| dc.description | The red-eared-turtle Trachemys scripta elegans, belonging to the suborder Cryptodira
and family Emydidae, is farmed in the Mississippi Valley in the USA and sold
throughout the world as one of the most traded pets. An increasing number of
species are frequently released by owners in natural wetlands and in urban areas.
This species is resistant and may spread parasites and threaten native turtle populations.
Many countries chose to perform euthanasia to control its population,
avoiding the threat to local biodiversity. Animals were studied here using Instrumental
Neutron Activation Analysis (INAA) to determine metallic elements Ca, Fe, Na,
Zn, aiming to assess the concentrations on different tissues in the body of ten female specimens. All of them donated already euthanized by DEPAVE (Parks and Green
Areas Department) U City of S??o Paulo. The bodies were open with electric saw,
with size between 18 and 23 cm of Carapace Length (CL), being all of them adults.
The samples analyzed were: superficial and bone carapaces liver, heart, lung, muscle
and kidneys. Approximately 200mg of the samples and reference materials, Soil 1
from IAEA and Montana II soil from NIST, were used. Those were irradiated at the
IEA-R1 nuclear research reactor at IPEN under a thermal neutron flux of 1012 n per
cm2 per s for 6h. Gamma spectrometry was used with a HPGe with relative efficiency
of 23% with an associated electronics, to perform the measurements. Methodology
validation regarding precision and accuracy were done using reference materials SL-
1 (Lake Sediment ??? IAEA) and Montana II soils (NIST). The Na, Ca, Zn and Fe
concentrations in shell bone and scute were in the same magnitude founded in the
literature. The majority of their growth occurs in early years of life then it would be
possible to infer that the concentrations found in the central part of their carapace
were related to previous years, and the concentrations that were found in the edges
can be related to the last months of animals life. Studies regarding cadmium intake
focuses in contamination based on animals diet, but as in this study there is few
information about the food source the animal received before living in city parks, and
before being euthanized they were put in a diet restricted to ration. The Zn concentrations
found in the carapace showed higher values in the scute when compared with
shell bone. Ca and Na presented the opposite behavior. Future studies related to
the metal concentrations in other parts of the animals could indicate the possibility
of using this specie as an environmental bioindicator. | |
