Species sensitivity

Schmitt-Jansen M, Altenburger R (2005) Predicting and observing responses of algal communities to photosystem Il-herbicide exposure using pollution-induced community tolerance and species-sensitivity distributions. Environ Toxicol Chem 24 304... 

PosthumaL, Suter GW, Traas TP (eds) (2001) Species sensitivity distributions in ecotoxicology. CRC press, Boca Raton, EL... 

Pedersen F, Petersen GI. 1996. Variability of species sensitivity to complex mixtures. Water Sci Technol 33 109-119. 

What is the magnetogyric ratio, and how does it affect the energy difference between two states and the nuclear species sensitivity to the NMR experiment ... 

Escher Bl, Hermens JLM. 2002. Modes of action in ecotoxicology their role in body burdens, species sensitivity, QSARs and mixture effects. Environ Sci Technol 36 4201 217. 

Once the organism has been identified and sensitivities are known, drug selection should be adjusted to reflect the susceptibilities of the organism. Streptococcal, staphylococcal, and enterococcal species sensitive to P-lactam antibiotics should be treated with continuous IP dosing to increase efficacy and minimize resistance.49 Peritonitis caused by S. aureus or P. aeruginosa are often associated with catheter-related... 

The distribution of aquatic species sensitivities to cypermethrin is typical of SPs [7] (Giddings JM (2006) Compilation and evaluation of toxicity data for synthetic pyrethroids. Unpublished report of Compliance Services International, Rochester). Crustacean and insect species (from the phylum Arthropoda) tend to be more sensitive to pyrethroids compared to other invertebrates such as worms and mollusks, and fish tend to be less sensitive than arthropods. These sensitivities are... 

Fig. 1 Species sensitivity distribution for aquatic organisms exposed to cypermethrin...

Maltby L, Blake N, Brock TCM et al (2005) Insecticide species sensitivity distributions the importance of test species selection and relevance to aquatic ecosystems. Environ Toxicol Chem 24 379-388... 

Acute inhalation lethality data for the rat, mouse, and rabbit for exposure times of 10 s to 12 h were located. A single inhalation study with the dog did not give an exposure duration. The data are summarized in Table 5-4. Data from studies with nonlethal concentrations are summarized in Table 5-5. Barcroft (1931) reported LC50 values and times to death for eight species of animals, the times to death at a constant concentration. Due to experimental design constraints, the LC50 values are not reported here, but relevant data are discussed in the section on relative species sensitivity (Section 4.4.1). 

Data Adequacy Although human data are limited to primarily occupational monitoring studies, the data base on animal studies is good. The test atmosphere in the key study was supplied via a face mask to the restrained test subjects restrained animals have been shown to be more sensitive than unrestrained animals to inhaled toxicants. Relative species sensitivity to inhaled HCN may be related to breathing rate. Compared to rodents, the slower breathing rate of humans and monkeys may make them less sensitive to the effects of HCN. 

A governing principle of pharmaceutical safety assessment is the determination of safety factors the ratio between the therapeutic dose (that which achieves the desired therapeutic effect) and the highest dose which evokes no toxicity. This grows yet more complex (but has less uncertainty) if one bases these ratios on plasma levels rather than administered doses. Traditionally based on beliefs as to differences of species sensitivity, it has been held that a minimum of a five-fold (5X) safety factor should be observed based on toxicity findings in nonrodents and a ten-fold (10X) based on rodents. 

Selection of one or more species sensitive to the endpoint being measured, for example, infections or pathologic sequelae and/or biological activity or receptor binding. 

In many studies on solid waste in which ecotoxicological tests have been used, little attention has been given to such aspects as the selection of test species, sensitivity of the tests, and the... 

Abou-Donia MB, Nomeir AA. 1986. The role of pharmacokinetic and metabolism in species sensitivity to neurotoxic agents. Fundam AppI Toxicol 6 190-207. 

Species sensitivity distributions are sometimes fitted by minimizing the sum of squared deviations between the empirical cumulative distribution function (cdf) and the fitted cdf. 

Reliable chronic toxicity data were available for 21 species of plants (13 phytoplankton and 8 macrophytes) and 15 species of animals. The species sensitivity distributions (SSDs) for atrazine chronic toxicity (no observed effect concentrations [NOECs]) to plants and animals are shown in Figure 4.4. A log-normal distribution model was fitted to each SSD by least-squares regression. 

The exposure distribution and species sensitivity distributions were integrated to generate risk curves for chronic effects. From the 504 000 values in the exposure exceedence curve, annual maximum concentrations corresponding to each 0.5th percentile were determined. The percentage of plant or animal species whose chronic NOEC would be exceeded at each of these concentrations was calculated from the log-normal SSD model. The percentage of plant or animal species affected at each exposure exceedence percentile was plotted as shown in Figure 4.5. 

FIGURE 4.4 Species sensitivity distributions for chronic toxicity of atrazine to plants (upper panel) and animals (lower panel). 

FIGURE 4.5 Risk curves based on exposure distribution for annual maximum atrazine concentrations in Tennessee ponds and chronic species sensitivity distributions for aquatic plants and animals. 

Confidence intervals nsing freqnentist and Bayesian approaches have been compared for the normal distribntion with mean p and standard deviation o (Aldenberg and Jaworska 2000). In particnlar, data on species sensitivity to a toxicant was fitted to a normal distribntion to form the species sensitivity distribution (SSD). Fraction affected (FA) and the hazardons concentration (HC), i.e., percentiles and their confidence intervals, were analyzed. Lower and npper confidence limits were developed from t statistics to form 90% 2-sided classical confidence intervals. Bayesian treatment of the uncertainty of p and a of a presupposed normal distribution followed the approach of Box and Tiao (1973, chapter 2, section 2.4). Noninformative prior distributions for the parameters p and o specify the initial state of knowledge. These were constant c and l/o, respectively. Bayes theorem transforms the prior into the posterior distribution by the multiplication of the classic likelihood fnnction of the data and the joint prior distribution of the parameters, in this case p and o (Fignre 5.4). 

Aldenberg T, Jaworska J. 2000 Uncertainty of the hazardous concentration and fraction affected for normal species sensitivity distrihutions. Ecotox Env Saf 46 1-18. 

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