Dr. Eva Sirinathsinghii tested the effects of Introban®, a commercial formulation of a Bacillus thuringiensis (Bt) subtype, Bacillus thuringiensis subsp. israelensis (Bti). She discovered that Introban® is toxic to tadpoles of an Argentinian species of frog at environmentally relevant concentrations. The Bti subtype is meant for mosquitoes, in order to prevent the spread of infectious disease.
Genotoxic effects occurred in days, not weeks or months. Intestinal enzymes that would normally protect the tadpoles from oxidative stress were affected, and the results were 100% lethal. The tadpoles’ immune systems were rendered useless.