Effect of Plastic Composition in the Combustion Material on the Persistent Organic Pollutant Content in Smoked Dried...

Smoking is a traditional preservation method in Vietnam, widely applied to shiitake mushrooms (Lentinula edodes) as well as meats, yet the use of plastic-contaminated fuels poses emerging food safety concerns. This study provides the first congener-specific characterization of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and polychlorinated dibenzo-p-dioxins and furans (PCDD/Fs) in smoke-dried shiitake produced with wood and wood adulterated by polyethylene (PE), polystyrene (PS), or polyvinyl chloride (PVC). Using GC-MS/MS combined with multivariate analyses, we observed clear differences in contaminant accumulation driven by fuel composition. Clean wood (W) yielded the lowest burdens, with PCB levels < 150 ng/kg, PCDD/Fs negligible, and PAHs < 650 µg/kg. Plastic-adulterated fuels significantly increased contamination (Kruskal-Wallis p < 0.001), with PAH and PCB/PCDD/F levels following robust gradients of W < PE < PS < PVC (PCBs/PCDD/Fs) and W < PE < PVC < PS (PAHs). PE was characterized by light PAHs (naphthalene, acenaphthylene, and acenaphthene) and moderate PCB increases; PS, by high-molecular-weight PAHs and coplanar PCBs; and PVC, by the broadest enrichment, including nearly all tested PCDD/F congeners. Hierarchical cluster analysis and PCA confirmed clustering by fuel type and revealed pollutant fingerprints specific to each plastic. These findings demonstrate, for the first time, the toxicological risks of plastic-contaminated smoking fuels in Vietnamese shiitake processing and provide baseline data essential for risk assessment and food safety policy.