Acute fish toxicity Additive

BASE SET Mutagenicity Toxicity to reproduction Toxicity to algae Acute daphnia and fish toxicity Abiotic and readily biotic degradability Additional physico-chemical properties 1 t/annum or 5 t cumulative... 

Fish Prolonged Toxicity Test - 14 Day Study (OECD 204, 1984) is a variant of the acute fish test used when a longer exposure time is needed, for example when testing highly lipophilic and poorly water soluble substances, and/or when reporting of additional information is considered necessary. The principle of the test is that threshold levels of lethal and other observed effects and NOEC are determined at intervals during the test period. The test requires at least ten fish per concentration plus control(s). 

Environmental Considerations. The phosphate flame retardants, plasticizers, and functional fluids have come under intense environmental scmtiny. Results pubUshed to date on acute toxicity to aquatic algae, invertebrates, and fish indicate substantial differences between the various aryl phosphates (159—162). The EPA has summarized this data as well as the apparent need for additional testing (147). 

Waterborne solutions of zinc-cadmium mixtures were usually additive in toxicity to aquatic organisms, including freshwater fishes (Skidmore 1964) and amphipods (de March 1988), and to marine fishes (Eisler and Gardner 1973), copepods (Verriopoulos and Dimas 1988), and amphipods (Ahsanullah et al. 1988). However, mixtures of zinc and cadmium were less toxic than expected to Daphnia magna, as judged by acute lethality studies (Attar and Maly 1982). 

Copper complexes of substituted malonic acids had no influence on the acute toxicity towards adult zebra fish [227], possibly due to stronger chelating groups at the gill epithelia. In contrast, hatching of zebra fish, which is already very sensitive to Cu2+ alone, was delayed in the presence of hydrophobic ra-hexade-cyl malonate, and was not influenced by the less hydrophobic benzyl malonate [227], Overall, it appeared that the toxicity of free Cu2+ and the Cu-hexadecyl malonate complex was additive [227],... 

For highly potent APIs, profound effects can occur at low ng levels, the adverse effect of ethynylestradiol on fish populations is one example [107]. Another example is the development of resistant bacterial strains induced by the release of antibiotics into the environment [112, 113]. Dome et al. [114] concluded that fluoxetine, ibuprofen, diclofenac, propranolol and metoprolol exhibit relatively high acute toxicity to aquatic species. In addition, due to the inherent properties of these chemicals, pharmacodynamic effects were observed in the heart rate of Daphnia magna for the (3-blockers propranolol and metoprolol. 

Requiring low-sample volume micro-scale tests for its cost-effective application, the PEEP index has thus far employed bioassays with bacteria, algae and microinvertebrates. While well-standardized toxicity tests using freshwater fish existed at the time of the PEEP s conception in the early 1990 s (e.g., the Environment Canada fingerling rainbow trout 96-h lethality test to assess industrial wastewaters), they were excluded because of their large sample volume needs (e.g., close to 400 L of effluent sample required to undertake a multiple dilution 96-h LC50 bioassay in the case of the trout test). In addition to effluent sample volume, the cost of carrying out salmonid fish acute lethality bioassays for the 50 priority industrial effluents identified under SLAP I (the first 1988-93 Saint-Lawrence River Action Plan) was prohibitive. 

Methamidophos may cause harm to nontarget species with approved applications. Field studies indicate bird mortality can occur with methamidophos use. Methamidophos residues on food that birds may eat (e.g., leaves, insects, invertebrates) show high acute and persistent exposure. In addition, residue data on food that wild mammals may eat indicate that there would be sufficient persistent residues to cause adverse chronic effects. Methamidophos is highly toxic to bees and some beneficial insects. Freshwater and estuarine invertebrate aquatic species may be affected with normal use of methamidophos but acute risks to fish are minimal. 

Netherlands Toxicity testing is used primarily for investigation and there is currently no regulatory requirement of such tests. Bacteria, algae, macrophytes, invertebrates and fish are used and, in addition to the acute and chronic end-points, mutagenicity, endocrine and enzymatic responses are measured. 

The development of serum-free medium for fish cell lines has had some success3 20 and could be used to overcome the difficulty of toxicant availability3. In addition, FBS contains protective molecules, such as antioxidants, which could inhibit death elicited by reactive oxygen species (ROS). This means that basal medium can be more appropriate for acute assays and even simpler exposure solutions might be best. Schirmer et al.115 used an extremely simple one, termed L-15 exposure or L-15/ex. L- 15/ex contains only salts, galactose and pyruvate at their concentrations in the basal medium, Leibovitz s L-15. The expression of cytotoxicity appeared to be aided by the absence in L-15/ex of most antioxidants. Also, for photocytotoxicity studies, the lack of vitamins and aromatic amino acids prevented the inadvertent generation of toxicants from some of these compounds during the UV treatment. 

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