LOS ANGELES (CNS) — Researchers from the UCLA Fielding School of Public Health and the University of Southern California have found that more than a half million Americans are exposed to oil and gas “flaring” events — the burning off of excess natural gas at production sites — resulting in potentially serious health risks, it was announced Monday, March 8.

“There is growing evidence linking residence near unconventional oil and gas operations with negative health impacts for nearby residents, including impacts on fetal growth and preterm birth,” said Dr. Lara Cushing, assistant professor of environmental health sciences at the UCLA Fielding School of Public Health. “This includes our recent finding that living within about three miles of flaring is associated with increased risk of preterm birth.”

The report, published this month in the peer-reviewed journal Environmental Research Letters, found that three basins in the US are responsible for most flaring activity in the lower 48: the Permian (Texas-New Mexico), Western Gulf/Eagle Ford (Texas), and the Williston/Bakken Shale (North Dakota and Montana).

Some 535,000 people live within three miles of flaring sites in these regions. Of those, 39% — roughly 210,000 — lived near more than 100 nightly flare events, the report shows.

Flaring is used during the exploration, production and processing of fossil fuels and is common in oil-producing areas where natural gas recovered with the oil cannot be used commercially.

Air quality monitoring studies indicate that flares — which often operate continuously for days or weeks — release a variety of hazardous air pollutants, including volatile organic compounds and polycyclic aromatic hydrocarbons along with carbon monoxide, nitrogen oxides (NOx), and black carbon.

Along with links to preterm births and other adverse birth outcomes, these pollutants contribute to the development and exacerbation of asthma, effects on the respiratory, cardiovascular, and nervous systems, as well as cardiopulmonary problems and cardiovascular mortality.

“Our findings also show that flaring is an environmental justice issue,” said Dr. Jill Johnston, an environmental health scientist at the USC Keck School of Medicine, who co-led the study.

“We found that a significant number of Black, Indigenous, and Latinx people live near flaring. High rates of poverty and other barriers to health in rural areas — such as a lack of access to health care — could worsen the health effects of flaring-related exposures.”

Other studies have revealed that in Los Angeles count approximately 500,000 residents in Los Angeles county live within a half-mile (2640 ft) of an actively producing oil and gas well that can release natural gas flares, and that the county is considered the largest urban oil field in the country.