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This research project will seek to identify compounds that might be considered to act via a threshold mechanism.
<p>The project is generating a database that collates information on genotoxic chemicals that may occur in food. These will be categorised by their mechanisms of genotoxic activity.
<p>Compounds with a potentially thresholded mechanism of action will then be subjected to further investigation. This will generate a priority list of compounds that will be subject to laboratory testing using in vitro models.
<p>In addition, experimental work will be carried out on a small number of chemicals that have already been identified as possibly meeting the criteria of acting via a threshold mechanism.
<p>Those selected are: bisphenol A, rotenone, fisetin and acrylamide. In addition, the project will include a study of whether exposure of mice to low levels of bisphenol A in vivo leads to an increase in abnormalities of oocyte meiosis leading to aneuploidy.
Food may contain a number of genotoxic substances, present at very low levels as natural constituents or as a result of unavoidable contamination.
<p>Current UK policy is that it is prudent to assume a non-threshold dose response for chemicals that are genotoxic in vivo.
<p>The Committee on Mutagenicity of Chemicals in Food, Consumer Products and the Environment recently reviewed its general approach to risk assessment of in vivo mutagens and concluded that for certain substances (such as aneugens) it may be possible to identify potential threshold-related mechanisms of action.
<p>These mechanisms include DNA repair activity, compound detoxification and the existence of multiple targets for genotoxin interaction.
<p>Mechanistic and dose-response studies may support identification of a critical No Observed Adverse Effect Level (NOAEL), to which uncertainty factors could be applied in establishing a Tolerable Daily Intake (TDI).
<p>Find more about this project and other FSA food safety-related projects at the <a href="http://www.food.gov.uk/science/research/" target="_blank">Food Standards Agency Research webpage</a>.