Publication
Study of OCDD, 1,2,3,4,6,7,8–HPCDD, 1,2,3,6,7,8-HXCDD and 1,2,3,7,8-PECDD congeners of dioxin absorption in poultry
| Summary: | This thesis concerns a study which has integrated four main lines of investigation converging to a main goal – to contribute to the risk management of food crisis resulting from the contamination of the poultry chain with dioxins. Specifically, it includes: the development of a suitable analytical methodology to detect and quantify dioxins congeners in wood matrix; a study of the contaminant of biocides used for industrial wood treatments, the analyses of the pathway on how the contaminations are maintained and transferred throughout the poultry production chain in terms of level of contamination and respective chemical speciation and also depletion of the dioxins from poultry during production. The study of the dioxin contamination of different industrial wood preservatives, allowed to establish a clear correlation with the contamination profile of poultry and the previous contamination profile incidents found in wood shavings used as poultry litter. The study of the analytical methodology for wood shavings, adapted from the 1613B EPA method, showed recovery rates of labelled compounds ranging between 71.3% and 86.3%. These rates are considered acceptable, considering the reference method and also the criteria stated in the European Union legislation, for both food and feed. The study of contamination fingerprint along the poultry chain, allows to establish the relationship with the wood shavings, identified as the source of the dioxins. In muscle samples of poultry, the average concentration of OCDD was about 50% lower when compared to the profile of the wood shaving samples. On the other hand, the average relative concentration of 1,2,3,7,8-PeCDD, 1,2,3,6,7,8-HxCDD and 1,2,3,4,6,7,8-HpCDD in poultry muscle samples was 50% higher when compared to the litters. These findings suggest the existence of a transformation in vivo of the most chlorinated congeners. The study of depletion of dioxins in a holding of ducks presented an average daily depletion rate ranging between 1.43% and 4.35%, showing a clear reduction of contamination after the removal of the source of contamination. The depletion rates are factors that must be taken in consideration to assess risk and, indirectly, helpful to manage risk of dioxins in food. |
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| Main Authors: | Cardo, Miguel José Sardinha de Oliveira |
| Subject: | Dioxins Fingerprint Poultry meat Depletion Wood preservatives Dioxinas Impressão digital Carnes de aves Depleção Tratamento de madeiras |
| Year: | 2017 |
| Country: | Portugal |
| Document type: | doctoral thesis |
| Access type: | open access |
| Associated institution: | Universidade de Lisboa |
| Language: | English |
| Origin: | Repositório da Universidade de Lisboa |
| Summary: | This thesis concerns a study which has integrated four main lines of investigation converging to a main goal – to contribute to the risk management of food crisis resulting from the contamination of the poultry chain with dioxins. Specifically, it includes: the development of a suitable analytical methodology to detect and quantify dioxins congeners in wood matrix; a study of the contaminant of biocides used for industrial wood treatments, the analyses of the pathway on how the contaminations are maintained and transferred throughout the poultry production chain in terms of level of contamination and respective chemical speciation and also depletion of the dioxins from poultry during production. The study of the dioxin contamination of different industrial wood preservatives, allowed to establish a clear correlation with the contamination profile of poultry and the previous contamination profile incidents found in wood shavings used as poultry litter. The study of the analytical methodology for wood shavings, adapted from the 1613B EPA method, showed recovery rates of labelled compounds ranging between 71.3% and 86.3%. These rates are considered acceptable, considering the reference method and also the criteria stated in the European Union legislation, for both food and feed. The study of contamination fingerprint along the poultry chain, allows to establish the relationship with the wood shavings, identified as the source of the dioxins. In muscle samples of poultry, the average concentration of OCDD was about 50% lower when compared to the profile of the wood shaving samples. On the other hand, the average relative concentration of 1,2,3,7,8-PeCDD, 1,2,3,6,7,8-HxCDD and 1,2,3,4,6,7,8-HpCDD in poultry muscle samples was 50% higher when compared to the litters. These findings suggest the existence of a transformation in vivo of the most chlorinated congeners. The study of depletion of dioxins in a holding of ducks presented an average daily depletion rate ranging between 1.43% and 4.35%, showing a clear reduction of contamination after the removal of the source of contamination. The depletion rates are factors that must be taken in consideration to assess risk and, indirectly, helpful to manage risk of dioxins in food. |
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