Postexposure effects of brief cadmium, zinc, and phenol exposures on freshwater organisms

Abstract

Abstract-Conventional toxicity testing has relied heavily on fixed duration continuous exposure conditions. These conditions have little relevance to the exposure conditions of many environmental pollutants, particularly the highly variable and often brief exposure regimes of episodic pollution events. This research was designed to assess the effects of brief exposures using a postexposure observation period. The common freshwater organisms Ceriodaphnia dubia, Hyalella azteca, and Pimephales promelas were exposed to a range of cadmium (Cd), zinc (Zn), and/or phenol concentrations for durations ranging from 15 to 240 min. Immobility was measured for up to 7 d after the exposure period. Results showed that organisms exposed to Cd and Zn exhibited delayed effects that resulted in increasing immobility for up to 172 h after the exposure period. Ceriodaphnia dubia, H. azteca, and P. promelas exposed to Cd for as short as 30 min exhibited 100, 95, and 85% immobility, respectively, during postexposure observation. Ceriodaphnia dubia and H. azteca exposed to Zn for as short as 30 min exhibited 100 and 30% immobility, respectively, during postexposure observation. Ceriodaphnia dubia exposed to phenol exhibited recovery of mobility after the exposure period. The presence of delayed effects or organism recovery suggests that toxicity tests used to monitor brief exposures should use environmentally relevant exposure durations and postexposure observations.

The Role of Traditional and Novel Toxicity Test Methods in Assessing Stormwater and Sediment Contamination

“…Other laboratory studies have also shown acute 130343.pgs 10/3/00, 11:53 AM 11 and chronic toxicity of short-term exposures using fish and amphipods exposed to chloroamines, metals, and pesticides (Abel, 1980;Abel and Gardner, 1986;Holdway et al, 1994;Jarvinen et al, 1988ab;Meyer et al, 1995;Parsons and Surgeoneer, 1991ab;Pascoe and Shazili, 1986). In general, it appears that exposure to higher concentrations of toxicants for brief time periods is more important that exposure to lower concentrations for longer time periods (Brent and Herricks, 1998;Liess, 1996;Meyer et al, 1995). However, increased amphipod depuration or metallothionein induction in the presence of Zn allowed greater tolerance (Borgmann and Norwood 1995;Brent and Herricks 1998).…”

“…A growing preponderance of data, however, is showing that toxicity is commonly observed during stormwater runoff events and that short-term pulse exposures can be more toxic than long-term continuous exposures (e.g., Brent and Herricks, 1998;Crunkilton et al, 1997;Curtis et al, 1985). Short pulse exposures in stormwater produced lethality several days to weeks later (Abel, 1980;Bascombe et al, 1980;Bascombe et al, 1989;Brent and Herricks, 1998;Ellis et al, 1992;Liess, 1996).…”

“…Short pulse exposures in stormwater produced lethality several days to weeks later (Abel, 1980;Bascombe et al, 1980;Bascombe et al, 1989;Brent and Herricks, 1998;Ellis et al, 1992;Liess, 1996). Some of this apparent response delay may be a result of uptake and accumulation kinetics (Bascombe et al, 1989;Bascombe et al, 1990;Borgmann and Norwood, 1995;Borgmann et al, 1993).…”

“…Some of this apparent response delay may be a result of uptake and accumulation kinetics (Bascombe et al, 1989;Bascombe et al, 1990;Borgmann and Norwood, 1995;Borgmann et al, 1993). Recent investigations have identified acute toxicity problems and the importance of an adequate post-exposure observation period in side-stream studies with P. promelas in urban streams (Crunkilton et al, 1997), and in laboratory spiking studies (Cd, Zn, phenol) with Ceriodaphnia dubia, Pimephales promelas, and Hyalella azteca (Brent and Herricks, 1998;Van Der Hoeven and Gerritsen, 1997). Other laboratory studies have also shown acute 130343.pgs 10/3/00, 11:53 AM 11 and chronic toxicity of short-term exposures using fish and amphipods exposed to chloroamines, metals, and pesticides (Abel, 1980;Abel and Gardner, 1986;Holdway et al, 1994;Jarvinen et al, 1988ab;Meyer et al, 1995;Parsons and Surgeoneer, 1991ab;Pascoe and Shazili, 1986).…”

“…In general, it appears that exposure to higher concentrations of toxicants for brief time periods is more important that exposure to lower concentrations for longer time periods (Brent and Herricks, 1998;Liess, 1996;Meyer et al, 1995). However, increased amphipod depuration or metallothionein induction in the presence of Zn allowed greater tolerance (Borgmann and Norwood 1995;Brent and Herricks 1998). Griffin et al (1991) state that traditional toxicity testing is inappropriate for time-scale studies of runoff effects due to the exposure design of constant toxicant concentrations.…”