reproductive health problems. The authors concluded that the quality of most studies was poor and without good quality data, the results were difficult to assess, though it was noted that no single category of negative pregnancy outcome was found consistently across studies. The authors concluded that a causal link between atrazine and adverse pregnancy outcomes was not warranted due to the poor quality of the data and the lack of robust findings across studies. Syngenta was not involved in the design, collection, management, analysis, or interpretation of the data and did not participate in the preparation of the manuscript. Amphibians Atrazine has been a suspected teratogen, with some studies reporting causing demasculinization in male northern leopard frogs even at low concentrations, and an endocrine disruptor. A 2002 study by Tyrone Hayes, of the University of California, Berkeley, found that exposure caused male tadpoles to turn into hermaphrodites – frogs with both male and female sexual characteristics. However, this study has not been able to be replicated, and a 2003 EPA review of this study concluded that overcrowding, questionable sample handling techniques, and the failure of the authors to disclose key details including sample sizes, dose-response effects, and the variability of observed effects made it difficult to assess the study's credibility and ecological relevance. A 2005 study, requested by EPA and conducted under EPA guidance and inspection, was unable to reproduce Hayes' results. The EPA's Scientific Advisory Panel examined relevant studies and concluded in 2010, "atrazine does not adversely affect amphibian gonadal development based on a review of laboratory and field studies". It recommended proper study design for further investigation. As required by the EPA, two experiments were conducted under Good Laboratory Practices (GLP) and were inspected by EPA and German regulatory authorities, concluding 2009 that "long-term exposure of larval X. laevis to atrazine at concentrations ranging from 0.01 to 100 μg/L does not affect growth, larval development, or sexual differentiation". A 2008 report cited the independent work of researchers in Japan, who were unable to replicate Hayes' work. "The scientists found no hermaphrodite frogs; no increase in aromatase as measured by aromatase mRNA induction; and no increase in vitellogenin, another marker of feminization." A 2007 study examined the relative importance of environmentally relevant concentrations of atrazine on trematode cercariae versus tadpole defense against infection. Its principal finding was that susceptibility of wood frog tadpoles to infection by E. trivolvis is