Submitted to: American Chemical Society Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: March 23, 1999
Publication Date: N/A
Technical Abstract: A multi-component earthworm toxicity experiment was conducted on four herbicides and one insecticide. Experiments were carried out on an artificial soil matrix according to a protocol developed under the Commission of the European Communities. Test chemicals included atrazine, acetochlor, chlorpyrifos, dimethenamid, and metolachlor; all pesticides used extensively for production of corn, soybean, and sorghum in the Midwest. A full factorial experimental design resulted in LC50 determinations on adult Eisenia Foetida earthworms. This species, easily reared to adulthood in-house in order to reduce variation in the genetic base, is recommended in the protocol. Activity and mortality responses were recorded at 72-, 168-, and 336-hr. following exposure. LC50 mortality rates for the individual compounds ranged between 110-2800 ppm. Observed acute toxicities for some compound combinations were an order of magnitude different than for single compounds, and could not be accounted for by simple additivity. Classes of similar compounds that resulted in correspondingly sub-lethal responses are identified.