Published online by Cambridge University Press: 18 September 2007
The reduction in levels of organochlorine pesticide residues in food of animal origin in the past 30 years has been achieved especially by controlling entrance via the feed chain. A further reduction was achieved by registration and use of less persistent pesticides both for direct treatment of animals and of plant material. The remaining problems (e.g. dioxins and PCB's) are much harder to tackle. They are either of a ubiquitous nature and their impact might be enlarged by the present welfare trend requiring more contact of the animals with their environment, or they are of a sporadic nature making checking and control quite hard to execute. The present public demand for a farm animal production that is in balance with the animals' needs and a residue free product adds even more complications to the system.