Polychlorinated biphenyls (PCBs) are a group of 209 chemicals with varying chlorine substitutions that influence their absorption, distribution, metabolism, and excretion (ADME). These differences affect how PCBs behave in the body, including their lipophilicity, tissue distribution, and biological half-life. Humans and animals can absorb PCBs through inhalation, ingestion, or skin contact, with the compounds accumulating in fatty tissues and eliminating at variable rates—some over decades.

Pharmacokinetic (PK) models help estimate internal doses and assess health risks by accounting for species-specific ADME properties. However, modeling PCBs is challenging due to their persistence, bioaccumulation, and structural diversity. While PK models can support risk assessment and interspecies extrapolation, they require accurate data—particularly biological half-lives, which are unavailable for many congeners.

This study aims to compile half-life data for individual PCB congeners from the literature in support of future explorations of the use of Quantitative Structure Activity Relationship (QSAR) models to predict half-lives of unstudied congeners using structural features like chlorine substitution patterns, building on prior work.

Database curation: The HERO PCBs project page (https://hero.epa.gov/hero/index.cfm/project/page/project_id/384) was searched using terms related to half-life or elimination. Studies retrieved by the literature search were screened to identify studies containing PCB congener half-life data. Select details from each relevant study were entered into the database (e.g., citation information, congener name and number, exposure context, population descriptors, biological matrix, and reported half-life).