Effects of three organic wastewater contaminants on American toad, Bufo americanus, tadpoles.

Recent surveys of aquatic habitats suggest that organic wastewater contaminants (OWCs) may be common in aquatic ecosystems. However, relatively little is known about the impacts of OWCs on amphibians. We studied the lethal and sublethal effects of three OWCs (acetaminophen, caffeine, and triclosan) on American toad (Bufo americanus) tadpoles. High concentrations of triclosan increased activity, whereas acetaminophen had a significant effect on activity but there was no discernable pattern or trend with concentration. Caffeine did not affect activity in B. americanus tadpoles. None of the OWCs we studied had a significant effect on growth. Caffeine had no effect on survivorship. Higher concentrations of acetaminophen increased mortality. Intermediate concentrations of triclosan had a negative effect on survivorship, but the highest concentration apparently had a positive effect on survivorship. Our results suggest that there is variation in the toxicity of the three OWCs we studied.