Page 41 - PR 2014 2016 07 Nuclear Science and Technology

Nuclear Science and Technology | Progress Report 183

the fish ranged from 29,56 ± 0,26 ng g to 44,54
-1
± 0,67 ng g , which can be considered as low,
-1
if compared to the standards established by
the Brazilian legislation (ANVISA).

Nuclear and non-

nuclear analytical
techniques applied to

archaeological studies

Classification of archaeological ceramics by
multi-elemental analysis generally consists
of two steps: sampling and measurement of
many chemical elements with multi-elemental
techniques, such as instrumental neutron acti-
vation analysis. The first significant application
of activation analysis in archaeology occurred
Fig 28. Collection of hair samples of children living in 1954, when Robert Oppenheimer suggested
in the state of Tocantins, for mercury analysis. to a colleague R.W. Dodson the possibility of
using trace elements analysis via NAA to es-
studied children. The mean concentration of tablish the provenance of archeological ceram-
mercury in children in Chapada de Natividade ics. The samples were irradiated in a nuclear
was significantly higher than in Porto Nacional. reactor and measured with a sodium iodide
Children exposed to artisanal gold mining ar- detector coupled to a 100-channel analyzer.
eas had higher concentrations of mercury than The elements Mn and Na were determined,
children living in non-artisanal gold mining and the results were expressed as ratios of
areas. There was no significant relationship 56 Mn/ Na showing distinct differences be-
24
between mercury concentrations and gender, tween ceramics from different regions, but
monthly fish consumption, parental profession similar for samples from the same region. The
and amalgam presence in dental restorations. next major advancement occurred with the
The results suggest that the children living in modern detectors that greatly increased the
an area exposed to mining experience greater energy resolution of gamma rays relative to
environmental exposure to mercury, regard- the sodium iodide detector.
less of their eating habits or gender. Since it is
known from many studies in the literature that The more abundant and important artifacts
hair mercury concentrations may be related to found in many areas worldwide are ceramics
fish consumption, it was considered as relevant which combine, in the most part, durability
to analyze some of the fish most consumed with ubiquity. Today several analytical meth-
by the studied populations. The fish species ods including the nuclear and non-nuclear
chosen were: Lutjanus cyanopterus (Caranha) analytical methods are used for the study of the
,Leporinus fasciatus (Piau), Piaractus mesopo- characterization and the manufacturing of the
tamicus (Pacú) and Colossoma macropomum artifacts. From the chemical and physical anal-
(Tambaqui).The concentrations obtained for yses, it is possible to infer information about