GENOTOXIC AND DEVELOPMENTAL EFFECTS IN SEA-URCHINS ARE SENSITIVE INDICATORS OF EFFECTS OF GENOTOXIC CHEMICALS

Purple sea urchin (Strongylocentrotus purpuratus) gametes and embryos were exposed to three known mutagenic chemicals (phenol, benzidine, and pentachlorophenol) over concentration ranges bracketing the effect levels for fertilization success. Normal development and cytogenetic effects (anaphase aberrations) were assessed after the cultures were allowed to develop for 48 h. Using radiolabeled chemicals, we also characterized concentrations in the test water as well as doses in the embryos following 2- and 48-h exposures. We observed dose responses for all chemicals and all responses, except for phenol, which showed no significant effect on development. Fertilization success was never the most sensitive end point. Anaphase aberrations were the most sensitive response for phenol, with an LOEC of 2.5 mg/L exposure concentration. Anaphase aberrations and development were equivalent in sensitivity for benzidine within the tested dose range, and an LOEC of <0.1 mg/L was observed. Development was the most sensitive response for pentachlorophenol (LOEC 1 mg/L). The LOEC values for this study were generally lower than comparable data for aquatic life or human health protection. We conclude that genotoxicity and development evaluations should be included in environmental management applications and that tests developed primarily for human health protection do not reliably predict the effects of toxic substances on aquatic life.