Ewm. Roex et al., Reproductive impairment in the zebrafish, Danio rerio, upon chronic exposure to 1,2,3-trichlorobenzene, ECOTOX ENV, 48(2), 2001, pp. 196-201
Most organic pollutants are supposed to act via the mechanism of nonpolar n
arcosis upon acute exposure. Because the chronic effects of these compounds
are still relatively unknown, in this study a chronic toxicity experiment
was performed with zebrafish, Danio rerio, exposed to 1,2,3-trichlorobenzen
e (123TCB), a nonpolar narcotic. Fish were exposed in a flow-through system
for 68 and 147 days. Parameters measured are survival, growth, reproductio
n, and glycogen and protein content. The only parameter which was influence
d was the number of eggs produced per female, resulting in an EC50 of 30 mu
g/L. Using this value and acute toxicity data for 123TCB, an acute to chron
ic ratio (ACR) of 80 was calculated, which is larger than ACRs for other sp
ecies exposed to nonpolar narcotics. This finding might indicate that compo
unds acting by nonpolar narcosis in acute tests can have completely differe
nt effects upon chronic exposure. (C) 2001 Academic Press.