Contamination Of Coastal Sediments Research Articles

Determination and investigation of heavy metal concentrations in sediments of the Persian Gulf coasts and evaluation of their potential environmental risk

The contamination of coastal sediments with toxic heavy metals caused to a serious concern due to their environmental consequences. The aim of this study was to determine the concentration of heavy metals such as lead (Pb), copper (Cu), nickel(Ni) and manganese (Mn) in the sediments of the Persian Gulf coast in Kangan and Siraf ports in Bushehr province. In this regard, the sampling was performed in 10 stations with different uses in two depths of 0-5 and 5-20 cm along the coast of the Persian Gulf. The concentration of heavy metals was measured after drying, acid digestion and microwave by using flame atomic absorption spectrometry (F-AAS). The results showed that the average concentrations of Mn(II), Ni(II), Cu(II) and Pb(II) was measured 121.47, 11.51, 11.59 and 5.30 in surface sediments, and 131.59, 10.81, 12.56 and 4.88 µg g-1 in deep sediments. All analysis validated by electrothermal atomic absorption spectrometry (ET-AAS).

Development and Evaluation of Olive Flounder cyp1a1-Luciferase Assay for Effective Detection of CYP1A-Inducing Contaminants in Coastal Sediments.

Flounders have been widely used as indicator species for monitoring the benthic environment of marine coastal regions owing to their habitat and feeding preferences in or on sandy sediments. Here, a single-step, sensitive, specific, and simple luciferase assay was developed, using the olive flounder cyp1a1 gene, for effective detection of CYP1A-inducing contaminants in coastal sediments. The developed cyp1a1-luciferase assay was highly sensitive to the widely used CYP1A inducers 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), benzo[a]pyrene (B[a]P), and 3,3',4,4',5-pentachlorobiphenyl (PCB 126). In the case of TCDD, significant dose-dependent increases in luciferase activity (0.3-300 ng/L) were detected. The assay was more sensitive to PCB 126 than to B[a]P. The assay also involved the highly sensitive expression of luciferase to extracted mixtures of PCBs and polycyclic aromatic hydrocarbons (PAHs) collected from coastal sediments. PCBs were more capable of cyp1a1 induction in the assay system at small doses than PAHs in environmental samples. Using the cyp1a1-luciferase assay along with water or sediment chemistry will certainly aid in diagnosing CYP1A-inducing contaminants in coastal environments.

Contrasting distributions of bacteriophages and eukaryotic viruses from contaminated coastal sediments.

Viruses are ubiquitous, abundant and play an important role in all ecosystems. Here, we advance understanding of coastal sediment viruses by exploring links in the composition and abundance of sediment viromes to environmental stressors and sediment bacterial communities. We collected sediment from contaminated and reference sites in Sydney Harbour and used metagenomics to analyse viral community composition. The proportion of phages at contaminated sites was significantly greater than phages at reference sites, whereas eukaryotic viruses were relatively more abundant at reference sites. We observed shifts in viral and bacterial composition between contaminated and reference sites of a similar magnitude. Models based on sediment characteristics revealed that total organic carbon in the sediments explained most of the environmental stress-related variation in the viral dataset. Our results suggest that the presence of anthropogenic contaminants in coastal sediments could be influencing viral community composition with potential consequences for associated hosts and the environment.

Contamination of Coastal Sediments in El-Hamrawein Harbour, Red Sea, Egypt

Contamination of Coastal Sediments in El-Hamrawein Harbour, Red Sea, Egypt

Is the polychaete, Perinereis rullieri (Pilato 1974), a reliable indicator of PCB and PAH contaminants in coastal sediments?

A field survey in a transitional environment (lagoon of Venice, Italy) and a laboratory exposure experiment were carried out to validate the use of polychaetes, Perinereis rullieri, as indicators of PCB and PAH contaminants in the sediments. Results from the field study showed that PCBs, predominantly the hexa- and hepta-chlorinated biphenyls, were promptly bioaccumulated in the tissues of P. rullieri, whereas PAH levels were generally low and fluctuating among seasons. Organisms experimentally exposed to natural polluted sediments bioaccumulated all the examined PCB congeners, whereas those exposed to the reference sediments were able to reduce them, at least to some extent. A PAH depletion was always observed, although the time variations for the single compounds differed from each other. The biomarker malondialdehyde (MDA), evaluated both in native and in treated organisms, was helpful as a supporting parameter in elucidating their oxidative stress condition, although depending on numerous natural confounding factors.

Risks posed by trace organic contaminants in coastal sediments in the Pearl River Delta, China

Local marine environments in China’s Pearl River Delta (PRD), the most rapidly developing region in one of the world’s fastest growing economies, have been experiencing significant environmental stress during the past decades. This investigation was conducted to determine the status and trends of persistence organic pollutants (POPs) such as polycyclic aromatic hydrocarbons (PAHs), petroleum hydrocarbons (PHCs), polychlorinated biphenyls (PCBs), organochlorine (OC) pesticides and dioxin-related compounds in marine sediments collected from sixteen coastal stations in the Pearl River Delta (PRD) in March 2003. Elevated concentrations of PAHs (94–4300 ng/g), PCBs (6.0–290 ng/g), PHCs (14–150 μg/g), and DDTs (1.4–600 ng/g) were detected in sediment samples. In addition, 2,3,7,8-tetrachlorodibenzo- p-dioxin (TCDD)-like activities in the sediment samples were estimated to range from 0.3 to 440 pg TCDD-EQ/g. Sediments collected from Xiashan contained the greatest concentrations of trace organic contaminations amongst all the sampling stations in the present study. The degree of trace organic contamination was, in general, more severe at stations situated along the west shores of the PRD than their counterparts in the east. A preliminary assessment was performed to examine the probable risks to the marine ecosystem due to POPs. The results showed that OC pesticide contamination in the PRD was particularly serious and might pose a threat to the health of the marine inhabitants.