Research Article Summary
• Primary focus:
This article reviews how persistent organic pollutants (POPs) — a broad class of environmental contaminants — can induce hormesis (biphasic, non-linear dose responses) in organisms at low exposure levels, and discusses the implications and challenges this poses for environmental risk assessment. ScienceDirect
• Evidence of low-dose responses:
The authors synthesize literature showing that numerous POPs can trigger hormetic effects in a range of species at low concentrations. These effects include increased growth or stress resistance at low exposure levels, contrasting with inhibitory effects at higher exposures. ScienceDirect
• Mechanistic insights:
Hormetic responses appear to be driven by mild oxidative stress and activation of adaptive cellular pathways, such as upregulation of antioxidant enzymes, enhanced detoxification mechanisms, and coordinated stress signaling. These adaptive mechanisms are transient and context dependent, reflecting dynamic survival strategies. ScienceDirect
• Environmental and ecological relevance:
The review emphasizes that hormesis is observed across a wide range of POPs and biological endpoints, suggesting that low-dose adaptive responses could have significant ecological consequences — such as changes in species competition, stress resistance, and ecosystem dynamics — if not accurately understood and managed. ScienceDirect
• Challenges for risk assessment:
Conventional environmental risk models often assume linear responses with increasing exposure. The authors argue that biphasic dose–response relationships must be integrated into risk assessment frameworks to improve prediction of ecological and human health effects, and to set biologically informed safety thresholds. ScienceDirect
Please click here to read the full research article:
https://www.sciencedirect.com/science/article/pii/S0269749125017154