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W pracy omówiono przykłady zastosowania metod badania zależności między strukturą chemiczną a aktywnością biologiczną dioksyn i ich znaczenie w ustalaniu mechanizmu działania halogenowych węglowodorów aromatycznych.
Dioxins and related chemical compounds, toxic industrial pollutants which are ubiquitous and persistent in the environment, accumulate in the fat tissue of animals. Food of animal I origin is the primary source of human exposure to dioxins and represents a very significant public health concern. In Poland the official control of dioxin levels in food or animal feed is conducted by the ' National Veterinary Research Institute in Puławy. Beginning from 2006, dioxin levels in food and animal feeds are being tested on an annual basis. The result of four year monitoring program has revealed low dioxin concentrations in food of animal origin, usually about 30-40% of EU permitted levels required by Regulation No 1881/2006/EC. Baltic fish are the exception to this.
The efficiency of four extraction techniques (shaking extraction, column extraction, accelerated solvent extraction (ASE), and ultrasonic assisted extraction) and two clean-up procedures was evaluated in order to find the best procedure. The ASE proved to be the best extraction method with the highest recovery rales (84%-91%) and imprecision less than 15%. Application of the three- column cleanup procedure delivered slightly better cleanup efficiency in comparison with two-step cleanup but the use of two columns is less time consuming, cost-effective, and enabled to process more samples with the bioassay.
The major route of human exposure to dioxins is food: over 90% of these compounds come within food. On 24 October 2001 the Commission of the European Communities (since 2009 the European Commission), as the first organization in the world, has undertaken a comprehensive solution to the dioxin problem, adopting the Community Strategy to reduce the presence and the harmful effects of dioxins (PCDD, PCDF) and polychlorinated biphenyls (PCBs) on the environment and on human health (COM [2001] 593). The strategy taken by all Community countries allowed the integration and harmonization of laws relating to environmental pollution and the food chain. Monitoring and analysis of the implemented regulations which limit emissions of these contaminants - the monitoring of dioxin levels in food, scientific analysis of the problem - made it possible to apply more severe regulatory requirements, leading to a planned reduction of dioxins in food and feed. The paper discusses the conditions which guided announcing the EU strategy, whose primary purpose was to reduce exposure of the European population to dioxins, as well as strategy implementation and achieved results. Also presented are the legislation in force since 2012 for the maximum permissible concentrations of dioxins and PCBs in food and the test methods used in the official control of undesirable contaminants.
This article reviews the present state of the science concerning the polybrominated dibenzo-p-dioxins (PBDDs) and dibenzofurans (PBDFs). Even where in the world people are exposed to anthropogenic origin chemicals. Some of them are long- lived organic compounds, which persist over the years in the environment. Persistent organic pollutants, such as organohalogen compounds, accumulate in environmental and biological compartments and have adverse effects on the health of humans and animals. Little is known about the brominated and mixed chloro/bromo dioxin and furans. Existing literature suggests that brominated dioxins and furans have similar toxicity profiles to their chlorinated analogues. The exposure data are extremely limited, showing a major data gap in estimating the potential environmental and health risk of these chemicals. The rapid increase in the use of brominated flame retardants (the main source of these pollutants) has raised the level of concern over environmental and health damage from brominated dioxins and furans. It is likely that human as well as wildlife exposure to these contaminants will increase with their greater use. The findings reported here present strong evidence of the PBDDs and PBDFs as an emerging new class of contaminants.
An official monitoring programme was started in 2006 with the aim of estimating the concentrations of PCDD/Fs, dl-PCBs, and ndl-PCBs in raw cow's and goat's milk. A random sampling scheme was applied to selected voivodeships. The average concentration of dioxins and furans in cow's milk was 0.88 and 1.46 pg WHO-TEQ/g fat in goat's milk. The mean dioxin-like PCBs concentrations were 0.58 and 0.76 pg WHO-TEQ/g fat; subsequently the WHO-PCDD/F-PCB-TEQ were 1.47 and 2.22 pg/g fat for cow's and goat's milk, respectively. The mean concentrations of PCDD/Fs and dl-PCBs in cow's milk samples were in the range of ¼ of the maximum levels established in European Union. The mean ndl-PCBs concentrations were 1.27 and 1.59 ng/kg fat for cow's and goat's milk, respectively, well below recently-discussed maximum levels.
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