Abstract
The identification of contamination sources within the food chain with polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzo-furans (PCDFs), (“dioxins”), and PCBs is difficult and complex. PCDD/PCDF can be formed as unintentional compounds in a number of chemical processes as well as in almost every combustion process. PCBs were intentionally produced chemicals that were manufactured for decades before the ban in marketing and use in many countries around 1985. The pattern of occurrence can change from the original source in particular via feedingstuffs to food of animal origin as result of bioaccumulation. A number of examples illustrate the challenging detective work and key scientific aspects for identification of the sources, for support of the risk management and for performance of monitoring programs. The contamination of milk and milk products in European countries with dioxins was caused by compound feeds containing citrus pulp pellets from Brazil which had high dioxin levels as a result of the use of heavily contaminated lime used for neutralization. The Belgian dioxin crisis was caused by a feed additive heavily contaminated with PCBs which were discharged into a recycled fat used in the production of animal feed. Guar gum from India was contaminated with sodium pentachlorophenate and dioxins. Clay was found to be possibly highly contaminated with dioxins possibly formed by geothermal processes over time; use of such clay as feed additive or for human intake led to elevated dioxin levels in food and humans. Bioanalytical screening in combination with comprehensive physicochemical investigations led to the detection of brominated flame retardants and brominated dioxins in a feed additive. Buffalo milk was contaminated in Italy presumably caused by illegal deposition of waste. High PCB levels in fuel oil for drying of breadcrumb used as a feed ingredient caused a major dioxin crisis with pork meat in Ireland. Fatty acids for technical purposes originating from a biodiesel company were used for production of feed fat which contaminated parts of the food chain in Germany. In addition to effects on human and animal health these incidents also have serious economic consequences which could be mitigated by more frequent control on food and feed. Addressing both these issues, the European Community has developed a strategy to reduce the presence of dioxins and PCBs in the environment and in feed and food comprising the establishment of maximum and action levels.
Highlights
PCDDs and polychlorinated dibenzofurans (PCDFs), collectively known as “dioxins”, can be formed as unintentional by-products in a number of chemical processes and in many combustion processes
It was only with these findings, that the very comprehensive detective work was completed, which started with detection of elevated dioxin levels in cow’s milk in South-Western Germany, continued with tracing of the source via feedingstuff first to citrus pulp pellets, which were imported from Brazil, to lime as additive for neutralization and to waste from a PVC production process which eventually found its way into the food chain
The European Union (EU) Commission raised the question to the EU Reference Laboratory (EURL) for Dioxins and Polychlorinated biphenyls (PCBs) in Feed and Food as to whether PCP analyses would be sufficient as a screening method to ensure that guar gum samples did not exceed the level of 0.75 pg World Health Organization (WHO)-PCDD/F-toxicological equivalents (TEQ)/g product [21]
Summary
PCDDs (polychlorinated dibenzo-p-dioxins) and PCDFs (polychlorinated dibenzofurans), collectively known as “dioxins”, can be formed as unintentional by-products in a number of chemical processes and in many combustion processes. Polychlorinated biphenyls (PCBs) are intentionally produced chemicals that were manufactured for decades before adoption of the ban in marketing and use in many countries around 1985; they are unintentionally formed in processes that generate PCDD/PCD. Both groups of contaminants are chemically and physically stable, and are environmentally and biologically persistent. They are lipopohilic which results in bioaccumulation in the foodchain in fatty tissues These chemicals are mixtures of hundreds of closely related compounds or congeners, and the occurrence pattern can change during the transitions from original source to (in particular) feedingstuff and on to food of animal origin. Key examples have been selected to illustrate the challenging detective work and key scientific aspects for identification of the sources, for support of the risk management and for performance of appropriate monitoring programs
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
