Justyna Rogowska

Sources and Fate of PAHs and PCBs in the Marine Environment

The assessment of a hazard resulting from the pollution of the environment by chemical compounds is in principle limited to the determination of their concentrations in its various compartments. But for solving many problems in this context, knowledge of the emission sources, transport pathways, and sites of deposition is of great benefit. By far the largest amounts of pollutants, regardless of where they were discharged, end up in the soil or the aquatic environment. By defining the source of origin of compounds like PAHs, and PCBs in the environment, especially in areas where they are emitted from different sources, it is possible to obtain information on the nature of different materials that are sources of these compounds (e.g., petroleum), or on the processes during which they are formed (e.g., combustion). In addition, the fate of toxic compounds in the environment can be tracked. This knowledge enables hypotheses to be formulated regarding the course of environmental phenomena; it also supplies a tool for taking administrative action and for resolving disputed issues concerning environmental pollution.

Environmental Implications of Oil Spills from Shipping Accidents

Since ancient times, ships have sunk during storms, either as a result of collisions with other vessels or running onto rocks. However, the ever-increasing importance of crude oil in the twentieth century and the corresponding growth in the worlds tanker fleet have drawn attention to the negative implications of sea transport. Disasters involving tankers like the Torrey Canyon or the Amoco Cadiz have shown how dramatic the consequences of such an accident may be. The effects of oil spills at sea depend on numerous factors, such as the physicochemical parameters of the oil, the characteristics of the environment affected, and the physical, chemical, and biological processes occurring there, such as evaporation, dissolution, dispersion, emulsification, photo-oxidation, biodegradation, and sedimentation. The combination of these processes reduces the concentrations of hydrocarbons in sediments and water and alters the chemical composition of spilled oils. In every case, oil spills pose a danger to fauna and flora and cause damage to sea and shores ecosystems. Many of the petroleum-related chemicals that are spilled are toxic, otherwise carcinogenic or can be bioaccumulated in the tissues of marine organisms. Such chemicals may then be biomagnified up the marine food chain from phytoplankton to fish, then to seals and other carnivorous sea mammals. Moreover, oil products can be accumulated and immobilized in bottom deposits for long periods of time. Oil spills are particularly dangerous when they occur in small inland seas that have intense sea traffic, e.g., the Baltic Sea.

Polychlorinated biphenyls (PCBs) in bottom sediments: Identification of sources

Polychlorinated biphenyls (PCBs) can enter the environment from various sources. They are synthetic chemicals and as such are present in the environment mainly as mixtures containing various amounts of PCB congeners. It is therefore difficult to pinpoint the source of PCB emissions into the environment and the pathways along which they migrate there. The situation is different where locating the emission sources of polycyclic aromatic hydrocarbons (PAHs) is concerned. There is much information in the literature on the molecular markers that can be used to identify the sources of PAH emissions into the environment. Environmental samples like soil or bottom sediments are usually analysed for their contents of both groups of compounds. Therefore, with data on the origins of PAHs to hand, and seeking and comparing mutual correlations, one can attempt to define the probable sources of emission of PCBs. The purpose of this work was to identify the probable PCBs emission sources in bottom sediments using available data, that is polycyclic aromatic hydrocarbon diagnostic ratios. The numerical ratios of pairs of compounds such as fluoranthene/pyrene, phenanthrene/anthracene, fluoranthene/(fluoranthene+pyrene) and chrysene/benzo[a]anthracene are generally used as a tool for identifying and assessing pollution emission sources.

Surface sediments pollution due to shipwreck s/s ''Stuttgart'': a multidisciplinary approach

Shipwrecks may pose a serious source of pollution for marine ecosystems. For this reason, it is of great importance to perform a marine ecosystem risk assessment due to plausible wreck presence. One of elements of such an assessment is determining the state of the environment in the vicinity of the wreck. In the work presented, the results of studies on surface sediments samples collected around the s/s Stuttgart ship sunk during WW2 in the Gulf of Gdańsk (Southern Baltic) are given. 23 samples of sediments were collected and subsequently 12 metals (Cd, Co, Cr, Cu, Fe, Hg, Mg, Mo, Ni, Pb, V, Zn), 16 PAHs and 7 PCBs were determined. Metals were measured with ICP-MS and AAS while organics with GC–MS. The chemometric evaluation was performed in order to determine possible similarity patterns between the chemicals measured. Clear dependence between PAHs and PCBs was stated as well as spatial similarities between the content of the chemicals determined.

Toxicity assessment of sediments associated with the wreck of s/s Stuttgart in the Gulf of Gdańsk (Poland).

The paper presents the results of toxicity determinations carried out on sediment samples collected in the vicinity of the wreck of the German s/s Stuttgart (the southern part of the Gulf of Gdańsk, off the Polish coast) in relation to the determination of polycyclic aromatic hydrocarbons (PAHs). The toxicity of surface and core sediment samples was assessed using two biotest organisms-the bioluminescent bacteria Vibrio fischeri and the ostracod Heterocypris incongruens. PAH levels in these samples were determined by GC-MS. The surface sediments collected at W2 (ca. 34 m north of the shipwreck) and W4 (ca. 415 m north-east of the wreck) as well as the core sediments collected at WR3 (ca. 400 m north-east of the wreck) were the most heavily polluted with substances toxic to the biotest organisms. The chronic and acute toxicities in the case of most of the surface sediment samples studied are correlated. This may suggest that not only hydrophobic chemicals (like PAHs from fuel residues) but also more polar chemicals (resulting from the conversion of aromatic hydrocarbons) are responsible for the toxicity levels found. There is a clear dependence between the levels of chronic toxicity and PAH concentrations in the core sediment samples. In addition, a simultaneous decrease in the PAH content and chronic toxicity was noted in all the core sediment samples at depths below 80 cm.

Gadolinium as a new emerging contaminant of aquatic environments

Since the 1980s, gadolinium (Gd)-based contrast agents (GBCAs) have been routinely used in magnetic resonance imaging as stable chelates of the Gd3+ ion, without toxic effects. Generally, GBCAs are considered some of the safest contrast agents. However, it has been observed that they can accumulate in patient tissue, bone, and probably brain (causing nephrogenic systemic fibrosis in patients with kidney failure or insufficiency and disturbance of calcium homeostasis in the organism). The GBCAs are predominantly removed renally without metabolization. Subsequently, they do not undergo degradation processes in wastewater-treatment plants and are emitted into the aquatic ecosystem. Their occurrence was confirmed in surface waters (up to 1100 ng/L), sediments (up to 90.5 μg/g), and living organisms. Based on a literature review, there is a need to investigate the contamination of different ecosystems and to ascertain the environmental fate of Gd. Long-term ecotoxicological data, degradation, metabolism, bioaccumulation processes, and biochemical effects of the Gd complexes should be explored. These data can be used to assess detailed environmental risks because currently only hotspots with high levels of Gd can be marked as dangerous for aquatic environments according to environmental risk assessments. Environ Toxicol Chem 2018;37:1523-1534.

Novel approach to ecotoxicological risk assessment of sediments cores around the shipwreck by the use of self-organizing maps

Marine and coastal pollution plays an increasingly important role due to recent severe accidents which drew attention to the consequences of oil spills causing widespread devastation of marine ecosystems. All these problems cannot be solved without conducting environmental studies in the area of possible oil spill and performing chemometric evaluation of the data obtained looking for similar patterns among pollutants and optimize environmental monitoring during eventual spills and possible remediation actions - what is the aim of the work presented. Following the chemical and ecotoxicological studies self-organising maps technique has been applied as a competitive learning algorithm based on unsupervised learning process. Summarizing it can be stated that biotests enable assessing the impact of complex chemical mixtures on the organisms inhabiting particular ecosystems. Short and simple application of biotests cannot easily explain the observable toxicity without more complex chemometric evaluation of datasets obtained describing dependence between xenobiotics and toxicological results.

Environmental Risk Assessment of WWII Shipwreck Pollution

The pollution of the sea is a global problem that has arisen as a consequence of the industrialization of the world and the intensified shipment of crude oil and the products of its refinement. As sailing vessels were replaced by motor propelled ships towards the end of the nineteenth century, a new source of sea water pollution came into being. Every emergency involving a tanker carrying crude oil and its products is a potential source of pollution, not only of the sea water but also of shorelines. An important though little understood problem is the seepage of bunker fuel or cargoes from sunken ships, many of which went to the bottom as a result of hostilities at sea during the two World Wars. Among these wrecks are vessels that still contain fuel or other dangerous substances in their tanks/holds. Most wrecks that have lain on the seabed for more than 60 years succumb to corrosion, so there is a considerable likelihood of petroleum products seeping out of many of them.