The study is based on the measure of the Cs-134, Cs-137 content in samples belonging to species of macromicetes, collected in 13 stations in Lombardy and in Trentino; most samples have been collected in autumn 1986; a number of samples has been collected in autumn 1987 and 1988. Significant differences in contamination are recorded both among species collected in the same station, and among average values of the stations themselves. The differences among stations are tentatively correlated with the amount of precipitations in the days following the Chernobyl disaster. Comparison is made among the 1986 data and the data of the following years. In many samples the presence of Ag-110 (metestable) is evidenced; the concentration of K-40 naturally occuring radioisotype is measured for most samples. A brief discussion of the results is presented.
