The highly toxic man-made substance referred to as dioxin (polychlorinated dibenzo-para-dioxins (PCDDs) and polychlorinated dibenzoFurans (PCDFs)) causes severe health damages both to humans and other organisms, with lethality as its worst. Because of the toxicity several risk assessments has been performed on dioxins trying to determine at what concentration there are no risk of exposure. Resent years of research has discovered that these substances are not only anthropogenically but also producedin natural processes, like volcanoes and forest fires. To investigate if there is a need to take these naturally formed dioxins into account in the risk assessment processes, interviews with persons at relevant institutions in Sweden has been made. Analyses of existing risk assessment methods and political documents were also made to complete the picture.

Abstract.The levels of dioxin and comparable substances rose to a large extent in our environment during the second half of the 20'Th century. This was the result of the synthesis of, and careless usage of these substances in cooling fluids, hydraulics, pesticides etc. Background levels of dioxins and Furans in sealed samples prior to this era suggest that former sources of these substances existed. Salt glazing is a method of adding a smooth acid resistant exterior to stoneware ceramics. The technique has been in use since the 16'Th century, maybe even earlier than that.

Abstract.The levels of dioxin and comparable substances rose to a large extent in our environment during the second half of the 20'Th century. This was the result of the synthesis of, and careless usage of these substances in cooling fluids, hydraulics, pesticides etc. Background levels of dioxins and Furans in sealed samples prior to this era suggest that former sources of these substances existed. Salt glazing is a method of adding a smooth acid resistant exterior to stoneware ceramics. The technique has been in use since the 16'Th century, maybe even earlier than that.