European Science Foundation Workshop on Dioxin Food Contamination Bayreuth, September 29 – 1 October 2000
Dioxin and PCB monitoring programmes for food and feedstuff in most countries of the world, including many European countries are currently inadequate. Better control of food production lines and food processing procedures is needed to minimise entry of dioxin to the food chain and will help to avoid dioxin contamination accidents. This would also improve the ability to trace back a possible contamination to its source. European guidelines for monitoring programmes should be established to ensure comparable and meaningful results. These guidelines should define the minimum requirements for the design of monitoring programmes, analytical methods and quality assurance.
Though data from Northern Europe shows that the general population exposure to dioxin and PCB has decreased during the last 10 years there continue to be a risk of accidental contamination of the food chain by these compounds. The most prominent recent example is the Belgian dioxin contamination of feedstuff in 1999. The Belgian dioxin contamination was not detected due to dioxin monitoring programmes but by their direct biological effects seen in animals. Four other cases of dioxin contamination have been detected in Europe since 1997 due to local monitoring programmes. One of the contamination incidents (citrus pulp pellets 1998) was on a much larger scale than the Belgian dioxin contamination.
The general population’s exposure to dioxins and PCBs is still in the same range (1-4 pg WHO-TEQ/kg body weight and day) as the recently revised WHO tolerable daily intake (TDI). There is concern that short-term high level exposure to dioxin and PCB may cause biological effects on the human fetal development and further research is required.
Further actions to control sources building on considerable advances already made in many countries may need to be supplemented by measures to prevent direct contamination of feedstuff or food to reduce general population exposure further.
This was the main conclusion of a rapid response workshop on Dioxin Food Contamination arranged by the European Science Foundation in Bayreuth the 29 September – 1.October 2000, with participation of more than 20 key scientists from Europe and USA.
Background
On the recommendation of the EERO committee a rapid response workshop on Dioxin Food Contamination was arranged by the European Science Foundation in Bayreuth the 29 September – 1 October 2000, with participation of more than 20 key scientists from Europe and USA.
Major efforts have been made in several European countries to reduce sources with a combination of specific emission controls, control of chemical use and general improvement in standards of air and water pollution and control of industry. The general population exposure to dioxins, furans and related PCB in Europe appears to be in the region of the recently recommended limits set by WHO (Tolerable Daily Intake =1-4 picogram WHO toxicity equivalents/kilogram body weight and day). There is concern that there is a relatively small margin between current exposure and the level where biological effects can be seen on experimental animals.
Where monitoring programmes are available important reductions in general population exposure in blood and mothers milk have been accomplished. Some studies indicate a reduction of levels of dioxin and PCB exposure by about 60% during the last 10 years, but this reduction now seems to be levelling off, and further action needs to be taken to continue the reduction of dioxin and PCB exposure.
Most actions over the past decade to control exposure to dioxins and furans have been based on identification and control of sources from the industry. Recent incidents of high food contamination (e.g. the Belgian food contamination case) have illustrated that other routes of contamination of food can be highly significant and require a more sophisticated approach to monitoring and food production management compared to the general reduction in dioxin sources to the environment.
Consumption of fish and food of animal origin contributes to more than 90 % of the dioxin exposure to the European population. Control of dioxin sources and exposure is more complex than setting exposure limits for food. Food production practises need to be studied and there is a need for more traceable quality-assured lines of production of food. Also waste management and recycling of food and feedstuff need to be studied and regulation of waste streams should be applied to waste management in the food and feedstuff industry, to avoid cross-over between waste streams and food production lines.
Recent major dioxin contamination cases in Europe
The Belgium dioxin food contamination 1999
In January 1999 a storage tank for animal fat in Belgium was badly contaminated with dioxins, furans and PCB. The contamination seems to have been caused by the discharge of about 25 liters of PCB transformer oil into a waste collection unit for animal fats recycled into animals feed.
In March 1999 serious animal health problems in poultry production were discovered in Belgium. There was a marked reduction in egg hatchability and an increased mortality of chickens. At the end of May, analysis of feedstuff samples, hens and breeding eggs showed high levels of dioxins and furans. After the discovery, the dioxin contamination could be traced back to its origin.
As a starting point, 107 tonnes of fat was contaminated. From this, about 90 tonnes fat was used for production of feedstuff for poultry, and the remaining fat was used for production of milk and meat. At the beginning of October 1999, the number of effected or suspected farms was 505 poultry farms, 1625 pig farms and 411 cattle farms. The first analyses showed dioxin concentrations 1000-times above background level, the contamination dropped by more than 100-times from February to March 1999. The estimated costs for Belgium in connection with the dioxin food contamination is about 1 billion US$, indirect costs are estimated to be 3-times higher. A correct waste disposal of the 25 l transformer oil would have cost about 1000 US$.
Though the Belgium dioxin contamination had a major effect on Belgium food production economy, it gave only a short-term peak exposure to dioxins and furans for humans, which cannot be detected in the general population.
The citrus pulp pellet contamination
From July 1997 to March 1998 a German monitoring institute (CVUA Freiburg) detected increased levels of dioxin in milk. The average content of dioxin was 100 % higher than normal. From the beginning it was clear that the contamination was at least at national level. Later on it was discovered that many member states of the EU were effected.
The contamination was traced back to citrus pulp pellets imported from Brazil. The pellets were used in compound feed for ruminants, and the Brazilian citrus pellet production had been contaminated by dioxin containing lime, which was a by-product from a chemical factory. The lime was apparently used for feed production against the advice of the supplier who believed it was for construction.
The Brazilian citrus pellets was used in compound feed for ruminants all over Europe, and effected the level of dioxin in cows milk, beef and veal. This contamination may have had an impact on the general level of dioxin exposure to the European population and a slight increase of the dioxin content in breast milk and tissue was observed in Germany. This example shows that when a large contamination affects major population groups, the contamination can be detected by local monitoring programmes but on a very late stage when the contamination is beginning to show its effects.
The caolinitic (ball) clay case
In 1999 a dioxin contamination of poultry and mink was traced back to the use of caolinitic clay as anti-caking agent in poultry feed and in mineral feed for mink. The origin of the contamination was traced back to a ball clay mine in Germany.
This was a more local dioxin contamination, but it shows that there are also natural sources for dioxin contamination, which may enter the food chain.
The Brandenburg case
Repeated detection of elevated dioxin levels in eggs produced in the German state of Brandenburg was identified in 1999, and traced back to its origin. In an open system, grass meal (for feedstuff production) was dried by burning wood as the fuel. All types woods were burned, including waste wood with chemical contamination from former paintings or use of wood preservatives.
This case shows that also the processing of feedstuff need to be controlled.
The choline chloride case
This year (2000) a dioxin contamination in choline chloride pre-mixtures for feedstuff was detected in Germany. The original choline chloride from a Belgium producer was not contaminated but the Spanish feedstuf premix producer who sold the premix to Germany had added pine sawdust to the product as a carrier. This pine sawdust was heavily contaminated with dioxin (with pentachlorophenol being the source of the dioxin contamination).
The use of pine sawdust and other materials derived from wood treated with wood protection products is prohibited in compound feedstuff within EU and it seems that the enforcement was inadequate. The case is another example on how additives in the feed and food producing process may cause dioxin contamination.
Contact addresses for more information on dioxin
General information on dioxin and environment policy:
Professor J. Gijs Kuenen
Delft University of Technology and Enzymology
+31 15 278 5308
General information on dioxin source and exposure limits:
Dr. Heidelore Fiedler
UNEP Chemicals
typo3/esf_contacts_form.php?mail=7c53b0c3af21d58dd41c3078ab094974
+41 22 917 8187
Major dioxin contaminations in Europe:
Dr. Rainer Malisch
Chemisches und Veterinäruntersuchungsamt Freiburg
typo3/esf_contacts_form.php?mail=0d2534b62f45fd4009d7188e3a48085c
+49 761 8855-133
Information on limit values and analytical methods:
Dr. Peter Fürst
Chemisches Landes- und Staatliches Veterinäruntersuchungsamt, Münster
typo3/esf_contacts_form.php?mail=f50b2b875401a4fbf7b84b4caeaf6537
+49 251 9821 213
Effects of dioxin:
Dr. Annika Hanberg
Karolinska Institutet
+46 8 728-7526
Press contacts:
Mr. Jens Degett
Head of Communication and Information, ESF
+33 (0)3 88 76 71 32
Issued 12.10.2000
For further information contact : Jens Degett
Category: Media Centre, Press Releases 2000