Are single species toxicity tests alone adequate for estimating environmental hazard?

1984 ◽  
Vol 4 (3) ◽  
pp. 259-273 ◽  
Author(s):  
John Cairns
1988 ◽  
Vol 20 (10) ◽  
pp. 101-108 ◽  
Author(s):  
Nelson A. Thomas

A biomonitoring program has been developed in support of the National Policy for the Development of Water Quality-Based Permit Limitations for Toxic Pollutants. The program focuses on the use of laboratory toxicity tests on aquatic plants and animals to predict ecosystem impact caused by toxic pollutants. Both acute and chronic toxicity tests were developed to test effluents and ambient waters. Laboratory and biological field studies were conducted at nine sites. Single species laboratory toxicity tests were found to be good predictors of impacts on the ecosystem when two or more species were used. Biomonitoring can be undertaken either on effluents and/or on the receiving waters. In that toxicity related to seeps, leachates and storm sewers has often been found upstream from dischargers, it is beneficial to conduct both effluent and ambient biomonitoring.


2018 ◽  
Vol 374 (1764) ◽  
pp. 20180021 ◽  
Author(s):  
Ben J. Kefford

The salinity of many freshwaters is increasing globally as a result of human activities. Associated with this increase in salinity are losses of Ephemeroptera (mayfly) abundance and richness. The salinity concentrations at which Ephemeroptera decline in nature are lower than their internal salinity or haemolymph osmolality. Many species also suffer substantial mortality in single species laboratory toxicity tests at salinities lower than their internal salinity. These findings are problematic as conventional osmoregulation theory suggests that freshwater animals should not experience stress where external osmolality is greater than haemolymph osmolality. Here I explore three hypotheses to explain salt sensitivity in Ephemeroptera. These conceptual hypotheses are based on the observations that as the external sodium ion (Na + ) concentration increases so does the Na + turnover rate (both uptake and elimination rates increase). Sulphate ( ) uptake in mayflies also increases with increasing external although, unlike Na + , its rate of increase decreases with increasing external . The first hypothesis is premised on ion turnover being energetically costly. The first hypothesis proposes that individuals must devote a greater proportion of their energy to ion homeostasis at the expense of other uses including growth and development. Lethal levels of salinity presumably result from individuals not being able to devote enough energy to maintain ion homeostasis without critical loss of other vital functions. The second hypothesis is premised on the uptake of Na + exchanged for (an outgoing) H + , leading to (localized) loss of pH regulation. The third hypothesis is premised on localized Na + toxicity or poisoning with increased Na turnover as salinity increases. None of the proposed hypotheses is without potential problems, yet all are testable, and research effort should be focused at attempting to falsify them. This article is part of the theme issue ‘Salt in freshwaters: causes, ecological consequences and future prospects’.


2016 ◽  
Vol 177 ◽  
pp. 464-475 ◽  
Author(s):  
T.C.M. Brock ◽  
D.A. Bas ◽  
J.D.M. Belgers ◽  
L. Bibbe ◽  
M-C. Boerwinkel ◽  
...  

2001 ◽  
Vol 29 (3) ◽  
pp. 259-267 ◽  
Author(s):  
Lee Põllumaa ◽  
Alla Maloveryan ◽  
Marina Trapido ◽  
Helgi Sillak ◽  
Anne Kahru

The environmental hazard was studied of eight soil and solid waste samples originating from a region of Estonia heavily polluted by the oil shale industry. The samples were contaminated mainly with oil products (up to 7231mg/kg) and polycyclic aromatic hydrocarbons (PAHs; up to 434mg/kg). Concentrations of heavy metals and water-extractable phenols were low. The toxicities of the aqueous extracts of solid-phase samples were evaluated by using a battery of Toxkit tests (involving crustaceans, protozoa, rotifers and algae). Waste rock and fresh semi-coke were classified as of “high acute toxic hazard”, whereas aged semi-coke and most of the polluted soils were classified as of “acute toxic hazard”. Analysis of the soil slurries by using the photobacterial solid-phase flash assay showed the presence of particle-bound toxicity in most samples. In the case of four samples out of the eight, chemical and toxicological evaluations both showed that the levels of PAHs, oil products or both exceeded their respective permitted limit values for the living zone (20mg PAHs/kg and 500mg oil products/kg); the toxicity tests showed a toxic hazard. However, in the case of three samples, the chemical and toxicological hazard predictions differed markedly: polluted soil from the Erra River bank contained 2334mg oil/kg, but did not show any water-extractable toxicity. In contrast, spent rock and aged semi-coke that contained none of the pollutants in hazardous concentrations, showed adverse effects in toxicity tests. The environmental hazard of solid waste deposits from the oil shale industry needs further assessment.


2015 ◽  
Vol 2015 ◽  
pp. 1-16 ◽  
Author(s):  
Tarryn L. Botha ◽  
Tanyn E. James ◽  
Victor Wepener

Gold nanoparticles (nAu) are used in drug delivery systems allowing for targeted cellular distribution. The effects of increased use and release of nanoparticles into the environment are not well known. A species sensitivity distribution (SSD) allows for the ecotoxicological hazard assessment of a chemical based on single species toxicity tests. Aquatic toxicity needs to be related to particle characterization in order to understand the effects. The behaviour of nAu in the medium changed as the concentration increased. The toxic potential of ionic gold and nAu was expressed as a hazardous concentration where 5% of species will be harmed (HC5). The HC5 for nAu was much higher (42.78 mg/L) compared to the ionic gold (2.44 mg/L). The differences between the hazard potentials of nAu and ionic gold were attributed to the nAu not releasing any Au ions into solution during the exposures and following an aggregation theory response. Exposures to ionic gold on the other hand followed a clear dose dependent response based on the concentration of the ionic metal. Although SSDs present an indication of the relative hazard potential of nanoparticles, the true worth can only be achieved once other nanoparticle characteristics and their behavior in the environment are also considered.


Chemosphere ◽  
1999 ◽  
Vol 38 (14) ◽  
pp. 3277-3290 ◽  
Author(s):  
Patrick van Beelen ◽  
Arja K. Fleuren-Kemilä

1987 ◽  
Vol 19 (11) ◽  
pp. 1-12 ◽  
Author(s):  
John Cairns ◽  
James R. Pratt

Ecotoxicology has evolved from a modest number of single species, acute toxicity tests to an integrated system of hazard evaluation for predicting adverse effects of chemicals and complex mixtures on environmental health. The process of screening and regulating chemicals and industrial discharges has improved water quality but has generally not been validated in receiving ecosystems. This deficiency results from the regulation of individual chemicals that rarely occur alone in the environment and from the size of the problem. Many receiving ecosystems have literally hundreds of discharges of complex effluents. Typical single species laboratory tests fail to account for the complexity of ecosystems and the strong interactions that may occur among the component species. Evidence is accumulating that complex test systems such as microcosms and mesocosms can fill this void. Microcosms and mesocosms can be constructed and experiments conducted in a cost-effective manner, and several end points can be measured in complex systems using the standard dose-response paradigm. For example, the current regulation of chlorine discharges is based on three chronic exposures to chlorinated sewage effluent. In a microcosm test, we determined adverse biological effects at nearly an order of magnitude less chlorine (1 μg/1) for the loss of microbial species. To be effective hazard evaluation tools, microcosms and mesocosms must include ecologically meaningful processes and must be useful in making decisions regarding environmental safety and harm. This can only be done with adequate statistical design and intensive sampling. Nevertheless, laboratory ecosystems can be useful in making direct measurements of effects on a large number of interacting species and can be tied to a site-specific problem in a particular ecosystem or can be standardized by using regional type ecosystems as references. By using complex natural communities, the ability to validate test system predictions increases since the test system complexity mimics that found in the real world. Despite hopes that a few sensitive species might be used to make decisions quickly on environmental effects, ecological health will only be maintained when scientists and regulators come to grips with the problem of protecting ecologically important processes as well as sensitive species. This will mean developing tests with increasing environmental realism in which environmentally realistic concentrations of chemicals can be tested without resorting to the use of safety factors or extrapolation from limited data bases. Developing such tests does not mean skyrocketing costs for screening chemicals and effluents, but suggests that regulators and toxicologists will need to deal with new information and learn new skills rather than relying on historically pleasing but ecologically deficient testing programs.


2021 ◽  
Author(s):  
Jian Sun ◽  
PengFei Xiao ◽  
XH Yin ◽  
Kun Zhang ◽  
Guonian Zhu ◽  
...  

Abstract In China, the fungicide fludioxonil, that accumulates and persists in sediments, has a widespread agricultural use to control various fungal diseases. Its residues may cause toxic effects to benthic aquatic fauna, thereby impacting ecosystem service functions of aquatic ecosystems. To assess the potential environmental effects of fludioxonil in the sediment compartment of edge-of-field surface waters, sediment-spiked single-species toxicity tests with benthic macroinvertebrates were performed. In all experiments artificial sediment was used with an organic carbon content of 2.43% on dry weight basis. The single-species tests were conducted with 8 benthic macroinvertebrates covering different taxonomic groups typical for the Yangtze River Delta, China. The 28d-EC10 and 28-LC10 values thus obtained were used to construct species sensitivity distributions (SSDs). In addition, our data were supplemented with similar fludioxonil-spiked sediment toxicity data for benthic invertebrates from the Netherlands. Based on SSDs constructed with 28d-EC10 values of 8 benthic species from our experiments in China, hazardous concentrations to 5% of the species tested (HC5’s) of respectively 0.57 mg fludioxonil/kg dry weight sediment and 5.4 µg fludioxonil/L pore water were obtained. Supplementing our data from China with 8 similar toxicity data for other benthic species from the Netherlands, these HC5 values became respectively 1.2 mg fludioxonil/kg dry weight sediment and 11 µg fludioxonil/L pore water.


1994 ◽  
Vol 22 (4) ◽  
pp. 243-253
Author(s):  
Boris Isomaa ◽  
Henrik Lilius ◽  
Christina Råbergh

There is an urgent need for effective in vitro tests in aquatic toxicology, because only a very small proportion of the chemicals in common use have been adequately tested for their toxicity to aquatic organisms and aquatic ecosystems. Toxicity tests with higher animals, besides being time-consuming and expensive, are ethically questionable, which further increases the importance of developing efficient in vitro toxicity tests. In developing in vitro tests for toxicity assessments, aquatic toxicology lags behind mammalian toxicology. Aqueous environmental chemistry is complex, and the sensitivity of the organisms living in a particular aquatic environment may vary considerably. The predictive value of single-species or cell culture tests is therefore generally considered to be low. Nevertheless, single-species tests, utilising bacteria, algae, protozoans and invertebrates, have frequently been used in in vitro toxicity studies of aquatic pollutants (mainly as screening tests). Attempts at large-scale validations are few. Such attempts seem to be hampered by the complexity of the aquatic ecosystem. Although cells from aquatic organisms have been isolated and cultured for many years, the use of isolated or cultured cells in aquatic toxicology has been limited. However, during the last few years, interest in the use of fish cells in toxicity testing has grown rapidly. For aquatic in vitro toxicology to develop further, a more comparative and mechanistic approach needs to be adopted.


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