A bioindicator-based approach for evaluating environmental dioxin-like POPs burden: Implications for contamination surveillance and exposure risk assessment.

Recent global emission inventories, attributing significant releases of dioxin-like persistent organic pollutants (dl-POPs) to open burning activities, necessitate surveillance and emission control measures that invariably extend to non-point sources alongside conventionally weighed stationary point sources. The study presents an integrated field-based approach that employs foraging animal-origin food as bioindicators to systematically investigate and compare the environmental fingerprints and exposure risks of dl-POPs under such emission scenarios. The chosen study sites, viz. a legacy municipal solid waste (MSW) dumpsite and a biomedical waste incinerator (BMWI), along with a rare case of accidental fire incidents, represented classic real-world instances of transient/non-point and continuous/point sources. The observed substantially higher median dl-POPs levels in cow's milk and chicken eggs from the BMWI site (8.04 and 10.8 pgTEQ/g fat), relative to the MSW dumpsite (2.78 and 2.89 pgTEQ/g fat), highlighted continuous point sources as critical contributors to environmental burdens. Notably, dynamic trends of PCDD/Fs levels in milk and eggs over successive sampling phases suggested the contributive effect of fire breakouts to locally produced food contamination. Based on dietary exposure assessment, median dl-POPs weekly intake from the BMWI site and MSW dumpsite ranged up to 11.2 and 3.88 pgTEQ kg-1bw week-1, respectively, which are up to 5.6 and 1.9 times the EFSA-assigned tolerable weekly intake, indicating elevated health risk for consumers. The study upholds great relevance for data-deficient emerging economies to validate emission inventories, strengthen monitoring and source-specific emission control, and support regulatory frameworks in food commodities.