available information describing the absence of any significant
farming activity in the area.
The Tisza River area exhibited very high numbers of positive
samples both for human and animal viruses, with
increasing downstream levels reflecting the urban discharges
in the area. Intensive livestock farming is practiced
throughout the basin, specifically around Szolnok, where 13
pig farms and 20 dairy farms are located immediately upstream
of the sampling sites. All the farms and slaughterhouse
effluents are treated in the urban WWTP. Both porcine
and bovine contaminations were highly abundant and
exhibited lower concentrations in winter, while higher values
for both human and animal contamination were present in
summer and autumn. The Tisza is one of the main rivers of
Central Europe, with seasonal flooding in early spring and
early summer. Although these flows will dilute fecal
contamination, may represent a significant microbiological
risk for the population, considering the high level of human
and animal contamination observed all over the sampling
periods.
Two rivers were studied in the Mediterranean area: the
Llobregat River (17 m3/s), in Catalonia, which is heavily
impacted by more than 50 urban sewage treatment plant
secondary effluents, and the Glafkos River in the European
East Mediterranean, a smaller river (5m3/s) with a flow that is
also highly dependent on rainfall and that drastically decreases
in summer up to 1m3/s. The Llobregat River exhibited
human fecal contamination as the most significant source of
pollution, which reflects the high amount of secondary
effluent discharged into the river basin (from more than fifty
plants). The Glafkos River presented a different profile, with
variable concentrations over the year from both human and
farm animals. Human settlements and animals drinking
directly in the river were observed during the summer period
posing a risk of direct voiding of urine/feces and uncontrolled
discharges. Rain events in the Glafkos River may rapidly affect
water quality. Rainy periods with higher river flows represent
higher dilution levels of fecal contamination and viral
markers in river and seawater. In agreement with this, lower
numbers of HAdV and JCPyV were observed in autumn (the
most common rainy season in Mediterranean areas) in Greece
and Spain. The Patras River samples that were tested presented
high levels of animal pollution, while seawater