Rationale underlying the contamination study
In the general population, exposure to PCBs mainly occurs through food consumption. An assessment carried out by the Agency on food-related exposure of the French population to PCBs in 2007 showed that the health-based guidance value (Tolerable Daily Intake - TDI) was exceeded in children and adults most exposed to these substances, specifically in subjects who consume large quantities of fish.
At the European and international levels, measures have been taken to reduce exposure of the population to PCBs. For example in 2006, the European Commission established maximum content values for dioxin-like PCBs that are not to be exceeded in commercially available fish. In France, like in other European countries, these values have been found to be exceeded in freshwater fish in many waterways.
In 2008, further to these results and as part of the national action plan on PCBs, the French Ministry of Health requested that ANSES undertake a study on PCB contamination based on blood concentrations in consumers of freshwater fish.
The main objective of this study was to identify the primary determinants of exposure to PCBs and specifically to assess whether there is a link between the consumption of freshwater fish known to be strong bioaccumulators of PCBs and individual contamination, taking into account other contamination factors such as socio-demographic or diet considerations.
The study also aimed to determine acceptable frequencies for consumption of these fish, which ensure an absence of long-term health risks to humans.
Partners in the study
ANSES was the principal investigator in the study, conducted in collaboration with the InVS. The study was funded entirely by the Ministry of Health. ANSES was also assisted by the French National Fishing Federation (FNPF) and by the National Committee on Professional Freshwater Fishing (CONAPPED) which agreed to provide contact information for their members.
The study protocol was validated and followed-up by the Ile-de-France IX (Créteil Henri Mondor) Ethics Committee and by the French Data Protection Authority (CNIL), providing the regulatory approvals required for conduct of this type of biomedical research.
How the study was implemented
Six investigation sites were identified along the Somme, the Seine, the Rhone, the Rhine / Moselle, the Loire and the Garonne, representing approximately 900 km of waterways in 18 départements.
After the preparatory phase which began in the spring of 2008, the study was launched in the field in April 2009.
Study participants were recruited from the population of amateur and professional anglers active at the investigation sites and included members of their households. More than 21,000 households of amateur anglers and 26 households of professional anglers from around the six sites were contacted by telephone.
Further to this initial contact, 5793 households fulfilling the criteria for participation in the study, i.e. possession of a recent fishing license, and fishing from at least one of the sites under study, were selected. All regular consumers of strong PCB-bioaccumulator freshwater fish, along with some non-consumers and more occasional consumers were included in the study, provided that they gave consent, did not have any serious health conditions, and were not exposed to environmental PCBs other than through food (no occupational or accidental exposure).
In total, 606 amateur anglers and members of their households, and 16 professional anglers were included in the study.
For each participant, the study involved three main stages:
- a telephone interview of the anglers and members of their households on their fishing and consumption habits regarding strong PCB-bioaccumulator freshwater fish;
- a survey of eating habits (fish and other foods) during an interview at home;
- a blood sample taken at a participating medical testing laboratory.
The company GfK ISL was commissioned to carry out this part of the study.The Laboratory for Research on Residues and Contaminants in Food (LABERCA) of the Nantes Atlantic National College of Veterinary Medicine, Food Science and Engineering (ONIRIS) performed the analyses on PCBs in blood samples.
In parallel, the French National Agency for Water and Aquatic Environments (ONEMA) provided additional data by measuring the PCB content in fish collected at the six fishing sites under investigation.
The results of the study were published at the beginning of 2012.