CONICET | Buscador de Institutos y Recursos Humanos

From public and environmental health concern, arsenic (As) occupies the first place in the list of priority substances of the Agency for Toxic Substances and Diseases Registry (ATSDR) because of a high occurrence in different environments, its toxicity at different organization levels, and potential threat for human health. In Argentine, the effects of As on environmental and human health are mainly associated with the entering of As in sources of drinking water and groundwater by leaching from geological formations and volcanic activity. Monitoring of metals in the aquatic ecosystems can be evaluated by a combination of chemical and biological methods. However, biomonitoring has the advantage of retaining a memory of pollutant emissions, thus overcoming the difficulty of detecting contaminants that are irregularly emitted and quickly diluted in large volumes, for instance in lakes and streams. The model organism Pomacea canaliculata fulfills the requirements of a species that could be used for environmental monitoring studies. In addition, two types of symbiotic corpuscles have been identified within cells of the digestive gland of this snail. This work envisaged the possibility of using this previously unrecognized association of a freshwater snail with a bacterium as a bioindicator of arsenic pollution. Our results showed that digestive gland showed the highest bioconcentration factor of As (BCF=426). Also, we have been surprised by the ability of both C and K symbiotic corpuscles to accumulate arsenic (about 35 and 26 times above aquarium water). Our findings show that P. canaliculata is a sensitive organism for biomonitoring of As in freshwater bodies since it is the entrance doorway of these elements in the trophic web. From a toxicological view, the potential use of apple snails as a suitable substitute for protein sources will depend on the identification of arsenic in natural aquatic ecosystems.