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International Water Quality Guidelines for PAHs: Advances to Improve Jurisdictional Uptake of Guidelines Derived using the Target Lipid Model.

Angeline R TillmannsJoy A McGrathDominic M Di Toro
Published in: Environmental toxicology and chemistry (2023)
A large diversity of polycyclic aromatic hydrocarbons (PAHs) is found in environmental media yet water quality guidelines (WQGs) are only available for a small subset of PAHs limiting the ability to adequately assess environmental risks from these compounds. The target lipid model (TLM) was published over 20 years ago and has been extensively validated in the literature, but it has still not been widely adopted by jurisdictions to derive WQGs for PAHs. The goal of this study was to better align the methods for deriving TLM-based WQGs with international derivation protocols. This included updating the TLM with re-screened data to identify datapoints where effect concentrations were estimated rather than measured, modernizing the statistics used to generate the hazard concentration, and testing the applicability of a chronic TLM model rather than using the acute to chronic ratio (ACR). The results show that the acute TLM model did not deviate substantially from the previous iteration indicating the model has reached a point of stability after over twenty years of testing and improvements. WQGs derived directly from a chronic TLM provided a similar level of protection to previous iterations of the TLM. The major advantage of adopting TLM-derived WQGs is the expanded list of PAH WQGs which will allow a more fulsome quantification of environmental risks and the ability to apply the model to mixtures.
Keyphrases
  • human health
  • polycyclic aromatic hydrocarbons
  • water quality
  • systematic review
  • risk assessment
  • liver failure
  • clinical practice
  • machine learning
  • randomized controlled trial
  • working memory