Gli idrocarburi policiclici aromatici: valutazione dell’impatto ambientale del fiume Tevere nel mar mediterraneo.

Nel presente lavoro sono state valutate le concentrazioni, le fonti ed il rischio ecologico dell’inquinamento da idrocarburi policiclici aromatici (IPA) nel fiume Tevere ed il conseguente impatto ambientale sul Mar Tirreno e, quindi, sul Mediterraneo centrale. Sono stati determinati i 16 IPA, definiti “inquinanti prioritari” dall’USEPA, nella fase disciolta (DP), nel particolato sospeso (SPM) e nei sedimenti raccolti in 21 siti di campionamento nell’arco di un anno solare, in modo da poter valutare anche le variazioni stagionali. Le concentrazioni totali di IPA variano da 10,3 a 951.6 ng L-1 nei campioni di acqua (somma di DP e SPM) e da 36.2 a 545.6 ng g-1 nei campioni di sedimenti. È stato calcolato anche il carico totale di IPA che giunge in mare, pari a circa 3161,7 kg/anno. I dati rilevati mostrano che il fiume Tevere è una delle principali fonti di contributo di questi contaminanti al Mar Tirreno

Polychlorinated biphenyls and organochlorine pesticides in Tiber River and Estuary: Occurrence, distribution and ecological risk

The polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) pollution in the Tiber River and its environmental impact on the Tyrrhenian Sea (Central Mediterranean Sea) were estimated. 32 PCBs and 17 OCPs (aldrin, α-BHC, β-BHC, δ-BHC, lindane, p,p'-DDD, p,p'-DDE, p,p'-DDT, dieldrin, endosulfan I, endosulfan II, endosulfan sulfate, endrin, endrin aldehyde, heptachlor, heptachlor epoxide, methoxychlor) were determined in the water dissolved phase (DP), suspended particulate matter (SPM) and sediment samples. Total concentrations of PCBs ranged from 0.54 to 74.75ngL-1 in water (sum of DP and SPM) and from 3.73 to 79.30ngg-1 dry weigh in sediment samples; while the concentrations of total OCPs collected in water (sum of DP and SPM) ranged from 0.07 to 7.04ngL-1 and from 0.66 to 10.02ngg-1 dry weigh in sediment samples. Contaminant discharges into the sea were calculated in about 227.08kgyear-1 for PCBs and 24.91kgyear-1 for OCPs, showing that this river should account as one of the main contribution sources of PCBs and OCPs to the Tyrrhenian Sea. The ∑TEQPCB from the sediment samples ranged from 0.0006 to 0.37ngg-1 with an average level of 0.13ngg-1. Based on Sediments Quality Guidelines, biological adverse effects on aquatic ecosystem were rare to occasional for PCB and OCP levels in Tiber water syste

Distribution, sources and ecological risk assessment of polycyclic aromatic hydrocarbons in water and sediments from Tiber River and estuary, Italy

The concentration, source and ecological risk of polycyclic aromatic hydrocarbons (PAHs) in the Tiber River and its environmental impact on the Tyrrhenian Sea (Central Mediterranean Sea) were estimated. The 16 priority PAHs were determined in the water dissolved phase (DP), suspended particulate matter (SPM) and sediments collected from 21 sites in four different seasons. Total concentrations of PAHs ranged from 10.3 to 951.6ngL-1 and from 36.2 to 545.6ngg-1 in water (sum of DP and SPM) and in sediment samples, respectively. The compositions of PAHs showed that 2- to 4-ring PAHs were abundant in DP, 4- to 6-ring PAHs were predominant in SPM samples, and 4- to 5-ring PAHs were abundant in sediments. The diagnostic ratio analysis indicated that the PAHs mainly had a pyrolytic source. The toxic equivalent concentration of carcinogenic PAHs was 45.3ngTEQg-1, suggesting low carcinogenic risk for Tiber River. Total PAHs loads into the sea were calculated in about 3161.7kgyear-1 showing that this river is one of the main contribution sources of these contaminants to the Tyrrhenian Sea

Estimates of Tiber River organophosphate pesticide loads to the Tyrrhenian Sea and ecological risk

The organophosphate pesticides pollution in the Tiber River and its environmental impact on the Tyrrhenian Sea (Central Mediterranean Sea) were estimated. Eight selected organophosphate pesticides (diazinon, dimethoate, malathion, chlorpyrifos, pirimiphos-methyl, fenitrothion, methidathion, tolclofos-methyl) were determined in the water dissolved phase, suspended particulate matter and sediment samples collected from 21 sites in different seasons. Total organophosphate pesticides concentrations ranged from 0.40 to 224.48 ng L-1 in water (as the sum of the water dissolved phase and suspended particulate matter) and from 1.42 to 68.46 ng g(-1) in sediment samples. Contaminant discharges of organophosphate pesticides into the sea were calculated in about 545.36 kg year(-1) showing that this river should be consider as one of the main contribution sources of organophosphate pesticides to the Tyrrhenian Sea. In relation to the eco-toxicological assessment, the concentrations of most OPPs in the water and sediments from the Tiber River and its estuary were lower than guideline values

Estimation of heavy metal loads from Tiber River to the Tyrrhenian Sea and environmental quality assessment

In order to evaluate the heavy metal pollution in the Tiber River and its environmental impact on the Tyrrhenian Sea (Central Mediterranean Sea), eight heavy metals (As, Hg, Cd, Cr, Cu, Ni, Pb and Zn) were determined in the water dissolved phase, suspended particulate matter and sediment samples collected from 21 sites in different seasons. Total heavy metal concentrations ranged from 34.88 to 4201.23 μg L−1 in water (as the sum of the water dissolved phase and suspended particulate matter) and from 42.81 to 1686.84 mg kg−1 in sediment samples. The total selected heavy metal load contribution into the sea is calculated in about 21,257.85 kg year−1, showing that this River should account as one of the main contribution sources of heavy metals in the Mediterranean Sea. In relation to the ecological assessment, the Tiber River and Estuary would be considered as an area in which the ecological integrity is possibly at risk