Asbestos-containing Materials Research Articles

Selective extraction of magnesium from asbestos-containing raw materials

Selective extraction of magnesium from asbestos-containing raw materials

Thermal treatment of asbestos containing materials (ACM) by mixing with Na2CO3 and special clays for partial vitrification of waste

Thermochemical processes, using special clays as flux, have been developed for a complete mineralogical conversion of ACM waste into non-asbestos materials. This transformation manages to turn these wastes into a secondary raw materials reducing waste generation, principles in which is based on the Circular Economy.

Accuracy of a mobile app to identify suspect asbestos-containing material in Australian residential settings

In situ asbestos in the built environment is a remaining source of exposure in countries that have prohibited the manufacture and use of asbestos. However, it is difficult to identify in situ asbestos-containing material in residential settings. The objective of this study was to evaluate the accuracy of the mobile phone application (“app”), ACM Check, in identifying in situ asbestos located inside and outside of homes compared with onsite inspections conducted by an experienced environmental consultant. A cross-sectional study was undertaken that involved participants completing ACM Check on their homes built pre-1990 and located throughout metropolitan Perth, Western Australia, and an onsite inspection conducted at each home by an environmental consultant. Cohen’s kappa statistic was calculated to evaluate the strength of agreement between the two methods. The 40 houses sampled were built between 1898 and 1988 with a median year of 1966. Thirty-eight (95%) homes had at least one type of material categorized as positive for asbestos by both ACM Check and the environmental consultant (κ = 1.00). Agreement between the two methods differed when categorizing specific materials as positive or negative for asbestos with substantial agreement for fencing (κ = 0.918), outbuilding walls (κ = 0.844), backing board to electrical meter box (κ = 0.826), exterior wall cladding (κ = 0.771), and interior walls (κ = 0.754), and fair agreement for outbuilding roofs (κ = 0.375) and interior flooring (κ = 0.304). ACM Check is a tool that can be used by tradespeople, home renovators, and householders to screen residential settings for the presence of in situ asbestos-containing material. Mobile phone apps have the potential to be developed or modified for use in other countries to help users identify asbestos and reduce their risk of asbestos exposure.

Workplace Respiratory Protection Factors during Asbestos Removal Operations.

Numerous changes have been made to the French labour regulations in recent years relating to the prevention of risks of exposure to asbestos fibres for operators removing asbestos-containing materials. These changes refer to the method used to count fibres, the collective and personal protective devices to be used on these worksites, and the occupational exposure limit value, which was reduced to 10 f.L-1 on 2 July 2015. In this context, this study assessed the level of respiratory protection afforded by supplied-air respirators and powered air-purifying respirators by monitoring exposure for several operators on nine worksites. The levels of dustiness measured in personal samples taken outside masks showed significant evidence of potential exposure during removal of asbestos-containing plaster or sprayed asbestos, and when using abrasive blasting to treat asbestos-containing materials. For these tasks outside concentration regularly exceeds 25000 f.L-1. Measurements inside masks were generally low, under 10 f.L-1, except in some situations involving the removal of asbestos-containing plaster. This partial penetration of fibres inside masks could be due to the high loading linked to this material. The distributions of Workplace Protection Factors obtained for the two types of respiratory protective devices studied were broad, and the fifth percentile values equal to 236 and 104, respectively, for supplied-air respirators and powered air-purifying respirators. This work highlights once again the need to prioritize collective protection when seeking to prevent asbestos-related risks.

Assessment of occupational exposure to asbestos fibers: Contribution of analytical transmission electron microscopy analysis and comparison with phase-contrast microscopy

ABSTRACTFrom November 2009 to October 2010, the French general directorate for labor organized a large field-study using analytical transmission electron microscopy (ATEM) to characterize occupational exposure to asbestos fibers during work on asbestos containing materials (ACM). The primary objective of this study was to establish a method and to validate the feasibility of using ATEM for the analysis of airborne asbestos of individual filters sampled in various occupational environments. For each sampling event, ATEM data were compared to those obtained by phase-contrast optical microscopy (PCOM), the WHO-recommended reference technique. A total of 265 results were obtained from 29 construction sites where workers were in contact with ACM. Data were sorted depending on the combination of the ACM type and the removal technique. For each “ACM-removal technique” combination, ATEM data were used to compute statistical indicators on short, fine and WHO asbestos fibers. Moreover, exposure was assessed taking into account the use of respiratory protective devices (RPD). As in previous studies, no simple relationship was found between results by PCOM and ATEM counting methods. Some ACM, such as asbestos-containing plasters, generated very high dust levels, and some techniques generated considerable levels of dust whatever the ACM treated. On the basis of these observations, recommendations were made to measure and control the occupational exposure limit. General prevention measures to be taken during work with ACM are also suggested. Finally, it is necessary to continue acquiring knowledge, in particular regarding RPD and the dust levels measured by ATEM for the activities not evaluated during this study.

Australia's Ongoing Legacy of Asbestos: Significant Challenges Remain Even after the Complete Banning of Asbestos Almost Fifteen Years Ago.

The most effective way of reducing the global burden of asbestos-related diseases is through the implementation of asbestos bans and minimising occupational and non-occupational exposure to respirable asbestos fibres. Australia’s asbestos consumption peaked in the 1970s with Australia widely thought to have had among the highest per-capita asbestos consumption level of any country. Australia’s discontinuation of all forms of asbestos and asbestos-containing products and materials did not occur at a single point of time. Crocidolite consumption ceased in the late 1960s, followed by amosite consumption stopping in the mid 1980s. Despite significant government reports being published in 1990 and 1999, it was not until the end of 2003 that a complete ban on all forms of asbestos (crocidolite, amosite, and chrysotile) was introduced in Australia. The sustained efforts of trade unions and non-governmental organisations were essential in forcing the Australian government to finally implement the 2003 asbestos ban. Trade unions and non-government organisations continue to play a key role today in monitoring the government’s response to Australian asbestos-related disease epidemic. There are significant challenges that remain in Australia, despite a complete asbestos ban being implemented almost fifteen years ago. The Australian epidemic of asbestos-related disease has only now reached its peak. A total of 16,679 people were newly diagnosed with malignant mesothelioma between 1982 and 2016, with 84% of cases occurring in men. There has been a stabilisation of the age-standardised malignant mesothelioma incidence rate in the last 10 years. In 2016, the incidence rate per 100,000 was 2.5 using the Australian standard population and 1.3 using the Segi world standard population. Despite Australia’s complete asbestos ban being in place since 2003, public health efforts must continue to focus on preventing the devastating effects of avoidable asbestos-related diseases, including occupational and non-occupational groups who are potentially at risk from exposure to respirable asbestos fibres.

Asbestos Consumption in Mongolia: 1996-2014.

Asbestos is still used in Mongolia in the energy and construction sectors, among others. However, limited data is available on asbestos consumption and asbestos-related disease in Mongolia. The purpose of this paper is to present the available information on the importation of asbestos into Mongolia. We used data on annual asbestos imports between 1996 and 2014 from Mongolian Customs Statistics and the National Council on Toxic and Hazardous Substances Affairs. The uses of this material are also presented with respect to chrysotile alone. Most asbestos is used for construction. Mongolia started using asbestos in the energy and construction industries as thermal insulation in 1961. Asbestos is still allowed for use in Mongolia under the Law on Toxic and Hazards Substances. There are no asbestos mines in Mongolia, and the manufacture of asbestos-containing materials does not take place there. Thus, asbestos is mainly imported from China and Russia. Mongolia used 44,422 metric tons of asbestos-containing materials between 1996 and 2014. In Mongolia, with the current use of asbestos, there will be a continuing risk of developing asbestos-related diseases from past use, and proper oversight of asbestos-involving activities and the safe removal and disposal of asbestos must be considered.

Identifying Asbestos-Containing Materials in Homes: Design and Development of the ACM Check Mobile Phone App.

BackgroundAsbestos-containing materials (ACMs) can still be found in many homes in Australia and other countries. ACMs present a health risk when they are damaged or disturbed, such as during do-it-yourself home renovations. However, community members lack knowledge and awareness about asbestos identification and its safe management in residential settings.ObjectiveThe objective of our study was to describe the process of developing a mobile phone app, ACM Check, that incorporates a questionnaire designed to identify and assess ACMs located in residential settings.MethodsA multidisciplinary team was involved in the formative development and creation of the mobile phone app. The formative development process comprised 6 steps: defining the scope of the app; conducting a comprehensive desktop review by searching online literature databases, as well as a wider online search for gray literature; drafting and revising the content, questionnaire, conditional branching rules, and scoring algorithms; obtaining expert input; manually pretesting the questionnaire; and formulating a final content document to be provided to the software development company. We then constructed ACM Check on the iOS platform for use in a validation study, and then updated the app, replicated it on Android, and released it to the public.ResultsThe ACM Check app identifies potential ACMs, prioritizes the materials based on their condition and likelihood of disturbance, and generates a summary report for each house assessed.ConclusionsACM Check is an initiative to raise community members’ awareness of asbestos in the residential environment and also serves as a data collection tool for epidemiologic research. It can potentially be modified for implementation in other countries or used as the basis for the assessment of other occupational or environmental hazards.

History of Asbestos Ban in Hong Kong.

As millions of immigrants moved to Hong Kong (HK) from China in the recent decades, large amount of residential housings were built in the early years and a substantial proportion of those buildings used asbestos-containing materials (ACMs). Since the number of new cases of ARDs diagnosed has increased year by year since 1990’s, the remarkable increase of incidences had drawn the attention of the public and most importantly the HK government. It became one of the trigger points leading to asbestos ban in HK history. Comparatively, non-governmental organizations (NGOs), labor unions and patients’ self-help organizations demonstrated a more aggressive and proactive attitude than the HK government and have played a key role in the development of asbestos banning policy in HK. After numerous petitions and meetings with the government representatives by those parties in the past decade, the HK government eventually changed its attitude and started to consider terminating the endless threat from asbestos by amending the policy, and the new clause of legislation for banning of all forms of asbestos was enacted on 4 April 2014. Other than the restriction of asbestos use, the compensation system about ARDs has also made some great moves by the effort of those parties as well. Based on the experience we learnt through the years, efforts from different stakeholders including patients’ self-help organizations, NGOs, legislative councilors, and media power are absolutely essential to the success of progression and development in today’s asbestos banning in HK.

Framework for assessment and phytoremediation of asbestos-contaminated sites.

We examine the feasibility of phytoremediation as an alternative strategy to limit the exposure of asbestos in site with asbestos-containing materials. We collected soils from four locations from two sites-one with naturally occurring asbestos, and another, a superfund site, where asbestos-containing materials were disposed over decades-and performed ecotoxicology tests. We also performed two experiments with crop cultivar and two grasses from serpentine ecotype and cultivar to determined best choice for phytoremediation. Asbestos concentrations in different size fractions of soils varied by orders of magnitude. However, different asbestos concentrations had little effect on germination and root growth. Presence of co-contaminants such as heavy metals and lack of nutrients affected plant growth to different extents, indicating that several of these limiting factors should be considered instead of the primary contaminant of concern. Crop cultivar survived on asbestos-contaminated soil. Grasses from serpentine ecotype did not show higher biomass than the cultivar. Overall, these results showed that soil conditions play a critical role in screening different crop species for phytoremediation and that asbestos concentration has limited to no effect on plant growth. Our study provided a framework for phytoremediation of asbestos-contaminated sites to limit long-term asbestos exposure.

Managing Asbestos-Containing Materials in the Built Environment: Report of a Health and Safety Executive and Government Office for Science Workshop.

The duty to manage asbestos in non-domestic premises is described in the Control of Asbestos Regulations 2012. Health and Safety Executive (HSE) policy and guidance on asbestos in the built environment in Great Britain is that asbestos-containing materials (ACMs) that are in good condition and unlikely to be disturbed can be managed in place. Where ACMs are in poor condition or likely to be disturbed they should be repaired, encapsulated or, if necessary, removed. HSE and Government Office for Science hosted a stakeholder workshop to consider evidence on the management of ACMs in public buildings. Invitees attended from a range of backgrounds (including regulatory, government, academic, medical, public interest groups, and professional service providers). Participants considered the evidence, suggested nine evidence gap areas and ranked these according to preference in an anonymous vote. The top three suggested evidence gaps were: (i) the comparative risks of managing ACMs in place versus removal; (ii) improved measurement techniques at lower fibre concentrations; and (iii) building the evidence base on the effectiveness of asbestos management and safe removal. HSE will use the workshop outputs to inform its research planning. It is anticipated that a number of initiatives for shared research will be explored.

Grouping by Visual Appearance of Construction and Demolition Waste for Sorting Time Reduction with the Aim of Removing Asbestos-Containing Materials

As asbestos-containing waste from building demolitions has to undergo special treatment prior to recycling or final disposal, the demolition of buildings and the sorting of waste materials are conducted after checking for asbestos content in the construction materials (according to ISO, EPA or JIS). However, as solid waste is usually a mixture, it is possible that asbestos-containing material (ACM) is present in construction and demolition waste (CDW) that is transported to an intermediate treatment facility for CDW. In addition, the presence of ACM in disaster waste cannot be avoided. Therefore, a rapid method for the determination of asbestos at an intermediate treatment facility for CDW is required. In this study, the separation efficiency and the sorting time of CDW particles by grouping by visual appearance (GVA) were determined. In the case that the separation efficiency by GVA in this study was equivalent to that by visual observation with a loupe (DVL) in a previous study, the reduction of sorting time by GVA was evaluated. Newton’s separation efficiency by GVA and recovery rate were equivalent to that by DVL for 5.1 cm2 observation. In this case, the sorting time by GVA was 1/7 of that by DVL. Therefore, sorting time could be shortened by GVA under the condition of equivalent separation efficiency. In order to reduce the sorting time per worker to less than 1 h/t, only CDWPs having particle size larger than 12 cm for GVA or 20 cm for DVL for 5.1 cm2 observation should be subjected to sorting. Aiming to avoid diffusion of asbestos-containing waste, the authors suggest that grouping by visual appearance as a primary sorting step is effective to reduce sorting time of CDW from disaster waste or unknown origin.

A Bayesian Model and Stochastic Exposure (Dose) Estimation for Relative Exposure Risk Comparison Involving Asbestos-Containing Dropped Ceiling Panel Installation and Maintenance Tasks.

Assessing exposures to hazards in order to characterize risk is at the core of occupational hygiene. Our study examined dropped ceiling systems commonly used in schools and commercial buildings and lay-in ceiling panels that may have contained asbestos prior to the mid to late 1970s. However, most ceiling panels and tiles do not contain asbestos. Since asbestos risk relates to dose, we estimated the distribution of eight-hour TWA concentrations and one-year exposures (a one-year dose equivalent) to asbestos fibers (asbestos f/cc-years) for five groups of workers who may encounter dropped ceilings: specialists, generalists, maintenance workers, nonprofessional do-it-yourself (DIY) persons, and other tradespersons who are bystanders to ceiling work. Concentration data (asbestos f/cc) were obtained through two exposure assessment studies in the field and one chamber study. Bayesian and stochastic models were applied to estimate distributions of eight-hour TWAs and annual exposures (dose). The eight-hour TWAs for all work categories were below current and historic occupational exposure limits (OELs). Exposures to asbestos fibers from dropped ceiling work would be categorized as "highly controlled" for maintenance workers and "well controlled" for remaining work categories, according to the American Industrial Hygiene Association exposure control rating system. Annual exposures (dose) were found to be greatest for specialists, followed by maintenance workers, generalists, bystanders, and DIY. On a comparative basis, modeled dose and thus risk from dropped ceilings for all work categories were orders of magnitude lower than published exposures for other sources of banned friable asbestos-containing building material commonly encountered in construction trades.

Application of Microwave Energy at Treatment of Asbestos Cement (Eternit)

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. It is therefore advisable to attempt to dispose of asbestos minerals in asbestos-containing materials and to convert them into a harmless material. One of methods may be microwave thermal decomposition of asbestos minerals. The research was used for old etemit roof ceiling. X-ray analysis indicated the presence of undesirable chrysotile. Its thermal destruction was carried out in a microwave oven in the power of 2500 W. In case the heating time was 15 min, X-ray analysis was confirmed chrysotile change into harmless minerals. Thermal analysis was used for characterization and the thermal behaviour of the asbestos cement sample.

Detection of asbestos-containing materials in agro-ecosystem by the use of airborne hyperspectral CASI-1500 sensor including the limited use of two UAVs equipped with RGB cameras

ABSTRACTThis study aims to identify asbestos-containing materials (ACM) through the use of innovative technology such as aerial hyperspectral sensors. The development of operational methodologies and ad hoc processing were also applied for the purpose of this study. The activity was part of the ICT Living Labs DroMEP project carried out by Water Research Institute of the National Research Council (IRSA-CNR) and Servizi di Informazione Territoriale S.r.l. (SIT Srl). This was funded by the Apulia Region to support the growth and development of specialized SMEs in offering digital content and services. Uncontrolled abandoned wastes pose a threat to the human health and ecosystem. The presence of harmful or dangerous substances released without any control can become a dangerous source of pollution. Many areas of the Apulia region generally, in southern Italy, are subjected to this type of phenomena because most often, these areas are not easily accessible to Authorities for the control and management of the territory. Land monitoring and characterization operations would be carried out in a very long time and would require significant financial resources and considerable effort if done by conventional methods. The project activities include the testing and integration of several technologies already available, but not engineered for specific purposes. The work has been focused on the development of a methodology with a defined and high reliability capable of identifying the presence of ACM in various piles of rubbish abandoned in agro-ecosystems. The developed methodology analyses the spectral behaviour of ACM highlighting and emphasizing certain features through the use of a procedure based on an if–then–else control structure. It also allows the selection of the most effective features to combine that significantly reduces the number of false positives.

Estimating the Additional Greenhouse Gas Emissions in Korea: Focused on Demolition of Asbestos Containing Materials in Building.

When asbestos containing materials (ACM) must be removed from the building before demolition, additional greenhouse gas (GHG) emissions are generated. However, precedent studies have not considered the removal of ACM from the building. The present study aimed to develop a model for estimating GHG emissions created by the ACM removal processes, specifically the removal of asbestos cement slates (ACS). The second objective was to use the new model to predict the total GHG emission produced by ACM removal in the entire country of Korea. First, an input-equipment inventory was established for each step of the ACS removal process. Second, an energy consumption database for each equipment type was established. Third, the total GHG emission contributed by each step of the process was calculated. The GHG emissions generated from the 1,142,688 ACS-containing buildings in Korea was estimated to total 23,778 tonCO2eq to 132,141 tonCO2eq. This study was meaningful in that the emissions generated by ACS removal have not been studied before. Furthermore, the study deals with additional problems that can be triggered by the presence of asbestos in building materials. The method provided in this study is expected to contribute greatly to the calculation of GHG emissions caused by ACM worldwide.

An Australian stocks and flows model for asbestos.

All available data on asbestos consumption in Australia were collated in order to determine the most common asbestos-containing materials remaining in the built environment. The proportion of asbestos contained within each material and the types of products these materials are most commonly found in was also determined. The lifetime of these asbestos containing products was estimated in order to develop a model that projects stocks and flows of asbestos products in Australia through to the year 2100. The model is based on a Weibull distribution and was built in an excel spreadsheet to make it user-friendly and accessible. The nature of the products under consideration means both their asbestos content and lifetime parameters are highly variable, and so for each of these a high and low estimate is presented along with the estimate used in the model. The user is able to vary the parameters in the model as better data become available.

Assessment of Health Risk from Historical Use of Cosmetic Talcum Powder.

This study's objective is to assess the risk of asbestos-related disease being contracted by past users of cosmetic talcum powder. To our knowledge, no risk assessment studies using exposure data from historical exposures or chamber simulations have been published. We conducted activity-based sampling with cosmetic talcum powder samples from five opened and previously used containers that are believed to have been first manufactured and sold in the 1960s and 1970s. These samples had been subject to conflicting claims of asbestos content; samples with the highest claimed asbestos content were tested. The tests were conducted in simulated-bathroom controlled chambers with volunteers who were talc users. Air sampling filters were prepared by direct preparation techniques and analyzed by phase contrast microscopy (PCM), transmission electron microscopy (TEM) with energy-dispersive x-ray (EDX) spectra, and selective area diffraction (SAED). TEM analysis for asbestos resulted in no confirmed asbestos fibers and only a single fiber classified as "ambiguous." Hypothetical treatment of this fiber as if it were asbestos yields a risk of 9.6 × 10-7 (under one in one million) for a lifetime user of this cosmetic talcum powder. The exposure levels associated with these results range from zero to levels far below those identified in the epidemiology literature as posing a risk for asbestos-related disease, and substantially below published historical environmental background levels. The approaches used for this study have potential application to exposure evaluations of other talc or asbestos-containing materials and consumer products.

Evaluation of asbestos-containing products and released fibers in home appliances

ABSTRACTThe purpose of this study was to detect asbestos-containing products and released asbestos fibers from home appliances. The authors investigated a total of 414 appliances manufactured between 1986 and 2007. Appliances were divided into three categories: large-sized electric appliances, small-sized electric appliances, and household items. Analysis for asbestos-containing material (ACM) was performed using polarized light microscopy (PLM) and stereoscopic microscopy. Air sampling was performed to measure airborne concentration of asbestos using a phase-contrast microscope (PCM). The results of the analysis for ACM in appliances show that large-sized electric appliances (refrigerators, washing machines, kimchi-refrigerators) and household items (bicycles, motorcycles, gas boilers) contain asbestos material and small-sized electric appliances do not contain asbestos material. All appliances with detected asbestos material showed typical characteristics of chrysotile (7–50%) and tremolite (7–10%). No released fibers of ACM were detected from the tested appliances when the appliances were operating. This study gives the basic information on asbestos risk to people who use home appliances.Implications: All appliances with detected asbestos material showed typical characteristics of chrysotile (7–50%) and tremolite (7–10%). No released fibers of ACM were detected from the tested appliances when the appliances were operating.

Asbestos in recycled materials – modern risks and future concerns

The presence of asbestos fibres and asbestos-containing materials within recycled building materials is not a new phenomenon, but due to increased awareness and therefore increased analysis of these recycled materials, it has become an additional contaminant for developers to consider when investigating construction sites. Further to this, asbestos replacements such as man-made mineral fibre and refractory ceramic fibre currently being used in construction may be the problems of the future, the risks of which should be considered now.