Ecological hazard assessment of aqueous soil extracts using FETAX. Frog Embryo Teratogenesis Assay--Xenopus

Frog Embryo Teratogenesis Assay--Xenopus (FETAX) testing of a series of diverse hazardous waste-site soil samples was performed to evaluate the efficacy of FETAX as a rapid developmental toxicity screening tool for environmental hazard assessment. Soil samples were collected from six different hazardous waste sites, three from eastern and three from western Washington State. The type of waste site samples studied, based on the contaminants identified, included: heavy metals (2), polynuclear aromatic hydrocarbons, petroleum products (2) and organochlorine pesticides. Three to five samples from each site representing baseline and increasing levels of contamination were collected. Aqueous extracts of the soil samples were prepared and used for FETAX studies. Samples collected from the polynuclear aromatic hydrocarbon- and petroleum product-contaminated sites induced greater levels of embryolethal effects, although embryonic malformation was also observed. The metal-contaminated sites induced greater levels of embryonic malformation, but induced less embryolethality than the other samples evaluated. The organochlorine pesticide-contaminated site samples caused significant levels of embryonic deformities but failed to induce embryolethal effects. Results from these studies suggested that FETAX was sensitive enough to detect low levels of developmental toxicants but robust enough to be suitable for aqueous soil extract testing. FETAX may be used as a component of a battery of tests designed to assess potential ecological hazard.