Effect of sodium pentachlorophenate on growth of fathead minnow
Fathead minnows (Pimephales promelas) were exposed to sodium pentachlorophenate concentrations ranging from 32 to 512 micro g/L in a 7-day larval survival and growth test. The average dry weight was measured.
data(P.promelas)
A data frame with 24 observations on the following 2 variables.
conc
a numeric vector of sodium pentachlorophenate concentrations (micro g/L).
dryweight
a numeric vector dry weights (mg)
The data are analysed in Bruce and Versteeg (1992) using a log-normal dose-response model (using the logarithm with base 10).
Bruce, R. D. and Versteeg, D. J. (1992) A statistical procedure for modeling continuous toxicity data, Environ. Toxicol. Chem., 11, 1485–1494.
## Model with ED50 on log scale as parameter p.prom.m1<-drm(dryweight~conc, data=P.promelas, fct=LN.3()) plot(fitted(p.prom.m1), residuals(p.prom.m1)) plot(p.prom.m1, type="all", broken=TRUE, xlim=c(0,1000)) summary(p.prom.m1) ED(p.prom.m1, c(10,20,50), interval="delta") ## Model with ED50 as parameter p.prom.m2<-drm(dryweight~conc, data=P.promelas, fct=LN.3(loge=TRUE)) summary(p.prom.m2) ED(p.prom.m2, c(10,20,50), interval="fls")
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