title: The ecological risk of heavy metals in sediment from the Danube Delta.
abstract: The objectives of this study were to assess the sediment contamination with heavy metals and to investigate accordingly the ecological risk posed in the SE of the Danube Delta. Sediments are important in assessing the contamination as they act as reservoirs, transporters and contamination sources. Sediment samples were collected and analysed for lead, cadmium, arsenic and mercury, revealing levels higher than the background, especially for cadmium and mercury (Pb > As > Cd > Hg). Concentrations exceeding the probable effect limit were noticed for arsenic and mercury. The contamination indexes describe the study area as having almost half of the samples as contaminated (pollution load index-PLI 1.04), however the contamination is mostly low-to moderate (modified contamination degree-mCd 1.36). The sediment contamination poses mostly a low ecological risk (RI 94.8). The sediment quality guideline quotient (SQG-Q 0.29) describes a moderate impact, while the probable effect concentration quotient (PEC-Q 0.16) confirms that there are no levels likely to affect the aquatic biota. In our study area, the main Branch of the Danube River and the Secondary Delta are the most affected by contamination, while the narrow, reed abundant channels as the preferred habitat of most aquatic organisms, have a low contamination level.
authors.affiliation: Environmental Health Center, 58 Busuiocului str., 400240, Cluj-Napoca, Romania. gabriel.gati@ehc.ro.|University of Agricultural Sciences and Veterinary Medicine, 3-5 Manastur str., 400372, Cluj-Napoca, Romania. gabriel.gati@ehc.ro.
authors.forename: Gabriel
authors.initials: G
authors.lastname: Gati
authors.affiliation: Environmental Health Center, 58 Busuiocului str., 400240, Cluj-Napoca, Romania.
authors.forename: Cristian
authors.initials: C
authors.lastname: Pop
authors.affiliation: University of Agricultural Sciences and Veterinary Medicine, 3-5 Manastur str., 400372, Cluj-Napoca, Romania.
authors.forename: Florin
authors.initials: F
authors.lastname: Brudaşcă
authors.affiliation: Environmental Health Center, 58 Busuiocului str., 400240, Cluj-Napoca, Romania.
authors.forename: Anca Elena
authors.initials: AE
authors.lastname: Gurzău
authors.affiliation: University of Agricultural Sciences and Veterinary Medicine, 3-5 Manastur str., 400372, Cluj-Napoca, Romania.
authors.forename: Marina
authors.initials: M
authors.lastname: Spînu
mesh_terms: D004784:Environmental Monitoring; D019015:Geologic Sediments / Q000737:chemistry*; D019216:Metals, Heavy / Q000032:analysis*; D045483:Rivers / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D019216:Metals, Heavy; D014874:Water Pollutants, Chemical
keywords: Danube Delta; Ecological risk; Heavy metals; Sediment