Trace elements (Pb, Zn, Cu) in blood of mute swan (Cygnus olor) from the Isonzo river nature reserve (Italy)
G Isani*,
M Cipone,G Andreani, E Carpenè, E Ferlizza, K Kravos1
and F Perco1
Department of Veterinary Medical Sciences, Alma Mater Studiorum-University
of Bologna, Via Tolara di sopra 50, 40064, Ozzano Emilia (Bologna),
Italy; 1Stazione Biologica Isola Cona, Isonzo River Mouth
Nature Reserve, Staranzano 34079 (Gorizia), Italy *Corresponding author:
gloria.isani@unibo.it
Abstract
Lead
concentrations in blood of 45 specimens of mute swan from the molting area of
the Isonzo River Mouth Nature Reserve (Italy) were determined in two consecutive
years (2006-2007), some birds were neck ringed to identify their homing
behavior. The second sampling included whole body X-ray radiography and Cu and
Zn plasma analyses to investigate the health impact of putative Pb exposure.
X-ray images of all investigated specimens did not show any radiopacity due to
the ingestion of metal bodies. Lead levels (0.08-0.44 mg/ml) were in the range of those reported for
swans living in unpolluted or slightly polluted environments and excluded acute
intoxication, as confirmed by clinical investigation. Zinc concentrations ranged
between 2.93 and 7.59 mg/ml and were one order of magnitude higher than
Cu concentrations (0.21-0.42 mg/ml). The negative correlation between Pb and Zn
concentrations could be indicative of adverse health effects caused by chronic
lead exposure. To our knowledge this is the first study reporting Pb, Zn and Cu
blood levels, X-ray radiographies and data on the origin of swan populations.