Characterisation of cholinesterases and evaluation of the inhibitory potential of chlorpyrifos and dichlorvos to Artemia salina and Artemia parthenogenetica

In this study, the acute toxicity of the organophosphorous pesticides dichlorvos and chlorpyrifos to two different species of Artemia (A. salina and A. parthenogenetica) was evaluated. In addition, the in vivo effect of these two pesticides on cholinesterase (ChE) activity of both A. salina and A. parthenogenetica was also determined. The characterisation of the ChE, using different substrates and specific inhibitors, and the normal range of activity in non-exposed individuals were previously investigated for both species. The results obtained indicate that the ChE of A. salina is different from that of A. parthenogenetica and that both enzymes cannot be classified neither as acetylcholinesterase nor as butyrylcholinesterase since they show intermediary characteristics between the two vertebrate forms. The range of normal ChE activity was 2.65+/-0.15 U/mg protein for A. salina, and 3.69+/-0.17 U/mg protein for A. parthenogenetica. Significant in vivo effects of both pesticides on Artemia ChE activity were found, at concentrations between 5.38 and 9.30 mg/l for dichlorvos and between 1.85 and 3.19 mg/l for chlorpyrifos. Both Artemia species are resistant to these pesticides and they are able to survive with more than 80% ChE inhibition. However, A. parthenogenetica is more resistant than A. salina, with about a 95% reduction in its ChE activity respect to the control for nauplii exposed to the median lethal concentrations (LC50), without lethal effects after 24 h of exposure.     

Efficacy and toxicity of self-polishing biocide-free antifouling paints

The ban on harmful substances in antifouling paints requires the development of new antifouling strategies. Alternatives should be as effective as conventional paints but of lower toxicity. In the present study two commercially available, self-polishing antifouling paints were examined in order to get information on their antifouling properties and toxicological potential. Efficacy was shown in settlement assays with the marine barnacle species Balanus amphitrite, however, efficacy was related to toxic effects observed on target and non-target organisms. Toxicity of the paint extracts was concentration-dependent and differed according to the paint and the species investigated. Toxicity could at least partially be attributed to zinc leached from the paints. Effects of a water-soluble paint were more pronounced in larvae of B. amphitrite, Artemia salina and in the green algae Dunaliella tertiolecta. Embryos of the freshwater species Danio rerio and Vibrio fisheri were more affected by a paint based on organic solvents.     

Nonylphenol algal bioaccumulation and its effect through the trophic chain

Nonylphenol is a metabolic intermediate from the microbial transformation of detergents used worldwide. While nonylphenol shows some acute toxicity, it is also able to mimic important hormones resulting in the disruption of several processes by interfering with the signals that control the overall physiology of the organism. The effect of the pollutant nonylphenol (NP) through the trophic chain was studied. Microalgae Isochrysis galbana was able to bioconcentrate NP 6940 times, where 77% of initial NP (100microgl(-1)) is accumulated intracellularly after 1-h incubation. Crustacean Artemia fransiscana showed 25% higher growth when fed with NP-rich algae. However, Artemia metabolized almost all NP ingested and only traces of NP could be found in the organism, eliminating future NP effects. Zebrafish (Brachydanio rerio) were affected by the presence of 171microgg(-1) of NP in the diet, showing higher levels of the hormone vitellogenin and lower levels of cytochrome P450 activity. These results showed that organisms placed in the first level of trophic chain are able to significantly bioconcentrate the pollutant and endocrine disruptor NP. These grassed organisms affect the growth of crustacean. Moreover, the organisms placed on the top of some trophic chains, such as fish, could be affected by the presence of NP in their food, in both the hormone levels and metabolic enzymes. This work shows that the environmental presence of NP should be considered as a risk for the organisms living in an ecosystem.     

Aquaculture effects on environmental and public welfare - the case of Mediterranean mariculture

Aquatic farming has been considered, during the last decades, as the fastest growing food production industry powered by governmental and technological impulsion. Compensation for fisheries decline, creation of new jobs and source of financial windfall are the most important benefits. However, similar to most of the human food-production activities, aquaculture raised several issues related to the environmental welfare and consumer safety. An effort to record the aquaculture-environment and -human safety interactions with regard to the Mediterranean mariculture, is attempted herein. We focused on this geographical area due to its individualities in both the hydrological and physicochemical characteristics and the forms of aquaculture activities. The cage farming of euryhaline marine fish species and more recently of bluefin tuna and mollusk farming are the dominating aquaculture activities. The impacts of these activities to the environment, through wastes offloads, introduction of alien species, genetic interactions, disease transfer, release of chemicals, use of wild recourses, alterations of coastal habitats and disturbance of wildlife, are analytically considered. Also the consumer safety issues related to the farming are assessed, including generation of antibiotic-resistant microorganisms, contaminants transferred to humans though food chain and other hazards from consumption of aquacultured items. Within these, the major literature findings are critically examined and suggestions for scientific areas that need further development are made. The major tasks for future aquaculture development in this region are: (i) to ensure sustainability and (ii) to balance the risks to public or environmental health with the substantial economical benefits. In regard with monitoring, tools must be created or adapted to predict the environmental costs and estimate consumer impact. At a canonistic and legal basis, the establishment of appropriate legal guidelines and common policies from all countries involved should be mandatory.     

Direct comparison of amphipod sensitivities to dredged sediments from Spanish ports

The sensitivity of the benthic amphipod species Ampelisca brevicornis and Corophium volutator to dredged sediments was compared through simultaneous testing on the standard 10 days sediment toxicity test. The results of mortality obtained for 22 harbor sediments sampled at several Spanish ports were studied together with the physico-chemical characteristics of the samples to obtain the incidence of toxicity in terms of dredged material categories and to identify possible differences in the amphipod mortality results when using one or another test species. The results showed a similar incidence of toxicity for medium-high and highly contaminated sediments for both amphipod species, similar to that obtained through the comparison of the chemical concentrations measured in sediments with the single limit values used in Spain for dredged material characterization and management. On the contrary, C. volutator presented a higher mortality and a higher incidence of toxicity when exposed to low and medium-low contaminated sediments, which may have been caused by the lower sensitivity of A. brevicornis when exposed to sediments from its natural environment. When compared to other amphipod species used for whole sediment toxicity assessment, both amphipod species used in this study reported slightly higher sensitivities although these differences could have been associated to the different set of chemical compounds considered when characterizing the sediment samples. In this sense, the amphipod mortality results were better predicted through the use of mean quotients than just by comparing the measured chemical concentrations with the single limit values used in Spain, which indicates that the toxic response of both species was caused by the cocktail of contaminants present in the sediments. Finally, the correlation analysis identified a higher association between A. brevicornis mortality and the metallic contaminants while C. volutator was more correlated with the organic micro-pollutants. Despite these differences, the results indicate that Ampelisca brevicornis can be used as test organism for dredged material characterization when enough individuals of other recommended species such as Corophium volutator are not available.     

Sediment quality guidelines: challenges and opportunities for improving sediment management

During the International Conference on Deriving Environmental Quality Standards for the Protection of Aquatic Ecosystems held in Hong Kong in December 2011, an expert group, comprising scientists, government officials, and consultants from four continents, was formed to discuss the important scientific and regulatory challenges with developing sediment quality guidelines (SQGs). We identified the problems associated with SQG development and made a series of recommendations to ensure that the methods being applied were scientifically defensible and internationally applicable. This document summarizes the key findings from the expert group. To enable evaluation of current SQG derivation and application systems, a feedback mechanism is required to communicate confounding factors and effects in differing environments, while field validation is necessary to gauge the effectiveness of SQG values in sediment quality assessments. International collaboration is instrumental to knowledge exchange and method advancement, as well as promotion of ‘best practices’. Since the paucity of sediment toxicity data poses the largest obstacle to improving current SQGs and deriving new SQGs, a standardized international database should be established as an information resource for sediment toxicity testing and monitoring data. We also identify several areas of scientific research that are needed to improve sediment quality assessment, including determining the importance of dietary exposure in sediment toxicity, mixture toxicity studies, toxicity screening of emerging chemicals, how climate change influence sediments and its biota, and possible use of new toxicity study approaches such as high throughput omic-based toxicity screenings.     

Integrated assessment of the impacts of agricultural drainwater in the Salinas River (California,USA)

The Salinas River is the largest of the three rivers that drain into the Monterey Bay National Marine Sanctuary in central California. Large areas of this watershed are cultivated year-round in row crops and previous laboratory studies have demonstrated that acute toxicity of agricultural drainwater to Ceriodaphnia dubia is caused by the organophosphate (OP) pesticides chlorpyrifos and diazinon. In the current study, we used a combination of ecotoxicologic tools to investigate incidence of chemical contamination and toxicity in waters and sediments in the river downstream of a previously uncharacterized agricultural drainage creek system. Water column toxicity was investigated using a cladoceran C. dubia while sediment toxicity was investigated using an amphipod Hyalella azteca. Ecological impacts of drainwater were investigated using bioassessments of macroinvertebrate community structure. The results indicated that Salinas River water downstream of the agricultural drain is acutely toxic to Ceriodaphnia, and toxicity to this species was highly correlated with combined toxic units (TUs) of chlorpyrifos and diazinon. Laboratory tests were used to demonstrate that sediments in this system were acutely toxic to H. azteca, which is a resident genus. Macroinvertebrate community structure was moderately impacted downstream of the agricultural drain input. While the lowest macroinvertebrate abundances were measured at the station demonstrating the greatest water column and sediment toxicity and the highest concentrations of pesticides, macroinvertebrate metrics were more significantly correlated with bank vegetation cover than any other variable. Results of this study suggest that pesticide pollution is the likely cause of laboratory-measured toxicity in the Salinas River samples and that this factor may interact with other factors to impact the macroinvertebrate community in the system.     

Data ranges in aquatic toxicity of chemicals

A significant problem for effect assessment of aquatic ecosystems arises from the large ranges of toxicity data, which can be found in different databases and literature. Here, ranges are given for the aquatic toxicity of 27 high production volume chemicals. Based on these illustrative examples and on the current literature on uncertainty in aquatic effect assessment, toxicity ranges are discussed for their possible causes (variation in experimental condition, species, endpoint, time) and ways to handle them (safety factors). Implications and recommendations on the procedure of risk analysis of chemical substances are drawn. Two main requirements for a comprehensive risk assessment are identified, which often play a minor role in current practice (as they are often neglected) as well as in scientific discussion (as they are meant to be trivial). First, data quality must be checked critically before applying any result of a toxicity test. Secondly, experimental data should take into account different species and acute as well as chronic data. If these aspects are considered in risk analysis, which is common practice in ecotoxicology but not always in the context of practical applications in risk engineering, a more comprehensive picture of the environmental toxicity of a chemical substance can be obtained.     

A Regulatory Analysis

The information presented in this paper is directed to those individuals interested in future air quality control programs aimed at areas that are attaining one or more air quality ambient standards. Section 116 of the Clean Air Act, as amended, requires the Environmental Protection Agency to promulgate regulations for the prevention of significant deterioration (PSD) of air quality in order to protect the nation's clean air resources from hydrocarbons, carbon monoxide, ozone, nitrogen oxides, and lead (Set II pollutants). This program will affect industry siting in many areas of the country, particularly in the rural, undeveloped areas. Among the many alternatives currently being considered by EPA to meet the PSD Set II goals are emission management systems, marketable emission permits, air quality increments, emission fees, and control of transportation related sources. The final regulation may be a combination of several options or may present several alternatives from which a State would choose its specific program.     

Oxidant generation and toxicity enhancement of aged-diesel exhaust

Diesel exhaust related airborne Particulate Matter (PM) has been linked to a myriad of adverse health outcomes, ranging from cancer to cardiopulmonary disease. The underlying toxicological mechanisms are of great scientific interest. A hypothesis under investigation is that many of the adverse health effects may derive from oxidative stress, initiated by the formation of reactive oxygen species (ROS) within affected cells. In this study, the main objective was to determine whether aged-diesel exhaust PM has a higher oxidant generation and toxicity than fresh diesel exhaust PM. The diesel exhaust PM was generated from a 1980 Mercedes-Benz model 300SD, and a dual 270 m³ Teflon film chamber was utilized to generate two test atmospheres. One side of the chamber is used to produce ozone–diesel exhaust PM system, and another side of the chamber was used to produce diesel exhaust PM only system. A newly optimized dithiothreitol (DTT) method was used to assess their oxidant generation and toxicity. The results of this study showed: (1) both fresh and aged-diesel exhaust PM had high oxidant generation and toxicity; (2) ozone–diesel exhaust PM had a higher toxicity response than diesel exhaust PM only; (3) the diesel exhaust PM toxicity increased with time; (4) the optimized DTT method could be used as a good quantitative chemical assay for oxidant generation and toxicity measurement.     

Are deep eutectic solvents benign or toxic?

In continuation of investigation for environmentally benign protocol for new solvents termed deep eutectic solvents (DESs), it is herein reported results concerning the toxicity and cytotoxicity of choline chloride (ChCl) based DESs with four hydrogen bond donors including glycerine, ethylene glycol, triethylene glycol and urea. The toxicity was investigated using two Gram positive bacteria Bacillus subtilis and Staphylococcus aureus, and two Gram negative bacteria Escherichia coli and Pseudomonas aeruginosa. The cytotoxicity effect was tested using the Artemia salina leach. It was found that there was no toxic effect for the tested DESs on all of the studied bacteria confirming their benign effects on these bacteria. Nevertheless, it was found that the cytotoxicity of DESs was much higher than their individual components (e.g. glycerine, ChCl) indicating that their toxicological behavior is different. For our best knowledge this is the first time that toxicity and cytotoxicity of DESs were studied. The toxicity and cytotoxicity of DESs varied depending on the structure of components. Careful usage of the terms non-toxicity and biodegradability must be considered. More investigation on this matter is required.     

Preliminary field study of hepatic porphyrin profiles of Astyanax fasciatus (Teleostei, Characiformes) to define anthropogenic pollution

The implementation of eco-toxicological assessment in South America is presently limited due to significant scientific information gaps concerning native species and their potential use as biomarkers. Recently, a common southern hemisphere fish species, Astyanax fasciatus, has been pointed out as a potential bio-indicator to anthropogenic pollution. This is a small, abundant, Neotropical characid, which is widely distributed from Central America south, to the Rio de la Plata Basin of western Uruguay. Our study found a statistically significant increase of coproporphyrin, uroporphyrin and protoporphyrin concentrations in hepatic tissues of A. fasciatus collected from a stream segment with high anthropogenic disturbance (due mainly to agricultural derivatives and motor vehicle transportation activities). Although the area studied showed differences in up and downstream limno-chemical parameters, these differences were not related to the increase of hepatic porphyrin concentrations. Based on the results of our study, we conclude that A. fasciatus is a good bio-indicator of exposure to environmental contaminants, and we propose that this abundant fish species be considered as a sentinel organism for monitoring potential disturbances to freshwater ecosystems.     

Acute,chronic and biochemical effects of chlorothalonil on <Emphasis Type="Italic">Agalychnis callidryas</Emphasis>, <Emphasis Type="Italic">Isthmohyla pseudopuma</Emphasis> and <Emphasis Type="Italic">Smilisca baudinii</Emphasis> tadpoles

Declines of amphibian populations have been a worldwide issue of concern for the scientific community during the last several decades. Efforts are being carried out to elucidate factors related to this phenomenon. Among these factors, pathogens, climate change, and environmental pollution have been suggested as possible causes. Regarding environmental pollutants, some pesticides are persistent in the environment and capable of being transported long distances from their release point. In Costa Rica, some pesticides have been detected in protected areas, at locations where amphibian populations have declined. Information about toxicity of pesticides used in Costa Rican agriculture to amphibians is still scarce, particularly for native species.Toxicity tests with chlorothalonil, a fungicide intensively used in Costa Rica, were carried out exposing tadpoles of three Costa Rican native species: Agalychnis callidryas, Isthmohyla pseudopuma, and Smilisca baudinii in order to evaluate acute and chronic toxicity as well as the biomarkers cholinesterase activity (ChE), glutathione-S transferase activity (GST), and lipid peroxidation (LPO).96-h LC₅₀: 26.6 (18.9–35.8) μg/L to A. callidryas, 25.5 (21.3–29.7) μg/L to I pseudopuma and 32.3 (26.3–39.7) μg/L to S. baudinii were determined for chlorothalonil. These three species of anurans are among the most sensitive to chlorothalonil according to the literature. Besides, GST was induced in S. baudinii after exposure to sub-lethal concentrations of chlorothalonil while evisceration occurred in S. baudinii and A. callidryas tadpoles exposed to lethal concentrations of the fungicide. Chronic exposure to sub-lethal concentrations accelerated development in S. baudinii and caused lesions in tail of S. baudinii and I. pseudopuma tadpoles. Our results demonstrate that chlorothalonil is highly toxic to native amphibian species and that low concentrations can cause biochemical responses related to phase II of biotransformation and effects on development.     

Causes of change in nitrophytic and oligotrophic lichen species in a Mediterranean climate: impact of land cover and atmospheric pollutants

With the aim of determining the main drivers of changes in nitrophytic and oligotrophic macro-lichen communities in an industrial region with a Mediterranean climate, we considered both land-cover types and atmospheric pollutants. We determined the relation between the abundance of nitrophytic and oligotrophic species with environmental factors considering the distance of influence of land-cover types. The results showed that oligotrophic species decreased in the proximity of artificial areas, barren land and agricultural areas, associated with higher concentrations of NO₂ and Zn, and Ti, probably dust of industrial and agricultural origin. Nitrophytic species were positively related to all the mentioned land-cover types, and with higher concentrations of Fe and N. Magnesium, probably from ocean aerosols, was negatively related to oligotrophic species and positively to nitrophytic.     

Nickel and other metal uptake and accumulation by species of Alyssum (Brassicaceae) from the ultramafics of Iran

Some plants growing on serpentine (ultramafic) soils are able to hyperaccumulate nickel in their above-ground parts. The genus Alyssum L. contains the greatest number of Ni-hyperaccumulator plants so far reported. There are substantial areas of serpentine soils at many locations in Iran. This paper presents the analyses for Ni, Cr, Mn, Fe, Mg and Ca in soils and Alyssum species from the ultramafics of west and northwest Iran. Soil analysis for total elements in these areas indicates that typical concentrations of Ni, Cr, Mn, Fe, Mg and Ca are up to about 1240, 365, 800, 51,150, 152,390 and 11,790 microg g(-1), respectively. During this study, seven Alyssum species were collected. Analysis of leaf dry matter shows that Alyssum bracteatum can contain up to 2300 microg Nig(-1), while the other species contain much lower concentrations of Ni and other elements. A. bracteatum is endemic to Iran and the first Ni hyperaccumulator reported from this species.     

Comparing sediment quality in Spanish littoral areas affected by acute (Prestige, 2002) and chronic (Bay of Algeciras) oil spills

The quality of sediments collected from two areas of the Spanish coast affected by different sources of contaminants has been compared in this study. The areas studied are the coast of Galicia affected by the oil spill from the tanker Prestige (November 2002) and the Gulf of Cádiz which suffers continuous inputs of contaminants from industries located in the area and from oil spills. Contamination by several chemicals (metals, PCBs and PAHs) that bind to sediments was analyzed, and two toxicity tests (Microtox) and amphipod 10-day bioassay) were conducted. PAHs were identified as the compounds responsible for the toxic effects. Results show differences between an acute impact related to the sinking of the tanker Prestige and the chronic impact associated with continuous oil spills associated with the maritime and industrial activities in the Bay of Algeciras, this being the most polluted part of the two coastal areas studied in this work.     

Heavy metal contamination from mining sites in South Morocco: 2. Assessment of metal accumulation and toxicity in plants

Metalliferous soils cover a relatively large surface area in Morocco, and up to now no hyperaccumulating plants have been identified on these mining or these industrial sites. The aim of this work was to assess the extent of metal accumulation by plants found in three mining areas in southern Morocco with the ultimate goal of finding metal hyperaccumulating species by using the MetPAD biotest. The biotest helps to obtain information on the selective metal toxicity of aqueous extracts from the plants. A strong metal toxicity, as revealed by the biotest is an indication of a hyperaccumulating plant. Toxicity tests were run concurrently with chemicals analyses of metals in plants and their water extracts. The chemical analyses allow the determination of the hyperaccumulated metal(s). Specimens of the plant species mainly growing on and in the vicinity of the three mines were sampled with their corresponding soils. The results show that all plants analyzed had lower heavy metal content and toxicity despite the relatively very high soil concentrations. A comparison of our results with the criterion used to classify the hyperaccumulator plants indicates that plants we collected from mining sites were hypertolerant but not hyperaccumulators. This was confirmed by transfer factors generally lower than 1. Nevertheless, these tolerant plants species can be used as tools for revegetation for erosion control in metals-contaminated sites (phytostabilization).     

Tierische organismen als bioindikatoren für chlorkohlenwasserstoffe

In order to find “bio-indicators” for monitoring the spread of persistent environmental chemicals (in this case chlorinated hydrocarbons), several animal species were sampled in three areas with different types of contamination. The concentrations measured were related to the results obtained from grass root analyses as the basic data for the assessment of the respective environmental contamination ¹. The organisms' suitability as indicative matrices for the chlorinated hydrocarbon burdens was investigated according to the following criteria: analytical detectability of the chemical concentrations (A), accumulation characteristics in relation to the grass roots (B), and indicative function reflecting parallel accumulation (C). An “ideal” matrix serving as a bio-indicator able to detect all apparent chlorinated hydrocarbons accordingly could not be found. Instead, an order of suitability oriented along the above criteria could be attained. Finally, the gauging of an indicator with respect to the three different areas of contamination seems to be within reach, although apparently the variety of chemical burden in the selected areas is not sufficiently significant for this aim.     

Comparative study on the environmental risk induced by several pyrethroids in estuarine and freshwater invertebrate organisms

The acute toxicity of permethrin, resmethrin, and cypermethrin to four species of aquatic non-target invertebrate organisms, found in estuarine and freshwater ecosystems, was evaluated. Artemia franciscana and Brachionus plicatilis larvae, as estuarine organisms, and Brachionus calyciflorus and Thamnocephalus platyurus larvae, as freshwater organisms, were exposed for 24 h to concentrations of these pyrethroids, and the LC(50) values were compared. The freshwater organisms were more sensitive to these pyrethroids than estuarine organisms tested. A. franciscana larvae were more tolerant organisms than B. plicatilis larvae. The freshwater organisms tested have demonstrated to be a good alternative to the standard acute toxicity assays using Daphnia, although Brachionus plycatilis larvae were more sensitive to these pyrethroid insecticides than T. platyurus. Analysis of 24 h LC(50) values of these pyrethroids, determined by static bioassays, revealed that the rank order of toxicity was: permethrin相似文献   

Electrospray Ionization Mass Spectrometry (ESI-MS) monitoring of the photolysis of diazinon in aqueous solution: Degradation route and toxicity of by-products against Artemia salina

The photolytic degradation of diazinon, an organophosphorus pesticide, in aqueous medium under assorted pH values was continuously monitored by direct infusion electrospray ionization mass spectrometry (ESI-MS). The results indicated that the UV radiation was quite efficient in promoting the pesticide degradation at the three pH levels evaluated (5, 7 and 8). The m/z of the most abundant ions observed in the mass spectra (MS), in conjunction with the fragmentation patterns of such ionic species (MS/MS data), made possible the proposition of chemical structures for the main by-products formed. As a result, routes for the photodegradation of diazinon in aqueous solution could thus be suggested. In the assays using Artemia salina (brine shrimp) it was verified that the photodegradation products exhibited much lower toxicity than the primary substrate. Aiming at mimicking the conditions ordinarily found in water treatment plants, an additional series of tests was conducted with a solution containing sodium hypochlorite and diazinon. This solution, when not exposed to UV radiation, exhibited high toxicity against the microorganisms. Under the influence of UV radiation, however, the toxicity rates decreased dramatically. This result is relevant because it points toward the confident application of UV radiation to neutralize the deleterious effects caused by diazinon (and perhaps other organophosphorus pesticides) as well as sodium hypochlorite to the environment.