Asbestiform amphiboles in a marble quarry: A case study from the province of Córdoba (Argentina)
Date
2014Author
Locati, Francisco
Lescano, Leticia
Murra, Juan
Marfil, Silvina
Maiza, Pedro
Baldo, Edgardo
Metadata
Show full item recordAbstract
Pure and impure marbles in Argentina have been exploited for hundreds of years for different
purposes. Marble processing is varies depending on its use and could include chemical
treatments, burning, crushing, milling and polishing. More impure marbles are crushed and
used for construction, or discarded in spoil heaps in quarries. There are numerous studies
related to the physical and mechanical properties of marbles from the province of Córdoba;
however, there are no records about the potential presence of asbestos that could be liberated
during processing procedures or degraded by natural agents in spoil heaps. Fibrous samples
from a metasomatic zone in an abandoned marble quarry in the Altautina area (Córdoba,
Argentina) were studied through polarized light microscopy, X-ray diffraction and electron
probe microanalyses. Asbestiform (tremolite) and non-asbestiform amphiboles (tremolite and
magnesio-hornblende) were identified as the main phases. Asbestiform amphiboles were
concentrated and studied through a stirring degradation test to evaluate morphological and size
changes in the fibres by simulating natural water degradation. This process was monitored by
stereomicroscopy and scanning electron microscopy. During the test, fibres underwent length
(L) and width (W) reduction, maintaining or increasing the initial L/W ratio. Although the
action of natural agents can differ from data obtained in laboratory tests, results indicate that
the asbestiform fibre size decreases reaching values that can be harmful to human health.