Spatio-Temporal dynamics of beached asbestos cement wastes colonized by terrestrial and shallow marine organisms: New insights and environmental implications

Salvatore Giacobbe¹Roberta Somma^2*

• ¹Department of Chemical, Biological, Pharmaceutical and Environmental Sciences, University of Messina, Messina, Italy
• ²Department of Mathematics and Computer Science, Physics and Earth Sciences, University of Messina, Messina, Italy

Investigations carried out on the geological/ecological asset of Peloro Cape, north-eastern Sicily, revealed the occurrence of hundreds of Asbestos Cement Material (ACM) fragments, whose features indicated their origin as undulated roofs left by dumps of demolition waste, later exposed to marine coastal erosion. Part of them showed clear traces of biotic activity, both as corrosion and encrustation. Evidence of a first colonization was identified in organic weathering that occurred under sub-aerial conditions, as bared substrates left by lichens. A second colonization step was recognized in the calcareous remains of marine encrusting organisms occurring in shallow marine environments. In such latter phase, evidence of biotic overgrowth by spirorbids, large serpulids, oysters, bryozoans and vermetid gastropods testified for a successional process, likely developed in a decadal timespan. Repeated phases of immersion and stranding due to storm events, however, may be also considered. Subaerial and subaqueous colonization may be indirectly tied, since lichen may contribute to make inert Asbestos materials, facilitating the later settlement of marine encrusting biota. The co-action of continental and marine biota thus contributes to reducing the release of dangerous asbestos fibers into the environment. Such process, nevertheless, cannot affect the smallest fragments, which cannot be colonized because too much instable on the sea bottom. In conclusion, multiple interference by uncontrolled ACM waste affected both emerged and submerged coastal environments, whose impact needs to be evaluated, also in terms of threat to human health. It follows that the sites affected by environmental and health risk for asbestos exposure should be remediated to avoid damage to humans, living organisms, and ecosystems, whose relationships in marine environments have been almost neglected. The present research, contributing to filling a gap in knowledge on ACM dangerous waste, especially on source and fate after their transfer and transport through alluvial and marine waters, could support competent public administrations and technicians in planning real remediation activities, once understood the great complexity of the coastal area contamination phenomenon.