Jean Bartocci

Petroleum and PAH contamination of the Black Sea

Concern has been expressed regarding the extent of contamination of the Black Sea. Analyses of coastal sediments taken from throughout the region indicate, however, that levels of petroleum hydrocarbons (2-300 microg g(-1) dry wt total hydrocarbons) are generally comparable to those encountered in the Mediterranean and are lower than concentrations reported for highly contaminated areas such as the Gulf, Hong Kong, Taiwan and New York Bight. Highest concentrations of total hydrocarbons (>100 microg g(-1) dry wt) were associated with discharges from Odessa, Sochi and the River Danube. Chronic/degraded petroleum was the major contributor at these sites. Samples from the Ukrainian coastline were comparatively clean (<10 microg g(-1) dry wt total hydrocarbons). Major contributions of fresh oil (as indicated by sigma n-C14-34) occur through the River Danube. Concerning total PAH, concentrations (7-638 ng g(-1) dry wt) compare to relatively unpolluted locations in the Mediterranean and are much lower than levels reported for polluted UK estuaries (e.g. Mersey, Tyne, Thames). Both pyrolytic and petrogenic PAH are present in most samples, although petroleum derived PAH are dominant at Sochi and pyrolytic sources are prevalent in the Bosphorus region. The absence of a correlation between total hydrocarbons and PAH (R2 = 0.04) indicates different primary sources for the two.

Aliphatic and aromatic hydrocarbons in coastal Caspian Sea sediments

This investigation represents the first extensive study of the spatial distribution and sources of aliphatic (n-alkanes and unresolved complex mixture of fossil hydrocarbons) and polycyclic aromatic hydrocarbons (PAHs) in coastal sediments from the Caspian Sea. PAH concentrations, n-alkanes and biomarker profiles all suggested that there was limited petrogenic contamination in the shallow North Caspian Sea sediments, which are coarse with a low total organic carbon content. In contrast, moderate to high petrogenic contamination was found in the South Caspian Sea, in particular in the offshore oil fields near Baku, Azerbaijan. Contaminant patterns indicated that the PAHs were mainly from fossil sources, with higher contributions of pyrolytic only near industrialized and urban areas. A high contribution of perylene, a geochemically derived PAH, to the total PAHs was found in the west and south at sites influenced by the Kura, Safid Rud, Terek, Sulak and Samur Rivers.

Persistent organochlorine residues in sediments from the Black Sea

The extent of contamination of the Black Sea by selected organochlorine compounds has been assessed through the analysis of surficial sediments taken from throughout the region. Concentrations of HCHs at sites influenced by the Danube delta are among the highest recorded on a global basis (up to 40 ng g(-1) dry wt). The ratio between the alpha- and gamma-isomers was relatively low indicating contamination through the use of lindane. Concentrations of DDTs (0.06-72 ng g(-1) dry wt) and PCBs (0.06-72 ng g(-1) dry wt) were not especially high in comparison to levels reported from throughout the world. The DDE/DDT ratio was, however, low indicating fresh inputs and hence current usage of DDT within the Black Sea region.

Recovery of the coastal marine environment in the Gulf following the 1991 war-related oil spills

Results from a 1991 rapid assessment survey to investigate the extent of hydrocarbon contamination resulting from the massive spillage of petroleum and the burning of oil wells revealed that war-related pollution in the Gulf was restricted to approximately 400 km from the sources. Subsequent surveys of the impacted zone were organized during 1992 and 1993 to investigate temporal changes in petroleum hydrocarbon contamination and recovery. Sub-tidal surface sediments from the coastlines of Kuwait and Saudi Arabia were sampled and analysed for petroleum hydrocarbons and polycyclic aromatic hydrocarbons (PAHs). At most locations by 1992, degradation had resulted in a composition (as determined by gas chromatography) dominated by an unresolved complex mixture, with only the most resistant resolved compounds surviving. Levels of contamination at impacted sites were generally shown to have decreased by approximately 50% between 1991 and 1992. A much lesser reduction in contamination was recorded for the period 1992 to 1993, and an increase in hydrocarbon concentrations was noted for stations in Kuwait and northern Saudi Arabia, possibly as a result of increased tanker activity and associated deballasting. PAH concentrations are shown to remain comparatively low, with oil rather than combustion being the major source.

Persistent Organophosphorus Pesticides in Tropical Marine Environments

Abstract ‘New generation’ organophosphorus insecticides are extensively used in tropical agriculture. Investigations into the distribution of a selection of these highly toxic compounds in coastal areas of Central America and Mexico have revealed that some are sufficiently heavily used and persistent to potentially impact sensitive tropical marine ecosystems. In sediments from the areas chosen for study, chlorpyrifos was found to be the most widely distributed compound. Traces of parathion and methyl-chlorpyrifos were, however, also encountered. Concentrations of the other major organophosphorus agrochemicals applied in these regions (including methyl-parathion, malathion, monocrotofos, and fenitrothion) were generally found to be below the limits of detection of the analytical techniques employed (typically −1 dry wt).

Discrete bands of petroleum hydrocarbons and molecular organic markers identified within massive coral skeletons

The tissues of corals deposit an aragonite exoskeleton beneath their outer living film at a rate dependent on growth and hence on environmental conditions. This typically results in annual (seasonal) bands being formed within colonies. By analysing molecular organic markers within these bands, our research suggests that coral skeletons record contamination from oil and potentially could be used to investigate other anthropogenic and biogenic organic inputs. Our analyses of sections from within corals (Porites lutea) sampled from the Gulf coasts of Kuwait and Saudi Arabia demonstrate discrete bands of oil contamination which, using selected terpenoid biomarkers, can be source-indexed to specific oil fields (i.e. Kuwait, Iranian or Arabian crude oils). Together with dating using microscopic and X-ray inspection, this offers the potential to investigate contamination during recent years. Further research is, however, necessary to elucidate degradation mechanisms during, and following, the occlusion process of organics within coral skeletons.

Main results of the 2012 joint Norwegian–Russian expedition to the dumping sites of the nuclear submarine K-27 and solid radioactive waste in Stepovogo Fjord, Novaya Zemlya

This paper reports the main results of the 2012 joint Norwegian-Russian expedition to investigate the radioecological situation of the Stepovogo Fjord on the eastern coast of Novaya Zemlya, where the nuclear submarine K-27 and solid radioactive waste was dumped. Based on in situ gamma measurements and the analysis of seawater and sediment samples taken around the submarine, there was no indication of any leakage from the reactor units of K-27. With regard to the radioecological status of Stepovogo Fjord, activity concentrations of all radionuclides in seawater, sediment and biota in 2012 were in general lower than reported from the previous investigations in the 1990s. However in 2012, the activity concentrations of (137)Cs and, to a lesser extent, those of (90)Sr remained elevated in bottom water from the inner part of Stepovogo Fjord compared with surface water and the outer part of Stepovogo Fjord. Deviations from expected (238)Pu/(239,240)Pu activity ratios and (240)Pu/(239)Pu atom ratios in some sediment samples from the inner part of Stepovogo Fjord observed in this study and earlier studies may indicate the possibility of leakages from dumped waste from different nuclear sources. Although the current environmental levels of radionuclides in Stepovogo Fjord are not of immediate cause for concern, further monitoring of the situation is warranted.