Chemical variability of artificial stone powders in relation to their health effects

Giordano Montegrossi,Massimo Innocenti,Alfonso Zoleo,Giovanni O. Lepore,Luca A. Pardi,Carla Poli,Francesco Di Benedetto,Andrea Giaccherini,Francesco d’Acapito,Fabio Capacci,Tonina Enza Iaia,Maurizio Romanelli,Antonella Buccianti,Ferdinando Capolupo

doi:10.1038/s41598-019-42238-2

Abstract

The occurrence of highly severe silica-related diseases among the resin- and silica-based artificial stone workers was claimed, associated to an extremely short latency. High levels of exposure and intrinsic properties of AS are thought to modulate the development of silicosis and auto-immune diseases. This study compares parent materials and processed dusts, to shed light on changes of AS occurring in the manufacturing process, through an XRF, EPR and XAS investigation. We point out the extremely wide variability of the materials, the occurrence of chemical signatures impressed by the processing techniques, and the unprecedented generation of stable radicals associated to the lysis of the Si-O chemical bond inside the resin coated respirable crystalline silica. These results suggest that the AS processing in industrial stone workshops can create respirable dusts with peculiar physical and chemical properties, to be correlated to the observed clinical evidences.

Highlights

The occurrence of highly severe silica-related diseases among the resin- and silica-based artificial stone workers was claimed, associated to an extremely short latency
Assuming conventional limits to discriminate major, minor and trace elements (i.e. 1% and 0.1%), one can observe that only Na and Ca are seldom occurring as major elements, in agreement with the Artificial stone (AS) mineralogical composition
The processed dusts clearly differ in the chemical signature from the parent AS, and they differ in response to the operated dry/wet process

Summary

Introduction

The occurrence of highly severe silica-related diseases among the resin- and silica-based artificial stone workers was claimed, associated to an extremely short latency. We point out the extremely wide variability of the materials, the occurrence of chemical signatures impressed by the processing techniques, and the unprecedented generation of stable radicals associated to the lysis of the Si-O chemical bond inside the resin coated respirable crystalline silica These results suggest that the AS processing in industrial stone workshops can create respirable dusts with peculiar physical and chemical properties, to be correlated to the observed clinical evidences. The study of Pavan et al.[19] represents, to the authors’ knowledge, the unique attempt to link the health effects on ASW to specific physico-chemical and morphological features of the processed materials These authors suggested the occurrence of a film of resin coating the respirable crystalline silica (RCS) particles. The present experimental study compares parent materials and processed dusts, obtained from different production lines, to shed light on changes of AS through the manufacturing process

Methods

Results

Discussion

Conclusion