Development of a field-deployable analytical workflow for determining current status and indicative human health risks at a historic dl-POPs hotspot

Critical validation of a GC-MS/MS methodology for confirmatory quantification of dioxins and PCBs in fish/ fish oil: Integrating a tiered surveillance strategy

Dioxins and polychlorinated biphenyls (PCBs) are toxic, bioaccumulative persistent organic pollutants (POPs) requiring sensitive analysis in critical matrices, such as fish and fish products, to meet stringent regulatory standards. This study introduces a cost-effective complement to high-resolution mass spectrometry through a refined gas chromatography-tandem mass spectrometry workflow. The methodology integrates streamlined sample preparation, validation under European Union, 2017, and comprehensive measurement uncertainty estimation. Key performance metrics include low limits of quantification: 0.36 and 0.04 pg TEQ/g wet weight in fish, and 0.73 and 0.08 pg TEQ/g (12 % moisture basis) in fish oil for dioxins and dl-PCBs, respectively, along with 25.1 pg/g for ndl-PCBs in both matrices. Moreover, excellent linearity (R2 > 0.999), high accuracy (bias: ±20 %), strong precision (RSD < 15 %), and consistent internal standard recovery (70-105 %) ensured reliability and reproducibility. A practical multi-level pyramid framework is proposed for dl-POPs surveillance, enabling scalable and efficient monitoring-particularly valuable in resource-limited regions.

Foraging animal origin food samples as passive indicators of dioxin-like POPs contamination in industry sites: Method development, characterisation and risk assessment

Titanium dioxide (TiO2) is an important industrial chemical, and studies suggest its major production route - the chloride process could lead to the generation of unintentional dl-POPs. However, no relevant studies assessed the occurrence of dl-POPs associated with TiO2 production in the industrial zones, which is mostly due to the ultra-trace level distribution of these compounds in environmental compartments. The present study explored the novel possibility of utilising foraging animal-origin foods as sensitive indicators for addressing this challenge and generated a globally beneficial dataset by assessing the background levels of dl-POPs in the vicinity of a TiO2 production house in Southern India. Systematic sampling of foraging cow's milk and free-ranging hen's eggs was carried out from the study site, and the dl-POPs assessments were conducted utilising an in-house developed cost-effective GC-MS/MS-based analytical methodology. The median dl-POPs levels in milk and egg samples were about 3 times higher than the control samples collected from farm-fed animals and retail markets. The contaminant loads in the foraging animal-origin food samples were further traced to their presence in environmental compartments of soil and sediment and admissible degree of correlations were observed in congener fingerprints. Elevated health risks were inferred for the population in the industrial zones with weekly intakes weighing about 0.15-17 times the European Food Safety Authority-assigned levels. The consumption of foraging cow's milk was observed to have a higher contribution towards the hazard indices and cancer risk estimates and were significantly higher (p < 0.05) for children. The study also presents a critical validation of the GC-MS/MS-based method for the purpose of regulatory monitoring of dl-POPs, which could be of practical significance in economies in transition.