Toxins in fracking fluid and wastewater
Toxins found in fluids used during hydraulic fracturing or fracking have been linked with reproductive and developmental health problems in a research conducted by Yale School of Public Health.
Fracking is the process of drilling into the earth for extracting gas. Liquids mixed with chemicals and sand are injected into these pits, which can be as deep as two miles. This creates fractures in the rock, causing the gas trapped inside to release. The process creates significant amounts of wastewater and fractures in the bedrock, posing a potential threat to both surface water and underground aquifers that supply drinking water, the researchers noted.
The team of researchers at Yale evaluated available data on 1,021 chemicals used in fracking and found that majority of the substances had undetermined toxicity due to insufficient information.
“Further exposure and epidemiological studies are urgently needed to evaluate potential threats to human health from chemicals found in fracking fluids and wastewater created by fracking,” the research team said in their paper, published in the Journal of Exposure Science and Environmental and Epidemiology.
According to Nicole Deziel, senior author and assistant professor of public health, the evaluation was a first step to prioritise the vast array of potential environmental contaminants from hydraulic fracturing for future exposure and health studies.
“Quantification of the potential exposure to these chemicals, such as by monitoring drinking water in people’s homes, is vital for understanding the public health impact of hydraulic fracturing.”
This research, however, lacks definitive information on the toxicity of the majority of the chemicals.
The team analysed 240 substances and concluded that 157 of them — chemicals such as arsenic, benzene, cadmium, lead, formaldehyde, chlorine, and mercury — were associated with either developmental or reproductive toxicity. According to the scientists, of these, 67 chemicals were of particular concern because they had an existing US federal health-based standard or guideline and the data on whether levels of chemicals exceeded the guidelines were too limited to assess.
Previous studies have observed associations between proximity to hydraulic fracturing sites and reproductive and developmental problems, but they did not investigate specific chemicals.
The latest evaluation could be useful in giving direction and design to future studies by highlighting which chemicals could have the highest probability of health impact, the researchers noted. “We focused on reproductive and developmental toxicity because these effects may be early indicators of environmental hazards.
Gaps in our knowledge highlight the need to improve our understanding of the potential adverse effects associated with these compounds,” said Elise Elliott, a public health doctoral student and the paper’s first author.
According to the researchers, the wastewater produced by fracking may be even more toxic than the fracking fluids themselves leading to a conclusion that more focus was required to study not only the inputs used in fracking but also the chemicals and by-products generated during the process.
The researchers also said that the 781 chemicals for which information is currently lacking need to be rigorously analysed to determine if they pose health threats.
(Views expressed are personal)