Living near oil and gas sites in Colorado could make irregular heartbeat symptoms worse, CU study says

Hart Van Denburg/CPR News
Oil pump jacks in Weld County, June 25, 2024.

A new study from researchers at the University of Colorado has found strong evidence that older adults and women with AFIb, atrial fibrillation, living near oil and natural gas wells may experience a worsening of their condition during development of those sites. 

The period when a well is being developed is when there's the most activity on the well pad, said Colorado School of Public Health researcher Lisa McKenzie, the study’s senior author, in an interview. “It seems to really be concentrated around that development phase of the well,” she said.

“They're drilling, they're fracking, there's a lot more potential for noise on the well site and emission of air pollutants,” said McKenzie, an associate professor at the Colorado School of Public Health. “The closer you got to the well site, the higher the risk was.”

Atrial fibrillation is an irregular and often rapid heart rhythm, also called an arrhythmia. It can lead to blood clots in the heart, according to the Mayo Clinic, and also increased risk of stroke, heart failure and other heart-related complications.

AFib is the most common type of irregular heart rhythm. It affects up to 6.1 million people in the U.S. at any given time, and causes about 450,000 hospitalizations each year, according to Yale Medicine.

The study found AFib patients older than 80 living close to an oil and natural gas well site, defined as within 0.39 miles (2059 feet), experienced an 83 percent increased risk of an exacerbation of AFib-related symptoms. Those include heart palpitations, chest pain and dizziness. That group of patients also saw a doubling of the risk for emergency room visits for symptoms related to the condition.

Female AFib patients living in the same proximity to oil and gas wells experienced a 56 percent increase in exacerbation risk.

Researchers found the increased risk extended up to nearly a mile (0.8 miles or 4,224 feet) from well sites. But it did not persist after development of the well finished. 

The study did not identify similar increases in younger people and men.

“I think this matter really deserves more attention and more study,” McKenzie said. She noted the information could be useful to regulators as they consider decisions on where wells go and for health care providers so they can advise patients who might be living near wells.

At least 6 percent of Colorado’s population lives within one mile of an active oil and natural gas well development site and wells cannot be within 2,000 feet of homes, McKenzie said.

Prior studies have linked AFib with exposure to air pollution and noise. But McKenzie said this study did not measure noise and air pollution levels directly, so researchers could not establish specific links.

The research team followed 1,197 AFib patients living within a mile of an oil and natural gas well site and 9,764 AFib patients living more than two miles away, after wells were established. 

They used data from Colorado’s All Payer Claims Database, a database that provides anonymized data on the health conditions of most people with health insurance in the state, including Medicaid and Medicare. The study accounted for other key factors like chronic health conditions, personal behaviors, and regional environmental trends.

The research was published in the peer-reviewed journal Frontiers in Epidemiology. It was conducted at the Colorado School of Public Health at the CU Anschutz medical campus. Study co-authors include William Allshouse and Dr. Barbara Abrahams, both from CU Anschutz, and Dr. Christine Tompkins, from Emory University.

A spokesperson for the Colorado Oil and Gas Association said they had not had a chance to review the results and declined to comment.

The research was funded by the National Institutes of Health and Center for Improving Value in Health Care

“Studies like this present an opportunity for Colorado School of Public Health faculty and researchers to inform policy makers and guide regulators on mitigation strategies that will ultimately protect the health and well-being of Coloradans,” said Travis Leiker, Colorado School of Public Health assistant dean of external relations in a press release.

A 2019 University of Colorado Anschutz study, on which McKenzie was the lead author, found mothers living near more intense oil and gas development had a 40 to 70 percent higher chance of having children with congenital heart defects.

Researchers studied more than three thousand babies born in Colorado from 2005 to 2011. McKenzie said that research found that more children were being born with congenital heart defects in locations that had the highest intensity of oil and gas activity than in areas with lower intensity or no oil and gas wells.

The Colorado Oil and Gas Association said that the data McKenzie used in the research was outdated. They said researchers used “(d)ata that has no relevance to current regulations or to the common practices used by today’s operators.”.

McKenzie said further study is needed and noted a couple of limitations with the AFib study. One is that the claims database doesn’t include the state’s uninsured population, which is around five percent of Coloradans. “The risk might be a little higher if we had all AFib patients,” McKenzie said.

Also, she said, researchers assumed a patient’s address in the all payers claim database was the address that they were living at, which is probably the case for most people, but there might be a few people who have an address at which they're not actually residing.