Page 174 - 00. Complete Version - Progress Report IPEN 2014-2016

174 Nuclear Science and Technology | Progress Report

area of 8,511 km2). Vehicle emissions are one in aquatic environments. They are classified
of the main contributions to atmospheric par- as rooted and emerged plants, with floating or
ticle concentrations, including their exhaust, submerged leaves and submerged or free float-
the mechanical wear of tires and brakes and ing plants. Macrophytes are used for monitor-
the ejection of particles from the pavement ing aquatic environments by changes in the
by resuspension processes. Several studies of composition of the communities as impact
metal flows in the anthroposphere point to indicators and by chemical essays to evalu-
the traffic sector as a major contributor of dif- ate contaminant bioaccumulation. Nowadays,
fuse metal emissions. Tunnel dusts have been there is not sufficient information about trace
the subject of several environmental studies elements contamination in sediments, water
worldwide, since measurements inside traf- and macrophytes in the Guarapiranga reser-
fic tunnels can provide an evaluation of emis- voir. The present study aims to assess the con-
sion factors of vehicles in real conditions. In tamination of metallic elements in water, sed-
this study, the results of metals and metal- iment and macrophytes in the Guarapiranga
loids concentrations of tunnel dusts of the reservoir, to provide a more current diagnosis
Jânio Quadros tunnel, in São Paulo city, were of this important and strategic environment.
determined by Neutron Activation Analysis.
The results showed higher concentration lev- Sediment and macrophytes sampling was
els of Ba, Cr, Fe, Sb e Zn in relation to similar made with the support of the Environmen-
studies, mainly in the finer fractions (<63μm). tal Agency of the state of São Paulo (CETESB),
Principal component analysis (PCA) indicate following the CETESB guidelines of sampling
that the elements As, Ba, Co, Sb e Zn are origi- and sample preparation. The samples were
nated from vehicular sources. (Financial sup- analyzed by Instrumental Neutron Activation
port: CAPES, CNPq). Analysis (INAA), ICP OES e CV AAS in order to
determine the following elements: As, Cd, Cr,
Bioaccumulation of potentially toxic Cu, Hg, Ni, Pb and Zn. The results obtained
elements in floating aquatic macrophytes for the sediments were compared to the lim-
of Guarapiranga reservoir, São Paulo it values reported by The Canandian Council
of Ministers of the Environment. These values,
The Guarapiranga reservoir is one of the main TEL (Threshold Effect Level) and PEL (Probable
water supply reservoirs in the São Paulo Met- Effect Level) indicate the concentrations lim-
ropolitan Region, providing water for about its which can cause adverse effects to the bi-
4 million inhabitants. The contamination of ota. The Cu levels exceeded TEL values in all
aquatic ecosystems by trace elements originat- sites. It should be noticed that Cu is frequent-
ing from anthropogenic activities is of great ly used as algaecide in the reservoir, as CuSO4.
concern. Besides the increase of metallic ele-
ments, the eutrophication of aquatic systems The results obtained for the macrophytes
is a serious problem, since it can affect aquat- were compared to reference values for aquat-
ic community dynamics. In Brazil, domestic ic plants, and most of the analyzed elements
sewage is the main input of nutrients, which presented concentration levels above refer-
in turn aggravates the process of eutrophica- ence values. There was no statistical differ-
tion. This results in excessive growth of aquatic ence of the analyzed metals among the studied
macrophytes. Macrophytes are defined as mac- species of macrophytes: Eichhornia crassipes
roscopic size higher plants, which are present (Mart.) Solms. (Aguapé), Pistia stratiotes L.

Instituto de Pesquisas Energéticas e Nucleares