PARENT SESSION
PM2 - Soil Toxicology
Monday, 18 November 2002
8:00 AM to 6:30 PM
Exhibit Hall

(P233) The Effects of Perchlorate on Earthworm Survival and Reproductive Success.

Anderson, Todd¹, Landrum, Mindy^*,1, ¹ The Institute of Environmental and Human Health, Lubbock, Texas, USA

ABSTRACT- The effects of the perchlorate anion on Eisenia fetida survival and reproductive success were evaluated using three types of tests: dermal contact, artificial soil, and sand. All studies utilized a range of perchlorate concentrations in order to simulate levels which are likely to occur in the environment under different scenarios (typical soil levels vs. spill levels). The OECD filter paper contact test involved exposing earthworms to the test compound on moist filter paper for 14 days in order to evaluate earthworm survival. A similar test involved exposing the earthworms to perchlorate-spiked sand. Earthworm survival decreased as concentration of perchlorate increased, with no worms surviving 14 days at the highest treatment concentration (> 2000 ppm). However, the perchlorate concentrations which affected survival of Eisenia fetida are likely to occur only under extreme conditions (spills). The effect of perchlorate on the reproductive success (cocoon production) of Eisenia fetida over a 4-week test period was also examined. Production of cocoons was observed in soil containing up to 100 ppm perchlorate, with no production in the uppermost treatment groups (> 1000 ppm). Cocoon production was highest in the control group, although overall cocoon production was low. As was the case with the dermal contact toxicity tests, perchlorate did not affect earthworm reproduction at environmentally relevant soil concentrations. Preliminary data also suggested that cocoons produced under perchlorate contamination did not hatch as well as cocoons produced in control soil despite incubation in clean soil or sand.

Key words: perchlorate, earthworm, reproduction, cocoon