Human beings and wild organisms are exposed daily to a broad range of environmental stressors. Among them are the persistent organic pollutants that can trigger adverse effects on these organisms due to their toxicity properties. There is evidence that metabolomics can be used to identify biomarkers of effect by altering the profiles of endogenous metabolites in biological fluids or tissues. This approach is relatively new and has been used in vitro studies mainly. Therefore, this review addresses those that have used metabolomics as a key tool to identify metabolites associated with environmental exposure to POPs in wildlife and human populations and that can be used as biomarkers of effect. The published results suggest that the metabolic pathways that produce energy, fatty acids, and amino acids are commonly affected by POPs. Furthermore, these pathways can be promoters of additional effects. In the future, metabolomics combined with other omics will improve understanding of the origin, development, and progression of the effects caused by environmental exposure.

17β-estradiol (E2) is the natural estrogen with the most significant potential for endocrine disruption in the biota of aquatic ecosystems at trace concentrations. It is, therefore, essential to study treatments for water polluted with E2 that would guarantee its complete elimination and mineralization. Denitrification is a biological process shown to have the capacity to completely biodegrade drugs, such as ampicillin. This work is aimed to evaluate the biotransformation of 17β-estradiol by employing a denitrifying sludge. The assays performed were: (I) abiotic with 3.5 mg E2-C L⁻¹ and (II) denitrifying with 10 mg CH₃COO⁻-C L⁻¹ as the reference, 10 mg E2-C L⁻¹ as the sole electron donor, and a mixture of (mg L⁻¹) 10 E2-C with 10 CH₃COO⁻-C at C N⁻¹ of 1.1. The E2-C and NO₃⁻-N consumption efficiencies were greater than 99%, and HCO₃⁻-C and N₂ production yields were close to 1 in all assays. The denitrifying sludge could biodegrade up to 10 mg E2-C L⁻¹ as the sole electron donor and when mixed with 10 mg CH₃COO⁻-C L⁻¹. No intermediate metabolites were generated from the process.