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Deactivated (detoxified) asbestos-cement (DAC), i.e. asbestos-cement slates thermally treated at 1100 °C in order to convert the harmful asbestos fibers into non harmful mineral phases, has been successfully mixed with 74.6 wt% quartz sand and up to 63.2 wt% basalt sand, to produce stone wool with mechanical properties and composition competitive with commercial stone wool. The sample with 50 % DAC and 50 % basalt provided the best comparison with commercial stone wool in terms of liquidus temperature (lower than for the other mixtures) and Young's modulus (higher). Through further composition optimization and utilization of multiple components, we estimate that future batches could utilize 70–75 % of DAC. These promising results and expectations highlight a feasible reuse of DAC as secondary raw material for stone wool production and a possible route to the elimination of a toxic waste from the environment and the preservation of primary raw materials. [Display omitted] • Asbestos-containing materials still represent a serious health problem. • Thermally deactivated asbestos-cement can be successfully reused. • Rock-wool can be produced using deactivated asbestos-cement. • A rapid conclusion of the "asbestos problem" is envisaged. [ABSTRACT FROM AUTHOR]

Light roofs, especially those made of asbestos-cement have been widely used in Cuba. Their use includes a wide range of building types, such as industrial facilities, warehouses, temporary facilities and that which is the focus of this paper: the one-story single-family home. These coverings have a high incidence of damage as a result of high winds produced by hurricanes and tornadoes. This paper presents a study of how the force of the wind acts on these buildings, the identification of points on the roof more susceptible to damage and a proposal of solutions - in addition to stipulations in the building code on the assembly of these roofs - to increase their resistance. [ABSTRACT FROM AUTHOR]

The effects of asbestos on human health have spurred numerous studies examining its risks in urban environments. Recent works have shifted towards less-invasive techniques for remote detection and classification of asbestos-cement. In this context, this study combines visible (VIS) and near-infrared (NIR) reflectance data collected in-situ with reference signals from the USGS spectral library, utilizing optimized regression analysis to determine the surface composition of corrugated asbestos-cement rooftops. An outlier filter was successfully implemented to enhance the accuracy of regression calculations, achieving a high level of agreement with actual field observations. The regression analysis revealed varying proportions of weathered cement, hazardous asbestos fibers (specifically chrysotile and cummingtonite), and biological growth (such as lichens and moss). These results are consistent with previous research on the composition of asbestos-cement rooftops, including a comparable field study and XRD analysis conducted in 2019. This underscores the importance of using regression analysis, preceded by an outlier filtering step, on VIS and NIR reflectance data to ascertain the surface composition of asbestos-cement rooftops. This methodology holds potential for application to larger hyperspectral datasets across more extensive sample surfaces and areas. [Display omitted] • Asbestos-cement (AC) surface composition can be assessed using reflectance analysis in the visible and near-infrared ranges. • Regression analysis can determine the surface composition of AC corrugated rooftop sheets. • Outlier detection applied to raw data can enhance the regression analysis to become comparable to in-situ observations. • Non-invasive identification and surface composition assessment of AC material is essential for the protection of human health. • The assessment of AC surfaces contributes to "sustainable cities and communities", a part of sustainable development goals. [ABSTRACT FROM AUTHOR]

The "asbestos problem" arises from the fact that asbestos is still abundant in many buildings and represents a hazard for human health. Current strategies adopted by law aiming at mitigating this hazard are far from being ideal. A smarter solution would be an energy sustainable detoxification treatment followed by recycling. If adopted, it would preserve the environment from pollution, natural resources from depletion and human health from hazard. Asbestos-cement slates were thermally deactivated through a sustainable process and reused in mortar for plaster applications. We found that the addition up to 7 wt% of the deactivated product does not affect significantly the water demand; does not affect thixotropy, stickiness and spreadability of the plastic mixture; slightly increases the strength of the mortar; does not compromise mechanical properties after aging. Considering the huge amount of traditional mortar employed worldwide, a rapid end of the "asbestos problem" is envisaged. [Display omitted] • Asbestos containing materials are still abundant in civil and public buildings. • Efficient, sustainable detoxification methods have been designed. • Addition of detoxified asbestos up to 7 wt% to traditional mortar is beneficial. • A rapid end of the "asbestos problem" is envisaged within a frame of circular economy. • Landfills and raw materials shortage can be mitigated. [ABSTRACT FROM AUTHOR]

Abstract Background Despite the available information on cancer risk, asbestos is used in large areas in the world, mostly in the production of asbestos cement. Moreover, questions are raised regarding the shape of the dose response relation, the relation with time since exposure and the association with neoplasms in various organs. We conducted a study on the relationship between cumulative asbestos exposure and mortality from asbestos related diseases in a large Italian pool of 21 cohorts of asbestos-cement workers with protracted exposure to both chrysotile and amphibole asbestos. Methods The cohort included 13,076 workers, 81.9% men and 18.1% women, working in 21 Italian asbestos-cement factories, with over 40 years of observation. Exposure was estimated by plant and period, and weighted for the type of asbestos used. Data were analysed with consideration of cause of death, cumulative exposure and time since first exposure (TSFE), and by gender. SMRs were computed using reference rates by region, gender and calendar time. Poisson regression models including cubic splines were used to analyse the effect of cumulative exposure to asbestos and TSFE on mortality for asbestos-related diseases. 95% Confidence Intervals (CI) were computed according to the Poisson distribution. Results Mortality was significantly increased for ‘All Causes’ and ‘All Malignant Neoplasm (MN)’, in both genders. Considering asbestos related diseases (ARDs), statistically significant excesses were observed for MN of peritoneum (SMR: men 14.19; women 15.14), pleura (SMR: 22.35 and 48.10), lung (SMR: 1.67 and 1.67), ovary (in the highest exposure class SMR 2.45), and asbestosis (SMR: 507 and 1023). Mortality for ARDs, in particular pleural and peritoneal malignancies, lung cancer, ovarian cancer and asbestosis increased monotonically with cumulative exposure. Pleural MN mortality increased progressively in the first 40 years of TSFE, then reached a plateau, while peritoneal MN showed a continuous increase. The trend of lung cancer SMRs also showed a flattening after 40 years of TSFE. Attributable proportions for pleural, peritoneal, and lung MN were respectively 96, 93 and 40%. Conclusions Mortality for ARDs was associated with cumulative exposure to asbestos. Risk of death from pleural MN did not increase indefinitely with TSFE but eventually reached a plateau, consistently with reports from other recent studies.

Deterioration of asbestos–cement (AC) water pipes was assessed using accelerated acid exposure experiments coupled with measurements of physical and mechanical properties. The experiments were conducted in three phases using a strong acid (nitric acid) at concentrations ranging from 0.00158 to 3.16 M. The AC pipe deterioration was determined using phenolphthalein staining and the measurement of calcium and magnesium. Results from the experiment indicate that a linear rate of deterioration with time is the most appropriate for estimating the rate of deterioration in the field and for estimating the remaining service life of the AC pipe. In addition, the use of high‐concentration acids to understand the strength loss of AC pipes in the field was evaluated by comparing the crushing and hydrostatic capacity of a full‐scale acid‐degraded specimen and a naturally degraded specimen. Similar loss of crushing and hydrostatic capacity with increasing deterioration was observed between the acid‐degraded and naturally degraded specimen. [ABSTRACT FROM AUTHOR]

The World Health Organization estimates that 100 thousand people in the world die every year from asbestos-related cancers and more than 300 thousand European citizens are expected to die from asbestos-related mesothelioma by 2030. Both the European and the Italian legislations have banned the manufacture, importation, processing and distribution in commerce of asbestos-containing products and have recommended action plans for the safe removal of asbestos from public and private buildings. This paper describes the quantitative mapping of asbestos-cement covers over a large mountainous region of Italian Western Alps using the Multispectral Infrared and Visible Imaging Spectrometer sensor. A very large data set made up of 61 airborne transect strips covering 3263 km2 were processed to support the identification of buildings with asbestos-cement roofing, promoted by the Valle d’Aosta Autonomous Region with the support of the Regional Environmental Protection Agency. Results showed an overall mapping accuracy of 80%, in terms of asbestos-cement surface detected. The influence of topography on the classification’s accuracy suggested that even in high relief landscapes, the spatial resolution of data is the major source of errors and the smaller asbestos-cement covers were not detected or misclassified.

Background The aim of this study was to describe the mortality of a cohort of asbestos-cement workers in the largest plant in the most industrialized Italian region (Lombardy). Methods A cohort study was carried out on 1818 subjects, corresponding to 47 536.1 person-years of observation. Standardized mortality ratios (SMRs) were computed for the major causes of death. Results Increased SMRs were observed for pleural, peritoneal and lung cancers, and for asbestosis (SMR 26.73, 95% Confidence Interval (CI) 20.99-33.55; 9.15, 95%CI 5.00-15.34; 1.48, 95%CI 1.27-1.72; and 368.05, 95%CI 214.40-589.29, respectively). No excess in mortality for laryngeal cancer was observed (SMR 0.70, 95%CI 0.30-1.39). An increased mortality for ovarian cancer (SMR 3.64, 95%CI 0.99-9.33) was observed, although it was not statistically significant. Among men, mortality for pleural malignant mesothelioma was observed to be related to the duration of exposure, though not to latency. Conclusions The results of this study are generally consistent with present knowledge. Conversely, our results do not support the hypothesis that pleural malignant mesothelioma risk indefinitely increases after exposure, suggesting instead that the alternative hypothesis of a risk plateau or decrease after a time since first exposure of more than 40 years is more consistent with the observed data. [ABSTRACT FROM AUTHOR]

There is a need for a detoxification system that is capable of processing debris in the aftermath of urban disasters into less-harmful waste, quickly and efficiently. The research reported in this paper investigated the potential for transforming asbestos-cement into harmless waste using microwave heating, in small-scale and full-scale experiments. The small-scale setup investigated the relationship between temperature and the number of asbestos fibers in cement slates at various microwave treatment times, during which both the internal and surface temperatures were measured for the samples. Subsequently, the full-size apparatus, which was capable of processing 2 t/day of asbestos-contaminated debris, was constructed at a location affected by the Tohoku earthquake in 2011. This system could successfully process 80 kg/h of asbestos-contaminated material and 80-160 kg/h of wood waste. The test results demonstrate that compact asbestos-treatment systems possess efficiency advantages and can operate in full compliance with applicable legal restrictions. [ABSTRACT FROM AUTHOR]

There are several environmental issues in urban areas that are caused by the unintentional consequences of past activities. One of these issues is the wide application of asbestos cement in roofing materials in the 2nd half of the 1900s. In this study, our goal was to identify different roof types and to determine those with asbestos components using high-ground (1 m) and spectral (126 bands) resolution airborne hyperspectral imagery (AISA Eagle II) and several classification approaches. In addition, we aimed to identify those wavelengths that play a significant role in distinguishing the different roof types. In the image analysis, the SAM, MLC and SVM classification methods were used to evaluate the different types of roofs. These methods resulted in accurate maps of the roof types, and asbestos cement roofs were identified with over 85% accuracy. [ABSTRACT FROM AUTHOR]

The World Health Organization estimates that 100 thousand people in the world die every year from asbestos-related cancers and more than 300 thousand European citizens are expected to die from asbestos-related mesothelioma by 2030. Both the European and the Italian legislations have banned the manufacture, importation, processing and distribution in commerce of asbestos-containing products and have recommended action plans for the safe removal of asbestos from public and private buildings. This paper describes the quantitative mapping of asbestos-cement covers over a large mountainous region of Italian Western Alps using the Multispectral Infrared and Visible Imaging Spectrometer sensor. A very large data set made up of 61 airborne transect strips covering 3263 km² were processed to support the identification of buildings with asbestos-cement roofing, promoted by the Valle d'Aosta Autonomous Region with the support of the Regional Environmental Protection Agency. Results showed an overall mapping accuracy of 80%, in terms of asbestos-cement surface detected. The influence of topography on the classification's accuracy suggested that even in high relief landscapes, the spatial resolution of data is the major source of errors and the smaller asbestos-cement covers were not detected or misclassified. [ABSTRACT FROM AUTHOR]

Copyright of La Medicina del Lavoro is the property of Mattioli 1885 SpA and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Asbestos is the common name applied to a group of natural, fibrous silicate minerals, which were once one of the most popular raw materials to be used in building materials. Asbestos was mainly used for the production of assortment asbestos-cement products. Today it is generally known that asbestos belongs to the group of hazardous materials and shows carcinogenic activity. In Poland, asbestos-containing materials are stored in special landfills. This is not the final solution to the asbestos problem because the fibrous structure of asbestos is still maintained. Therefore, methods based on recycling must be found which will be able to destroy asbestos' dangerous fibrous structure. One of these methods may be thermal decomposition, where chemically combined water is released from the asbestos materials during heating. This leads to changes in the crystal structure and to the formation of new mineral phases. The aim of the preliminary research presented in this study was to determine the thermal behaviour as well as the structural and phase transformations of asbestos-cement materials during heating to high temperature. In the present study, three different types of asbestos-containing materials from Poland were examined. Differential thermal analysis, thermogravimetry with evolved gas analysis, X-ray diffraction, infrared spectroscopy and scanning electron microscopy were used to study the thermal decomposition of asbestos-cement samples. It was found that there were no significant differences between the type of asbestos-cement samples used-their thermal decomposition takes place in a similar way. [ABSTRACT FROM AUTHOR]

Copyright of Italian Journal of Remote Sensing / Rivista Italiana di Telerilevamento is the property of Italian Journal of Remote Sensing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Asbestos-cement is a material with valuable strength and durability. It was extensively used for water distribution pipes across the world from the 1950s until the early 1980s. The network of pipes in this case study dates from the 1970s, and after more than 30 to 40 years of service, some pipes have been found to break under common service pressure with no apparent reason. A set of mechanical tests was performed including bending, compression, pressure and crushing tests. Microscopy analysis was also used to understand the material behaviour. Tests showed that there was a clear loss of strength in the pipes and that the safety factor was under the established threshold in most of the specimens. Microscopy results showed morphological damage to the pipes. The loss of strength was attributed to a leaching effect. Leaching damages the cement matrix and reduces the frictional interfacial shear stress. [ABSTRACT FROM AUTHOR]

Abstract: The first aim of this study was to characterise total and size-fractionated particulate matter (PM) aerosol, including fibres, released from the processing operations of cement roofing slates. The second aim was to compare particle emissions from asbestos-cement and non-asbestos cement sheets, with respect to total and size-fractionated particulate matter as well as fibres emissions. Asbestos and cellulose-based cement sheets were compared during slate treatment processes, namely crushing, rubbing, rasping and scrubbing. Generated PM and fibres were classified by a variety of methods (PM2.5 and PM10 cyclones, aerodynamic particle spectrometer and optical particle counter). A substantial variation in the mass of generated particles has been noticed, both within each PM fraction and between different treatment processes. The PM10/PMtotal concentration ratio ranged from 70 to 98% and PM2.5/PMtotal ratio equalled to ∼20%. The new generation non-asbestos sheets produced three times higher PM emissions than asbestos-cement sheets during crushing operation. Particle size distribution of number concentrations was mostly bimodal (two modes at 0.5 and 2.5 μm). With respect to fibres, the release of cellulose fibres from non-asbestos slates was from 1.8 to 13 times lower in comparison with asbestos fibres. At the same time, cellulose fibre length was 1.4–1.6 times lower. Hence, new generation non-asbestos roofing slates were proved to be less hazardous from the point of view of fibre release, but more hazardous with respect to total particle release. [Copyright &y& Elsevier]

Asbestos–cement roofs, the most widespread sources of airborne, toxic and carcinogenic asbestos fibres, are often colonized by lichens. Since these latter are physical and chemical weathering agents, they have been often considered as significant responsible of disaggregation processes increasing fibre dispersion. Consequently, official guidelines for the management of asbestos often suggest their removal. Weathering and/or covering effects of lichens on asbestos–cement, however, have never been deeply investigated and available procedures to evaluate asbestos–cement aging do not take the biological colonization into account. In this study we show that a 25% lichen cover modifies physical and chemical properties of asbestos–cement sheets containing chrysotile and crocidolite fibres. By innovatively coupling pull up tests and image analysis of linear structures, we show that fibre loss is significantly lower (∼30%) where lichens develop and offer a physical barrier to the fibre detachment. Below the most covering lichens (Acarospora cervina, Candelariella ssp.), chrysotile and crocidolite undergo a partial incongruent dissolution, which in laboratory assays generally determined a reduction of their surface reactivity. Because of their biocovering and bioweathering effects, lichens on asbestos–cement play a role which differs from the current public opinion and the assumptions of some official regulations, acting as effective spontaneous bioattenuation agents. [Copyright &y& Elsevier]

Although asbestos has been used throughout Africa in the past decades, no reports of asbestos-related malignant mesothelioma are available from sub-Saharan Africa, except from South Africa and Zimbabwe. We present a case of a 39-year-old man who died from a histologically proven malignant mesothelioma of the peritoneum in Lubumbashi, DR Congo. No occupational exposure to asbestos could be found in his history. In view of his young age, we speculated that he had been exposed to asbestos as a child, which was highly plausible because he had grown up in one of the numerous mining estates of the region. The houses of these estates were often built with asbestos-containing materials, notably roofs made of corrugated asbestos-cement. The possibility of past domestic or environmental exposure to asbestos was substantiated by the identification of chrysotile and crocidolite fibres in samples of asbestos-cement collected from the home where the patient had lived as a child. To our knowledge, this is the first report of malignant mesothelioma from a country in the Central African region. We expect that heightened awareness and improved diagnosis will lead to the detection of more asbestos-related diseases in Africa. [ABSTRACT FROM AUTHOR]