Health

Study Points to Greater Prevalence of Congenital Heart Defects in High-Intensity Oil and Gas Areas

Mothers living near more-intense oil and gas development activity have a 40–70% higher chance of having children with congenital heart defects compared with those living in areas of less-intense activity, according to a new study.

Doctor pointing at sonogram image

Mothers living near more-intense oil and gas development activity have a 40–70% higher chance of having children with congenital heart defects (CHDs) compared with those living in areas of less-intense activity, according to a new study from researchers at the Colorado School of Public Health.

"We observed more children were being born with a congenital heart defect in areas with the highest intensity of oil and gas well activity," said the study's senior author Lisa McKenzie, of the Colorado School of Public Health at the University of Colorado Anschutz Medical Campus.

At least 17 million people in the US and 6% of Colorado's population live within 1 mile of an active oil and gas wellsite.

The study was published in the peer-reviewed journal Environment International.

The researchers studied 3,324 infants born in Colorado from 2005 to 2011. They looked at infants with several specific types of CHDs.

Researchers estimated the monthly intensity oil and gas well activity at mother's residence from 3 months before conception through the second month of pregnancy. This intensity measure accounted for the phase of development (drilling, well completion, or production), size of wellsites, and production volumes.

They found mothers living in areas with the most-intense levels of oil and gas well activity were about 40–70% more likely to have children with CHDs. This is the most common birth defect in the country and a leading cause of death among infants with birth defects. Infants with a CHD are less likely to thrive, more likely to have developmental problems, and more vulnerable to brain injury.

Animal models show that CHDs can happen with a single environmental exposure during early pregnancy. Some of the more common hazardous air pollutants emitted from wellsites are suspected teratogens—agents that can cause birth defects—known to cross the placenta.

The study builds on a previous one that looked at 124,842 births in rural Colorado between1996 and 2009 and found that CHDs increased with increasing density of oil and gas wells around the maternal residence. Another study in Oklahoma that looked at 476,000 births found positive but imprecise associations between proximity to oil and gas wells and several types of CHDs.

Those studies had several limitations including not being able to distinguish between well development and production phases at sites, and they did not confirm specific CHDs by reviewing medical records.

The limitations were addressed in this latest study. Researchers were able to confirm where the mothers lived in the first months of their pregnancy, estimate the intensity of well activity and account for the presence of other air pollution sources. The CHDs were also confirmed by a medical record review and did not include those with a known genetic origin.

Read the full story here.

Find the study here.