Frogs endocrine disruption

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... 

Human health biomonitoring may also use animal surrogates in the environment to assess potential health hazards to humans - the proverbial canary in the coal mine . For example, chemical and biomarker analysis of bodily fluids or tissue biopsies from family pets, especially dogs, are sometimes used to assess potential chemical exposure and effects in children. This is because dogs often accompany children in the outdoor environment, and both have a tendency to (accidentally or intentionally) consume environmental media such as soil and surface water There has also been an increasing trend to use native animals as sentinel species, that is, fish, wildlife, or invertebrates that are indicators of possible human health risks from environmental hazards. For example, increased incidences of tumors or endocrine disruption in fish may indicate the presence of compounds in the water that may cause cancer or reproductive dysfunction in humans. Concern has also been raised over the increased incidence of deformities in frogs, because these may indicate an increased level of chemicals in the environment, which can cause birth defects in humans. 

Erb J, et al. (2001) Data from an estrogen receptor-based biosensor correlates with evidence of frog malformation and demonstrates a differential response of hERot and f to beneficial and harmful estrogenic compounds. In Proceedings of the 2nd International Conference on Pharmaceuticals and Endocrine Disrupting Chemicals in Water, pp. 203-217. Westerville, OH The National Ground Water Association. 

Renner R. (2002). Atrazine linked to endocrine disruption in frogs. Environmental Science and Technology 36 55A-56A. 

Ohtani, H., Miura, I., Ichikawa, Y. (2000 Dec) Effects of Dibutyl Phthalate as an environmental endocrine disrupter on gonadal sex differentiation of genetic males of the frog Rana rugosa. Environ Health Perspect 108(12). 

Effects have also been observed on the environment. Rachel Carson s Silent Spring in the 1960s drew attention to effects on wildlife. Our Stolen Future (Colbom et al. 1996) created an interest in disruption of the endocrine system by chemicals, even in animals. Many cases of effects on natural animal populations can now be inferred from laboratory experiments, although confirmation in the environment is extremely difficult. For instance, organochlorinc concentrations in adult male bottlenose dolphins are approaching the levels associated with adverse effects found in marine mammals (Carballo et al. 2008), and exposures of tadpoles to a mixture of nine pesticides at environmentally occurring levels lead to developmental effects in most frogs, while none were observed when the pesticides were applied one at a time (Hayes et al. 2006). 

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