Chicken, dioxin

A consistent pericardial edema in chickens gave rise to the term chick edema disease (chick edema factor) (I). Two known outbreaks of the disease in the broiler industry resulted in a great loss of chickens. A lipid residue from the manufacturing fatty acids, being used as a feed ingredient, was a principal source of the toxic substance. Contamination of the lipid component with polychlorodibenzo-p-dioxins was attributed as the causal agent. 

In ovo exposure to dioxins is associated with development of grossly asymmetric avian brains, especially the forebrain and tectum. Brain asymmetry was observed in herons, cormorants, eagles, and chickens exposed to 2,3,7,8-TCDD under controlled conditions. Asymmetry appears with increasing frequency and severity in embryos and hatchlings exposed to increasing doses of... 

Ryan, J.J., R. Lizotte, T. Sakuma, and B. Mori. 1985. Chlorinated dibenzo-p-dioxins, chlorinated dibenzo-furans, and pentachlorophenol in Canadian chicken and pork samples. Jour. Agric. Food Chem. 33 1021-1026. 

Harnly, M.F., Petreas, M.X., Flattery, J. and Goldman, F.R. 2000. Polychlorinated dibenzo-p-dioxin and polychlorinated dibenzofuran contamination in soil and home-produced chicken eggs near pentachlorophenol sources. Environmental Science and Technology 34 1143-1149. 

In several European countries, higher dioxin levels have been reported in eggs of free-range chickens, compared to chickens kept indoors (DeVries et al., 2006). High levels were found mostly on smaller farms, possibly because the chickens made more extensive use of the outdoor run. Plants appeared to be a relatively unimportant source of dioxins, as well as commercial feed. It was concluded that the high dioxin levels were related to the consumption of worms, insects and soil. 

Goldman LR, Hayward DG, Flattery J, et al. 1989. Serum, adipose, and autopsy tissue PCDD and PCDF levels in people eating dioxin-contaminated beef and chicken eggs. Chemosphere 19 841-848. 

Kennedy SW, Lorenzen A, Norstrom RJ. 1996. Chicken embryo hepatocyte bioassay for measuring cytochrome P4501A-based 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalent concentrations in environmental samples. Environ Sci Technol 30 706-715. 

Norback DH, Allen JR. 1973. Biological responses of the nonhuman primate, chicken, and rat to chlorinated dibenzo-p-dioxin ingestion. Environ Health Perspect 5 233-240. 

Ryan JJ, Lizotte R, Sakuma T, et al. 1985b. Chlorinated dibenzo-para-dioxins, chlorinated dibenzofiirans and pentachlorophenol in Canadian chicken and pork samples. J Agric Food Chem... 

Ryan JJ, Pilon JC. 1982. Chlorinated-dibenzodioxins and dibenzofiirans in chicken litter and livers arising from pentachlorophenol contamination of wood shavings. In Hutzinger O., ed. Chlorinated dioxins and related compounds Impact on the environment. New York, NY Pergamon Press, 183-189. 

Eerrario J. and Byrne C. (2000) The concentration and distribution of 2,3,7,8-dibenzo-p-dioxins/-furans in chickens. Chemosphere 40, 221-224. 

Fish eaten by people residing in northern Norway are contaminated with PCBs, chlorinated pesticides, and their metabolites. Fish living in mangrove habitats in Singapore are contaminated with polybrominated diphenyl ethers (PBDEs). I5 Dioxins and PCBs are found in the eggs of free-range chickens. 

Schoeters G, Hoogenboom R. Contamination of free-range chicken eggs with dioxins and dioxin-like polychlorinated biphenyls. Mol Nutr Food Res 2006 50(10) 908 14. 

The accidental contamination of chicken feed with dioxin contaminated fat in Europe shows how food exposure could occur. Because dioxin does not cause immediate symptoms, authorities did not discover the contamination for months in 1999, and Europeans probably consumed the dioxin in chicken meat and eggs sold that year. One lesson learned from this event is that physicians and public health officials need to recognize and report unusual or suspicious health problems in animals as well as humans (1). The 1999 West Nile virus epidemic in birds and humans in New York City reinforced this lesson. Fortunately, biological and chemical contamination of public water supplies will usually pose little risk due to dilution by the large volume of water. 

Several years ago in Belgium, terrorists contaminated chickens by adding dioxin to fat used to make animal feed. Authorities did not discover the contamination for several months, long after Europeans sold and ingested contaminated chicken meat and eggs in early 1999 (4,6). Besides pointing out the vulnerability of commercial food supplies, the experience demonstrated that our public health disease surveillance system must promptly recognize suspicious patterns of disease in animals to protect human health (4). 

PCBs (Olsson et al. 1994). Reproductive effects in birds and piscivorous mammals appear to be Ah receptor-mediated, since planar, dioxin-like PCB congeners are more effective in inducing these effects than non-dioxin-like congeners (Giesy and Kannan 1998). In a comprehensive review of the literature concerning the ecotoxicology of planar PCBs, DOI (1996) concluded that the Chinook salmon, domestic chicken, mink, and Rhesus macaque were among the most sensitive species to effects from planar PCB exposure. 

The toxicity of the dioxins was first observed in 1895 in workers in the chemical industry in Germany. They developed a skin complaint called chloracne, believing it was caused by chlorine. In 1957, millions of chickens in the eastern and midwestem U.S. died of a disease characterized by excessive fluid in the pericardial sac. The name chick edema factor was therefore applied to the component(s) in the feed responsible for this symptom. Liver and kidney damage was also observed. Similar outbreaks of the disease occurred in 1960 and 1969. A contaminant in trichlorophenol, or products produced from trichlorophenol, caused the chick edema disease and chloracne. Twelve years later its structure was published (Cantrell et al., 1969). The Dow Chemical Company had been aware of a highly toxic impurity formed in small amounts from the production of 2,4,5-T as early as 1950. 

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