No abstract

There is a need for a method of preliminary estimation of bioconcentration factors in fish and soil sorption coefficients for chemicals. A data base was assembled for 170 compounds having average values for these two parameters and also average values for water solubility and n-octanol-water partition coefficients. Binary regression equations between the logarithms of these values gave correlation coefficients that were all significant below the 1 percent level. Using these equations, measured average values for any of the four parameters could be used to estimate average values for the unmeasured parameters. The 95 percent confidence limits for the calculated values were about ±1 to 3 orders of magnitude of the measured values. The relatively large variation of the actual from the predicted values was due both to the variation in the type of methodology used to make the measurements and also to the intrinsic variation in values attributable to the nature of the chemicals, the characteristics of the soils and fish, and the environmental conditions employed in the studies. Much less variation between actual and predicted values has been achieved when more uniform methodology is adopted for measuring these parameters. Despite the variability, the data are useful for early assessment of the potential for bioconcentration and mobility in the environment. Knowledge of the two factors is needed for hazard assessment in the environment. Bioconcentration factor values for Daphnia appear to be as valid for correlation purposes as those for fish.

No abstract

No abstract

The relationship of the acute LC,, of chemicals to their chronic toxicity for aquatic animals can be expressed as the acute chronic ratio (ACR). Based on ACR data accumulated from the literature, the size ranges of ACRs for various chemicals were determined for different species. The relationship and significance of the size of the ACR for various species, LC,, values, bioconcentration factors, classes of chemicals and their uses and mode of toxic action are given. Eighty-six percent of the LC,, acute toxicity data were less than two orders of magnitude different from the chronic toxicity no-effect concentration for the same chemicals and species. Among the industrial organic chemicals (i.e., excluding pesticides and metals) the average ACR for four species of organisms was 12. Ninety-three percent of these ACR values were 25 or below. Industrial organic chemicals have a higher percentage of ACR values below 25 do than pesticides and heavy metals. These data offer a statistical basis for the prediction of chronic toxicity from acute toxicity.