Monitoring of Asbestos in urban and industrial environments of selected Italian sites. The case of a ceramic factory

Transcription

1 Monitoring of Asbestos in urban and industrial environments of selected Italian sites. The case of a ceramic factory D. Mangano 1, A. F. Gualtieri 1, G. Torri 1, S. Ferrari 1, A. Ricchi 2, E. Foresti 3, G. Lesci 3, N. Roveri 3, M. Mariotti 4, G. Pecchini 5, M. Zapparoli 6 1 Dipartimento di Scienze della Terra, Università degli Studi di Modena e Reggio Emilia, Modena, Italy 2 Dipartimento di Sanità Pubblica, Azienda USL Modena Città, Modena, Italy 3 Dipartimento di Chimica "G. Ciamician" Alma Mater Studiorum, Università di Bologna, Bologna, Italy 4 Dipartimento di Sanità Pubblica, Azienda USL Bologna Città, Bologna Italy 5 ARPA, Sezione Provinciale di Reggio Emilia, Reggio Emilia, Italy 6 Centro Interdipartimentale Grandi Strumenti, Università degli Studi di Modena e Reggio Emilia, Modena, Italy

2 Introduction Air-dispersed particulate may contain asbestos released from different sources (ACM in urban and/or industrial buildings, quarries or mines, ACM removal sites, ACM in work or life private/public buildings, and others) It is of critical importance to monitor the presence of asbestos particulate not only in air but also in the so called fall-out particulate and soil to carefully assess the actual levels of exposure risk in life and work environment The aim of this project, granted by the Fondazione Cassa di Risparmio di Modena, is the long-term asbestos and inorganic particulate (with a special care to PM10 particulate) monitoring in civil and industrial environments of selected Italian sites

3 Location and main characteristics of the sites selected for the investigation Locality District Site Main characteristics Reggio Emilia Modena Modena Temporary waste deposit with cement-asbestos materials in a highly industrialized area Civil environment nearby the ceramic area in Sassuolo Ceramic factory in Pavullo, a mountain area (Modena Apennine) source of dispersion blank possible source dispersion Modena Ceramic factory in Sassuolo source of dispersion Modena Monitoring station in an unpolluted mountain area (Monte Cimone, Modena Apennine) blank Bologna Train Station of Bologna source of dispersion Bologna Reggio Emilia Reggio Emilia Civil University area nearby the centre of the city (Dipartimento di Chimica, Bologna) Recreational building with the cover made of cementasbestos nearby a primary school in the small village of Roncocesi (Reggio Emilia) Civil area in Reggio Emilia before, during and after the removal of cement-asbestos covering blank source of dispersion / blank source of dispersion

4 The investigated sites m 2 shed

5 Monitoring and Analysis The monitoring spots are located at H=0.5 m; V=0.0 m (primary dispersion?) and H=50 m; V=10.0 m (secondary dispersion?) with respect to the dispersions source. The dispersion source: cement-asbestos roof with clinochrysotile 12.5(5) wt%, calcite, quartz, gypsum, clay minerals, and minor CHS phases/portlandite The monitoring of the airborne dispersed particulate was possible using an especially modified high flux volumetric (ca. 1 m 3 /min ) sampler and large cellulose filters (A4 paper size, porosity 0.8 μm). Given the high flux, filters tend to be quickly over-saturated and were changed every second day Monitoring time = 1 week long over four seasons The fall out particulate is collected in a 1 m2 wide collector filled with water. Water samples are then filtered to separate the solid fraction and dried for the lab investigation Samples of soil were also collected in the proximity of the monitoring sites (H=20.0 m; V=10.0 m) to assess the nature and concentration of the particulate deposited in the long term

6 Monitoring and Protocol of analysis 1. Collection of the environmental and weather condition reports + PM10 concentration during the monitoring shift 2. Thermal treatment at 500 C for 1 h of all the samples for the decomposition of clay minerals such as kaolinite (which gives interference with chrysotile in diffraction), organic matter and the cellulose filter 3. On the thermally treated samples: quali-quantitative XRPD with the Rietveld method, optical microscopy (MOLP), SEM (necessary for life and outdoor environments to detect even the ultra-thin fibers: Lauria, 2005), TEM 4. Wet separation/enrichment of asbestos using the Appiani levigator method of all the thermally treated residue of the filters and XRPD, optical microscopy (MOLP), SEM/TEM 5. DSC+TA, FTIR analyses on selected samples

7 Results: thermal treatment of the filters Weight of ½ filter (g) Crucible weight (g) Weight after treatment at 150 C (g) Weight after treatment at 500 C (g) 4A season A season A season A season B season B season B season B season Solid residue (g)

8 XRPD: QPA with the Rietveld method and correlations air-dispersed 4a 500 C phase fraction (%) Quarzo Calcite Dolomite Plagioclasio Hematite Zircone mica k-feldspato Anidrite Kaolinite 5 0 1^ 2^ 3^ 4^ Shift/season

9 MOLP study (no grain size classes separation: Cazzola et al. 2005) material collected during the third monitoring shift 5 μm 2 μm 10 μm

10 SEM image of a bundle of asbestos fibres found in the airborne dispersed material collected during the third monitoring shift

11 SEM study: fibres of other nature Fall-out and air-dispersed third shift/season

12 TEM study Various TEM images of the airborne dispersed material collected during the third monitoring shift

13 Wet separation/enrichment of asbestos using the Appiani levigator method of all the thermally treated residue of the filters Basically a confirmation of the previous results

14 TEM image of an (amphibole?) asbestos fibre discovered in the soil of the blank site

15 Correlation with the blank site The observed concentration of the asbestos fibres in the airborne and fall-out samples collected in the blank site (a civil private building about 1 Km away from the Ceramic factory) for all the seasons was zero indicating that far away from the source of dispersion the risk of exposure is practically null Surprisingly, fibre bundles were found in the samples of soil. This may be indicative of past activity involving the removal of ACM and eventual widespread dispersion in air, and concentration of the particulate in the soil fraction

16 Results The physical state of the cement-asbestos shed was fairly good (damage percentage < 10%) and not necessarily subject to undergo abatement procedure Asbestos fibres (L> 5 μm and D < 3 μm) in very low concentration were found only during the third and fourth shifts (both air-dispersed and fallout) in the monitoring at H=0.5 m; V= 0.0 m. An indicative estimate of 0.03 ff/l (2260 ff/mg) for the airborne particulate collected during the third shift. No fibres were detected at the monitoring site at H=50 m; V= 10.0 m. This finding is somehow in concert with the results described in Cattaneo et al. 2005: Asbestos bundle number decreases with distance from source, especially as a function of the horizontal component Wet separation/enrichment of asbestos using the Appiani levigator method did not reveal higher concentrations of fibres

17 Results Literature data are contradictory albeit seem to point to higher concentrations of airborne (asbestos?) with respect to our result How to explain this inconsistency? Should we assume that our results are affected by an undefined bias or that the bias resides in the literature data? The following causes may plausibly play a role: (i) lack of statistical significance due to the monitoring of only one site; (ii) nature of the investigated monitoring site and environmental conditions; (iii) random causes; (iiii) lack of accuracy of the analytical protocol. The issue is still open to us but it should be remarked that the literature itself proposes a number of unexplained issues such as the high concentration of asbestos fibres in monitoring sites which apparently should be considered as blank (with zero fibres concentration) These inconsistencies have already been underlined and the reliability of the determination of some high concentrations has been considered suspicious.

18 Crystalline phases present in the various media and origin *Original gypsum transformed at 500 C into anhydrite; **Frits raw material; ***Formed during the process of industrial volatile fluorine abatement with CaO; ****Formed during the tiles firing processes and/or tiles waste (chamotte) ORIGIN AIRBORNE FALL-OUT SOIL CERAMIC RAW MATERIALS quartz, plagioclase, zircon, mica, K-feldspar, mullite, kaolinite, chlorite, wollastonite, Basulphate**, Pb, Pb-oxides** quartz, plagioclase, mica, anatase, rutile quartz, plagioclase, K- feldspar, mica, anatase, rutile, chlorite, illite, interlaminated CEMENT- ASBESTOS calcite, dolomite, anhidrite* chrysotile, calcite, anhydrite calcite, dolomite SUB-AERIAL ALTERATION calcite, anhydrite*, hematite, Fe and Mn-oxides anhydrite, calcite calcite SECONDARY PROCESSES fluorite*** cristobalite**** AIR POLLUTION Pb and Pb-oxides CHEMICAL PRECIPITATION halite, carobbiite

19 Concluding remarks and future activity 1. Asbestos in low concentration was found during the fall and winter shifts in both air-dispersed and fall-out media. The concentration of asbestos fibres very low and much lower than that generally reported in the literature 2. No clear correlation with the weather conditions and PM10 concentration was found 3. The explanation of the results are open to debate: are the results affected by a bias, or the results are accurate and the bias resides in the literature data? 4. A comprehensive model to explain asbestos concentration in life and work environment is missing 5. The analysis of the data relative to the other monitoring sites of different typology will be of help to draw such general model Delivery of the results of the project granted by the Fondazione Cassa di Risparmio di Modena 2007