Acute and chronic toxicity of some chlorinated benzenes, chlorinated ethanes, and tetrachloroethylene toDaphnia magna

Modeling Acute and Chronic Toxicity of Nonpolar Narcotic Chemicals and Mixtures toCeriodaphnia dubia

“…While this regression had a slope similar to that determined for other published data (P"0.4932), TOXICITY OF NARCOTIC CHEMICALS TO Ceriodaphnia dubia the QSARs calculated from different experiments were not coincident (P"0.0051). When constrained to the common slope of 0.8463, the intercept from this study was significantly different from that calculated from the data of Richter et al (1983; intercepts of !4.1207 vs !4.6135, respectively; P"0.0071), but not from those for other studies. The maximum difference in intercept [0.6952 between !3.9183 and !4.6135 (Richter et al, 1983)] corresponds to variation by a factor of 4.96 in acute responses for the different experiments.…”

“…Regression models from other published data on D. magna had similar slopes (P"0.7643), but were not coincident (P"0.0152). When constrained to the common slope (0.8530), the intercept for the data of Calamari et al (1983;0.1272) was similar to that for this study (!0.0541), while intercepts for the data of Hermens et al (1984) and Richter et al (1983) were significantly higher (intercept"0.8400, P"0.0009, and intercept:0.6838, P"0.0023, respectively). The maximum difference in intercepts (0.9481 between this study and that of Hermens et al, 1984) corresponds to variation in chronic response by a factor of 8.87 for the different experiments.…”

“…The maximum difference in intercept [0.6952 between !3.9183 and !4.6135 (Richter et al, 1983)] corresponds to variation by a factor of 4.96 in acute responses for the different experiments. Dummy variable analysis found QSARs based on tests with C. dubia (this study and Marchini et al, 1993) and Daphnia magna (Calamari et al, 1983;Hermens et al, 1983;Richter et al, 1983;Galassi et al, 1988;Tosato et al, 1993) to be coincident (P"0.8918).…”

“…When constrained to the common slope of 0.8463, the intercept from this study (!4.4880) was not significantly different from any of the other studies. The maximum difference in intercept [0.5043 between !4.6223 (DeWolf et al, 1988) and !4.1180 (Richter et al, 1983)] corresponds to variation in chronic response by a factor of 3.19 for the different experiments.…”

Toxicity Evaluation of Waters from a Tributary of the River Po Using the 7-DayCeriodaphnia dubiaTest

“…Geiger et al (1980), Winner (1981), andVan Leeuwen et al (1987) have found that growth of Daphnia, measured in terms of carapace length, was a highly sensitive parameter for detecting the effects of toxicants such as cadmium, chromium, zinc, naphthalene, and phenanthrene. On the other hand, the opposite result as well as an equal sensitivity of reproduction and growth was also observed with other toxicants such as ammonia (Gersich et al, 1985), bromide, 2,4-dichloroaniline (Van Leeuwen et al, 1987), or other chlorinated hydrocarbons (Ritcher et al, 1983). Several of these pollutants were directly measured or found to be bioavailable in the area of study (Ciceri et al, 1991;Camusso et al, 1994); thus, if similar responses can be expected for Ceriodaphnia (Knight and Waller, 1987), it is likely that variable compositions of toxicant mixtures in Lambro water can mainly affect either growth or reproduction, or both, at the different time periods, i.e., consistent with present findings (Table 1).…”