Quantitative structure activity relationships and mixture toxicity studies of alcohols and chlorohydrocarbons: Effects on growth of Daphnia magna

Hermens, Joop L. M.; Broekhuyzen, Els; Canton, Hans; Wegman, R.C.C.

doi:10.1016/0166-445x(85)90005-0

Cited by 71 publications

(34 citation statements)

References 7 publications

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“…Nevertheless, the fact that the differences in the EC 50 values of chloroacetanilides are largely explicable as a function of differing lipophilicities gives a strong additional indication for a similar mechanism of action. The same conclusion has been drawn from analogous results of QSAR analyses for other groups of chemicals 15, 36, 37. It must be emphasized that the QSAR model obtained includes also butachlor.…”

Section: Resultssupporting

confidence: 75%

Predictability of combined effects of eight chloroacetanilide herbicides on algal reproduction

Junghans

Backhaus

Faust

et al. 2003

Pest Management Science

109

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Chloroacetanilides are pre-emergence herbicides for the control of annual grasses and broadleaf weeds. As a result of their extensive use, residues are often found in surface waters. Observed simultaneous occurrence of different chloroacetanilide herbicides gives reason for concern about potential combination effects on aquatic non-target organisms. This study aimed to clarify whether joint effects of various chloroacetanilide herbicides may be predictable from knowledge of concentration-response relationships of single substances. Whether the chloroacetanilides all share the same mode of action is unclear. Therefore we investigated the predictive value of two alternative concepts for the prediction of combined effects: concentration addition, which assumes a similar mode of action, and independent action, which is based on the idea of a dissimilar mode of action of the mixture components. Eight chloroacetanilides (acetochlor, alachlor, butachlor, dimethachlor, metazachlor, metolachlor, pretilachlor and propachlor) were experimentally tested for their individual as well as for their combined effects in mixtures on the reproduction of the green alga Scenedesmus vacuolatus. Individual chloroacetanilides impaired algal reproduction, with EC50 values ranging from 3 to 232 microg litre(-1). The differences in EC50 values were strongly correlated with the lipophilicities of the compounds. Effects of chloroacetanilide mixtures were considerably higher than those of the individual components: a complete inhibition of algal reproduction was observed when every mixture component was present in a concentration that would cause only 5% effect if applied singly. However, the combined effects proved to be predictable by using the concept of concentration addition. The alternative concept, independent action, distinctly underestimated the mixture toxicity. These findings (1) indicate a similar mechanism of action of chloroacetanilides in algae and (2) reinforce the view that concentration addition is a reasonable assumption for the predictive hazard assessment of groups of similarly acting herbicides.

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Section: Resultssupporting

confidence: 75%

Predictability of combined effects of eight chloroacetanilide herbicides on algal reproduction

Junghans

Backhaus

Faust

et al. 2003

Pest Management Science

109

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“…Toxicol. Mixed exposure to 25 or 50 kinds of organic chemicals below their no-observedeffect concentrations additively affected growth or mobility, respectively, of Daphnia magna [40,41]. 24, 2005 595 to complex mixtures of environmental contaminants.…”

Section: Discussionmentioning

confidence: 99%

Early–life-stage toxicity in offspring from exposed parent medaka, Oryzias latipes, to mixtures of tributyltin and polychlorinated biphenyls

Nakayama

Oshima

Nagafuchi

et al. 2005

Environmental Toxicology and Chemistry

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The present study examined the effects of tributyltin (TBT), polychlorinated biphenyls (PCBs), and mixtures of both chemicals on reproduction in Japanese medaka, Oryzias latipes. For 21 d we gave groups of medaka freeze-dried brine shrimp flakes contaminated with a mixture of either 0, 1, 5, or 25 microg TBT g(-1) plus 0 or 25 .micro PCBs g(-1). We measured the fecundity and fertility of the parent fish and assessed the deformity, hatchability, time-to-hatching, and swim-up failure rate of the next generation. Fertilization success in the third week of the administration period was significantly decreased by administration of 25 microg TBT g(-1) (77%) compared with the control group (87%). Both TBT and PCBs were transferred maternally into the eggs of the next generation, causing early life-stage toxicity. Administration of 1 microg TBT g (-1) was not toxic to embryological development, but abnormal eye development (i.e., small eyes or no eyes) occurred when TBT at the same concentration was mixed with PCBs (6.4%). Administration of TBT alone significantly decreased hatchability and increased swim-up failure, and administration of PCBs alone significantly increased time-to-hatching. Statistical analysis by two-way analysis of variance detected an interaction between TBT and PCBs in these three parameters. TBT induces abnormal development of the eyes, reduced hatchability, and increased swim-up failure, whereas PCBs delay time-to-hatching. Administration of mixtures of TBT and PCBs has more adverse effects on the developmental stage of medaka than does that of each chemical alone.

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“…The results of calculated vs. measured EC50 (benzene, ethanol) are shown in Tables 1 and 2. The joint EC50s (benzene, ethanol) calculated by the concentration-addition model ( Table 1, Equations 1 and 2 are much closer to the measured EC50s than those calculated by the effect-addition model ( Table 2, Equations [3][4][5].…”

Section: Resultsmentioning

confidence: 72%

“…in [18]). Techniques of quantitative structure-activity relationships (QSAR) were applied to estimate the toxicity of chemical mixtures to aquatic organisms ( [5,6,9] and others; for a review see, e.g. [18]).…”

Section: Introductionmentioning

confidence: 99%

Risk assessment of mixtures: possibility of prediction of interaction between chemicals

Tichý

Borek-Dohalský

Rucki

et al. 2002

International Archives of Occupational and Environmental Health

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Quantitative structure activity relationships and mixture toxicity studies of alcohols and chlorohydrocarbons: Effects on growth of Daphnia magna

Cited by 71 publications

References 7 publications

Predictability of combined effects of eight chloroacetanilide herbicides on algal reproduction

Predictability of combined effects of eight chloroacetanilide herbicides on algal reproduction

Early–life-stage toxicity in offspring from exposed parent medaka, Oryzias latipes, to mixtures of tributyltin and polychlorinated biphenyls

Risk assessment of mixtures: possibility of prediction of interaction between chemicals

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