"Silent Offspring": Multigenerational Epigenetic Toxicity of Aryl Hydrocarbon Receptor Agonists

In this review article, we build on the environmental warnings first articulated by Rachel Carson's Silent Spring, tracing pollutants from ecosystems and human-modified environments to their subtle inscription in molecular systems that control gene expression and associated biological functioning of future generations. Here, we use polycyclic aromatic hydrocarbons (PAHs) as the primary case study to examine associations among contaminant exposure, epigenetic alterations, and phenotypic outcomes across generations, while recognizing that evidence demonstrating causal mediation by specific epigenetic alterations remains limited. This evidence challenges the assumption that chemical effects are limited to directly exposed organisms. Instead, it suggests that certain environmental pollutants may influence biological outcomes across generation through persistent alterations in epigenetic regulation. Evidence that certain AhR agonists may produce effects across generations identifies a potential gap in current chemical risk assessment and highlights the need for further research on how such hazards could be evaluated within regulatory frameworks.