Toxic Tuesdays

Hydraulic fracturing (commonly known as fracking) is a technique that uses pressurized liquid to fracture bedrock in order to the extract the oil or gas inside.  Materials in the fracking fluid keep these cracks open so the oil or gas beneath can flow freely and be collected. After injection into the rock, some fracking fluid remains underground and some flows back to the surface.

Fracking fluid usually consists of water, sand or beads, and a mixture of chemicals. While many of the chemicals are not publicly known, some of the ones that are known can have harmful effects on human health. With up to millions of gallons of liquid being used to fracture a single well, these chemicals can be dangerous even if they constitute a small percentage of the fracking fluid. People can be exposed to these chemicals through contamination of drinking water supplies, physical contact with the flowback waste, or inhaling chemicals after they evaporate into the air from open-air waste pits.

Research has shown that living close to fracking wells is associated with adverse health outcomes, including poor birth outcomes like preterm birth (PTB) and low birth weight (LBW). However, not all this research is in agreement about these effects on birth outcomes because there are other confounding factors that can make drawing conclusions difficult. For example, most fracking wells are in rural areas, and rural communities have higher rates of many health conditions including PTB and LBW when compared to urban communities. Another confounding factor is that fracking wells have different mixtures of chemicals, so the health effects of living near a well may depend on the specific chemicals used in that well.

A recent study set out to clarify the link between living near active fracking wells and rates of PTB and LBW on a national scale. This study used publicly available, national, county-level 2014-2018 data from the US Census, Centers for Disease Control, US Department of Agriculture, WellExplorer, March of Dimes, and the National Birth Defects Prevention Network to analyze the association between exposure to fracking wells and the rate of PTB and LBW. It controlled for many socioeconomic and geographic factors that may impact PTB and LBW, thereby more directly analyzing the specific link between fracking wells and birth outcomes than previous studies. The factors this study controlled for included: race, ethnicity, poverty level, education level, percentage of population with health insurance, access to maternal care, marriage rates, drug-related death rates, population density, percentage of a county that is agricultural land, and amount of agricultural pesticides used in a county.

The study found that density of active fracking wells was associated with a higher average county-level PTB and LBW. For wells known to use chemicals that target the hormones estrogen or testosterone, well density had an even bigger effect on county-level PTB and LBW. This is one of the first studies to assess these associations on a national scale and to demonstrate that the chemical ingredients in fracking wells can have a major impact on PTB and LBW. Importantly, these findings are not a result of socioeconomic or geographic factors like race, poverty, health insurance, or population density. This study is one of the strongest yet in demonstrating that fracking wells are linked to the poor birth outcomes of preterm birth and low birth weight.