A multidisciplinary weight of evidence approach for classifying polluted sediments: Integrating sediment chemistry, bioavailability, biomarkers responses and bioassays

Evaluation of chemical bioavailability and onset of biological alterations is fundamental to assess the hazard of environmental pollutants, particularly when associated to sediments which need to be removed. In the present work, five sediment samples were collected from the Venice Lagoon and data from sediment chemistry were integrated with those of bioaccumulation of chemicals in European eel (Anguilla anguilla) exposed under laboratory conditions, responses of a wide battery of biomarkers, and standardized ecotoxicological bioassays. The overall results were elaborated within a recently developed, software-assisted weight of evidence (WOE) model which provides synthetic indices for each of considered line of evidence (LOE), before a general evaluation of sediment hazard. Levels of chemicals in sediments were not particularly elevated when compared to sediment quality guidelines of Venice Protocol. On the other hand, bioavailability was evident in some samples for Cd, Cu, Zn and, especially, polycyclic aromatic hydrocarbons. The ecotoxicological approach provided further evidence on the biological and potentially harmful effects due to released contaminants, and oxidative-mediated responses appeared of primary importance in modulating sublethal responses and the onset of cellular alterations. Biomarkers variations were sensitive, and more evident variations included significant changes of cytochrome P450 biotransformation pathway, antioxidant responses, onset of oxidative damages, lysosomal membrane stability and genotoxic effects. The results obtained from the battery of bioassays indicated that responses measured at organism level were in general accordance but less marked compared to the onset of sublethal changes measured through biomarkers. Overall this study revealed differences when comparing evaluations obtained from different LOEs, confirming the importance of considering synergistic effects between chemicals in complex mixtures. Compared to a qualitative pass-fail approach toward normative values, the proposed WOE model allowed a quantitative characterization of sediment hazard and a better discrimination of on the basis of various types of chemical and biological data.     

Assessment of contamination by heavy metals and petroleum hydrocarbons in sediments of Montevideo Harbour (Uruguay)

As part of the first environmental assessment within Montevideo Harbour, in summer and winter of 1998, sediments samples were collected at eight locations to determine the spatial distribution of anthropogenic pollutants. Muddy sediments with high organic matter content dominate the study area. Heavy metal levels indicated that sediments were highly polluted with Zn (overall mean: 312+/-102 microg g(-1) dry sediment), Pb (85+/-31), Cu (89+/-25), Cr (162+/-62), and Hg (0.63+/-0.3) and moderately with Ni (30+/-2) and Ag (1.2+/-0.4). Depending on location and season, aliphatic hydrocarbons reached from 21 to 120 microg g(-1), while the unresolved complex mixture represented up to 76% of the total aliphatic fraction. Total PAH concentrations ranged from 1.56 to 90.44 microg g(-1); except at one location, petroleum derivatives were identified as main local source. The results pointed out that almost all the harbour area presented some substances that can cause adverse biological effects, especially in the inner region where all metals are above PEL levels. Principal components analysis confirmed that the inner harbour region is most severely affected by the pollutants and it was possible to differentiate three regions according to their environmental quality.     

Metal concentrations in mussel Crenomytilus grayanus and oyster Crassostrea gigas in relation to contamination of ambient sediments

The relationship between Zn, Cu, Cd, Pb, and Ni concentrations in soft tissues of mussels and oysters and those in ambient sediments was examined. The study area was the coastal habitats of the northwestern Sea of Japan, which has a broad range of contamination due to urban sewage. Significant increases of all metals, except Ni, were observed in mussel Crenomytilus grayanus at concentrations of easily leachable metals in ambient sediments higher than 2, 100, and 800 microg/g for Cd, Cu, and Zn, respectively. Pb was accumulated by the mussels with no distinct threshold in Pb contamination of sediments. After 2 months, C. grayanus transplanted from a pristine to a contaminated locality increased in Pb up to 12%, and Cu up to 68% of concentrations of these metals in the contaminated local mussels, but Zn and Cd concentrations increased only in the excretory tissue, not in the somatic tissue, or in the soft tissue as a whole. Such regulation of metal accumulation puts limitations on the use of C. grayanus for monitoring of slightly and moderately contaminated localities. On the other hand, the oyster Crassostrea gigas showed definite accumulation of all metals, except Ni, at moderate contamination of ambient sediments. As contamination of sediments increased, increases of Pb, Zn and Cu concentrations in C. gigas slowed, possibly due to physiological control at very high metal concentrations in oyster soft tissue. Thus, the mussel C. grayanus should be used mainly for the monitoring of heavy contaminated localities, and the oyster C. gigas is more suitable as an indicator of low and moderate contamination.     

The pollution status and the toxicity of surface sediments in Izmit Bay (Marmara Sea), Turkey

Izmit Bay is one of the most polluted and populated enclosed sea in Turkey. It has been the centre of industrial activities for the last 30 years. Seven major sources enter the bay waters along the north coastline of the bay. This investigation forms part of continuing ecotoxicology studies in the Izmit Bay designed to constrain and minimise the pollution caused by flourishing industry and a growing population. Sediments sampled from the mouths of the major discharges of Izmit Bay were analysed for their organic carbon, total polycyclic aromatic hydrocarbon (t-PAH) and trace inorganic element (Cd, Al, As, Pb, Hg and Cu) contents and compared with those found in the sediments from the reference station in the outer bay (in the Marmara Sea). The toxicity of sediments was determined in the bulk and elutriate samples by using algal (Phaeodactylum tricornutum) batch bioassays. Chemical data showed that the sediments collected from the inner sites of the bay have been contaminated with Cd, Hg, As and PAHs. Organic carbon contents were also found higher. All the major industrial discharges into the bay are now biologically treated but bioassays performed with bulk sediments revealed that the recent sediments are toxic to the microalgae throughout the bay. The results are consistent with the previous toxicity studies performed with the industrial discharges.     

Heavy metal contamination of brown seaweed and sediments from the UK coastline between the Wear river and the Tees river

The concentration of Fe, Mn, Zn, Cu, Pb, Ni, Cr, Cd, and Ag were determined in the brown alga Fucus vesiculosus and intertidal surface sediments from coastal locations of northeast England. Levels of heavy metals similar to those of polluted areas of the British coastline were detected. There is evidence of contamination (especially with Zn and Pb) in sediments from sites affected by colliery spoil and from the Wear estuary. The pelitic fraction ( < 63 microm) is usually more enriched in heavy metals, but it represents a very small percentage of the bulk samples. The fine-grained sand is a very important repository of contaminants especially where particles of colliery spoil, secondary mineral, and amorphous phases are present. Aqua regia-extracted Zn, Cu, and Pb in sediments are significantly correlated with those in seaweed. Despite the closure of all base metal and coal mines, and the cessation of many industrial activities in the region, sediments and brown algae are contaminated with heavy metals. The control site (Holy Island) and the Tees estuary appear to be the least affected.     

Remobilisation of 109Cd, 65Zn and 54Mn from freshwater-labelled river sediments when mixed with seawater

A major fraction of trace metals transported by rivers is associated with sediments, especially during flooding, when erosion and resuspension increase sediment loads. Upon contact with seawater in estuaries, changes in ionic strength and pH may remobilise trace metals from sediment surfaces into more bioavailable forms. The objective of the present work was to investigate time-dependent interactions between trace metals and freshwater sediments and their potential remobilisation upon contact with seawater. Two river sediments (one organic and one inorganic) were labelled with 109Cd2+, 65Zn2+ and 54Mn2+ radioactive tracers for periods up to 6 months. Sorption of tracers occurred rapidly (> or = 80% sorption, < 1 h), followed by a slower approach to pseudoequilibrium. Kd(6 months) were estimated as 460, 480 and 2200 ml/g (inorganic sediment) compared to 5300, 4000 and 1200 ml/g (organic sediment) for 109Cd, 65Zn and 54Mn, respectively. Remobilisation of tracers from labelled sediments was studied using sequential extractions. Artificial seawater extracts simulated an estuarine environment. Subsequent extractions provided information about more strongly sorbed tracer fractions within sediments. Remobilisation of 109Cd by seawater was significant (> 65%) and least affected by sediment type or freshwater labelling time. Redistribution of Cd to strongly bound phases was minimal (4% and 1% of 109Cd in strongly oxidisable fractions). Seawater remobilisation of 65Zn was significantly greater from the organic sediment (54%) compared to the inorganic sediment (8%), where a large fraction of 65Zn (14%) became irreversibly bound. Similarly, more 54Mn was remobilised by seawater from the organic sediment than the inorganic sediment (66% and 3% remobilised, respectively), i.e., 54Mn became more strongly bound in the inorganic sediment. A simple three-box model, based on first-order differential equations, was used to describe the interaction between tracers in spiked freshwater and two operationally defined sediment fractions ("seawater exchangeable" and "seawater unexchangeable") up to 6 months of freshwater labelling. Model simulations were fitted to experiment data and apparent rate constants were calculated using numerical optimisation methods. Sorption ratios from modelling data (i.e., k1/k2) were greater for organic compared to inorganic sediments, while fixation ratios were higher in inorganic sediments. In conclusion, trace metals can be remobilised from sediments on contact with seawater in estuaries. High organic content in sediments increased initial sorption of tracers but inhibited redistribution to more strongly bound fractions over time, resulting in greater remobilisation of tracers when in contact with seawater.     

The distribution and history of nuclear weapons related contamination in sediments from the Ob River, Siberia as determined by isotopic ratios of plutonium and neptunium

Isotopic ratios of Pu and Np measured in sediment cores from 5 locations in the Ob River drainage basin show clear evidence of input from sources other than global fallout (non-fallout sources). Historical contaminant records obtained by combining isotopic ratio information with chronological information indicate that non-fallout inputs are from several sources that have varied significantly over the past 50 years. Unique isotopic signatures observed in sediments from tributaries that drain areas containing known or suspected sources of non-fallout contamination are used to identify the source of materials in sediments collected at downstream locations. These data can lead to a better understanding of the transport behavior, fate, and relative importance of particle reactive, weapons related contaminants originating from the nuclear facilities Mayak. Tomsk-7, and Semipalitinsk, which lie within the drainage basin. From our work to date, we draw the following conclusions: (1) Persistent non-fallout contamination is observed in the Ob River above its confluence with the Irtysh River, indicating contamination from the Tomsk-7 facility. (2) Non-fallout contamination in the Tobol River above its confluence with the Irtysh River indicates contamination from the Mayak facility. (3) Non-fallout contamination in the Irtysh River above its confluence with the Tobol River indicates contamination from the Semipalitinsk weapons test site. (4) The occurrence of isotopic ratios in Ob Delta sediments that are similar to those observed in source tributaries suggests that contamination from at least two sources has been transported along the length of the river system. (5) Global fallout, a result of high-yield atmospheric weapons tests conducted by the FSU and USA primarily, is the dominant source of Pu and Np to the region; however, there have been brief periods when inputs from non-fallout sources exceeded those from global fallout.     

Polycyclic aromatic hydrocarbon contamination in coastal sediments of the Izmit Bay (Marmara Sea): case studies before and after the Izmit Earthquake

Izmit Bay and its coastal environment was strongly affected by the August 17th, 1999 Izmit Earthquake. The changes in the Bay ecosystem and its chemical oceanography have been studied in detail previously [Okay, O.S., Tolun, L, Telli-Karako?, F., Tüfek?i, V., Tüfek?i, H. And Morko?, E. 2001. Yzmit Bay ecosystem after Marmara earthquake and subsequent fire: The long-term data. Marine Pollution Bulletin 42, 361-369; Balkys, N. 2003. The effect of Marmara (Izmit ) Earthquake on the chemical oceanography of Izmit Bay, Turkey. Marine Pollution Bulletin 46, 865-878.]. In this study surface sediments collected from the Izmit Bay before and after the earthquake have been analysed for total and individual (14 compounds) polycyclic aromatic hydrocarbons (PAH). Analyses have been performed by high performance liquid chromatography with fluorescence detection (HPLC/FD). Before the earthquake, total PAH concentrations in the Bay sediments ranged from 120 to 8900 ng/g while after the earthquake PAH concentrations varied between 240 and 11,400 ng/g. Molecular indices based on isomeric PAH ratios used to differentiate the pollution sources, clearly indicate the differences in molecular distribution of PAHs before and after the earthquake. Sediment data obtained before the earthquake shows that most of the contamination originated from high temperature pyrolytic inputs while after the earthquake it originated from petrogenic sources. This difference emphasises the environmental impact of uncontrolled discharges from petroleum industries after the earthquake. The LMW/HMW ratio (sum of the low molecular weight PAHs / the sum of higher molecular weight PAHs) predominance also changed after the earthquake as a result of the strong water movements. According to the characteristics of aromatic rings distributed in the bay sediments, the soluble parts of the total PAH were probably transferred to the water column after the earthquake as a result of resuspension process. The TEL/PEL (Threshold Effect Level / Probable Effect Level) analysis suggests that the Izmit Bay sediments were likely contaminated by acutely toxic PAH compounds.     

Preparedness of households and catering establishments for incidents involving radioactive contamination

This short paper describes a number of investigations carried out to ensure preparedness for crises involving radioactivity to catering operations and private households in Finland. The specific recommendations for catering kitchens during crises were published in 1994. A study to determine the level of adherence to these recommendations is summarised here, together with its findings and subsequent recommendations. Another study on the pre-planning of crisis menus is described. New challenges for the catering kitchens are touched upon. A crisis food preparation booklet for households is described and based on consumers' attitudes suggestions are made for how this can be improved in the future.     

中美大气污染的空间交互影响--来自国家和城市层面PM2.5的经验证据

准确识别中美大气污染的空间交互影响可以为两国在大气污染治理领域开展双边合作提供科学依据。以PM 2.5浓度表征大气污染程度,采用收敛交叉映射(Convergent Cross Mapping,CCM)方法,在采集伯克利地球发布的小时数据的基础上通过算数平均得到2018年1月1日至2018年12月31日的PM 2.5浓度日均数据,从国家和城市两个层面识别了中美大气污染的空间交互影响。研究发现,中美两国的大气污染是空间交互影响的。其中,国家层面,在CCM因果检验基础上的广义同步检验表明,在1%显著性水平上,大气污染仅存在由美国指向中国的单向因果关系。城市层面,中美两国10个样本城市之间理论上共存在50个可能的因果关系(5×5×2)。研究发现,在1%显著性水平上,美国城市指向中国城市的因果关系有12个,而中国城市指向美国城市的因果关系仅有5个。在影响强度上,美国城市的大气污染对中国城市的影响强度高于中国城市的大气污染对美国城市的影响强度,如重庆的大气污染对华盛顿的影响强度为0.21,而华盛顿的大气污染对重庆的影响强度为0.35。面对大气污染的空间交互影响,中美两国可通过积极开展联合科研攻关,厘清大气污染的传输路径及其驱动因素,进行污染物的联合监测与数据管理;通过共享大气污染治理技术和建立大气污染防治基金等方式,加强在大气污染治理领域的合作。一旦中美两国成功建立起大气污染双边合作治理体系,依靠两国的国际地位和国际影响力,必将吸引越来越多的国家参与进来共同行动,大气污染全球治理体系的构建将非常值得期待。     

Heavy metals in organisms and sediments from Turkish Coast of the Black Sea, 1997-1998

During the period 1997-1998, macroalgae, sea snail, mussel, fish and sediment samples were collected at different stations of the Turkish Black Sea coast in order to establish the concentration of selected heavy metals. Heavy metals analyzed were Cd, Co, Cr, Ni, Zn, Fe, Mn, Pb and Cu. The results showed that the Turkish Black Sea coast is facing heavy metal pollution. The metal concentrations in macroalgae, sea snail, mussel and sediment samples are very high. However, Cd, Pb and Cu concentrations in anchovy fish decreased, while Co, Fe, Zn, Cr, Mn and Ni contents had changed when compared previous data. The metal levels in macroalgae did not follow the same pattern as concentrations in sediments at the same station. On the other hand, concentrations of Cd, Co, Cr, Zn, Fe, Mn and Cu in sea snail, mussel and fish samples were related to sediment data in the examined stations.     

Air pollution and hospitalization for acute complications of diabetes in Chile

Exposure to air pollution has been shown to cause insulin resistance in mice. To determine the relevance to humans, we tested the association between daily air pollution concentrations and daily hospitalization for acute serious complications of diabetes, coma and ketoacidosis, in Santiago between 2001 and 2008, using generalized linear models with natural splines to control for long term trends.For an interquartile range (IQR) increase in air pollutant, the relative risks (95% CI) of hospitalization for diabetes were: 1.15 (1.10, 1.20) for carbon monoxide (IQR = 1.00); 1.07 (0.98, 1.16) for ozone (IQR = 63.50); 1.14 (1.06, 1.22) for sulfur dioxide (IQR = 5.88); 1.12(1.05, 1.20) for nitrogen dioxide (IQR = 27.94); 1.11 (1.07, 1.15) for particulate matter ≤ 10 μm diameter(IQR = 34.00); and 1.11 (1.06, 1.16) for fine particulate matter ≤ 2.5 μm diameter (IQR = 18.50). Results were similar when stratified by age, sex and season. Air pollution appears to increase the risk of acute complications of diabetes requiring hospitalization, suggesting that improvements in air quality may reduce morbidity from diabetes.     

Spatial correlation network and population mobility effect of regional haze pollution: empirical evidence from Pearl River Delta urban agglomeration in China

Based on relevant data from 2014 to 2018, we constructed a spatial network of haze pollution in the Pearl River Delta (PRD) region by using a modified gravity model, explored the network structure characteristics and influencing factors of urban agglomeration with the SNA and the QAP method, and discussed the population mobility effect brought by haze pollution. The results showed that the PRD region has spatial correlation in terms of haze pollution. Guangzhou was in the central position of the spatial network, yet Shenzhen and Foshan played a connecting role in the network. Economic development, urbanization, and environmental protection had significant positive impacts on the haze pollution spatial network. The results of the double-threshold regression showed that the city’s status in the haze pollution network represented by centrality had a positive impact on population mobility.

     

Effect of toxic pollution on fish populations and mechanisms for maintaining population size

The effect of pollution on fish populations has been analyzed. It has been demonstrated that the strategy of the fish life cycle changes in the direction corresponding to r-selection. Smaller individuals that mature at an earlier age and are preadapted to energy allocation for maintaining a higher metabolic rate and activating detoxification gain a survival advantage under toxic conditions. If young females whose gametogenesis is within the normal range join the spawning stock, the population size is successfully maintained but its parameters and gene pool are changed.     

Water quality and impacts of pollution sources for Eymir and Mogan Lakes (Turkey)

Mogan and Eymir Lakes are two shallow lakes, interconnected hydrologically in the close vicinity of Ankara, Turkey. A total of 245 km(2) of the total 971.4 km(2) watershed is under environmental protection status as "G?lba?i Specially Protected Area". Potential impacts from extensive agriculture, recreation, incomplete infrastructure and other human activities, such as residential settlements, are discussed with reference to previous and more recent pollution monitoring. Six monitoring stations enabling follow-up of previous work were selected in this study. These were on the creeks feeding the lake systems. Generally, summer months showed heavier pollution loads, with Eymir Lake concentrating the pollutants due to flow from Mogan Lake. When compared with the 1995 study; COD, total-P, Kjeldahl-N in the six stations were close or slightly decreased in the present study. Suspended solids significantly decreased; possibly due to erosion control measures and decreased domestic wastewater. The improvement in the pollution state of the lakes is attributed to the construction of a sewage system going around Mogan Lake and collecting wastewater discharges and restrictions to urban settlement development around the lakes brought by the 1/25,000 land use plan controlling further impact from residential developments within the protected area boundaries. The study, while addressing water quality and interactions due to human activities in shallow lakes, also discusses problems associated with human impacts in protected areas with the aim of presenting a complicated case study.     

Assessment of environmental estrogens and the intersex/sex reversal capacity for chinook salmon (Oncorhynchus tshawytscha) in primary and final municipal wastewater effluents

A trickling filter/solid contact (TF/SC) biological secondary treatment plant with chlorine disinfection serving a suburban population of 740,000 was assessed for environmental estrogens. Weekly grab samples were taken at established sampling points and analyzed for various pertinent environmental estrogens including industrial chemicals, and natural and synthetic steroidal estrogens. Additionally, human estrogen receptor (hER) activity and capacity to elicit intersex/sex reversal for the wastewater was monitored using a recombinant yeast assay and whole fish exposures, respectively. hER activity levels varied from 76 to 106 ng/L E2 equivalents in the primary effluent, and were reduced by 25% by biological treatment. For the primary and final effluent no evidence of sex reversal or intersex was apparent in any of the treatment groups (1%, 3%, 10%, or 100%) based on genetic sex determinations and histological examination of the gonads in alevin from 28 d exposed chinook salmon (Oncorhynchus tshawytscha) eggs.     

Estimation of sources of total phosphorus in a river basin and assessment of alternatives for river pollution reduction

The methodology of material flow analysis is presented and applied to developing a phosphorus balance in a river basin and evaluating different scenarios for pollution reduction. The method is based on the balance principle: inputs and outputs of each phosphorus-related subsystems were balanced. The application of the methodology strategies was illustrated by means of a case study of the Krka River, Slovenia. The results showed that besides effluents from wastewater treatment plants, agriculture contributed significantly to the total annual phosphorus load. After establishing the present levels of phosphorus balance, different scenarios were considered: different stages of wastewater treatment as well as management of agricultural activities. The present emission of phosphorus is estimated to be 81.8 tons/year; after implementation of measures, it would be 48.6 tons/year, a total reduction of 40%. Besides reduction of point sources by means of wastewater collection and implementation of nutrient removal technology, managing agricultural phosphorus to protect water quality should become a major challenge in the Krka river basin.