$Surreal illustration of fracking site disrupting hormonal balance.$

Fracking's Hidden Threat: How Wastewater Could Be Disrupting Your Hormones

Mira Elwood in Climate & Environment August 2025 • 5 min read.

"New research sheds light on the endocrine-disrupting potential of hydraulic fracturing flowback and produced water, raising concerns about water contamination and public health."

Hydraulic fracturing, or "fracking," has revolutionized energy production, unlocking vast reserves of oil and natural gas. However, this process comes with environmental concerns, particularly regarding the flowback and produced water (HF-FPW) that returns to the surface. This wastewater contains a cocktail of chemicals, including salts, metals, and naturally occurring organics, as well as the chemical additives used in the fracking process itself. These substances have raised alarms about potential contamination of aquatic environments and the subsequent effects on wildlife and human health.

A growing body of research suggests that HF-FPW can disrupt biological processes, especially those related to the endocrine system. The endocrine system, which regulates hormones, is vital for development, reproduction, and overall health. When disrupted, it can lead to a cascade of adverse effects. Recent studies have indicated that HF-FPW exposure can alter gene expression and interfere with biotransformation processes, prompting scientists to investigate the specific mechanisms behind these disruptions.

A recent study published in "Environment International" delves deeper into understanding the endocrine-disrupting potential of organic fractions extracted from HF-FPW. This research focuses on how these organic extracts affect receptor-binding activity, utilizing several transactivation assays to assess the impact on key nuclear receptors. The findings reveal some concerning insights into the temporal and spatial variability of endocrine-disrupting potentials in HF-FPW, underlining the need for careful risk assessment and remediation strategies.

What Makes Fracking Wastewater So Disruptive to Hormones?

Surreal illustration of fracking site disrupting hormonal balance.

The study examined six HF-FPW samples collected from two wells at different time points after the start of flowback. The researchers separated these samples into aqueous (water-based) and particulate (solid residue) phases and extracted the organic compounds from each. By analyzing these fractions, they aimed to identify which components contribute most to endocrine disruption.

One of the key findings was the presence of polycyclic aromatic hydrocarbons (PAHs), well-known environmental pollutants, and alkylated PAHs in significant concentrations. Sample B1-S had the highest concentration of Σ13PAH (11,000 ng/L), while B3-S contained the most Σ4alkyl-PAHs (16,000 ng/L). PAHs are concerning because they have been shown to possess estrogenic properties, meaning they can mimic or interfere with the hormone estrogen.

Here’s a breakdown of the key receptors and their roles:

Aryl Hydrocarbon Receptor (AhR): Influences the metabolism of foreign chemicals and can lead to oxidative stress and DNA damage.
Estrogen Receptor (ER): Vital for reproductive health and development; disruption can lead to reproductive issues and certain cancers.
Androgen Receptor (AR): Essential for male sexual development and function; interference can affect sexual health and development.

The study used in vitro assays to screen the nuclear receptor binding activity of the extracts on three key receptors: the aryl hydrocarbon receptor (AhR), estrogen receptor (ER), and androgen receptor (AR). These receptors play critical roles in regulating various physiological processes, and their disruption can have significant health consequences. The results indicated that HF-FPWs from different wells exhibited distinct nuclear receptor binding effects. The strongest AhR agonist activity was found in B3-S, with a 450 ± 20 µg BaP/L equivalency at 5x exposure. The greatest ER agonist activity was detected in A1-W, with a 5.3 ± 0.9 nM E2 equivalency at 10x exposures.

What This Means for the Future of Fracking Regulation

This study underscores the complexity of HF-FPW and the need for comprehensive risk assessment and remediation strategies. The temporal and spatial variability in endocrine-disrupting potentials highlights that a one-size-fits-all approach to managing fracking wastewater is insufficient. Reclamation and remediation efforts must consider the specific properties of each spill, taking into account the geological formation and physiochemical properties of the injected fluid. Further research is needed to identify all the endocrine-disrupting compounds present in HF-FPW and to understand their mechanisms of action. By filling these knowledge gaps, scientists and policymakers can develop more effective strategies to protect both environmental and human health from the potential hazards of hydraulic fracturing.

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This article is based on research published under:

DOI-LINK: 10.1016/j.envint.2018.10.014, Alternate LINK

Title: In Vitro Assessment Of Endocrine Disrupting Potential Of Organic Fractions Extracted From Hydraulic Fracturing Flowback And Produced Water (Hf-Fpw)

Subject: General Environmental Science

Journal: Environment International

Publisher: Elsevier BV

Authors: Yuhe He, Yifeng Zhang, Jonathan W. Martin, Daniel S. Alessi, John P. Giesy, Greg G. Goss

Published: 2018-12-01

Everything You Need To Know

What concerns have been raised about hydraulic fracturing flowback and produced water (HF-FPW)?

Hydraulic fracturing flowback and produced water (HF-FPW) raises environmental concerns due to the cocktail of chemicals it contains, including salts, metals, naturally occurring organics, and chemical additives used in the fracking process. Research indicates that HF-FPW can disrupt biological processes, especially those related to the endocrine system. This system regulates hormones vital for development, reproduction, and overall health, and disruption can lead to a cascade of adverse effects. Further research is needed to identify all endocrine-disrupting compounds present in HF-FPW and understand their mechanisms of action.

What key compounds were found in hydraulic fracturing flowback and produced water (HF-FPW) samples, and what properties make them concerning?

The study found that HF-FPW samples contained polycyclic aromatic hydrocarbons (PAHs) and alkylated PAHs in significant concentrations. PAHs can mimic or interfere with the hormone estrogen due to their estrogenic properties. Different HF-FPW samples exhibited distinct nuclear receptor binding effects. For example, sample B3-S showed the strongest aryl hydrocarbon receptor (AhR) agonist activity, while sample A1-W exhibited the greatest estrogen receptor (ER) agonist activity. The variance of compounds found illustrates the need for careful consideration of individual sites.

What are the roles of the aryl hydrocarbon receptor (AhR), estrogen receptor (ER), and androgen receptor (AR) in the context of hydraulic fracturing flowback and produced water (HF-FPW) exposure?

The aryl hydrocarbon receptor (AhR) influences the metabolism of foreign chemicals and can lead to oxidative stress and DNA damage. The estrogen receptor (ER) is vital for reproductive health and development, and disruption can lead to reproductive issues and certain cancers. The androgen receptor (AR) is essential for male sexual development and function, and interference can affect sexual health and development. By studying these receptors, researchers can better understand the wide-ranging health implications of HF-FPW exposure.

What implications does this study have for the future of fracking regulation and wastewater management?

The study highlights the temporal and spatial variability in endocrine-disrupting potentials, indicating that a one-size-fits-all approach to managing fracking wastewater is insufficient. Reclamation and remediation efforts must consider the specific properties of each spill, taking into account the geological formation and physiochemical properties of the injected fluid. Managing this effectively is vital to mitigating contamination of water supplies and ensuring public health is safe guarded.

What hormone receptors were not explored in the study, and what would be the benefit of researching their relationship with hydraulic fracturing flowback and produced water (HF-FPW)?

While the study examines the impact of hydraulic fracturing flowback and produced water (HF-FPW) on the aryl hydrocarbon receptor (AhR), estrogen receptor (ER), and androgen receptor (AR), it does not explore in detail the potential effects on other critical hormone receptors such as thyroid hormone receptor (TR) or glucocorticoid receptor (GR). Future research could broaden the scope to include these receptors to provide a more comprehensive understanding of the endocrine-disrupting capabilities of fracking wastewater.