Hazard Characterization and Dietary Risk Assessment of Pentachlorothiophenol in Food Using Health-Based Guidance Values Based on a Read-Across Approach.

Abstract

Pentachlorothiophenol is a persistent organic pollutant for which no health-based guidance values have been established. This study presents the first hazard characterization and dietary risk assessment of PCTP in food. A provisional reference dose (RfD) of 0.001 mg/kg-BW/day was derived using a read-across approach from hexachlorobenzene, incorporating quantitative human biomonitoring data and standard uncertainty factors. Dietary exposure was estimated by integrating PCTP occurrence data from 870 Korean food samples with consumption patterns from the Korea National Health and Nutrition Examination Survey (2019-2021, n=18,895). Owing to low detection frequency, non-detected concentrations were imputed using robust regression on order statistics (ROS), and exposure estimates were interpreted considering this uncertainty. Mean estimated daily intakes ranged from 6.59 ng/kg-BW/day in adults aged ≥65 years to 22.5 ng/kg-BW/day in children aged 1-2 years. The highest estimated exposure occurred in children aged 1-2 years at the 95th percentile, reaching 41.3 ng/kg-BW/day, approximately 24 times lower than the provisional RfD of 1000 ng/kg-BW/day. Hazard quotients were below 4.13% across age groups and scenarios. Agricultural products were primary contributors, followed by livestock and fishery products. Under the evaluated exposure scenarios, estimated dietary PCTP exposure in Korea remained below the provisional screening benchmark for all age groups. However, reliance on read-across methodology and extensive non-detects necessitate PCTP-specific toxicological studies and continued monitoring to refine risk conclusions.