Bioavailable DDT residues in sediments: laboratory assessment of ageing effects using semi-permeable membrane devices

We describe the reduction in bioavailability of DDT in contaminated soil after it was incubated as sediment for 365 d. Bioavailability was assessed using semi-permeable membranes. Contaminated soils from three cattle dip sites, one spiked paired uncontaminated site, and one spiked OECD standard soil were studied. Sandy soil with residues of 1880 mg/kg summation operator DDT incurred since 1962, initially had 4.6% of summation operator DDT available, reducing to 0.6% following 365 d. Clay soil (1108 mg summation operator DDT/kg) had 4.1% initially available, reducing to 0.3% after 365 d. Freshly spiked soils had a greater amount of DDT initially available (10.9%), but this reduced to 1.5% by the end of the incubation. Of the DDT congeners, both o,p'-DDD and p,p'-DDD were most bioavailable in the soils, but also had the most significant decrease following incubation.     

Polychlorinated biphenyls and hexachlorobenzene in atmosphere, sea-surface microlayer, and water measured with semi-permeable membrane devices (SPMDs).

The time evolution of polychlorinated biphenyl (PCB) levels and hexachlorobenzene (HCB) levels in air, seawater, and at the sea-air boundary layer was examined during autumn and winter at a near-shore location in the Western Wadden Sea (Netherlands), using semi-permeable membrane devices (SPMDs). Performance reference compounds (PRCs) were added to the SPMDs prior to exposure for measuring the in situ exchange kinetics. For PCBs, a fair degree of equilibrium between atmosphere and water was found. HCB concentrations in the atmosphere were about eight times higher than the equilibrium concentration. PCB concentrations in seawater and atmosphere fell by a factor of 2-10, respectively, during the sampling period. HCB concentrations in water increased by a factor of 2. Atmospheric concentrations of HCB showed a decrease by a factor of about 10. Results for the sea-surface microlayer (SSM) deployment showed that the chemical activities at the air-water interface did not differ from those in deeper water layers. This means that the SSM was of no special toxicological significance in this study as far as PCBs and HCB are concerned.     

Use of cyanobacteria to assess water quality in running waters

Epilithic cyanobacterial communities in rivers in the province of Madrid (Spain) and their relationship with water quality were studied. Sampling locations above and below outlets for sewage effluent and other wastes from human settlements were selected. We aimed to evaluate the use of cyanobacteria as potential indicators of pollution in running waters. Large increases in nutrient concentrations were always observed at downstream sampling sites. A decrease in species richness and the Margalef diversity index were associated with these increases in nutrient load. Differences in cyanobacterial community structure were also observed. A higher proportion of cyanobacteria belonging to the Oscillatoriales order predominated at sampling sites with higher nutrient content. However, Nostocales species were more abundant at upstream sites characterized by lower nutrient load than at downstream locations. The soluble reactive phosphate (SRP) had a threshold effect on cyanobacterial biomass: a decrease in phycobiliprotein content as SRP increased, reaching a minimum, followed by an increase in abundance. This increase may be attributed to hypertrophic conditions in those locations. Our results and literature data confirm the suitability of this phototroph community for monitoring eutrophication in rivers     

Approaches to assess the oral bioaccessibility of persistent organic pollutants: a critical review

Oral bioaccessibility, also known as in vitro gastrointestinal extraction or the physiologically based extraction test (PBET), is an important tool when assessing the risk to humans from persistent organic pollutants (POPs) (and metals). The approach seeks to mimic the processes of human food digestion and thereby assess the bioavailability of POPs (and metals) from materials consumed either accidentally or intentionally in the diet. In vitro conditions are created to simulate various actions in the stomach and intestines (although some methods also include the mouth compartment). This paper reviews the current status of oral bioaccessibility with respect to the release of POPs from soil and related samples of environmental importance. Particular emphasis is placed on the parameters that influence gastrointestinal extraction including gastric and intestinal pH, enzymes, bile salts, food constituents and residence time. In addition, important developments in the use of in vitro gastrointestinal extraction are highlighted. These developments include the use of epithelial Caco-2 cells to mimic the intestinal cell lining, the potential for biotransformation of POPs into estrogenic metabolites as a result of colon microbiota, and the use of in vivo studies to validate existing approaches.     

Monitoring of organic pollutants in marine environment by semipermeable membrane devices and mussels: accumulation and biochemical responses

This study involves the monitoring of organic pollutants using transplanted mussels (Mytilus galloprovincialis) as bioindicator organisms and semipermeable membrane devices (SPMDs) as passive samplers. Mussels and SPMDs were deployed to marinas, shipyards and shipbreaking yards on the coastal area of Turkey and retrieved after 60 days. Polycyclic aromatic hydrocarbons (PAH), polychlorinated biphenyls (PCB) and organochlorine pesticide (OCP) compounds were analysed with high-resolution GC-MS. Total PAH concentrations in SPMDs and mussels ranged from 200 to 4740 ng g sampler^?1 and from 7.0 to 1130 ng g^?1 in wet weight (ww). PCB and OCP concentrations in SPMDs changed between 0.04–200 and 4.0–26 ng g sampler^?1, respectively. The highest PCB (190 ng g^?1 ww) and OCP (200 ng g^?1 ww) concentrations in mussels were measured at shipyard stations. A strong correlation was observed between the PAH and PCB concentrations in SPMDs and mussels. Enzyme assays (acetylcholinesterase, ethoxyresorufin-O-deethylase, glutathione S-transferase, glutathion reductase and carboxylesterase activities) were performed as biomarkers to reveal the effects of pollution on the mussels. There was no clear relationship found between the enzyme levels and the pollutant concentrations in mussels. Integrated biomarker responses were calculated to interpret the overall effect of pollutants.

     

Use of hematological and plasma biochemical parameters to assess the chronic effects of a fungicide propiconazole on a freshwater teleost

Blood is an indicator of physiological condition of an animal. Therefore, the chronic effects of propiconazole, a triazole fungicide present in aquatic environment, on hematology of rainbow trout were investigated in this study. Fish were exposed at various concentrations of PCZ (0.2, 50 and 500 μg L(-1)) for 7, 20 and 30 d. Multiple biomarkers were measured, including hematological indices (hemoglobin concentration, red blood cells count, hematocrit, leukocyte count, mean erythrocyte hemoglobin, mean erythrocyte volume and mean color concentration) and plasma biochemical parameters (ammonia, glucose, total proteins, creatine kinase, lactate dehydrogenase, alanine aminotransferase and aspartate aminotransferase). Through principal component analysis and integrated biomarker response assessment, influence extent induced by PCZ-stress of each test group was distinguished. Additional, all parameters measured in this study displayed different dependent patterns to PCZ concentrations and exposure time by two-way ANOVA. The results of this study indicate that chronic exposure of PCZ has altered multiple physiological indices in fish hematology and CK activity may be an early biomarker of PCZ toxicity; however, before these parameters are used as special biomarkers for monitoring residual PCZ in aquatic environment, more detailed experiments in laboratory need to be performed in the future.     

Lipid-Filled semipermeable membrane devices and mussels as samplers of organochlorine compounds in lake water

Semipermeable membrane sampling devices (SPMDs) and caged lake mussels (Anodonta piscinalis) were simultaneously deployed at four lake watercourse sites in Central Finland four weeks in August 1992. This study was part of the regular annual monitoring of the organochlorine compounds (OCC) in pulp-mill recipient watercourses of Finland with bivalves. Chlorohydrocarbons (CHCs), chlorophenol compounds (PCPs), chloroanisoles (PCAs) and chloroveratroles (PCVs) were analyzed from lipid extract of mussels and from the synthetic triolein lipid of the SPMDs. Hexane-diethyl ether (9:1, v/v) dialysis using polyethylene membrane was applied in dean up of the SPMD lipids and, for comparison, to six sets of the mussel fat. Dialysis recovered CHCs but not PCPs from the mussel fat. CHCs, PCPs, PCAs and PCVs were all recovered in dialysis of the SPMD lipid. Handling of SPMDs in the transport and deployment operations caused significant OCC contamination for the blank SPMDs. Similar trends were revealed in the OCC profiles for mussels ans SPMDs. An exception was the lack of PCPs appearing in SPMDs that did appear in mussels and in a complementary manner the appearance of the PCAs and PCVs in SPMDs.     

RECOTOX,a French initiative in ecotoxicology-toxicology to monitor,understand and mitigate the ecotoxicological impacts of pollutants in socioagroecosystems

RECOTOX is a cross-cutting initiative promoting an integrated research to respond to the challenges of monitoring, understanding, and mitigating environmental and health impacts of pesticides in agroecosystems. The added value of RECOTOX is to develop a common culture around spatial ecotoxicology including the whole chain of pressure-exposure-impact, while strengthening an integrated network of in natura specifically equipped sites. In particular, it promotes transversal approaches at relevant socioecological system scales, to capitalize knowledge, expertise, and ongoing research in ecotoxicology and, to a lesser extent, environmental toxicology. Thus, it will open existing research infrastructures in environmental sciences to research programs in ecotoxicology of pesticides.     

Use of the physiologically-based extraction test to assess the oral bioaccessibility of metals in vegetable plants grown in contaminated soil

The oral bioaccessibility of metals in vegetable plants grown on contaminated soil was assessed. This was done using the physiologically-based extraction test (PBET) to simulate the human digestion of plant material. A range of vegetable plants, i.e. carrot, lettuce, radish and spinach, were grown on metal contaminated soil. After reaching maturity the plants were harvested and analysed for their total metal content (i.e. Cr, Cd, Cu, Fe, Mn, Mo, Ni, Pb and Zn) by inductively coupled plasma-mass spectrometry (ICP-MS). The plant samples were then subsequently extracted using an in vitro gastrointestinal approach or PBET to assess the likelihood of oral bioaccessibility if the material was consumed by humans.     

磷酸盐稳定化修复锌污染土壤小试和工程效果评估

采用磷矿粉和某商业药剂为主要稳定化修复材料,针对某典型锌污染场地（包括锌污染土壤和工业废渣）开展实验室小试、稳定化修复工程和长期跟踪稳定化效果评估。结果表明,采用磷矿粉+熟石灰组合对锌污染土壤和建筑废渣具有长期稳定并大幅降低污染介质中锌浸出浓度的效果,实验室小试时投加比为2%时,锌的浸出可完全满足场地修复目标值25 mg·L-1的浓度限值;在现场施工时,为保守起见,设定稳定化药剂投加比例4%,在稳定化过程中,pH变化趋势为逐渐升高到11左右,然后降低稳定至7.0左右,废渣和污染土壤中锌浸出分别为0.2 mg·L-1、0.05 mg·L-1以下;稳定化修复后450 d,再次采样测定锌的浸出和pH,结果分别为低于0.2~2.0 mg·L-1和7.3左右,完全达到预期长期稳定化效果。实验室小试和稳定化工程结果可为后续锌污染场地治理修复提供技术参考和借鉴。     

HPLC-PFD determination of priority pollutant PAHs in water,sediment, and semipermeable membrane devices

High performance liquid chromatography coupled with programmable fluorescence detection was employed for the determination of 15 priority pollutant polycyclic aromatic hydrocarbons (PPPAHs) in water, sediment, and semipermeable membrane devices (SPMDs). Chromatographic separation using this analytical method facilitates selectivity, sensitivity (ppt levels), and can serve as a non-destructive technique for subsequent analysis by other chromatographic and spectroscopic techniques. Extraction and sample cleanup procedures were also developed for water, sediment, and SPMDs using various chromatographic and wet chemical methods. The focus of this publication is to examine the enrichment techniques and the analytical methodologies used in the isolation, characterization, and quantitation of 15 PPPAHs in different sample matrices.     

A comparison of polycyclic aromatic hydrocarbon and petroleum hydrocarbon uptake by mussels (Perna viridis) and semi-permeable membrane devices (SPMDs) in Hong Kong coastal waters

The ability of mussels (Perna viridis) and semi-permeable membrane devices (SPMDs) to accumulate polycyclic aromatic hydrocarbons (PAHs) and petroleum hydrocarbons (PHCs) from five sites in Hong Kong's coastal waters was compared. Mussels consistently had higher levels of contaminants, but their utility was limited at one highly polluted site due to mortality. Mussels and SPMDs ranked sites differently in terms of individual contaminant levels. Although SPMDs overcome many of the disadvantages of using living organisms to measure contaminants in marine waters, they cannot be used as "mimics" due to different PAH and PHC accumulation patterns.     

Use of passive sampling devices for monitoring and compliance checking of POP concentrations in water

Background

The state of the art of passive water sampling of (nonpolar) organic contaminants is presented. Its suitability for regulatory monitoring is discussed, with an emphasis on the information yielded by passive sampling devices (PSDs), their relevance and associated uncertainties. Almost all persistent organic pollutants (POPs) targeted by the Stockholm Convention are nonpolar or weakly polar, hydrophobic substances, making them ideal targets for sampling in water using PSDs. Widely used nonpolar PSDs include semi-permeable membrane devices, low-density polyethylene and silicone rubber.

Results and discussion

The inter-laboratory variation of equilibrium partition constants between PSD and water is mostly 0.2?C0.5 log units, depending on the exact matrix used. The sampling rate of PSDs is best determined by using performance reference compounds during field deployment. The major advantage of PSDs over alternative matrices applicable in trend monitoring (e.g. sediments or biota) is that the various sources of variance including analytical variance and natural environmental variance can be much better controlled, which in turn results in a reduction of the number of analysed samples required to obtain results with comparable statistical power.

Conclusion

Compliance checking with regulatory limits and analysis of temporal and spatial contaminant trends are two possible fields of application. In contrast to the established use of nonpolar PSDs, polar samplers are insufficiently understood, but research is in progress to develop PSDs for the quantitative assessment of polar waterborne contaminants. In summary, PSD-based monitoring is a mature technique for the measurement of aqueous concentrations of apolar POPs, with a well-defined accuracy and precision.     

A comparison of mussels (Perna viridis) and semi-permeable membrane devices (SPMDs) for monitoring chlorinated trace organic contaminants in Hong Kong coastal waters.

A comparison of mussels (Perna viridis) and semi-permeable membrane devices (SPMDs) was carried out at five sites, representing a gradient of contaminant concentrations, in Hong Kong coastal waters. Mussels, originally collected from a “clean” location, were deployed along with SPMDs at each site for 30 days. Analyses for chlorinated pesticides and polychlorinated biphenyls (PCBs) indicated that SPMDs have potential as monitoring tools, and to some extent can overcome the problems associated with mussels, such as natural variability, differing age, sex, and physical condition. However, in most cases, SPMDs failed to rank the sites in the same order as mussels in terms of contaminant concentrations. Nonetheless, in localities where mussels cannot survive – as shown at Kwun Tong in the present experiment – SPMDs may be valuable in providing an indication of potentially bio-available lipophilic pollutants.     

A comparison of mussels (Perna viridis) and semi-permeable membrane devices (SPMDs) for monitoring chlorinated trace organic contaminants in Hong Kong coastal waters

A comparison of mussels (Perna viridis) and semi-permeable membrane devices (SPMDs) was carried out at five sites, representing a gradient of contaminant concentrations, in Hong Kong coastal waters. Mussels, originally collected from a “clean” location, were deployed along with SPMDs at each site for 30 days. Analyses for chlorinated pesticides and polychlorinated biphenyls (PCBs) indicated that SPMDs have potential as monitoring tools, and to some extent can overcome the problems associated with mussels, such as natural variability, differing age, sex, and physical condition. However, in most cases, SPMDs failed to rank the sites in the same order as mussels in terms of contaminant concentrations. Nonetheless, in localities where mussels cannot survive – as shown at Kwun Tong in the present experiment – SPMDs may be valuable in providing an indication of potentially bio-available lipophilic pollutants.     

Calibration and field performance of membrane-enclosed sorptive coating for integrative passive sampling of persistent organic pollutants in water

Membrane-enclosed sorptive coating (MESCO) is a miniaturised monitoring device that enables integrative passive sampling of persistent, hydrophobic organic pollutants in water. The system combines the passive sampling with solventless preconcentration of organic pollutants from water and subsequent desorption of analytes on-line into a chromatographic system. Exchange kinetics of chemicals between water and MESCO was studied at different flow rates of water, in order to characterize the effect of variable environmental conditions on the sampler performance, and to identify a method for in situ correction of the laboratory-derived calibration data. It was found that the desorption of chemicals from MESCO into water is isotropic to the absorption of the analytes onto the sampler under the same exposure conditions. This allows for the in situ calibration of the uptake of pollutants using elimination kinetics of performance reference compounds and more accurate estimates of target analyte concentrations. A field study was conducted to test the sampler performance alongside spot sampling. A good agreement of contaminant patterns and water concentrations was obtained by the two sampling techniques.     

An invertebrate embryo test with the apple snail Marisa cornuarietis to assess effects of potential developmental and endocrine disruptors

A novel invertebrate embryo test with the apple snail, Marisa cornuarietis, comprising a test protocol for the following developmental endpoints is described: formation of eyes and tentacles, heart rate, hatching, weight after hatching. To evaluate effects on embryonic development, the snails were treated in a first step with 250 or 500 microg/l cadmium. Sublethal effects in terms of a significant delay in hatching could be found in the 250 microg/l treated animals, whereas 500 microg/l Cd were lethal for the snail embryos. To test endocrine disrupting chemicals with this protocol, experiments with bisphenol A (50 microg/l, 100 microg/l) and 17alpha-ethinylestradiol (10 microg/l) were performed. In both treatments an increase of weight after hatching was observed as well as a significant decline in the heart rate of the embryos. As shown here, the sensitivity of M. cornuarietis embryos test is equal or even higher than other test species like zebrafish embryos and, therefore, this test can be regarded as an alternative or supplement for ecotoxicological studies.     

Use of a lux-marked rhizobacterium as a biosensor to assess changes in rhizosphere C flow due to pollutant stress

The flow of carbon from plant roots into soil supports a range of microbial processes and is therefore critical to ecosystem function and health. Pollution-induced stress, which influences rhizosphere C flow is of considerable potential importance, and therefore needs to be evaluated. This paper reports on a method, based on reporter gene technology, for quantifying pollutant effects on rhizosphere C flow. The method uses the lux-marked rhizobacterium Pseudomonas fluorescens, where bioluminescence output of this biosensor is directly correlated with the metabolic activity and reports on C flow in root exudate. Plantago lanceolata was treated with paraquat (representing a model pollutant stress) in a simple microcosm system. The lux-biosensor response correlated closely with C concentrations in the exudate and demonstrated that the pollutant stress increased the C flow from the plantago roots, 24 h after application of the herbicide. The lux-reporter system therefore potentially offers a technique for use in assessing the impact of pollutant stress on rhizosphere C flow through the soil microbial biomass.