Biomonitors and biomarkers as indicators of environmental change pdf

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biomonitors and biomarkers as indicators of environmental change pdf

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Biomonitors and Biomarkers as Indicators of Environmental Change 2

Pampanin a,b ,. Box , N, Stavanger, Norway. The purpose is to enable the use of biological responses biomarkers as Risk Indicators in procedures for Environmental Risk Assessment. The aim of the present paper is to discuss experiences gained from applying the Biomarker Bridges approach to existing data from the monitoring of an offshore oil field.

The data are from the biomonitoring case study of an oil field on the Norwegian Continental Shelf. The field had no discharge of produced water at the time of the survey and sediment contaminated with drill cuttings was expected to be the main source of contamination. Applying the Biomarker Bridges approach revealed that different response patterns could indeed be detected using this method when compared to responses that would commonly be associated with produced water.

Examination of the different biomarker responses in this pattern revealed effects of a different chemical discharge than produced water. Laboratory experiments have been performed to develop tools to integrate predictions and monitoring data obtained in field surveys []. A shortcoming in the management system prior to this was that there were no clear links between the variables that can be measured during monitoring and those used for risk characterisation [8].

Tools to integrate predictions of risk and measured effect i. The specific SSDs used in the present context were SSD Biomarkers established for different types of biomarker responses relevant to monitoring of oil based discharges [7]. The data to establish the SSDs were derived from statistically significant biomarker responses in organisms exposed to oil [6,7].

The application of these SSDs to link biomarkers to higher order effects and risk is called Biomarker Bridges and represents a method to link monitoring and predictions, or diagnosis to prognosis. Hence it allows biomarkers to be used as risk indicators in environmental risk assessment and to serve as assessment criteria for the measured biomarker responses [7,8]. In cases where effects deviate from the biomarker response pattern expected from PW or crude oil exposures it may therefore be caused by a different type of discharge, which is the particular interest in this study.

This program uses an environmental toxicological approach, and the main activity of the survey was to assess the chemical exposure and health status of fish populations living in the vicinity of an oil and gas installation.

Fish collected at a clean site, about 60 km away from the platform, were used as reference material. Fish were collected by rod and line within meters of the platform. Biomarkers were analysed in four species: redfish Sebastes sp. In saithe, 12 individuals were analysed and in all other species 20 individuals were analysed. At the reference site, 4 individuals of ling, 18 of tusk, and 20 of both redfish and saithe were collected.

Supplementary reference values for ling obtained in the sampling were added to the data set. The following biomarkers were included in the data set: polycyclic aromatic hydrocarbon PAH bile metabolites analysed by both gas chromatography-mass spectrometry GC-MS and fixed wavelength fluorescence FF [14,15], ethoxyresorufin O -deethylase EROD [16,17], lysosomal membrane stability LMS [18], DNA adducts [19] and histological evaluation of gills [20,21].

Acetyl choline esterase AChE [22] was also analysed in the study. PAH metabolites FF method. FF analysis was conducted as described by [23]. Slit widths were set at 2.

The fluorescence signal was transformed into pyrene fluorescence equivalents PFE through a standard curve made by pyrene. Fish bile was prepared for analysis as described by [14, 15]. Mass spectra were obtained at 70 eV in selected ion mode SIM.

Liver samples were homogenized in a potassium phosphate buffer 0. Pre-prepared resorufin standards duplicates were then added to subsequent wells. Transformation of 7-ethoxyresorufin to resorufin was read in 8 steps on the plate reader. Excitation was at nm and fluorescence emission was measured at nm.

Total protein content was determined according to [24]. The determination of LMS is based on the time of acid labilisation treatment required to produce the maximum staining intensity after demonstration of naphthol AS-BI phosphate activity in digestive cell lysosomes [18]. The longer the acid buffer exposure period needed to destabilise the lysosomal membrane represents high membrane integrity of lysosomes and vice versa. Following this treatment, sections were transferred to the substrate incubation medium for the demonstration of Hex activity.

The incubation medium consisted of 20 mg naphthol AS-BI phosphate dissolved in 2. Slides were then fixed for 10 min in Baker's formol calcium containing 2. Slides were evaluated under a microscope. Lysosomes stain reddish-purple due to the reactivity of the substrate with Nacetyl-b-hexosaminidase. The average labilisation period LP corresponds to the average incubation time s in the acid buffer that produces maximal staining reactivity.

Each set of tissue sections were analysed and compared with the staining intensity of the section showing maximal staining i. DNA adducts. Fish liver samples 70 to 90 mg per sample were taken for the DNA extraction. The DNA concentrations were calculated from the absorbance optical density at the wavelength of nm A The 32 P-postlabelling method used for this analysis is considered suitable for the detection of so-called "bulky" DNA adducts, which are additional compounds in DNA associated to complex molecules such as PAHs.

Method details are reported in [25,26]. In each set of analyses, DNA from both positive and negative controls was systematically included. Histopathology of gills. Tissues were dehydrated in ethanol, rinsed and cleaned in a tissue processor before embedding in paraffin wax. Finally, sections were evaluated using a microscope Zeiss Axioplan 2 and all micrographs were captured with a digital colour camera AxioCam. Slides were analysed blind by two analysts to ensure quality.

The method from [27] to determine the AChE activity in biota tissue was used to assess AChE in extracts from fish fillet samples. The microsomal fraction was obtained as for the EROD analysis. The enzyme activity was followed by the production of the yellow coloured 5-thionitrobenzoic acid TNB anion. Experiments were performed in well microplates and the protocol was automated on a robotic workstation a Biomek laboratory automation workstation to allow high-throughput analysis.

The enzyme activity was then followed by an absorbance plate reader at nm at room temperature. Statistical analysis of biomarkers. With the exception of histological evaluation of gills, all raw data and levels of significance were obtained from the report [13], where statistical differences between the groups of biological data were assessed with analysis of variance ANOVA. Where homogeneity could not be achieved non-parametric analysis was performed, either as a Kruskal-Wallis test or Mann-Whitney U test.

Affected fraction of species. In our study the number of significant biomarker responses in the different fish species were added up to yield the affected fractions of species in different biomarker groups. The distribution of the above biomarkers into groups are shown in Table 1. These numbers were examined using the SSD curves for the different biomarkers established in relation to PW exposures [7].

There were no PW discharges at the site during the survey [29], however seabed areas in the field are known to be contaminated with hydrocarbons and process chemicals originating from drilling discharges. The operator estimated the amount to be tons [30]. Chemicals in the green category are nonhazardous, those in the yellow category are usually defined as not being environmentally hazardous, while chemicals in the red and black categories are prioritized for substitution [31].

Biomarker raw data are reported in WCM final report [13]. The statistically significant biomarker responses in the four fish species used in this study are shown in Table 1, histopathology raw data are provided in supplementary file 1. The fraction of the affected species in Table 1 are plotted for each biomarker group in Figure 1a. Details regarding the use of AFF in term of biomarker reponses can be found in [8]. For biomarker unit see material and method section.

Figure 1a shows a backwards assessment made from affected species back to the probable exposure concentrations that could have caused the effect. Ideally, when applied to a crude oil based exposure it would be expected that in a backward assessment using the biomarker SSD concept the different biomarker responses would point back to a common exposure concentration. This is because we expect that one common exposure concentration has caused the different biomarker responses and given this particular fingerprint based on our set of SSD Biomarker curves.

In our study, it was considered likely that the fish had been exposed to toxicants other than those typically found in PW. A different distribution of concentrations might therefore be expected in the backwards assessment. This can be evaluated by a closer examination of the different biomarker group responses, and the fish species in which the responses were seen.

When the range of responses are projected to the linear PAF WOR scale different from the logarithmic concentration scale in Figure 1a , the wide response range is more clearly visualised, and the responses seem to be divided into two groups: PAH metabolites, Detox I and Histopathology are grouped together at a lower concentration and LMS and Genotoxicity are grouped together at a higher concentration.

The PAH metabolites and Detox I groups are typically biomarkers of exposure, and their responses are usually indications of ongoing or recent exposure of the organisms to PAHs [32,33]. Histopathology has been shown to give similar indications [7], especially in gill tissues.

This may be due to the fact that gills are exposed directly to the oil constituents in the water and have a large surface area i. During exposure to PW discharges more species will normally show a response in other biomarkers than in LMS and genotoxicity [7].

LMS is a biomarker of general cellular stress which responds to various chemicals, including PAHs [35]. The same fish species were affected in LMS as in AChE Table 1 , which may indicate that neurotoxins have contributed to the elevated lysosomal membrane stress [22]. Even if the biomarkers of exposure did not indicate an ongoing exposure of hydrocarbons, the DNA adduct responses could have originated from a recent, but ended hydrocarbon exposure. On the other hand, DNA adducts might also have responded to other chemicals.

Although the biomarker responses to different process chemicals are not known in great detail, simultaneous exposures to several different process chemicals in the yellow, red and black categories can generally be assumed to result in stress on lysosomal membranes, AChE and DNA.

Thus, a division in the two biomarker groups can be considered in accordance with the responses being caused by other sources than PW discharges. In the four sampled fish species, two have a more demersal lifestyle tusk and ling than the others redfish and saithe []. Therefore, the distribution of species affected by the different biomarkers might in some cases provide indications to the source of the toxicants inducing responses [41].

If the two species affected in LMS and genotoxicity biomarkers were the two demersal species it could be an indication that the sediment is the toxicant source for those effects. However, this was not the case Table 1 , and overall the significantly elevated biomarker responses were rather evenly distributed between demersal and pelagic species. The interpretation in this case points more towards a generally elevated level of affected species in the area.

This is in accordance with the conclusions reported from the survey, that the observed biological responses can partly be explained by the wide range of oil and gas related chemicals that were not measured but were likely to be present [13]. The point of value in our study is that deviances from the expected pattern of biomarker responses can guide further inspections of the data and may add information regarding toxicant types and sources.

Usefulness of Bioindicators and Biomarkers in Pollution Biomonitoring

Metrics details. A prerequisite for long-term survival of populations under multi-stress conditions is their capacity to set up efficient adaptive strategies. However, changes in the activity of molecular biomarkers have been for decades considered as early signals of the deterioration of the fish health and evidence of stress-related adverse biological effects. The aim of this study was to show that such changes actually represent adaptive response of fish to chemical stress. Gene expression and enzyme activity level in liver and brain of specimens from two populations of Abramis brama from contrasted habitats nature reserve and urban were examined. Selected parameters included biomarkers of general stress, antioxidative defence, xenobiotic metabolism, endocrine disruption, glucose homeostasis, iron homeostasis, and neurotoxicity.

DOI: Ocean sustainability thus constitutes a major issue for human health, as well as economic and ecological perspectives. Indicators of oceanic contamination have been selected in order to identify, but also further prevent impact of human activities on marine ecosystems. Go to Mini Review Abstract Introduction Discussion Conclusion Acknowledgement References Introduction Coastal Areas support increasing population worldwide, for whom marine ecosystems constitute either directly or indirectly, principal economic resources. For instance, over two billion people worldwide rely on seafood consumption and sea products for their diet [ 1 ].

We have different possibilities and tools to assess the impact of pollution on marine ecosystems. The ecotoxicological approaches are based on the use of biomonitors and biomarkers. They aim to study the effect of toxic chemicals on the biological organisms especially at the population, community and ecosystem levels. The ultimate goal of ecotoxicology is to be able to predict the effects of pollution so that the most efficient and effective action to prevent or remediate any detrimental effect. In order to assess the impact of anthropogenic activities on the aquatic ecosystem and to insure compliance with regulation or guidelines, we use biomonitoring.


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Biomonitors and Biomarkers as Indicators of Environmental Change 2

The sedentarism and wide global distribution of the blue mussel Mytilus edulis have made it a useful bioindicator to assess changes in the health status of the marine ecosystem in response to pollution and other environmental stresses. Effective biomonitoring of an ecosystem requires, however, that multiple biomarkers be used to obtain an accurate measure of the cumulative effects of different sources of environmental stress. Here, we provide a first integrated review of the biological, economical, and geographical characteristics of another species of mussels, the ribbed mussel Aulacomya ater. We discuss the use of Aulacomya ater as a complementary biomonitor to the blue mussel to assess the impact of pollutants and climate change. Recent findings have indeed shown that Mytilus edulis and Aulacomya ater have distinctive anatomy and physiology and respond differently to environmental stress.

Not a MyNAP member yet? Register for a free account to start saving and receiving special member only perks. Data from biomonitoring studies are becoming widely available and are increasingly used to understand the presence of chemicals in the human body and their effects on human health. At the same time, scientists, public-health officials, and the public have questions about the quality and scope of the available data, what the data tell us about potential risks to human health, and how future research can address these questions. Responding to a congressional request, the National Research Council established the Committee on Human Biomonitoring for Environmental Toxicants to review current practices in and recommend ways to improve the interpretation and uses of human biomonitoring for environmental toxicants.

Morado a. Parente b. Gomes a. The raised hypothesis is that Funil Reservoir acts as a filter for the xenobiotics of the PSR waters, improving river water quality downstream the dam.

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  • Ghebreyesus 1 , Z. Nick Y. - 11.06.2021 at 15:04
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