Polycyclic Aromatic Hydrocarbons (PAHs) in foods.

Project Name

Correlation of concentrations of Polycyclic Aromatic Hydrocarbons (PAHs) in foods.


May 2009 - May 2010

Project Collaborators

Martin Rose (Fera)

Alistair Murray ( Fera)



Project Description


PAHs are a group of substances, some of which are known or suspected as being genotoxic carcinogens.  As such there is no safe level of exposure and intake from food should be as low as reasonably practicable.  PAHs have been known for a long time to occur at low levels in food, especially where food is smoked or dried during the production process, or where heat is used in the extraction of oils from plant material.
Legislation has been introduced within the EU and establishes maximum limits for benzo[a]pyrene (B[a]P, the most toxic of the PAHs) in food.  The maximum limit in oils and fats is 2 μg/kg and there are other food types included in the legislation with limits ranging from 1 μg/kg for baby foods and infant formulae to 10 μg/kg for smoked bivalve molluscs.There is little data about other PAHs in food but the European Food Safety Authority (EFSA) have made a request to monitor other PAHs in food in order to assess whether B[a]P can act as a marker for these compounds or whether separate legislation will be necessary. 
Fera has a comprehensive method that can monitor 27 PAHs in food and has used this method for several food surveys including analysis of raw shellfish samples. The data sets typically have many values censored at the "Limit of Detection".  
This project is to analyse datasets held at Fera to establish whether or not B[a]P is a suitable marker for some or all of these other PAHs in some or all of the food types surveyed.  The project would explore the correlation structure of the  PAH data sets to see whether a single marker, e.g. B[a]P, or a much reduced subset of PAHs could provide most of the information in the full suite of analyses.  The challenge is to do this with large numbers of censored values.