Laurence D. Mee

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.

Trace organic contamination in the Americas: An overview of the US National Status & Trends and the International ‘Mussel Watch’ programmes

Abstract The National Status & Trends (NS&T, 1986–1993) and the International Mussel Watch (IMW, 1991–1992) programmes provide a good coverage of a broad range of environmental conditions along the North, Central and South American coasts. Total concentrations of DDTs, chlordane-related compounds, PCBs and PAHs present fairly homogeneous distributions along the northern Gulf of Mexico coast, with very few sites showing extremely high or low concentrations. In contrast, a larger variability in the geographical distribution of some of these organic contaminants was observed for IMW sites. For example, high concentrations of DDT and its metabolites, DDD and DDE, were generally found in tropical and subtropical areas as compared to more temperate zones of South America. ‘Industrial’ contaminants, such as PCBs and PAHs, have similar distributions with the highest concentrations encountered generally along the southern South Atlantic coast. An overall comparison of the concentrations of these organic contaminants measured at NS&T and IMW sites indicates that contamination is significantly higher along the northern coast of the Gulf of Mexico.

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.

Organotin compounds in the Mediterranean: A continuing cause for concern

Abstract Extensive survey data for butyltins are reported for Mediterranean coastal waters together with the first phenyltin concentrations from the region. Elevated levels of tributyltin (TBT) are reported for most marina/harbour waters. In the great majority of cases, the ‘no observable effect’ aqueous concentration of 20ng litre−1 is exceeded. The TBT concentrations encountered are comparable to those reported in a previous MEDPOL pilot survey. This questions the efficacy of current legislation in the Mediterranean. The movement of foreign vessels painted outside of the scope of legislation offers an explanation for this observation and endorses the need for region-wide control measures and enforcement. The Contracting Parties to the Barcelona Convention have recently agreed to adopt such control measures to protect the Mediterranean; these are described and discussed. Concerning triphenyltin, concentrations of 21–94 ng litre−1 are reported, with most of the compound associated with the particulate phase. The distribution in samples collected from marinas and in proximity to dry docks attributes the origin of the compound to antifouling paint leachates.

Comparison of the performance of solid-phase extraction techniques in recovering organophosphorus and organochlorine compounds from water

Solid-phase extraction (SPE) of 11 organochlorine and 24 organophosphorus compounds from aqueous solution was evaluated using different Amberlite (XAD-2 and XAD-7) resin mixtures, reversed-phase C18 bonded-silica disks, and poly(styrene-divinylbenzene) (SDB) co-polymer disks. Macroreticular resins provided low recoveries and unacceptable reproducibility for some compounds including malathion, methylparathion, ethylparathion, chlorthion and endosulfan compounds. This is probably due to irreversible adsorption or chemical degradation. No relationship was observed between the recoveries and the log Kow of the compounds. Octadecyl-bonded silica and styrene-divinylbenzene disks provided comparable results for the selected compounds with recovery efficiencies depending on the polarity of the compounds. Good recoveries were achieved for compounds with water solubilities below 300 mg/l or with log Kow greater than 2. Poor recoveries were obtained for dichlorvos, monocrotophos and dimethoate.

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.

Agrochemical residues in the Altata‐Ensenada del Pabellon coastal lagoon (Sinaloa, Mexico): A need for integrated coastal zone management

An in‐depth survey of agrochemical residues was carried out in the Altata‐Ensenada del Pabellon lagoon, on the Pacific coast of Mexico. A wide variety of residues originating from the surrounding agricultural lands were found in lagoon sediments, water, and biota samples. Persistence, cycling and fate of the most common pesticides were investigated using 14C labelled compounds in microcosms and mesocosms which simulated environmental conditions in the lagoon. Results from the study indicated that existent levels of contaminants in association with their persistence and trends in agrochemical usage, could compromise the future of this ecosystem including sustainable fisheries and the potential for developing aquaculture. Other activities in the area, namely those related to urban and industrial growth, cause additional impacts on the coastal lagoon system; therefore, coordinated actions are urgently needed to improve environmental management. A stepwise approach for integrated management of the coastal zon...

The Reliability of Analytical Data for Tributyltin (TBT) in Sea Water and its Implications on Water Quality Criteria

Abstract To investigate the reliability of analytical data for tributyltin (TBT) in sea water, split water samples were distributed to ten laboratories in six countries. The sub-surface samples comprised: (i) an offshore (0·5 km) water sample, (ii) the same sample but spiked with an undisclosed quantity of TBT standard compound (175 ng TBT+ liter−1), and (iii) a sample taken from a yacht marina. The seven acceptable data sets were in good agreement for the spiked sample (178 ± 26 ng TBT+ liter−1) but showed a greater variation in concentrations reported for the yacht marina sample (366 ± 93 ng TBT+ liter−1). Atomic absorption and gas chromatographic-flame photometric detection techniques produced results of similar accuracy and precision. Samples acidified with 1 ml of 10% ( v v ) acetic acid appeared stable for more than 2 weeks when stored refrigerated and in darkness. Analyses of the offshore seawater sample revealed TBT contamination (9 ± 7 ng TBT+ liter−1) indicating dispersion of the compound to the shelf waters off Monaco. The spread in values reported by the laboratories demonstrates inherent difficulties in obtaining good precision below approximately 20 ng TBT+ liter−1. This observation is discussed with respect to the setting and enforcing of water quality standards.