Dioxins in food from the area with high air pollution. Standards exceeded four times
Most chemicals in food are beneficial — carbohydrate, fat and protein are all composed of chemical compounds. However, some synthetic chemicals in food can be harmful. Substances that persist in the environment and accumulate up the food chain are of particular concern, including dioxins.
Dioxin is a catch-all term used to describe a large group of toxic chemicals, including polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs). Dioxins are by-products of industrial processes and are particularly dangerous because of their ability to accumulate in the fatty tissue of animals. Prolonged exposure, even at very low doses, can damage the immune, hormonal and reproductive systems and may even cause cancer.
Dioxins are found in the air, soil, sediments and vegetation, but over 90% of human exposure occurs through food, mostly through fish, meat and dairy products. The major source of dioxins in food of animal origin is animal feed, leading the European Commission to establish, besides maximum levels for food, maximum dioxin levels for feed. Animal feed may be contaminated by dioxins through soil (a natural reservoir for dioxins); the researchers indicate that 2–10% of feed may be made up of soil.
While industrial processes were previously the major source of environmental dioxin pollution, uncontrolled sources such as the burning of coal, wood and organic and synthetic materials are now thought to be the dominant source.
Some preservatives, including pentachlorophenol (PCP), contain dioxins that can be released directly into the atmosphere. PCP was used extensively as a preservative in animal facilities until its use was restricted in the 1980s, and has been associated with dioxin contamination of livestock and eggs.
As shown by measurements carried out in Krakow and Zakopane, in the winter season in Poland concentration of dioxin in the air can be 20 to 40 times higher than in Western Europe. Oversize amounts of dioxins are also found in food from domestic crops eg. in chicken eggs.
The Laboratory of Trace Analyses of Cracow University of Technology on behalf of the Krakow Smog Alert performed a study on dioxins and related compounds from the group of polychlorinated biphenyls in the hen's egg yolk.
The eggs come from hens free-range reared in several towns of Malopolska and Silesia: Rabka, Rybnik, Zory and Barwałd. The choice of the village was dictated by the desire to assess the pollution compounds of dioxins in the immediate vicinity of the low-stack emission sources.
Free-range eggs contained higher levels, exceeding the permitted EU level (2.5 pg/g — picograms per gram of fat).
In the case of one of the four surveyed eggs (Barwałd), the concentration of dioxin was equal to the maximum permissible value. The eggs from Rybnik and Żory dioxin content exceeded the accepted limit (2.7 pg / g). In the case of eggs Rabka amount of dioxins exceed a maximum value of nearly four times (9.5 pg / g).
The fact that the four randomly selected eggs, in three cases there was oversize dioxin, of which in one case exceeded the norm is very much shows that the problem of food contamination in Poland is very serious.