Mixtures and combined exposures in environmental toxicology

Environmental toxicology increasingly recognizes that organisms are rarely exposed to a single pollutant in isolation. Pesticides, heavy metals, pharmaceuticals, microplastics, persistent organic pollutants, and other anthropogenic contaminants frequently co-occur in soil, water, sediment, and air. These combined exposures can produce additive, synergistic, antagonistic, or otherwise modified effects that are not predicted by single-substance toxicology. However, many experimental designs and regulatory frameworks continue to rely primarily on individual-chemical exposure models. Recent advances in molecular biology, omics, multi-trophic bioassays, high-throughput screening, and computational toxicology are providing new opportunities to investigate mixture effects across species, biological organization levels, and exposure scenarios. Nevertheless, important gaps remain in understanding the mechanisms, ecological significance, and regulatory implications of real-world contaminant mixtures.This Research Topic aims to advance the understanding of the combined toxicity of environmental contaminants using in vitro, in vivo, and in silico approaches. It will examine how multiple stressors interact to affect organismal, population-level, cellular, physiological, behavioral, and molecular endpoints. Particular emphasis will be placed on identifying the mechanisms underlying additive, synergistic, antagonistic, and potentiating interactions; evaluating the influence of dose, exposure route, timing, sequence, and duration; and improving the prediction and assessment of mixture risks. The Research Topic will also consider how contaminant mixtures contribute to bioaccumulation, biomagnification, chronic effects, and long-term ecological consequences.To gather further insights into the toxicity, mechanisms, environmental fate, and risk assessment of combined exposures, we welcome contributions addressing, but not limited to, the following themes:• Joint and combined toxicity of pesticides, heavy metals, pharmaceuticals, microplastics, persistent organic pollutants, and other environmental contaminants.• Mechanistic and molecular pathways underlying additive, synergistic, antagonistic, and potentiating interactions.• Dose–response relationships and methods for distinguishing concentration addition from independent action.• Acute, subchronic, and chronic effects of contaminant mixtures.• Effects of co-exposures on oxidative stress, inflammation, endocrine disruption, neurotoxicity, immunotoxicity, genotoxicity, and reproductive toxicity.• Molecular, cellular, physiological, behavioral, and population-level responses to combined exposures.• Multi-trophic and cross-species comparative toxicity assessments.• Combined effects of chemical and non-chemical stressors, including temperature, hypoxia, salinity, nutritional stress, and climate-related changes.• Bioaccumulation, biomagnification, chemical transformation, and long-term ecological consequences of co-exposures.• Influence of exposure route, timing, sequence, frequency, and duration on mixture toxicity.• Toxicity of contaminant mixtures in aquatic, terrestrial, marine, freshwater, and sediment environments.• Development and application of indices, models, and computational frameworks for evaluating mixture risk.• In vitro, in vivo, in silico, omics-based, and high-throughput approaches to mixture toxicology.• Species sensitivity, interindividual variability, life-stage susceptibility, and transgenerational effects.• Environmental fate, transport, persistence, and bioavailability of contaminant mixtures.• Regulatory approaches, monitoring strategies, and ecological and human health risk assessment for combined exposures.• Remediation and mitigation strategies for reducing the toxicity and environmental impacts of combined pollutant mixtures. Topic editors: Yingcai Wang, PREM RAJAK, Xiangwei Wu Source: https://www.frontiersin.org/research-topics/84953/mixtures-and-combined-exposures-in-environmental-toxicology