Poluição difusa uma possível contribuição das fibras de amianto presentes em telhas de fibrocimento

Abstract

The studies on the dangers of using asbestos intensified from 1991 onwards, culminating in the prohibition of the industrial use of any type of asbestos. The National Cancer Institute (INCA) classifies contact with asbestos as highly carcinogenic due to the development of pathologies such as asbestosis, lung cancer, mesothelioma, cancer of the larynx, digestive tract and ovary, thickening of the pleura and diaphragm, strokes pleural lesions, pleural plaques and severe respiratory disorders. However, one of the forms of asbestos fibers, chrysotile [Mg3(OH)4Si2O5], is still used in the production of fiber cement roofing tiles all over the planet. Contamination of the environment by asbestos is still the subject of studies. In this sense, the objective of the present study was the analysis of the possible release of asbestos fibers into the environment from fiber cement tiles in water and particulate matter matrices. Degradation of fiber cement tiles with chrysotile can occur mechanically, chemically and biologically. Studies show that the degradation of tiles by the action of time can degrade the cement matrix and release chrysotile fibers into the environment. To identify this process and investigate the possibility of diffuse pollution, used fiber cement tiles were collected. A control system was set up to collect samples of water and particulate matter and the NIOSH 7402 methodology was adapted for this procedure. For the collection of water samples, washings were performed with ultrapure water and acid rain. Samples of particulate matter were carried out in two environments (i) at the University, (ii) at the Contestado Settlement. Sample evaluations were performed by Scanning Electron Microscopy (SEM), energy dispersive X-ray analysis (EDS) and Fourier-transform infrared spectroscopy (FTIR). The results indicate the existence of chrysotile fibers showing the influence of diffuse pollution in the environment.