[Microbiological monitoring of mussels and clams collected from the shellfish-growing marine areas in Rimini Province].
A 5 years survey (1996-2000) was performed on the microbiological quality of shellfish (mussels and clams) collected from authorized shellfish-growing area of the North Adriatic Sea (province of Rimini). 7.0% of mussel samples (33/474) and 21.9% of clam samples (218/996) exceeded the legal limits for faecal indicators (Dlgs 530/92). The faecal contamination of shellfish was related to the organic pollution arriving from inland surface waters. In fact shellfish harvested near the coast were more contaminated, as well as shellfish grown in the surface layers of the open sea, where the fresh waters of the streams tend to stratify. Faecal contamination was also directly correlated with rainfall, probably because the atmospheric precipitation, increasing the flow of the streams, favoured the transport of organic substances and micro-organisms deriving from the soil washing and the municipal sewage effluents. Furthermore, when rainfall was particularly plentiful, sewage inflow could also exceed the hydraulic capacity of the treatment plants; thus making necessary to discharge untreated waste directly into surface waters. Salmonellae were found in 0.7% of clam samples. Although this percentage is very low, it shows that pathogenic micro-organisms are present in this area of sea. This finding, together with the high variability of shellfish pollution due to occasional factors as rainfall, emphasise the importance of the systematic monitoring of the microbiological quality of shellfish.
Legnani
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PP
Dip. di Medicina e Sanità Pubblica, Sez di Igiene, Università degli Studi di Bologna.
Leoni
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E
Villa
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GC
D000818:Animals; D049872:Bivalvia / Q000382:microbiology*; D004755:Enterobacteriaceae / Q000302:isolation & purification*; D004784:Environmental Monitoring; D004926:Escherichia coli / Q000302:isolation & purification; D005516:Food Microbiology; D007558:Italy; D008685:Meteorological Concepts; D012475:Salmonella / Q000302:isolation & purification; D012623:Seawater / Q000382:microbiology*; D012722:Sewage; D014871:Water Microbiology; D014876:Water Pollution
D012722:Sewage
Monitoraggio microbiologico di mitili e vongole raccolti da aree di mare adibite a molluschicoltura della Provincia di Rimini.