Page 26 - PR 2014 2016 07 Nuclear Science and Technology

168 Nuclear Science and Technology | Progress Report

Environmental result in long-term cumulative health effects,
applications of neutron making them priority pollutants. Several au-

activation analysis thors studied metal contamination in soils
under and in the vicinity of discarded vehicle
scrapyards, mechanic workshops and vehicle
Trace elements status in the terrain dismantlers. Most of them observed moderate
of an impounded vehicle scrapyard to high contamination by Cd, Cu, Cr, Fe, Mn,

Ni, Pb and Zn in the top layer of soil (0-10 cm),
Urban soil contamination varies consider- decreasing with depth.
ably depending on different anthropogenic
activities within city perimeters. However, In Brazil, in spite of the increasing number of
one of the most common sources of pollution IVS, the consequent soil metal contamination
present in most cities is vehicular. Over the has still received little attention. Therefore,
past decade, worldwide vehicle production studies on metal contamination in soils of
has increased rapidly and tends to continue Brazilian vehicle impound scrapyards may
to rise due to demand. In Brazil, the number of provide valuable information to support re-
licensed vehicles has increased by 118% over mediation procedures, as well as encourage
the last decade, totaling a fleet of 89 million improvements in the management practices
vehicles in 2015. Impounded vehicle scrapyard of these areas.
(IVS) overcrowding has become a problem in
many Brazilian cities. Brazilian law states that The aim of this study was to evaluate topsoil
apprehended vehicles must not remain longer samples from an IVS located in Ribeirão Pires,
than 90 days in an impound yard. However, São Paulo, for potentially toxic elements (PTEs),
in spite of this, they remain longer than that such as As, Ba, Co, Cr, Cu, Mo, Ni, Pb, V and Zn,
and suffer from weathering action. Mostly, and rare earth elements. Mass fractions of all
the ground of these areas is not impermeable. elements, except for Co, Cu, Mo and Zn, were
The main sources of pollution are liquid res- higher than reference values. Hot spots were
idue spills, leachates produced by rainwater observed for most elements suggesting vehicu-
leaching and particulate material resulting lar source. The geoaccumulation index showed
from vehicle decomposition. moderate pollution of As. The enrichment fac-
tor pointed to a significant enrichment of As,
Metals and some metalloids are important Mo and Pb. The normalization of REEs to Earth’s
pollution sources in different parking areas. crust values indicated a positive anomaly of
Many metals are present at different levels Ce. The results indicate a potential risk to the
in leaded and unleaded gasoline, diesel oil, soil quality of the scrapyard. (Partnership: In-
anti-wear substances added to lubricants, stituto de Geociências da UNICAMP; Financial
brake pads, and tires, as well as emitted by support: CNEN, CNPq).
vehicle exhausts. The main components of
automobiles are steel materials, including Potentially toxic elements in tunnel
those that contain alloys and are composed dusts from São Paulo city
by elements such as Al, Co, Cr, Cu, Fe, Mn, Mo
and Ni . Metals are non-degradable in soil, The vehicle traffic is the major source of air
and their high toxicity and persistent nature pollution in São Paulo, one of the largest meg-
in the environment, even at low levels, may acities in the world (20 million inhabitants in

Instituto de Pesquisas Energéticas e Nucleares