Sublethal toxicity

Acute toxicity studies are often dominated by consideration of lethaUty, including calculation of the median lethal dose. By routes other than inhalation, this is expressed as the LD q with 95% confidence limits. For inhalation experiments, it is convenient to calculate the atmospheric concentration of test material producing a 50% mortaUty over a specified period of time, usually 4 h ie, the 4-h LC q. It is desirable to know the nature, time to onset, dose—related severity, and reversibiUty of sublethal toxic effects. 

Bosch C, Olivares A, Faria M, Navas JM, del Olmo I, Grimalt JO, Pina B, Barata C (2009) Identification of water soluble and particle bound compounds causing sublethal toxic effects. A field study on sediments affected by a chlor-alkali industry. Aquat Toxicol 94(1) 16-27... 

Barata C, Alanon P, Gutierrez-Alonso S, Riva MC, Fernandez C, Tarazona JV (2008) A Daphnia magna feeding bioassay as a cost effective and ecological relevant sublethal toxicity test for environmental risk assessment of toxic effluents. Sci Total Environ 405(l-3) 78-86... 

Ma, W.C. 1984. Sublethal toxic effects of copper on growth, reproduction and litter breakdown activity in the earthworm Lumbricus rubellus, with observations on the influence of temperature, and soil pH. Environ. Pollut. 33A 207-219. 

Sanchez, F.A.A. and M. de Ariz. 1997. Carbofuran acute and sublethal toxicity on freshwater algae and fish. Pages 743-764 in P.N. Cheremisinoff (ed.). Ecological Issues and Environmental Impact Assessment. Gulf Publishing, Houston, TX. 

Harnett (eds.). Cyanide Compounds in Biology. Ciba Found. Sympos. 140. John Wiley, Chichester. Knudson, T. 1990. Gold mining s deadly life blood. Sacramento (California) Bee (newspaper), March 21, 1990. Kovacs, T.G. and G. Leduc. 1982a. Sublethal toxicity of cyanide to rainbow trout (Salmo gairdneri) at different temperatures. Canad. Jour Fish. Aquat. Sci. 39 1389-1395. 

Hemalatha, S. and Banerjee, T.K. Histopathological analysis of sublethal toxicity of zinc chloride to the respiratory organs of the air breathing catfish 7/eferopneusfesAssi/is (Bloch), Biol Res., 30(1) 11-121, 1997. 

Hermens, J., Canton, H., Janssen, P., and de Jong, R. Quantitative structure-activity relationships and toxicity studies of mixtures of chemicals with an anaesthetic potency acute lethal and sublethal toxicity to Daphnia magna, Aquat. Toxicol, 5(2) 143-154, 1984. 

Granmo, A., R. Ekelund, K. Magnusson, and M. Berggren. 1989. Lethal and sublethal toxicity of 4-nonylphenol to the common mussel (Mytilus edilus L.) Environ. Pollut. 59, 115-127. 

CANMET (1997b) Laboratory screening of sublethal toxicity tests for selected mine effluents, Aquatic Effects Technology Evaluation (AETE) Program, Project 1.2.2, Canada Center for Mineral and Energy Technology (CANMET), Mining Association of Canada (MAC), Ottawa, Ontario, pp. 1-69. 

Lotufo, G.R. (1998) Lethal and sublethal toxicity of sediment-associated fluoranthene to benthic copepods application of the critical-body-residue approach, Aquatic Toxicology 44 (1-2), 17-30. 

Scroggins, R., van Aggelen, G. and Schroeder, J. (2002a, Monitoring sublethal toxicity in effluent under the metal mining EEM Program, Water Quality Research Journal of Canada 37 (1), 279-294. 

This chapter presents two Hazard Assessment Schemes that have been recently used to assess the relationship between laboratory sublethal toxicity data and field measurements of the Canadian pulp and paper Environmental Effects Monitoring program. The two methods are 1) the estimation of Zone of Potential Effect (ZPE) and 2) the Lab-to-Field Rating Scheme (LTF). The application of these schemes illustrates how to estimate the potential for effects in the receiving water environment (third use above). 

Both methods have been shown to be effective in illustrating the relationships between laboratory sublethal toxicity tests (using fish, invertebrates, and algae) and receiving environment measurements of fish and benthic invertebrates. The applications, strengths, and weaknesses of both the ZPE and LTF methods are discussed and compared. 

To estimate the extent of the toxic effects from effluent discharged to an aquatic receiving environment. To examine the relationship between effluent sublethal toxicity results from laboratory testing and field biological measurements at a specific EEM study site. 

The potential effects based on results of sublethal toxicity tests are illustrated by zones superimposed on the industrial effluent plume and then compared to field survey components of a monitoring program. The field survey components of a monitoring program are rated on a similar scale as the sublethal toxicity tests for weight-of-evidence comparison. 

Step 2. Determine the lowest IC25 from a battery of sublethal toxicity tests. Step 2. Assign an LTF rating of 1 to 5 to the fish survey based on the percentage of potentially effluent-related effects relative to all the endpoints measured. 

Thus, the ZPE scheme can be used to estimate the potential for effects from industrial effluent discharges in the local aquatic receiving environment without the need for field survey data or in cases where field surveys cannot be easily conducted. With sublethal toxicity data and a thorough plume delineation study, a ZPE can be estimated and can help establish the priority sites where confirmatory field studies might be required or help an EEM study team to locate their near-field biological sampling locations.The LTF rating scheme includes all endpoints... 

Sublethal toxicity tests that use species of relatively low sensitivity (z. e., fathead minnow) reduce the usefulness of both EEM Hazard Assessment Schemes to estimate potential effects observed in the field. Insensitive laboratory measurements can lead to an underestimation of potential field effects and reduce the strength of laboratory toxicity tests as good estimators of effects. 

Rating the relationship between ZPE andfield measurements The relationship between sublethal toxicity tests and field measurements can be rated on the basis of zones of potential effect (Environment Canada, 1999). The following points describe the criteria used for rating the relationship between zones of potential effect for each sublethal test (lowest IC25) and potential effluent-related effects on fish or the benthic invertebrate community (Moody, 1992). 

Table 6. Sublethal toxicity tests for secondary treated ASB final effluent collected at...

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