Soil and assimilatory organs of trees as indicators in dioxin monitoring of the forest environment

The balance of major processes of metabolism is the condition of a continuous existence of the forest ecosystem. Each significant change of chemical balance in the environment brings about disturbances to homeostasis, quantitative and qualitative succession of individual components of plant and animal world, resulting in degradation of forest environment. The initiation of the continuous complex forest areas monitoring dates back to the 80`s when a sudden increase of forests` stands segments dieback occurred. The network of forest monitoring is based on the fixed observation I and II spots (SPO). Monitoring research may be extended to other substances not included in the Polish Act if the spot pollution source imposes a serious burden on the environment. It corresponds mainly to the areas situated in the closest vicinity of industrial plants which may significantly deteriorate the condition of the environment. The plants in interest include: heat and power stations, combustion plants, aluminum works, chemical plants, cellulose works, iron foundries, and industrial and municipal refuse landfill sites. The paper identifies main dangers posed to the forest environment resulting from emission and migration of polychlorinated dibenzodioxins (PCDD), polychlorinated dibenzofurans (PCDF) and polychlorinated biphenyls (PCB) – compounds commonly called dioxins. Mechanisms of biological activity of dioxins are insufficiently investigated. A sequence of unfavourable changes in organisms as a result of exposition to dioxins has been observed. Dioxins reach human and animal organisms together with food, as well as while inhaling and penetrating through skin. Dioxins damage living cells and as a consequence cause growth and development disorders of organisms. A symptom of dioxin intoxication in humans is chloracne (acne chlorica), characterized by disorders in both anatomy and activity of sebaceous glands. The acne symptoms are only signs which indicate a general intoxication with chlorinated hydrocarbons. The paper presents representative results of the investigation obtained within the confines of the introductory dioxin monitoring carried out in the selected forest complexes. Table 1 presents the results of the analysis of forest soil from unpolluted areas (the Antonin Forest Division - Czarnylas Forestry and the Gniezno Division - Orchówek Forestry) and a comparison with the results of polluted soil measurement collected in the vicinity of Warsaw where the earlierconducted investigations showed the general dioxin content at the level of 12.275 ng PCDD/F-TEQ/kg of soil. The carried out research proves that dioxins may accumulate both in soil and plants, and include them in food system. To maintain the chemical balance in forest areas the authors suggest covering a selected group of forest biotopes situated in the vicinity of major emitters of chemical pollution for dioxin monitoring.