A review of non-exhaustive chemical and bioavailability methods for the assessment of polycyclic aromatic hydrocarbons in soil

• Small range of in vivo animal models for quantifying PAH bioavailability in soil.
• Absence of guidance documents for PAH in vivo models.
• In vivo to in vitro relationship studies on PAHs is limited.
• There is no certified reference material for assessment of bioavailability or bioaccessibility.
• Absence of PAH and metal or metalloid mixture effect on bioavailability or bioaccessibility.

Current environmental regulations relating to risk assessment for contaminated sites are often set assuming that the contaminant is 100% bioavailable. It is therefore not surprising that remediation of contaminated sites is very expensive and maybe it is unrealistic to achieve a “remediated state” under current regulatory guidelines using existing technologies. In fact the reality is that only a portion of the contaminant on site becomes available for absorption and goes into the systemic circulation. This article gives an overview of existing in vivo animal models that quantify oral bioavailability of polycyclic aromatic hydrocarbons (PAHs) in soil. It also provides a summary of in vitro gastrointestinal extraction methodologies and some of the key factors influencing absorption of PAHs in soil. For innovation, it highlights that bioaccessibility values derived from in vitro studies still require validation from in vivo animal models to gain regulatory acceptance. Additionally, this review highlights the use of non-exhaustive chemical methodologies as a valuable tool to understanding the bioavailability process and behaviour of PAHs in soil.