Although thousands of quantitative structure-activity and structure-property relationships (QSARs/QSPRs) have been published, as well as numerous papers on the correct procedures for QSAR/QSPR analysis, many analyses are still carried out incorrectly, or in a less than satisfactory manner. We have identified 21 types of error that continue to be perpetrated in the QSAR/QSPR literature, and each of these is discussed, with examples (including some of our own). Where appropriate, we make recommendations for avoiding errors and for improving and enhancing QSAR/QSPR analyses.

This toxicity data index gives a compilation of some 1350 acute toxicity data of individual organic compounds for the luminescent marine bacterium Photobacterium phosphoreum, commonly known as Microtox™ test. The index contains 5-min, 15-min and 30-min toxicity data in both logarithmic (log (L/mmol) and non-logarithmic (mg/L) formats for approximately 1300 chemicals sorted by Chemical Abstracts Service (CAS) accession numbers. In addition to the toxicity data, this index reviews correlations of the luminescent bacteria toxicity test data with a multitude of other acute toxicity tests on aquatic and terrestrial species, with emphasis on the 96-hr acute lethality data of 200 individual chemicals to the fathead minnow (Pimephales promelas). A high collinearity between these two tests is demonstrated over nearly ten orders of magnitude in toxicity variation as expressed on a molar basis for compounds acting with several known toxicity mechanisms. These results indicate the usefulness of the luminescent bacteria bioassay as a simple, fast and comparatively inexpensive alternative to in-vivo bioassays with higher organisms.

Published data on the toxicity of metal ions to aquatic biota, in particular Daphnia magna, were analyzed for their correlation with ion specific physico-chemical parameters. Significant correlations were obtained for three groups of ions with similar electron configurations in the outer orbitals. Group I ions include Na (I), Be (II), Ba (II), Al (III), and Cr (VI) with inert gas-like electron configurations; group II ions include Cr (III), Mn (II), Fe (III), Co (II), Ni (II), Cu (II), Zn (II), As (V), Cd (II), Pt (IV), Au (III), and Hg (II) with partially or completely filled d electron orbitals; group III ions include Sn (II), As (III), Se (IV), and Pb (II), with filled d and s, but unfilled p electron orbitals. The toxicity of an ion within a group can be calculated from the general equation[Formula: see text]where pT is the negative logarithm of a metal ion concentration with a certain toxicity in mol∙L−1; AN is the metal's atomic number; ΔIP is the difference between the ion's ionization potential with the oxidation number (OX) and the ionization potential of the next lower oxidation number (OX − 1) in electron volts (eV); and ΔE0 is the absolute value of the electrochemical potential between the ion and the first stable reduced state. The values for the constants a0, a1, and a2 depend on the group of ions, the biota, and the particular toxic effect determined. The equation is applied to predict the toxicities of other ions under similar test conditions.Key words: toxicity, metals, ions, correlations, Daphnia magna, aquatic tests

SynopsisThis review ofPhotobacteriumphosphoreum toxicity bioassay, commonly known as the Microtox'" tests, consists of two parts. The first part, I. Test Procedures and Applications, is a selective literature review which describes the principle, methodology, experimental conditions and procedures, and the applications of the Microtox'" test. It includes a list of relevant references and tables showingcomparisons of Microtox test results with those of various other acute toxicity assays for selected compounds and complex industrial eflluents. The second part of this review deals with toxicity data compilation.

Linear relationships of the median lethal concentrations of several hundreds of chemicals for a variety of organisms with Vibrio fischeri median effective concentrations are investigated. Significant correlations can be developed for many aquatic species including the fishes fathead minnow, bluegill, catfish, goldfish, goldorfe, guppy, killifish, rainbow trout, sheepshead minnow, and zebrafish; the water flea Daphnia sp.; such crustaceans as Artemia sp. and Crangon sp.; the ciliate Tetrahymena pyriformis; and algae, such as Chlorella sp. These interspecies relationships can be used to estimate order-of-magnitude type toxic effects of many substances for these aquatic organisms. Highly significant relationships can be obtained when selecting compounds on a chemical basis, such as alcohols, ketones, aromatics, etc., which allow the calculation of the compounds' toxicities to the corresponding aquatic species with increased accuracy and confidence. Analogous correlations with mammalian (rat and mouse) oral, intraperitoneal, and intravenous median lethal dose (LD50) data are much weaker than those for most aquatic species.However, there are significant differences between these three routes of administration and the intravenous LD50 data show the best relationship with the Vibrio data. Environ Health Perspect 106(Suppl 2):583-591 (1998). http:/lehpnetl.niehs.nih.govldocs/1998/Suppl-2/583-591 kaiserlabstract.html