Dermal Uptake is an Important Pathway for the Bioconcentration of Hydrophobic Organic Compounds by Zebrafish (Danio rerio)

For bioconcentration of hydrophobic organic compounds (HOCs), most of studies assumed that fish absorb HOCs mainly through gills but often ignored the dermal uptake. In this study, deuterated polycyclic aromatic hydrocarbons (PAHs-d(10), phenanthrene-d(10), and pyrene-d(10)) and polychlorinated biphenyls (PCB-153) were selected to study whether zebrafish can absorb freely dissolved and dissolved organic matter (DOM)-associated HOCs through dermal uptake. The results showed that the freely dissolved PAHs and PCBs could directly enter the body of zebrafish through its skin. However, PAHs and PCB-153 associated with DOM (similar to 10 kDa) could not enter zebrafish through the skin. When gill and dermal exposure coexisted, dermal uptake contributed 2.9 similar to 7.6% and 31.9 similar to 38.4% of PAHs and PCB-153 bioconcentration after exposure for 6 h, respectively. The present study demonstrates that dermal uptake is an important pathway for the bioconcentration of HOCs by fish, which should be considered when studying the toxicodynamics and toxicokinetics of HOCs in organisms.

Automated summary

This study found that zebrafish can absorb hydrophobic organic compounds (HOCs), such as polycyclic aromatic hydrocarbons (PAHs) and polychlorinated biphenyls (PCBs), through dermal uptake. The dermal uptake is an important pathway for HOCs bioconcentration in fish, and should be considered in the study of toxicodynamics and toxicokinetics of HOCs.