Several studies have found that living near oil and gas wells is associated with an increased risk for preterm birth. Now a new study has found one possible reason: flaring of natural gas.
Natural gas, a byproduct of oil extraction, may be flared, or burned off, to quickly reduce pressure in the well or because pipelines to collect it are not available.
Researchers studied gas flaring in South Texas using data from a satellite that detects combustion sources at night. Then they looked at 23,487 birth records in the area during the three-and-a-half year period of the study.
Compared with women not exposed, those living within three miles of a well and exposed to 10 or more nightly flare events had a 50 percent increased risk of delivering before 37 weeks’ gestation.
The study, in Environmental Health Perspectives, controlled for age, education, smoking, B.M.I., prenatal care and other health and behavioral characteristics. In addition, the researchers eliminated women living in cities of 75,000 or more, where other sources of pollution could affect the risk for preterm birth.
“This is an observational study and does not prove cause and effect,” said the lead author, Lara J. Cushing, an assistant professor at the University of California, Los Angeles, “but the association we saw is strong, on par with what you see in women who smoke in its effect on preterm birth.”