Eﬀects of Three Organic Wastewater Contaminants on American Toad, Bufo americanus, Tadpoles GEOFFREY R SMITH* AND AMBER A BURGETT Department of Biology, Denison University, Granville , Ohio, 43023, USA Accepted 26 May 2004 Abstract. 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. Keywords: acetaminophen; Bufo americanus; caﬀeine; lethal eﬀects; sublethal eﬀects; triclosan Introduction Amphibian larvae are potentially exposed to sev- eral pollutants in their aquatic habitats. Most of the focus has been on pesticides, herbicides, and agricultural fertilizers (e.g., Rouse et al., 1999; Cowman and Mazanti, 2000; Boone and Bridges, 2003). Recent surveys of aquatic habitats suggest another category of pollutants, organic wastewater contaminants (OWCs), may be common in aquatic ecosystems (Stuer-Lauridsen et al., 2000; Jones et al., 2001, 2002; Campagnolo et al., 2002; Kolpin et al., 2002; Boyd et al., 2003; Lalumera et al., 2004), and thus may inﬂuence amphibian performance. However, relatively little is known about the impacts of OWCs, or other organic contaminants, on amphibians (see Sparling, 2000). We studied the lethal and sublethal eﬀects of three OWCs, acetaminophen, caﬀeine, and triclo- san, on American toad (Bufo americanus) tad- poles. Acetaminophen is an over-the-counter analgesic. Caﬀeine is a stimulant found in many beverages and medications. Triclosan (5-chloro-2- (2,4-dichlorophenoxyl)phenol) is an antimicrobial agent that is used widely in consumer products such as antibacterial soaps. These three OWCs are among the most widely found in a survey of freshwater habitats in the USA by Kolpin et al. (2002). Little beyond the survey done by Kolpin et al. (2002) appears to be known about the pres- ence of acetaminophen in the environment. Caf- feine has been found in the inﬂuent and eﬄuent of wastewater treatment plants (Ternes et al., 2001; Buerge et al., 2003), as well as rivers and bays *To whom correspondence should be addressed: Tel: +1-740-587-6374; Fax: +1-740-587-6417; E-mail: smithg@denison.edu Ecotoxicology, 14, 477–482, 2005 Ó 2005 Springer Science+Business Media, Inc. Manufactured in The Netherlands.