Toxicology and Ecological Risk with Emphasis on Scenario-Describing Mechanisms

Persistent organic pollutants (POPs) have a high lipid solubility, making them susceptible to passing through the phospholipid structure of biological membranes and accumulating in fat deposits. POPs can resist environmental degradation through chemical, biological, and photolytic processes. POPs are becoming a major concern due to their toxicological characteristics and ambiguous ecological behavior. They can disrupt reproductive function and sociosexual behaviors via changes in neuroendocrine mechanisms. The toxic equivalent (TEQ) and risk quotient (RQ), toxicity-exposure ratio (TER), predicted no-effect concentration (PNEC), and lifetime cancer risk (ILCR) were used to evaluate the ecological risk of POPs. The impact of POPs on ecosystems and humans is discussed. The kinetics and behavior of POPs in humans and other animals depend on many parameters, including the mode of exposure, the particle size, and the molecular weight. Oxidative stress, cell apoptosis, and insulin/IGF-1 signaling pathway are the most common modes of action describing the toxicity of POPs. POPs’ effects on immune systems, carcinogenesis, endocrine, developmental, neural, and reproductive systems are reported. A model for the source, distribution, and toxicity of polycyclic aromatic hydrocarbons (PAHs) (chemical mass balance model and toxic equivalents—CMB-TEQ) is highlighted. Many equations are evaluated to benchmark human and ecological risks.