A lichen transplant study aimed at investigating
a strong increase in mercury concentrations
in lichens was run in a territory of NE
Italy where background values were very low only
8 years before. Thalli of the lichen Pseudevernia
furfuracea collected in a pristine area were exposed
for 1.5, 3 and 6 months at 31 sites selected
according to the observed pattern of Hg
concentrations, location of the suspected source (a new waste incinerator) and prevailing wind
direction. Hg strongly increased at eight sites after
1.5 months, at 12 after 3 months and at 20 after
6 months. The highest values were always located
SW and S of the incinerator, in good agreement
with the prevailing night wind direction. It was
concluded that, although the immediate risk for
the population living close to the incinerator is
low, long-term hazard due to Hg accumulation in
the surrounding environment should be seriously
taken into account.
