Pyrogallol is found naturally in plants and can also enter the environment through industrial activities, wastewater, and the breakdown of organic matter. Despite its widespread origins and long history of use, scientists say its potential effects on aquatic ecosystems have received far less attention than those of many synthetic pollutants.
A new review published in New Contaminants brings together the available evidence on the chemistry, environmental occurrence, biological effects, and potential health risks of pyrogallol. The analysis identifies oxidative stress as a central mechanism behind many of the toxic effects reported in aquatic organisms.
"Pyrogallol is a good example of why naturally occurring chemicals should not automatically be assumed to be environmentally harmless," said corresponding author Mohamed Hamed. "The evidence collected in this review shows that its biological effects can extend across several organ systems, while our knowledge of actual environmental exposure remains surprisingly limited."
Pyrogallol, also known as 1,2,3-trihydroxybenzene, can form during the degradation of tannins and other plant materials. It is also used in applications including dyes, photography, personal care products, pharmaceuticals, metal processing, and oxygen removal. These diverse sources create several pathways through which the compound can reach freshwater environments.
Studies summarized in the review have detected pyrogallol in tap water, river water, domestic wastewater, industrial areas, and sewage. However, measurements from real aquatic environments remain scarce, making it difficult to determine how frequently organisms encounter biologically significant concentrations.
Laboratory evidence provides greater cause for attention. Research in fish has associated pyrogallol exposure with changes in blood chemistry, immune function, antioxidant defenses, reproductive hormones, neural activity, and tissue structure. Experiments have also reported damage in organs including the liver, kidney, intestine, spleen, brain, heart, and reproductive tissues. Studies involving freshwater invertebrates have identified immune, neurological, reproductive, and histological effects.
At the cellular level, much of this toxicity appears to originate from pyrogallol's ability to undergo oxidation and generate reactive oxygen species. Excessive reactive oxygen species can overwhelm antioxidant defenses and damage lipids, proteins, mitochondria, and DNA. This process can then contribute to broader physiological and tissue level effects.
The review also points to possible human health concerns, particularly in occupational settings where inhalation or skin contact may occur. Experimental evidence has linked high or prolonged exposure with oxidative damage and effects on organs such as the liver and kidneys. However, the authors emphasize that data on human exposure and toxicokinetics remain incomplete.
A major limitation in the current evidence base is the gap between laboratory toxicology and real world environmental conditions. Research on pyrogallol has expanded rapidly, but field monitoring has not kept pace.
"The next priority is to understand where pyrogallol occurs, at what concentrations, and how long organisms are exposed under realistic environmental conditions," Hamed said. "Without that information, it is difficult to translate laboratory toxicity findings into reliable ecological and human health risk assessments."
The authors call for broader environmental surveillance, long term ecological studies, improved exposure assessment, and stronger risk assessment frameworks. Such efforts could help determine whether pyrogallol should receive greater attention as an emerging contaminant and provide a stronger scientific basis for future environmental management and regulation.
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Journal reference: Hamed M, Mo J, Said REM, El-Kurdi N, Martyniuk CJ, et al. 2026. Pyrogallol toxicity in aquatic ecosystems: chemistry, sources, and associated health risks. New Contaminants 2: e020 doi: 10.48130/newcontam-0026-0017
https://www.maxapress.com/article/doi/10.48130/newcontam-0026-0017
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About the Journal:
New Contaminants (e-ISSN 3069-7603) is an open-access journal focusing on research related to emerging pollutants and their remediation.
