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A Fargasová

Publications and source records attributed to A Fargasová.

At least 19 recordsLinked to original sources
PubMed2001

Winter third- to fourth-instar larvae of Chironomus plumosus as bioassay tools for assessment of acute toxicity of metals and their binary combinations.

The ecotoxicological effect expressed as mortality of four metal ions (Cd, Cu, Zn, Al) and their associations on winter third- to fourth-instar larvae of Chironomus plumosus was determined. The effect of individual metals was introduced as acute toxicological effect and expressed as LC(50) and LC95 values with 95% intervals of confidence. On the basis of the LC50 values the toxicity of metals after 96 h treatment was ranked Cu>>Cd>Zn>Al. Copper was at least 100 times more toxic than other metals tested. When the acute toxic effect of metal pairs was observed, in general, deleterious effects were directly proportional to metal concentrations. The toxicity of metals in combinations was different from that of individual metals, because of either antagonism or synergism. From the results obtained it can be concluded that when in metal pairs in which the original metal (the metal for which the interaction was determined) is at the lower concentration (Cd 10 mg x L(-1), Zn 25 mg x L(-1), Al 25 mg x L(-1), Cu 0.1 mg x L(-1)), the prevailing interaction is synergism (mortality was higher for metal combinations than for individual metals). Except for an overadditive effect (synergism), additivity was also confirmed in some cases (Al25+Cd10; Al25+Cd25; Al25+Cu0.1; Cu0.1+Cd10; Cu0.1+Cd25; Cu0.1+Al50). Synergism, in combinations in which the original metal is at the higher concentration (Cd 25 mg x L(-1), Zn 50 mg x L(-1), Al 50 mg x L(-1), Cu 1.0 mg x L(-1)), was observed only for the pairs Zn50+Al25 and Zn50+Cu1.0. Reciprocal additivity was observed after 96 h of treatment only for the combination Zn50+Al50. For all other binary combinations in which the original metal was at the higher concentration, an antagonistic effect was confirmed.

Animals↗
PubMed1999

Ecotoxicology of metals related to freshwater benthos.

The toxicity of Cu, Mn, Mo, Ni, V, As, Pb, Cr, Hg and Sn on the behaviour and survival of benthic worms Tubifex tubifex was studied. All tested metals were dissolved and determined in tap water under standardized conditions. The adverse effects of the metals were evaluated as acute toxicological effects upon exposure expressed as LC50 value with 95% confidence interval. On the basis of the LC50 values, the toxicity of the metals after an incubation for 96 h was ranked as follows: Cu(II)> Cu(I) > V > Hg > or = Mn > Ni > Cd > Cr > Mo > Pb > Sn(IV) = Sn(II) > As. From this sequence it is evident that copper was the most toxic metal ion. In addition, differences were found between Cu(II) and Cu(I) ions toxicity, the former being 2.5 times more toxic. In contrast, no differences could be confirmed between acute toxic effects of Sn(II) and Sn(IV). Arsenic showed the weakest toxicity of the tested metals. The LC50 value for As was 10,000 times higher than those for both copper ions.

Animals↗
PubMed1998

Comparison of tributyltin compound effects on the alga Scenedesmus quadricauda and the benthic organisms Tubifex tubifex and Chironomus plumosus.

The inhibitory and toxic effects of five tributyltin compounds and one dibutyltin compound were determined under standardized conditions on the freshwater plankton alga Scenedesmus quadricauda and the benthic organisms Tubifex tubifex and Chironomus plumosus. Observed were the mortality of benthos after 96 h and the inhibition of growth, photosynthesis, and chlorophyll a content of the alga after 12 days of cultivation. The effects of the compounds were expressed as LC50 values for mortality and EC50 values for inhibition. Attention was focused on the influence of the bound X anion on the toxicological effects of the test compounds [dibutyltin bis(N,N-diethyldithiocarbamate (DBTC); bis(tributyltin 3,4,5, 6-tetrachlorophthalate (TBTP); tributyltin sulfaminate (TBTS); tributyltin N,N-diethyldithiocarbamate (TBTC); tributyltin naphthenate (TBTN); bis(tributyltin) oxide) (TBTO)]. From the results obtained the following conclusions can be made: For benthic organisms the anionic group N,N-diethyldithiocarbamate as well as the anionic inorganic group oxide had a very large toxic effect. The lowest efficiency was indicated for the 3,4,5,6-tetrachlorophthalate anion. When the positions of the tested compounds with respect to dependence of the bound anion were evaluated for the alga, it was concluded that the position of the anionic group in inhibitory rank orders depended on the parameter. The efficiency of the organic anion N,N-diethyldithiocarbamate was low in all divisions tested (especially for photosynthesis inhibition). Strong effects for all parameters tested were noted for the compound with organic anion 3,4, 5,6-tetrachlorophthalate as well as the compound with the inorganic anion oxide, except for photosynthesis inhibition. From the results obtained the following rank orders of toxicity and/or inhibition are established: T. tubifex-TBTO>TBTC>TBTN>DBTC>TBTS>TBTP; Ch. plumosus-TBTS>/=TBTC>TBTO>TBTN>DBTC>TBT P; S. quadricauda, growth inhibition--TBTO>TBTP>TBTN>TBTC>DBTC=TBTS; S. quadricauda, chlorophyll a content-TBTO>/=DBTC>TBTP=TBTC>TBTN=TBTS; S. quadricauda, photosynthesis inhibition--TBTP>TBTS>/=TBTN>DBTC>TBTO>TBTC.

Animals↗
PubMed1997

Comparative study of ecotoxicological effect of triorganotin compounds on various biological subjects.

The toxic and inhibitory effect of 10 triorganotin compounds (triphenlyl-, tribenzyl-, and tributyltins) were determined under standardized conditions on four biological subjects: Tubifex tubifex, Chironomus plumosus, Sinapis alba seeds, and the alga Scenedesmus quadricauda. Observed were the mortality of T. tubifex and Ch. plumosus after 96 hr, the root growth inhibition of S. alba seeds after 72 hr, and the inhibition of growth, photosynthesis, and chlorophyll a content of S. quadricauda after 12 days of cultivation. The effect of triorganotins was expressed as LC50 values for mortality and EC50 values for inhibition. For each subject and observed parameter the rank order of toxicity/or inhibition was arranged.

Animals↗
PubMed1997

The effects of organotin compounds on growth, respiration rate, and chlorophyll a content of Scenedesmus quadricauda.

The inhibitory effect of 12 organotins in a four concentrations (0.001, 0.01, 0.1, and 1.0 mg/liter) of a 12-day growth and on the respiration rate and chlorophyll a content in 9-day tests were determined for the freshwater algae Scenedesmus quadricauda. Tested organotin compounds belonged to di-R2SnX2 (R:methyl, butyl) and triorganotins R3SnX (R:phenyl, benzyl, butyl).

Chlorophyll↗
PubMed1996

Effect of organotin compounds on the growth of the freshwater alga Scenedesmus quadricauda.

Organotin compounds (OTCs) are extensively used in a variety of industrial processes and their increasing discharge into the environment is a topic of current concern. Many OTCs are toxic to various organisms and they are used to a limited but significant extent as biocidal agents in agriculture and technology. The concentration and form in which tin (Sn) is present in the environment determines its toxicological effects. The present study was conducted to determine the inhibitory effect of 12 OTCs [A, dibutyl tin bis-N,N-diethyldithiocarbamate; B, dimethyltin bis(N, N-diethyldithiocarbamate); C, triphenyltin chloride; D, triphenyltin acetate; E, triphenyltin N,N-diethyldithiocarbamate; F, tribenzyltin bis(N,N-diethyldithiocarbamate); G, tribenzyltin chloride; H, bis (tributyltin)-3,4,5,6-tetrachlor phthalate; I, tributyltin sulfaminate; J, tributyltin N,N-diethyldithiocarbamate; K, tributyltin naphthenate; and L, tributyltin oxide (TBTO)] in four concentrations (0.001, 0.01, 0.1, and 1.0 mg/liter) on the growth of freshwater alga Scenedesmus quadricauda under standardized conditions. The inhibitory effect of OTCs after 12 days cultivation in percentages for each concentration used was determined and individual growth curves of S. quadricauda for tested concentrations of OTCs and for control were plotted. On the basis of the percentage of control growth the rank order of inhibition after 12 days application of OTCs in concentration 1.0 mg/liter was made: L = H = F = C > E > D > J = K > I > G > A > B. From this rank order, it is evident that the least inhibitive effects on algal growth were from the diorganotin compounds A and B, especially compound B with a methyl group in the n-alkyl chain. The most toxic was compound L (TBTO) with a butyl group in side chain.

Dose-Response Relationship, Drug↗
PubMed1994

Toxicity of metals on Daphnia magna and Tubifex tubifex.

The toxicity of Hg2+ [HgCl2], Cr6+(1) [(NH4)2CrO4], Cr6+(2) [CrO3], Cd2+ [CdCl2.2,5H2O], Pb2+ [Pb(CH3COO)2.3H2O], and As5+ [Na2HAsO4.7H2O] on the sensitivity and survival of Daphnia magna and Tubifex tubifex has been studied. All test metals were dissolved and determined under standardized conditions (dilution water, Bringmann and Kühn, 1982) and 96 hr LC50 for T. tubifex and 48 hr LC50 for D. magna were compared in rank orders toxicity. For D. magna rank order toxicity was Hg2+ > Cr6+(2) > Cd2+ = Cr6+(1) > Pb2+ > As5+ and for T. tubifex it was Hg2+ > Cd2+ > Cr6+(2) > Cr6(1) > Pb2+ > As5+. D. magna was a more sensitive organism than T. tubifex and its LC50 values for all metals were several times lower than LC50 values for T. tubifex. Correlation between toxicity of various metals and biological subjects may be useful in predicting toxicity to various biologically important organisms connected with food chains.

Animals↗