Transformation products of emerging contaminants and their formation pathways, environmental fate, predictive modeling, and regulatory risk implications
5 affiliations
- 1Goodnight Family Department of Sustainable Development, Living Learning Center, Appalachian State University, Boone, NC, USA
- 2Department of Community Medicine, Faculty of Clinical Sciences, Bayelsa Medical University, Yenagoa, Bayelsa State, Nigeria
- 3Department of Environmental Biology, Auchi Polytechnic, Auchi, Edo State, Nigeria
- 4Department of Microbiology, Faculty of Science, Bayelsa Medical University, Yenagoa, Bayelsa State, Nigeria
- 5Department of Research and Publications, Kampala International University, P. O. Box 20000, Kampala, Uganda
Abstract
Transformation products (TPs) of emerging contaminants are emerging as a major frontier in environmental chemistry, toxicology, and regulatory science because many exhibit greater persistence, mobility, bioavailability, or biological activity than their parent compounds. These transformation-driven changes can alter exposure pathways, trophic interactions, environmental transport, and long-term ecological and human health risks, challenging conventional parent-compound-centered approaches to chemical risk assessment. This review critically examines the formation pathways, environmental fate, analytical detection, predictive modeling, and regulatory implications of TPs derived from major contaminant groups, including pharmaceuticals, pesticides, industrial chemicals, plastic additives, and per- and polyfluoroalkyl substances (PFAS). Unlike many existing reviews that focus primarily on TP occurrence, analytical detection, or individual contaminant classes, this review advances a transformation-aware predictive systems framework that integrates formation mechanisms, environmental fate, analytical monitoring, predictive modeling, toxicity assessment, and regulatory decision-making into a unified risk-governance approach. Evidence from the reviewed literature shows that selected pharmaceutical, pesticide, PFAS-related, and plastic-associated contaminants and their transformation products are commonly detected in wastewater, surface water, groundwater, drinking-water systems, sediments, and biological matrices, with reported concentrations often ranging from ng/L to µg/L levels depending on contaminant class, matrix, source intensity, and treatment conditions. Particular attention is given to coupled biotic and abiotic mechanisms governing TP formation, including microbial metabolism, photochemical reactions, hydrolysis, oxidation–reduction processes, and treatment-induced transformations across aquatic, terrestrial, atmospheric, indoor, and engineered systems. The review further evaluates how physicochemical properties influence TP persistence, partitioning, trophic transfer, bioaccumulation, and long-range transport. Advances in high-resolution mass spectrometry, suspect and non-target screening, isotope-assisted pathway tracing, and machine-learning-assisted prediction are discussed as transformative tools for identifying overlooked contaminants and anticipating transformation-driven risks. Persistent regulatory blind spots are critically examined, particularly the limited incorporation of TPs into monitoring frameworks, exposure modeling, watch-list systems, and chemical governance. In response, the review proposes an integrated monitoring–modeling–toxicity–policy pathway to support adaptive environmental risk governance. Recognizing TPs as independent environmental risk entities rather than secondary degradation byproducts represents a necessary paradigm shift for advancing chemical safety assessment, sustainable pollution management, and proactive environmental protection in the era of emerging contaminants.
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BibTeX
@article{ogwu2026transformation,
title = {{Transformation products of emerging contaminants and their formation pathways, environmental fate, predictive modeling, and regulatory risk implications}},
author = {Matthew Chidozie Ogwu and Sylvester Chibueze Izah and Aliu Olugbemiga Ojo and Ayebapreye Kari and Esther Ugo Alum},
journal = {Discover Environment},
year = {2026},
month = jul,
doi = {10.1007/s44274-026-00829-7},
url = {https://doi.org/10.1007/s44274-026-00829-7},
note = {CC BY-NC-ND},
}
RIS
TY - JOUR
TI - Transformation products of emerging contaminants and their formation pathways, environmental fate, predictive modeling, and regulatory risk implications
AU - Matthew Chidozie Ogwu
AU - Sylvester Chibueze Izah
AU - Aliu Olugbemiga Ojo
AU - Ayebapreye Kari
AU - Esther Ugo Alum
PY - 2026
DA - 2026/07/01
JO - Discover Environment
DO - 10.1007/s44274-026-00829-7
UR - https://doi.org/10.1007/s44274-026-00829-7
AB - Transformation products (TPs) of emerging contaminants are emerging as a major frontier in environmental chemistry, toxicology, and regulatory science because many exhibit greater persistence, mobility, bioavailability, or biological activity than their parent compounds. These transformation-driven changes can alter exposure pathways, trophic interactions, environmental transport, and long-term ecological and human health risks, challenging conventional parent-compound-centered approaches to chemical risk assessment. This review critically examines the formation pathways, environmental fate, analytical detection, predictive modeling, and regulatory implications of TPs derived from major contaminant groups, including pharmaceuticals, pesticides, industrial chemicals, plastic additives, and per- and polyfluoroalkyl substances (PFAS). Unlike many existing reviews that focus primarily on TP occurrence, analytical detection, or individual contaminant classes, this review advances a transformation-aware predictive systems framework that integrates formation mechanisms, environmental fate, analytical monitoring, predictive modeling, toxicity assessment, and regulatory decision-making into a unified risk-governance approach. Evidence from the reviewed literature shows that selected pharmaceutical, pesticide, PFAS-related, and plastic-associated contaminants and their transformation products are commonly detected in wastewater, surface water, groundwater, drinking-water systems, sediments, and biological matrices, with reported concentrations often ranging from ng/L to µg/L levels depending on contaminant class, matrix, source intensity, and treatment conditions. Particular attention is given to coupled biotic and abiotic mechanisms governing TP formation, including microbial metabolism, photochemical reactions, hydrolysis, oxidation–reduction processes, and treatment-induced transformations across aquatic, terrestrial, atmospheric, indoor, and engineered systems. The review further evaluates how physicochemical properties influence TP persistence, partitioning, trophic transfer, bioaccumulation, and long-range transport. Advances in high-resolution mass spectrometry, suspect and non-target screening, isotope-assisted pathway tracing, and machine-learning-assisted prediction are discussed as transformative tools for identifying overlooked contaminants and anticipating transformation-driven risks. Persistent regulatory blind spots are critically examined, particularly the limited incorporation of TPs into monitoring frameworks, exposure modeling, watch-list systems, and chemical governance. In response, the review proposes an integrated monitoring–modeling–toxicity–policy pathway to support adaptive environmental risk governance. Recognizing TPs as independent environmental risk entities rather than secondary degradation byproducts represents a necessary paradigm shift for advancing chemical safety assessment, sustainable pollution management, and proactive environmental protection in the era of emerging contaminants.
SN - 2731-9431
ER -