Environmental exposure amphibians

More controversially, endocrine disruption as a consequence of exposure to the herbicide atrazine (2-chloro-4-ethylamine-6-isopropylamine-s-triazine), one of the most widely used herbicides in the world, has also been hypothesized to explain various adverse biological effects in frog populations in the United States. Exposure to atrazine in the laboratory at high concentrations, far exceeding those found in the natural environment, has been reported to induce external deformities in the anuran species Rana pipiens, Rana sylvatica, and Bufo americanus (Allran and Karasov 2001). Studies by Hayes et al. have suggested that atrazine can induce hermaphroditism in amphibians at environmentally relevant concentrations (Hayes et al. 2002 Hayes et al. 2003). Laboratory studies with atrazine also indicated the herbicide... 

Pauli, B.D., Coulson, D.R., BerriE, M. (1999) Sensitivity of Amphibian Embryos and Tadpoles to Mimic 240 LV Insecticide Following Single or Double Exposures. Environmental Toxicology and... 

Exposure of juvenile insects to methoprene results in various abnormalities associated with development and ultimately death. The environmental degradation product of methoprene, methoprenic acid was found to serve as an RXR agonist and specifically activate genes responsive to RXR homodimers. In addition exposure of frog larvae to methoprenic acid caused developmental deformities consistent with those that have been observed in recent years in wild populations and consistent with those caused by exposure to retinoic acid under laboratory conditions. These observations indicate that methoprenic acid functions as an RXR agonist, and that this activity could contribute to the occurrence of amphibians deformities documented in the environment. 

More work will be needed to establish the full environmental relevance of plastics in the transport of contaminants to organisms living in the natural environment, and the extent to which these chemicals could then be transported along food chains. However, there is already clear evidence that chemicals associated with plastic are potentially harmful to wildlife. Data collected using laboratory exposures show that phthalates and BPA affect reproduction in all studied animal groups, and impair development in crustaceans and amphibians (Oehlmann et al 2009). Molluscs and amphibians... 

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