Polycyclic aromatic hydrocarbons (PAHs) are a diverse group of organic compounds characterized by multiple fused aromatic rings. These compounds primarily arise from the incomplete combustion of organic materials, which can occur in various contexts, including vehicular emissions, industrial activities, and natural events such as wildfires and volcanic eruptions. PAHs are pervasive in the environment; they have been detected in air, soil, water, and sediments, and can enter the food chain, leading to bioaccumulation and biomagnification.

The formation and persistence of PAHs in the environment are largely influenced by their hydrophobic nature, which causes them to adhere to particulate matter. This affinity facilitates their transport and enhances their stability, raising significant concerns about their long-term effects on both human health and ecosystems. Epidemiological studies and toxicological research have linked PAH exposure to a variety of adverse health outcomes, including respiratory issues, cardiovascular diseases, and several forms of cancer. Their potential carcinogenic, mutagenic, and endocrine-disrupting properties have been extensively studied, emphasizing the critical need for a deeper understanding of their toxicological mechanisms and exposure pathways.

As environmental pollution escalates, particularly in the context of urbanization and industrialization, addressing the challenges posed by PAHs becomes increasingly urgent. New industrial practices and energy transitions aimed at combating climate change may inadvertently lead to increased PAH emissions, underscoring the importance of ongoing research in this area. By elucidating the complex interactions between PAHs and biological systems, we can gain valuable insights into their impacts and develop effective strategies for risk mitigation.

We invite researchers to contribute to this Collection, which serves as a platform for advancing knowledge on the toxicological implications of PAHs. We encourage submissions that explore a wide range of topics, including environmental fate, human exposure assessments, mechanistic studies, and risk characterization, with the ultimate goal of informing effective regulatory measures and public health interventions.

Topics of interest include, but are not limited to:

- Mechanisms of PAHs toxicity

- Human health risk assessments for PAHs exposure

- Environmental fate and transport of PAHs

- Strategies for PAHs remediation

- Novel analytical techniques for PAHs detection

This Collection supports and amplifies research related to SDG 3.

Keywords: Polycyclic Aromatic Hydrocarbons; PAHs; exposure assessment; toxicology; mechanism of action; health effect; risk assessment; bioanalysis; bioavailability

Toxicology is undergoing a profound transformation as the field moves beyond reliance on conventional animal testing toward more human-relevant, mechanistically informed, and efficient approaches. New approach methodologies (NAMs), including in vitro systems, omics technologies, computational modeling, in silico prediction, and integrated testing strategies, are increasingly reshaping how chemical hazards are identified, characterized, and interpreted. At the same time, regulatory science is evolving to consider how these tools can be applied in ways that are scientifically robust, transparent, and fit for decision-making. This collection aims to highlight recent advances in the development, evaluation, and application of NAMs across diverse areas of toxicology and regulatory science. We welcome contributions that improve mechanistic understanding of toxicity pathways, support hazard identification and prioritization, refine dose-response assessment, or strengthen exposure-informed risk evaluation. Particular interest is given to studies that demonstrate the regulatory relevance, readiness, interpretability, and limitations of NAM-based approaches in real-world contexts. Topics of interest include, but are not limited to, cell-based and organotypic models, high-throughput screening, transcriptomics and other omics-based profiling, physiologically based kinetic modeling, computational toxicology, artificial intelligence-assisted methods, defined approaches, integrated approaches to testing and assessment, and case studies that support next-generation risk assessment. Submissions addressing validation, uncertainty, reproducibility, data integration, and regulatory translation are also strongly encouraged. By bringing together original research, reviews, perspectives, and methodological advances, this collection seeks to provide a platform for interdisciplinary dialogue on how NAMs can strengthen contemporary toxicology and accelerate the transition toward more predictive, efficient, and human-relevant regulatory practices.

Keywords: New approach methodologies; Regulatory science; Computational toxicology; In vitro toxicology; Omics; High-throughput screening; Physiologically based kinetic modelling; Integrated approaches to testing and assessment; Next-generation risk assessment; Chemical hazard assessment