Pollution biomarkers in two estuarine invertebrates,Nereis diversicolor and Scrobicularia plana,from a Marsh ecosystem in SW Spain

The polychaete worm Nereis diversicolor and the clam Scrobicularia plana were collected from several sites, affected by different types of contamination, in a littoral enclosure in the SW Spain (Caño Sancti-Petri and Rio San Pedro). N. diversicolor was present in 6 sampling sites whereas S. plana in 4 of them. The aim of our study was to relate several pollution biomarkers to chemical sources (metals and organic pollutants e.g. PCB, PAH) in these species, thereby confirming their adequacy as sentinels for this habitat. The biomarkers surveyed in the two invertebrates were the activities of the antioxidant enzyme catalase (CAT), the phase II detoxifying enzyme glutathione S-transferase (GST) and the neurotoxicity marker acetylcholinesterase (AChE). Metallothionein (MT) levels were measured as a biomarker of exposure to metals. The results suggested a different response in the two sediment-dwelling organisms, the sediment-eating polychaete and the water-filtering clam, probably as a consequence of different contamination exposures. The results also suggested that samples from the “Caño Sancti-Petri” were exposed to biologically active compounds that altered some of their biochemical responses. Of all the biomarkers tested, AChE was the most sensitive one and N. diversicolor the potentially most robust sentinel in this ecosystem. In this low to moderately polluted environment, the biochemical approach better reflected temporal trends than site-related differences although it was also able to detect punctual chemical insults.     

Qualitative estimates of soil disturbance in the vicinity of CANDU stations, utilizing measurements of 137Cs and 210Pb in soil cores

Anthropogenically derived 14C has been used to trace recent carbon input in a study of carbon accumulation and turnover in Canadian soils. In order to do so, documentation of the undisturbed nature of the soil horizons sampled was of prime concern. Although all the sites chosen for coring were currently uncultivated, detailed information on long-term land usage was not available. To overcome this problem, 137Cs profiles were measured in all the cores used in the study. 210Pb measurements were also made in cases where total 137Cs deposition was lower than predicted. For some sample sites, the data obtained showed correlated losses of both radionuclides, indicating that land disturbance and/or erosion had indeed occurred in these areas over the past 50 years, hence invalidating the use of those cores for carbon cycling studies. In a few cases a marked lack of correlation between these two radionuclides has made it necessary to hypothesize that chemical, rather than physical, processes have been partially responsible for the observed anomalies. Since results of this nature raise doubts about the reliability of the 137Cs method for identification of land disturbance, further investigation is warranted.     

Autumn bed site selection by sika deer (<Emphasis Type="Italic">Cervus nippon</Emphasis>) in the Taohongling National Nature Reserve,China

To better understand the habitat requirements of sika deer in the Taohongling National Nature Reserve, transect lines were set out to collect data on bed sites used by sika deer during the autumn. The results showed that sika deer displayed a preference for bed sites with a moderate height of grass fallow and brush fallow, lower shrub density, higher herb density, lower canopy coverage, and higher undergrowth coverage. The bed sites were also characterized as being located on sunny slopes, gentle slopes, and upper slopes, with high elevation. In addition, most bed sites were located far away from human disturbance (more than 1000 m). A logistic regression analysis model indicated that undergrowth coverage, slope location, canopy coverage, and height of undergrowth were important factors that contributed to the difference between used and non-used plots. The habitat–animal relationship is one of the most important types of information, which could provide important references for the conservation and management of sika deer and their habitats in the Taohongling reserve.     

Development and application of an innovative expert decision support system to manage sediments and to assess environmental risk in freshwater ecosystems

With the aim of supporting decision makers to manage contamination in freshwater environments, an innovative expert decision support system (EDSS) was developed. The EDSS was applied in a sediment quality assessment along the Bormida river (NW, Italy) which has been heavily contaminated by an upstream industrial site for more than a century. Sampling sites were classified by means of comparing chemical concentrations with effect-based target values (threshold and probable effect concentrations). The level of each contaminant and the combined toxic pressure were used to rank sites into three categories: (i) uncontaminated (8 sites), (ii) mildly contaminated (4) and (iii) heavily contaminated (19). In heavily contaminated sediments, an environmental risk index (EnvRI) was determined by means of integrating chemical data with ecotoxicological and ecological parameters (triad approach). In addition a sediment risk index (SedRI) was computed from combining chemical and ecotoxicological data. Eight sites exhibited EnvRI values ≥ 0.25, the safety threshold level (range of EnvRI values: 0.14–0.31) whereas SedRI exceeded the safety threshold level at 6 sites (range of SedRI values: 0.16–0.36). At sites classified as mildly contaminated, sublethal biomarkers were integrated with chemical data into a biological vulnerability index (BVI), which exceeded the safety threshold level at one site (BVI value: 0.28). Finally, potential human risk was assessed in selected stations (11 sites) by integrating genotoxicity biomarkers (GTI index falling in the range 0.00–0.53). General conclusions drawn from the EDSS data include: (i) in sites classified as heavily contaminated, only a few exhibited some significant, yet limited, effects on biodiversity; (ii) restrictions in re-using sediments from heavily contaminated sites found little support in ecotoxicological data; (iii) in the majority of the sites classified as mildly contaminated, tested organisms exhibited low response levels; (iv) preliminary results on genotoxicity biomarkers indicate possible negative consequences for humans if exposed to river sediments from target areas.     

Soil mutagenicity as a strategy to evaluate environmental and health risks in a contaminated area

Soil can be a storage place and source of pollutants for interfacial environments. This study looked at a site contaminated with wood preservatives as a source of mutagens, defined routes and extent of the dispersion of these contaminants by particle remobilization and atmospheric deposition, considering an evaluation of risk to human health by quantifying mutagenic risk. Soil sampling sites were chosen at gradually increasing distances (150, 500 and 1700 m) from SI (industrial area pool) and indoor dust (pool in an area at risk at 385 m and at 1700 m). Mutagenesis was evaluated in the Salmonella/microsome assay, TA98, TA97a and TA100 strains with and without S9 mix, YGs strains 1041, 1042 and 1024 for nitrocompounds. Acid extracts were analyzed to define the effects of metals and organics for polycyclic aromatic hydrocarbons (PAHs) and nitroderivates, besides concentrations of these compounds and pentachlorophenol (PCP). Risk to human health was obtained from the relation between the quantified potential of mutagenic risk and estimated soil ingestion for children according to USEPA. Metal concentrations showed a gradient of responses with As, Cr and Cu (total metal) or Cr and Cu (fraction available) higher for SI. However, mutagenic effects of the mixtures did not show this grading. Site SR1700, without a response, was characterized as a reference. In organic extracts, the mutagenesis responses showed the mobility of these compounds from the source. In the surrounding area, a smaller pattern similar to SI was observed at SR150, and at the other sites elevated values of direct mutagenesis at SR500 and diminished effects at SR1700. Tests with YG strains indicated that nitrated compounds have a significant effect on the direct mutagenesis found, except SR500. The investigation of indoor dust in the surrounding area enabled confirmation of the particle resuspension route and atmospheric deposition, showing responses in mutagenicity biomarkers, PAH concentrations and PCP dosage similar to SI. The range of values obtained, considering the soil masses needed to induce mutagenicity was 0.02 to 0.33 g, indicating a high risk associated with human populations exposed, since these values found surpass the standard estimate of 200 mg/day of rate of soil ingestion for children according to USEPA. The study showed that it is essential to evaluate the extent of contamination from the soil to delimit remedial measures and avoid damage to the ecological balance and to human health.     

A review of factors affecting the release and bioavailability of contaminants during sediment disturbance events

The factors affecting the release and bioavailability of contaminants present in sediments during natural and anthropogenic disturbance events are discussed and our current state of understanding of these processes reviewed. Published data are focused on the distribution of contaminants within undisturbed sediment, their affinities to the various solid-phase fractions of sediment and the interaction of contaminants between sediment and pore water. Sediment disturbance can lead to changes in the chemical properties of sediment that stimulate the mobilisation of contaminants. Research shows that changes in both redox potential (Eh) and pH can accelerate desorption, partitioning, bacterial degradation and the oxidation of organic contaminants. However, these processes are both sediment- and compound-specific. By affecting the affinity of contaminants to sediments, disturbance events in turn can have a significant effect on their bioavailability. Few studies have examined this phenomenon, and it is clear from the data available that there are gaps in our understanding in a number of key areas when assessing the release of contaminants from sediments: the fate of contaminants in undisturbed sediments and those that are not subjected to major disturbances, the kinetic processes that regulate metal release during changes in redox potential, the release of organometallic compounds from sediments during resuspension, the bioavailability of organic and organometallic compounds and the processes affecting contaminant release.     

Field observations of the effects of protracted low levels of ionizing radiation on natural aquatic population by using a cytogenetic tool

In the present study, an effort is attempted to record the impact of chronic radiation on natural aquatic populations exposed to protracted doses (lower if compared to intervention levels but higher if compared to typical background) and to chemical pollution. The methodology is based on the analyses of chromosome aberrations observed in cells. Therefore, some preliminary research results on the cytogenetic effects on aquatic organisms of various taxa, in coastal ecosystems are presented, considering some selective regions of elevated natural gamma radiation and conventional pollution. These areas are the geothermal spring areas in the island of Ikaria-Eastern Aegean Sea and the port of Pireus, in Greece. The data are compared to the findings recorded in some organisms collected from the North Aegean Sea the early period after the Chernobyl accident. With regard to the different species examined, a first evaluation of the results is made using the reported field findings for the wide area of Chernobyl. The environmental assessment of the studied areas in terms of radiation impact is based on the cytogenetic injuries observed, and evidence of ecosystem disturbance is also pointed out. The final environmental assessment based on the quantified effects observed in the organisms from the studied areas takes into account a published conceptual model of zones of radiation dose rates and the resulting organism responses in a step function scale.     

Determining sediment quality for regulatory proposes using fish chronic bioassays

Sediment quality assessments for regulatory purposes (i.e. dredged material disposal) are characterized by linking chemical and acute ecotoxicological data. The design of chronic bioassays that incorporate more sensible endpoints than acute tests is discussed to address sediment quality for environmental quality assessment and regulatory proposes. The chronic tests use juveniles of commercial species of fish Sparus aurata and Solea senegalensis, to assess sediment toxicity in samples collected along different littoral areas in the North and the South of Spain. The organisms were exposed during 60 days and sublethal endpoints were selected including biomarkers of exposure to metals (metallothioneins - MTs) and to organic contaminants (ethoxyresorufin-O-deethylase activity - EROD activity) and biomarkers of effect (histopathology in different tissues, gill and liver). A Multivariate Analysis Approach was conducted in order to associate these biological responses with sediment metal concentration from the ports and with chemical residues in biological tissues exposed to sediments under laboratory conditions.     

Glutathione S-tranferases and cytochrome P450 activities in Mytilus galloprovincialis from the South coast of Portugal: effect of abiotic factors

To assess the health of aquatic organisms, biomarkers that measure changes at the biochemical level have been used as effective early warning tools in ecological risk assessment. In order to develop an integrated risk assessment strategy for the south coast of Portugal, mussels Mytilus galloprovincialis were collected from six sites along the coast with different organic contaminant characteristics. Additionally, an active biomonitoring approach was followed by transplanting indigenous mussels from site 4 to 6 and vice versa (from site 6 to 4) for 28 days. PAHs and PCBs contents were measured and the associated responses of phase I and phase II detoxification mechanisms evaluated by measuring cytochrome P450 and GST activities. GST activity was also determined on different tissues (gills, digestive gland, foot, mantle and gonads) of M. galloprovincialis and the impact of abiotic parameters (temperature, salinity, pH, conductivity and dissolved oxygen) on the GST activity assessed. Results indicate that CYP 450 follow the same pattern of PAHs and a direct relationship exist between CYP 450 and PAH levels from the different sites. Although there is a decrease between GST and PAHs concentrations it was not significant. The majority of the GST activity was in the gills and the digestive gland (around of 75% of the activity measured in all tissues) followed in decreasing order by the mantle, gonads. An inverse relationship between GST activity and salinity was detected along with temperature although not significant. These two biomarkers respond to changes of these two groups of compounds and to salinity especially for GST. In conclusion CYP 450 in mussels gives a reliable response as biomarker for organic contaminants in risk assessment in the South Coast of Portugal.     

Ultraviolet irradiation of municipal wastewater: Evaluation of effects on organic constituents

A comparison of chromatograms derived from the UV-absorbing and oxidizable constituents present in primary and secondary municipal wastewater effluents indicates that exposure to UV irradiation at disinfection levels results in only slight chemical changes. The most pronounced chemical effects to nonvolatile organic constituents in wastewater effluents have been observed at irradiation levels in excess of those necessary for disinfection. Aliquots of effluents before and after exposure to varying levels of UV irradiation were concentrated by lyophilization prior to liquid chromatographic (LC) analysis. Anion-exchange chromatographic techniques utilizing a modified ultraviolet detector coupled in series with a cerate oxidative monitor provided excellent resolution and sensitivity in the determination of chemical changes occurring in the effluents as a result of exposure to different irradiation levels. The total coliform counts for each irradiated effluent were determined by the membrane-filter technique to evaluate the effectiveness of UV irradiation as a disinfection process for municipal wastewaters. Changes in biochemical oxygen demand (BOD), chemical oxygen demand (COD), total organic carbon (TOC), and total Kjeldahl nitrogen (TKN) at different levels of exposure to UV irradiation are presented. The results of these determinations and the gas chromatography/mass spectrometry data characterizing the observed chemical changes are discussed.     

A basal area model responsive to thinning for a plantation forest.

The Tarawera Valley spacing and thinning trial data were used to develop a dynamical model for basal area prediction that is responsive to both spacing and thinning. The model is a 'critically damped' second-order model, i.e., it simulates a sigmoidal response, before and after thinning. It has a scalar spacing variable, which makes the model responsive to different spacing trials. It also has a vector 'reductor' term, which enables simulation over different productivity sites, although this still needs to be validated with measured data. The dynamical model has the potential of being applied across a forest estate with different productivity sites, if data are available for all sites.     

Environmental quality of transitional waters: the lagoon of Venice case study

The health status of European aquatic environments, including transitional waters such as coastal lagoons, is regulated by the Water Framework Directive (WFD), which requires the classification of the water bodies' environmental quality and the achievement of a good ecological status by 2015. In the Venice lagoon, a transitional water body located in the northeastern part of Italy, the achievement of a good ecological status is hampered by several anthropogenic and natural pressures, such as sediment and water chemical contamination, and sediment erosion. In order to evaluate the lagoon's environmental quality according to the WFD (i.e. 5 quality classes, from High to Bad), an integrated Weight-of-Evidence methodology was developed and applied to classify the quality of the lagoon water bodies, integrating biological, physico-chemical, chemical, ecotoxicological, and hydromorphological data (i.e. Lines of Evidence, LOE). The quality assessment was carried out in two lagoon habitat typologies (previously defined on the basis of morphological, sediment, and hydrodynamic characteristics) which were selected taking into account the ecological gradient from sea to land, and the differences in anthropogenic pressure and contamination levels. The LOE classification was carried out by using indicators scored by comparing site specific conditions to reference conditions measured in lagoon reference sites, or provided by local, national or European regulations (e.g. Environmental Quality Standards, EQS, for chemicals). Finally, the overall quality status for each water body was calculated by a probabilistic approach, i.e. by reporting the final result as the frequency distribution of quality classes. The developed procedure was applied by using data and information concerning selected LOE and collected from monitoring programs and research studies carried out in the last 15 years in the lagoon of Venice. A set of sampling stations characterized by spatially and temporally coherent information for each LOE was selected, and among these stations, potential reference sites for each water body typology were identified. The quality assessment highlighted that there are specific lagoon areas, especially those located near the industrially developed area, which are highly affected by anthropogenic activities, and that chemical contamination is one of the main pressures affecting ecological status (e.g. macro-benthonic biodiversity) in the Venice lagoon. The integrated quality assessment procedure that was developed provided a new tool supporting decision making, as well as lagoon assessment and management.     

An evaluation of a river health using the index of biological integrity along with relations to chemical and habitat conditions

We evaluated the health condition of a temperate river during June-November 1999 through applications of the index of biological integrity (IBI) using fish assemblages and qualitative habitat evaluation index (QHEI) as well as chemical analyses. Overall IBI values ranged from 13 to 37 and averaged 23 (n = 25, standard error = 1.16), indicating a "poor" or "very poor" condition according to the criteria of modified Karr [Fisheries 6 (1981) 21]. The values of mean IBI declined at a rate of 0.22 km(-1) (R2 = 0.91, p < 0.05) along the longitudinal distance from the headwaters to the downstream sites. Reduced IBI values at downstream sites reflected low forest cover, high population density and high nutrient enrichments. Ecotoxicity tests using the river water also showed that toxic impacts were evident in the downriver sites. These factors resulted in decreases of riffle benthic species and insectivores and increases of tolerant species, anormalies and exotic species in the river. Spatial pattern in IBI agreed with QHEI values, which showed a linear relation (R2 = 0.998, p < 0.001) with species richness. Field measurements of conductivity and pH, an indicators for variation of conservative ions, showed that the river water was diluted by 40% fold by summer monsoon rain and surface run-off from the watershed, resulting in a physical and chemical instability during the monsoon. For these reasons, average IBI values during the monsoon and postmonsoon decreased >20% compared to the premonsoon, indicating that IBI values were also affected by flow regime. Based on the overall physico-chemical data and IBI values, the river health is rapidly degrading due to the combined effect of chemical contaminations and habitat modifications.     

Interpretation of fish biomarker data for identification,classification, risk assessment and testing of endocrine disrupting chemicals

Chemical induced changes in fish biomarkers vitellogenin (VTG), secondary sex characteristics (SSC), and sex ratio indicate modes/mechanisms of action (MOAs) of EAS (estrogen, androgen and steroidogenesis) pathways. These biomarkers could be used for defining MOAs and the causal link between MOAs and adverse effects in fish for the identification of endocrine disrupting chemicals (EDCs). This paper compiled data sets of 150 chemicals for VTG, 57 chemicals for SSC and 38 chemicals for sex ratio in fathead minnow, medaka and zebrafish. It showed 1) changes in fish biomarkers can indicate the MOAs as anticipated; 2) in addition to EAS pathways, chemicals with non-EAS pathways induced changes in fish biomarkers; 3) responses of fish biomarkers did not always follow the anticipated patterns of EAS pathways. These responses may result from the interaction of chemical-induced multiple MOAs and confounding factors like fish diet, infection, culture conditions, general toxicity and stress response. The complex response of fish biomarkers to a chemical of interest requires EDC testing at multiple biological levels. Interpretation of fish biomarker data should be combined with relevant information at different biological levels, which is critical for defining chemical specific MOAs. The utility of fish biomarker data for identification, classification, PBT assessment, risk assessment, and testing of EDCs in the regulatory context was discussed. This paper emphasizes the importance of fish biomarker data in the regulatory context, a weight of evidence approach for the interpretation of fish biomarker data and the need for defining levels of evidence for the identification of EDCs.     

A framework to spatially cluster air pollution monitoring sites in US based on the PM2.5 composition

BackgroundHeterogeneity in the response to PM_2.5 is hypothesized to be related to differences in particle composition across monitoring sites which reflect differences in source types as well as climatic and topographic conditions impacting different geographic locations. Identifying spatial patterns in particle composition is a multivariate problem that requires novel methodologies.ObjectivesUse cluster analysis methods to identify spatial patterns in PM_2.5 composition. Verify that the resulting clusters are distinct and informative.Methods109 monitoring sites with 75% reported speciation data during the period 2003–2008 were selected. These sites were categorized based on their average PM_2.5 composition over the study period using k-means cluster analysis. The obtained clusters were validated and characterized based on their physico-chemical characteristics, geographic locations, emissions profiles, population density and proximity to major emission sources.ResultsOverall 31 clusters were identified. These include 21 clusters with 2 or more sites which were further grouped into 4 main types using hierarchical clustering. The resulting groupings are chemically meaningful and represent broad differences in emissions. The remaining clusters, encompassing single sites, were characterized based on their particle composition and geographic location.ConclusionsThe framework presented here provides a novel tool which can be used to identify and further classify sites based on their PM_2.5 composition. The solution presented is fairly robust and yielded groupings that were meaningful in the context of air-pollution research.     

Photochemical smog effects in mixed conifer forests along a natural gradient of ozone and nitrogen deposition in the San Bernardino Mountains

Toxic effects of photochemical smog on ponderosa and Jeffrey pines in the San Bernardino Mountains were discovered in the 1950s. It was revealed that ozone is the main cause of foliar injury manifested as chlorotic mottle and premature needle senescence. Various morphological, physiological and biochemical alterations in the affected plants have been reported over a period of about 40 years of multidisciplinary research. Recently, the focus of research has shifted from studying the effects of ozone to multiple pollutant effects. Recent studies have indicated that the combination of ozone and nitrogen may alter biomass allocation in pines towards that of deciduous trees, accelerate litter accumulation, and increase carbon sequestration rates in heavily polluted forests. Further study of the effects of multiple pollutants, and their long-term consequences on the mixed conifer ecosystem, cannot be adequately done using the original San Bernardino Mountains Air Pollution Gradient network. To correct deficiencies in the design, the new site network is being configured for long-term studies on multiple air pollutant concentrations and deposition, physiological and biochemical changes in trees, growth and composition of over-story species, biogeochemical cycling including carbon cycling and sequestration, water quality, and biodiversity of forest ecosystems. Eleven sites have been re-established. A comparison of 1974 stand composition with data from 2000 stand composition indicate that significant changes in species composition have occurred at some sites with less change at other sites. Moist, high-pollution sites have experienced the greatest amount of forest change, while dryer low-pollution sites have experienced the least amount of stand change. In general, ponderosa pine had the lowest basal area increases and the highest mortality across the San Bernardino Mountains.     

Adverse effects in wild fish living downstream from pharmaceutical manufacture discharges

A set of biochemical and histological responses was measured in wild gudgeon collected upstream and downstream of urban and pharmaceutical manufacture effluents. These individual end-points were associated to fish assemblage characterisation. Responses of biotransformation enzymes, neurotoxicity and endocrine disruption biomarkers revealed contamination of investigated stream by a mixture of pollutants. Fish from sampled sites downstream of the industrial effluent exhibited also strong signs of endocrine disruption including vitellogenin induction, intersex and male-biased sex-ratio. These individual effects were associated to a decrease of density and a lack of sensitive fish species. This evidence supports the hypothesis that pharmaceutical compounds discharged in stream are involved in recorded endocrine disruption effects and fish population disturbances and threaten disappearance of resident fish species. Overall, this study gives argument for the utilisation of an effect-based monitoring approach to assess impacts of pharmaceutical manufacture discharges on wild fish populations.     

Adverse effects in wild fish living downstream from pharmaceutical manufacture discharges

A set of biochemical and histological responses was measured in wild gudgeon collected upstream and downstream of urban and pharmaceutical manufacture effluents. These individual end-points were associated to fish assemblage characterisation. Responses of biotransformation enzymes, neurotoxicity and endocrine disruption biomarkers revealed contamination of investigated stream by a mixture of pollutants. Fish from sampled sites downstream of the industrial effluent exhibited also strong signs of endocrine disruption including vitellogenin induction, intersex and male-biased sex-ratio. These individual effects were associated to a decrease of density and a lack of sensitive fish species. This evidence supports the hypothesis that pharmaceutical compounds discharged in stream are involved in recorded endocrine disruption effects and fish population disturbances and threaten disappearance of resident fish species. Overall, this study gives argument for the utilisation of an effect-based monitoring approach to assess impacts of pharmaceutical manufacture discharges on wild fish populations.