ABSTRACT
On July 10, 1976, tetrachlorodibenzo-p-dioxin (TCDD) was accidentally released from a smokestack of the Industrie Chimiche Meda Societa Azionaria plant near Seveso, Italy. TCDD was spread primarily in a region of about 87 ha still closed to the public, but also partially in an area of about 270 ha along the direction of the blowing wind. An additional area of approximately 1430 ha has been kept under surveillance and control for safety purposes. One of the appealing problems in environmental science, in the case of a chemical accident, may be to describe the contaminant distribution in the geographical area implied in the phenomenon. The possibility of drawing "risk maps" is bound to the statistical handling of numerical values of the contaminant close to the "detection limit" of the apparati used in the chemical analysis.
