicole Jacobs.
"Further, in the highly unlikely event that hydraulic fracturing additives were to enter a water supply, it's absurd to think that a person would spend two weeks marinating in these fluids."
The latest study does not assert that water in fracking zones is contaminated, as some other Duke research has concluded. Kassotis emphasized that the study, published in the peer-reviewed journal Science of the Total Environment, does not prove that fracking causes obesity in people, only that it stimulates the growth of the fat cells of mice in a laboratory. The metabolism of mice is similar to that of humans.
But Kassotis said he and other researchers hope to follow up their study with epidemiology research on the public health of communities in the nation's fracking hot zones.
Fracking is an abbreviation for hydraulic fracturing, a technology that breaks up deep shale formations and releases natural gas trapped inside. The drilling and fracturing require chemical solvents that environmentalist groups consider dangerous and which the energy industry says are safe if properly managed.
There has never been any fracking in North Carolina, but the practice is common in sections of the country with giant underground shale rock formations.
In their study, Duke and Missouri researchers submerged mouse cells in solutions that contained fracking chemicals, fracking waste water and surface water found near fracking operations. After two weeks of soaking in these mixtures, the mouse fat cells increased in size between 20 percent and 80 percent, depending on the chemical concentrations.
The fat cells grew faster than cells in a control group and were exceeded in size only by mouse cells exposed to a medicine for diabetes that causes weight gain in humans as a side effect. The cells also increased in total number of cells, not just their size, Kassotis said. They saw fat cell activity in chemical solutions diluted by a thousandfold.
The waste water and surface water were collected in 2014 from oil and gas production sites in Colorado and West Virginia.
Duke University occasionally finds itself on the receiving end of accusations that its scientists are environmental zealots with an anti-energy agenda.
In 2011, a one-time natural gas executive who graduated from Duke University blasted his alma mater's research linking his industry's gas drilling to the contamination of drinking water. In an issue of Duke Magazine, Chesapeake Energy CEO Aubrey McClendon decried the university's liberal agenda and questioned the academic integrity of Duke's Nicholas School of the Environment.
At the time, McClendon's company was the nation's second-largest natural gas producer and hosted delegations of North Carolina lawmakers at its drilling sites in Pennsylvania. McClendon died in a car crash in 2016, a day after he was indicted by a federal grand jury on charges of bid rigging to acquire natural gas leases in Oklahoma.
The study issued Thursday also named the University of Missouri's Susan Nagel and Duke's Heather Stapleton as co-authors. It was primarily funded by the National Institute for Environmental Health Sciences. Additional funding came from the University of Missouri, a crowd-funding campaign through Experiment.com and an Environmental Protection Agency fellowship.