Fracking Linked to Elevated Hospitalization Rates
The complexity of oil and natural gas fracking has hindered efforts to measure specific impacts on human health, but a study by Penn’s Center of Excellence in Environmental Toxicology (CEET) found that the controversial drilling method is associated with increased hospital admissions, especially for cardiological and neurological problems. The study, published in PLoS One in July, compared inpatient admission rates in two northeast Pennsylvania counties, where fracking is prevalent, with a neighboring county with no active wells. The more wells a particular ZIP code contained, the higher its hospitalization rates were for residents. “If a ZIP code went from having no wells to having greater than .79 wells/km2,” the study concluded—noting that 18 ZIP codes exceeded that threshold, “we would expect cardiology inpatient prevalence rates to increase by 27 percent.”
“We suspect that residents are exposed to many toxicants, noise, and social stressors due to hydraulic fracturing near their homes and this may add to the increased number of hospitalizations,” said CEET deputy director and senior author Reynold Panettieri M’83 GPU’83. But identifying root causes will require further research. “Our findings provide important clues to design epidemiological studies to associate specific toxicant exposures with health end-points.”
The effects of stress can echo throughout a lifetime—and past it. Research by Tracy Bale, a professor of neuroscience at the School of Veterinary Medicine, has shown that male mice subjected to six weeks of varied stress—including loud noise, brief periods of physical confinement, and exposure to fox odor—bear offspring that exhibit dampened reactions to stress. The fathers’ exposure to stress triggered changes in their sperm, which showed elevated levels of nine microRNA molecules. MiRs are not a part of an organism’s DNA, but they can interfere with the expression of certain proteins.
In her latest study, published in PNAS in November, Bale isolated those miRs and injected them directly into mouse zygotes—where they attacked maternal RNA, “ultimately reprogramming gene expression in the offspring hypothalamus,” a part of the brain that coordinates responses to stress. The experiments illuminate a mechanism whereby “paternal lifetime experiences” can be transmitted to offspring in addition to otherwise ordinary DNA.