Characterisation of potentially genotoxic compounds in sediments collected from United Kingdom estuaries

The mutagenic activity bioassay Mutatox was used to assess the mutagenic activity associated with sediments collected from five UK estuaries. Assays were performed on extracts of sediment pore water and residual particulate material isolated from sediment samples collected from the rivers Tyne, Tees, Mersey, and Thames as well as Southampton Water. No mutagenic activity was associated with the pore water extracts, however, 7 of the 28 organic solvent extracts of sediment particulate material contained potential genotoxins. By using Mutatox in association with bioassay-directed fractionation, attempts were made to identify the mutagenic compounds present in the extracts. The fractionation procedure used normal phase solid phase extraction, C18 reverse phase HPLC and cyano/amino bonded silica normal phase HPLC. GC-MS (EI and NICI) analysis was used to identify polycyclic aromatic hydrocarbons (PAH), alkyl substituted PAH, nitro-polycyclic aromatic compounds (nitro-PACs), polycyclic aromatic ketones, oxygenated-PACs, and other known mutagens contributing to the genotoxicity measured in the samples. Some potentially genotoxic compounds remain unidentified.     

A case of polychlorinated biphenyl contamination of water and sediment in the Slovenian karst region (Yugoslavia)

An incident is described in which polychlorinated biphenyls (PCBs) from an electro-industrial plant waste tip draining into ground-water channels in karst terrain have contaminated a potable water source. PCB composition data were obtained using quadropole GC-MS and capillary GC. The average level of PCBs determined in water was 0.3 μg 1^?1 and in sediment 55 μg g^?1     

Chlorinated hydrocarbons and shell thinning in eggs of (Accipiter) hawks in Ontario, 1986-1989

Eggs of sharp-shinned hawks (Accipiter striatus), Cooper's hawks (A. cooperii), and northern goshawks (A. gentilis) were collected from nests in south-central Ontario from 1986 to 1989. Detectable levels of the chlorinated hydrocarbons DDE, DDT, DDD, mirex, photomirex, cis-nonachlor, trans-nonachlor, oxychlordane, dieldrin, heptachlor expoxide, HCB and PCB were present in all the eggs analyzed. Mean contaminant levels were highest in sharp-shinned hawks, slightly lower in Cooper's hawks, and significantly lower in goshawks; for example, mean DDE values were 7.23, 4.48 and 0.90 mg kg(-1) (wet weight), respectively. Total PCB levels were generally less than 1.5 mg kg(-1), lower than those associated with reproductive effects in field and laboratory studies with other species. Mean shell thicknesses of sharp-shinned and Cooper's hawk eggs were significantly less than mean pre-DDT era thicknesses (-10 and -8%, respectively), reductions that were probably not relevant to reproductive success. Goshawk eggs exhibited no significant reduction in shell thickness. Contaminant levels among the three species probably reflect differing food habits and migratory patterns.     

Biomagnification factors (fish to Osprey eggs from Willamette River,Oregon, U.S.A.) for PCDDs,PCDFs, PCBs and OC pesticides

A migratory population of 78 pairs of Osprey (Pandion haliaetus) nesting along the Willamette River in westernOregon was studied in 1993. The study was designed to determinecontaminant concentrations in eggs, contaminant concentrationsin fish species predominant in the Ospreys diet, andBiomagnification Factors (BMFs) of contaminants from fish specieseaten to Osprey eggs. Ten Osprey eggs and 25 composite samplesof fish (3 species) were used to evaluate organochlorine (OC)pesticides, polychlorinated biphenyls (PCBs), polychlorinateddibenzo-p-dioxins (PCDDs), and polychlorinated dibenzofurans(PCDFs). Mercury was also analyzed in fish. Geometric meanresidues in Osprey eggs were judged low, e.g., DDE 2.3 g g^-1 wet weight (ww), PCBs 0.69 g g^-1, 2,3,7,8-TCDD 2.3 ng kg^-1, and generally well below known threshold values for adverse effects on productivity, and the population was increasing. Osprey egg residue data presentedby River Mile (RM) are discussed, e.g., higher PCDDs were generally found immediately downstream of paper mills and eggsfrom the Willamette River had significantly elevated PCBs and PCDDs compared to reference eggs collected nearby in the CascadeMountains. Prey remains at nest sites indicated that the Largescale Sucker (Catostomus macrocheilus) and NorthernPikeminnow (Ptychocheilus oregonensis) accounted for an estimated 90.1% of the biomass in the Osprey diet, and composite samples of these two species were collected from different sampling sites throughout the study area for contaminant analyses. With the large percentage of the fishbiomass in the Osprey diet sampled for contaminants (and fisheaten by Ospreys similar in size to those chemically analyzed),and fish contaminant concentrations weighted by biomass intake, a mean BMF was estimated from fish to Osprey eggs for the largeseries of contaminants. BMFs ranged from no biomagnification(0.42) for 2,3,7,8-TCDF to 174 for OCDD. Our findings for themigratory Osprey were compared to BMFs for the resident HerringGull (Larus argentatus), and differences are discussed. Webelieve a BMF approach provides some basic understanding ofrelationships between contaminant burdens in prey species offish-eating birds and contaminants incorporated into their eggs,and may prove useful in understanding sources of contaminants inmigratory species although additional studies are needed.     

Nitrous oxide emissions from waste water

The estimation of nitrous oxide emissions is complicated by the high degree of uncertainty on the emission factors involved and by the limited acquaintance with all significant nitrous oxide sources. A potentially important source for which emission data are lacking is the sewage system transporting waste water from human activities. For this study an experimental measurement campaign has been carried out on waste water sampled at different sewage treatment plants. The nitrous oxide developing from the water samples was monitored by means of gas chromatography. The methodological analysis was based on the concentration/time curves obtained. Our results indicate that the formation of nitrous oxide from the waste water matrices results from microbiological denitrification. We deduced tentative emission factors for the waste water types studied.     

Metabolic regulation in methanogenic archaea during growth on hydrogen and CO2

Methanogenic Archaea represent a unique group of micro-organisms in their ability to derive their energy for growth from the conversion of their substrates to methane. The common substrates are hydrogen and CO₂. The energy obtained in the latter conversion is highly dependent on the hydrogen concentration which may dramatically vary in their natural habitats and under laboratory conditions. In this review the bio-energetic consequences of the variations in hydrogen supply will be investigated. It will be described how the organisms seem to be equipped as to their methanogenic apparatus to cope with extremes in hydrogen availability and how they could respond to hydrogen changes by the regulation of their metabolism.Abbreviations Coenzyme F₄₂₀ 5-dezaflavin derivative - F₄₂₀H₂ 1,5-dihydro-F₄₂₀ - F₃₉₀ 8-adenylylated-(F₃₉₀-A) or 8-OH-guanylylated-(F₃₉₀-G)-F₄₂₀ - H₄MPT 5,6,7,8-tetrahydromethanopterin - HS-CoM coenzyme M, 2-mercaptoethanesulfonate - methyl-S-CoM 2-methylthioethanesulfonate - HS-HTP 7-mercaptoheptanoylthreonine phosphate - CoM-S-S-HTP heterodisulfide of HS-CoM and HS-HTP - FDH formylmethanofuran dehydrogenase - FRH coenzyme F₄₂₀-reducing hydrogenase - HDR heterodisulfide reductase - MCR methylcoenzyme M reductase - MDH 5,10-methylene-H₄MPT dehydrogenase - MVH non-coenzyme F₄₂₀, Viologen-reducing hydrogenase     

National GHG inventories: Recent developments under the IPCC/OECD Joint Programme

This paper summarises key results of the Joint IPCC/OECD Programme, in particular the draft IPCC Guidelines for National GHG Inventories to be released in January 1994. The focus is on how these results are likely to improve the availability and the quality of national inventories of anthropogenic GHG emission sources and removals by sinks. The IPCC/OECD has already received nearly 50 inventories from 35 countries. Most of the data are for 1988, but some reports cover 1989 and 1990. In addition to CO₂, many of these inventories include CH₄, N₂O, NOx, CO, and NMVOC. Detailed analyses of these inventories have provided valuable insights about the strengths and weaknesses of the national inventories, differences in approach to estimation, reporting, available methods and data. These results in turn, have facilitated the development of the draft Guidelines, most notably the proposed reporting system, and also on estimation methods for the different anthropogenic sources and sinks of GHG. The paper previews key aspects of the draft Guidelines for non-CO₂ GHG. Experts are urged to actively participate in the IPCC/OECD Programme to continue to improve inventory methods and overall the Guidelines.The views presented in this paper are those of the authors and do not necessarily represent the views of the OECD or their Member countries.     

The Mid-Canada Radar Line and First Nations' people of the James Bay region, Canada: an evaluation using log-linear contingency modelling to analyze organochlorine frequency data

Abandoned radar line stations in the North American arctic and sub-arctic regions are point sources of contamination, especially for PCBs. Few data exist with respect to human body burden of organochlorines (OCs) in residents of communities located in close proximity to these radar line sites. We compared plasma OC concentration (unadjusted for total lipids) frequency distribution data using log-linear contingency modelling for Fort Albany First Nation, the site of an abandoned Mid-Canada Radar Line station, and two comparison populations (the neighbouring community of Kashechewan First Nation without such a radar installation, and Hamilton, a city in southern Ontario, Canada). This type of analysis is important as it allows for an initial investigation of contaminant data without imputing any values. The two-state log-linear model (employing both non-detectable and detectable concentration frequencies and applicable to PCB congeners 28 and 105 and cis-nonachlor) and the four-state log-linear model (using quartile concentration frequencies for Aroclor 1260, PCB congeners [99,118,138,153,156,170,180,183,187], beta-HCH, p,p'-DDT +p,p'-DDE, HCB, mirex, oxychlordane, and trans-nonachlor) revealed that the effects of subject gender were inconsequential. Significant differences (p < 0.05) between the groups examined were attributable to the effect of location on the frequency of detection of OCs or on their differential distribution among the concentration quartiles. In general, people from Hamilton had higher frequencies of non-detections and of concentrations in the first quartile (p < 0.05) for most OCs compared to people from Fort Albany and Kashechewan (who consume a traditional diet of wild meats that does not include marine mammals). An unexpected finding was that, for Kashechewan males, the frequency of many OCs was significantly higher (p < 0.05) in the 4th concentration quartile than that predicted by the four-state log-linear model, but significantly lower than expected in the 1st quartile for beta-HCH. The levels of PCBs found for women in Fort Albany and Kashechewan were greater than those reported for Dene (First Nation people) and Métis (mixed heritage) of the western Northwest Territories (NWT) who did not consume marine mammals, and for Inuit living in the central NWT (occasional consumers of marine mammals). Moreover, the levels of total p,p'-DDT were greater for Fort Albany and Kashechewan women compared to these same aboriginal groups.     

Monitoring of fate and effects of oil in the marine environment

Examples are presented of different techniques which are in use, or could be used, to monitor the fate and effects of oil pollution in Dutch marine waters by oil spills and chronic contamination by rivers, processing water from the oil industry, etc.A number of techniques are presented to quantify the fate of oil in water, sediments and biota, and some readily available methods to monitor possible effects in the ecosystem.In Dutch coastal waters much effort is being given to airborne detection of oil at the sea surface in order to reduce pollution and to take rapid measures in cases of severe pollution. Oil concentrations in sediments and selected organisms can be monitored as a general quality control measure, and to check the functioning of licensed installations. If concentrations above background levels are found, research on possible effects should be initiated. In this context short term studies on stress-indicators are very useful. Laboratory based investigations, for example in model ecosystems, can be carried out to test hypotheses from such studies. Elevated oil concentrations and indications for ecological effects may result in changes in the management of the marine area in question. Monitoring of population dynamics and species composition, notably of benthic macrofauna, should be carried out to verify long-term effects on the ecosystem.     

The Development of Biological Objectives for Streams in a Single Catchment: A Case Study on the Catchment of Western Port Bay, Victoria, Australia

Government environment protection policies for waterways have traditionally relied on water quality indicators and their objectives. In this paper we describe the development of biological objectives based on invertebrate indicators for inclusion in a government policy for the catchment of Western Port Bay, Victoria. The first step of defining segments (areas with streams in which the same objectives are applied) was problematic, requiring two different approaches, as follows. Site groups initially based on invertebrate community composition derived using multivariate techniques (ordination and classification) proved to be unsuitable for policy segments. Segment boundaries were subsequently defined using topographical (e.g. boundary of foothills and lowland plains), climate (e.g. rainfall) and land-use (e.g. urban) features. We used information and data from reference sites inside as well outside the catchment to derive specific biological objectives based on aquatic invertebrates for these segments. Objectives were specified for the following four indicators--number of invertebrate families, the SIGNAL index, the AUSRIVAS predictive model and the number of key families.