US EPA

2180594 

Journal Article 

Uptake and accumulation of DDT and PCB by Ephemera danica (Ephemeroptera) in continuous-flow systems 

Södergren, A; Svensson, B 

1973 

Yes 

Bulletin of Environmental Contamination and Toxicology
ISSN: 0007-4861
EISSN: 1432-0800 

HAPAB/73/2446 

9 

6 

345-350 

English 

4205303 

WOS:A1973P927700004 

HAPAB. Mayfly nymphs, collected from a stream in southern Sweden, were placed in a continuous-flow chamber with water at 14 DEG C or 8 DEG C containing p,p'-DDT or PCB dissolved in ethanol. The animals were given no food during the 9-day test period, so that uptake of test substances occurred exclusively via gills and integument. The organochlorine concentrations in the air bubbled through the chamber were determined so that a complete budget calculation for the substances within the system could be performed. Uptake and accumulation of both DDT and PCB by E. danica followed apparent first-order kinetics, and reached an apparent equilibrium level after 4-5 days of exposure. The p,p'-DDT in the system was rapidly metabolized by the animals, primarily to p,p'-DDE, while occasionally small amounts of p,p'-DDD (TDE) were detected. The DDE ratio was 1. 0 on the first day of exposure, but reached 3. 2 on the second day, and remained relatively constant thereafter. PCB apparently was not degraded.