Evaluation of the Effects of Water Disinfection By-products, Bromochloroacetic and Dibromoacetic Acids, on Frog Embryogenesis

Adverse developmental effects of two haloacetic acids, bromochloroacetic acid (BCA) and dibromoacetic acid (DBA), were determined by using the Frog Embryo Teratogenesis Assay—Xenopus (FETAX). Xenopus embryos (150–400/concentration group) were exposed to 0, 8000, 10,000, 12,000, or 14,000 ppm BCA or 0, 10,000, 12,000, 14,000, or 16,000 ppm DBA for 96 h beginning from stage 8 (mid-blastula) to stage 46 (when primary organogenesis is complete). BCA produced 29, 83, and 100% mortality at 10,000, 12,000 and 14,000 ppm, respectively. Incidence of malformations among surviving embryos at 96 h for 10,000 and 12,000 ppm BCA were 8.4 and 68%. Thus LC50 and EC50 for BCA were between 10,000 and 12,000 ppm. DBA did not produce any significant mortality or malformation at any of the concentrations tested. In summary, BCA affected development of Xenopus embryos only at high concentrations, while DBA did not affect Xenopus development at the concentrations tested.