Sustainable management of hazardous asbestos-containing materials: Containment, stabilization and inertization

Identification, mapping, and quantification of asbestos minerals in ACM and NOA using NIR-SWIR hyperspectral scan imaging: Preliminary study

Here, we aimed at extending the Near Infrared-Short-wave infrared (NIR-SWIR) spectroscopy approach in characterizing Asbestos Containing Materials (ACM) and Natural Occurring Asbestos (NOA) through the development and testing of a novel portable asbestos mapping tool based on Hyperspectral Imaging (NIR-HSI) tool. This was built using high resolution spectroscopy over a range of about 170 nm around the OH overtone bands (about 1370-1420 nm), a supercontinuum laser for vibrational excitation, compact XYZ translation stages, and dedicated software. The vibrational reflection data measured using this system allowed discriminating different asbestos minerals and to define the methodological basis for their quantification in various matrices. Point scan NIR-SWIR reflectance images with a spatial resolution of about 50 µm allowed successfully mapping asbestos inclusion in proximity of the surface of a set of samples. The experimentation demonstrated the possibility of characterizing asbestos in NOA or ACM directly in situ, through mineral mapping providing qualitative and semi-quantitative information on the asbestos fiber contents.

Mesothelioma carcinogenesis of chrysotile and forsterite compared and validated by intraperitoneal injection in rat

Asbestos, especially chrysotile, continues to be exposed to humans globally. Hence, it should be disposed properly to prevent asbestos-related diseases, including mesothelioma and lung cancer. This study aimed to verify whether forsterite, a heating product of chrysotile, can cause carcinogenicity, particularly mesothelioma. Forsterite (FO-1000) and enstatite (EN-1500) produced by heating chrysotile at 1,000°C and 1,500°C, respectively, were subjected. We injected 10 mg of chrysotile, FO-1000, or EN-1500 in rats intraperitoneally and observed the development of peritoneal mesothelioma until 24 months. The incidence of peritoneal mesothelioma in the chrysotile group was 91.2%, whereas in the FO-1000 and EN-1500 groups, peritoneal mesothelioma did not develop. Urinary 8-hydroxy-2'-deoxyguanosine and serum N-ERC/mesothelin concentrations significantly increased in the chrysotile group that developed peritoneal mesothelioma, while they only temporarily changed in the FO-1000 or EN-1500 groups during early treatment. Furthermore, there was a significant homozygous deletion of the CDKN2A/p16 gene in the chrysotile group compared to the control group, in contrast to no significant difference in the FO-1000 and EN-1500 groups. Therefore, this study provides clear evidence that forsterite is a nonmesothelioma carcinogen and suggests that forsterite and enstatite are sufficient substances for chrysotile detoxification.

Magnesium and silicon recovery from chrysotile asbestos waste of the deposit Zhitikara, Kazakhstan

Waste generated during asbestos manufacturing contains substantial quantities of iron, nickel, magnesium, and silicon. The existing techniques for processing chrysotile-asbestos waste (CAW) cannot fully recover these elements. Therefore this paper presents a hydrometallurgical method for processing the CAW of the Zhitikara deposit in the Kostanay region of Kazakhstan. Batch reactors are used in both laboratory and pilot experiments, and initial trials are conducted in a recently constructed industrial Ti reactor at the Kostanay Minerals JSC plant in the Kostanay region of Zhitikara. The primary benefits of the industrial reactor include operation without excessively grinding the feedstock and creation of a pulp with enhanced filtration properties. A moderate agitation speed (10 rpm) helps ensure a consistent pulp density and prevent the production of silica gel. Optimal leaching conditions are determined as a fraction size of CAW between - 1.25 and 0.25 mm, hydrochloric acid concentration of 18 wt%, temperature of ~ 85-90 °C, pressure of 1 atmosphere, and duration of 2 h. An investigation of the process kinetics reveals that diffusion is the rate-controlling step. Further, the activation energies are determined to be 54.4 kJ.mol- 1, and the leaching rates of Mg, Fe, and Ni under these conditions are 96.0, 87.8, and 81.3%, respectively. Washing and recycling water enhances helps to increase the recovery of magnesium chloride. Implementing pilot-scale hydrometallurgical processing of CAW can effectively address environmental issues that pose a threat to human health and provide commercial advantages.

Leaching and geochemical modeling of asbestos-cement waste and mine asbestos

Asbestos-Containing Materials (ACMs) were widely used in the construction sector but, due to their harmful health effects, many countries have banned their use. ACMs are classified as hazardous and, in contact with water, produce potentially harmful leachates. The objective of this work was to determine the leaching behavior of 20 elements from two asbestos-cement materials and mine asbestos samples across the entire pH range and varying liquid-to-solid ratios (column tests). The pH-dependence tests showed consistent leaching patterns across the three materials. Geochemical speciation model (LeachXS) predictions were successful in most cases of the batch experiments and were improved by adjusting iron oxides concentration for some elements. Model predictions were successful for fewer elements in the column experiments. Depending on the pH, element release was controlled by respective solid phase dissolution, sorption onto iron oxides and substitution in ettringite. Some leaching concentrations exceeded the EU limits for granular non-hazardous waste landfills. Considering the strongly alkaline nature of monolithic asbestos-cement waste undergoing carbonation, we propose all three materials to be disposed of in non-hazardous waste landfills, according to EU legislation. A case study concluded that geochemical modeling of ACMs leaching is a useful tool in estimating element release under various environmental conditions.

Efficient Management of Asbestos Waste Through Utilization as Mineral Additives in Portland Cement Production

This article presents research on the effectiveness of utilizing asbestos waste, particularly chrysotile asbestos, in the production of Portland cement. The study aimed to evaluate the feasibility of transforming asbestos cement (Eternit) through thermal treatment and its enrichment with mineral additives, enabling its integration into the clinker synthesis process. Differences in the physicochemical properties of types of cement produced from conventional raw materials and those manufactured using asbestos waste were analyzed. The research findings indicate that the presence of asbestos in cementitious materials leads to a significant mass loss of 29.4% due to thermal decomposition. Chemical analysis revealed the presence of aluminum oxide (Al2O3) and iron oxide (Fe2O3) at levels of 4.10% and 3.54%, respectively, suggesting the formation of brownmillerite, a phase typical of cement clinker. Furthermore, compressive strength tests on asbestos-modified cements demonstrated comparable mechanical properties to reference cement (CEM I), indicating their potential applicability in construction. This study provides essential insights into the mineralogical composition of asbestos cement, which is crucial for developing effective methods for its safe disposal. It represents a significant step toward sustainable asbestos waste management and the promotion of innovative solutions in the construction industry.

Impact of air quality on the health of present-day workers in an Asbestos roof manufacturing industry, Sri Lanka

The study's objective was to determine the air quality in an asbestos-related industry and its impact on current workers' respiratory health. Seventy-seven air and 65 dust samples were collected at 5-day intervals in an asbestos roofing sheets production factory in Sri Lanka having two production facilities. Sampling was performed in ten sites: Defective sheets-storage, Production-plant, Pulverizer, Cement-silo, and Loading-area. A detailed questionnaire and medical screening were conducted on 264 workers, including Lung Function Tests (LFT) and chest X-rays. Asbestos fibres were observed in deposited dust samples collected from seven sites. Free chrysotile fibres were absent in the breathing air samples. Scanning Electron Microscopy confirmed the presence of asbestos fibres, and the Energy Dispersive X-ray analysis revealed Mg, O, and Si in depositions. The average concentrations of trace metals were Cd-2.74, Pb-17.18, Ni-46.68, Cr-81.01, As-7.12, Co-6.77, and Cu-43.04 mg/kg. The average Zn, Al, Mg, and Fe concentrations were within 0.2-163 g/kg. The highest concentrations of PM2.52.5 and PM1010, 258 and 387 µg/m3, respectively, were observed in the Pulverizer site. Forty-four workers had respiratory symptoms, 64 presented LFT abnormalities, 5 indicated chest irregularities, 35.98% were smokers, and 37.5% of workers with abnormal LFT results were smokers. The correlation coefficients between LFT results and work duration with respiratory symptoms and work duration and chest X-ray results were 0.022 and 0.011, respectively. In conclusion, most pulmonary disorders observed cannot directly correlate to Asbestos exposure due to negligible fibres in breathing air, but fibres in the depositions and dust can influence the pulmonary health of the employees.

The impacts of earthquakes on air pollution and strategies for mitigation: a case study of Turkey

This study delves into the repercussions of the 2023 earthquake in Turkey, particularity its impact on air pollution. A year post-event, it is evident that scientific literature has paid limited attention to monitoring the situation. However, the release of hazardous substances, such as asbestos, lead, and other toxins, from damaged structures poses a significant threat by contaminating nearby air, soil, and water sources, thereby jeopardizing ecosystems and public well-being. The improper disposal of waste post-earthquake and the presence of mining and oil refinery sites in the region contribute to potential air pollutants. These circumstances create challenging environments conducive to the spread of respiratory diseases, with potential long-term health and social consequences. Unfortunately, existing data gaps hinder a comprehensive understanding of the situation. This paper pioneers the reporting and analysis of data regarding potential sources of air pollution resulting from the earthquake in Turkey. It also pinpoints gaps in knowledge, outlining areas that demand further investigation. To effectively prevent and mitigate air pollution risks and associated health concerns linked to earthquakes, strategic recommendations are proposed. A key suggestion is the establishment of post-disaster air pollution monitoring systems capable of swiftly identifying emerging health issues, facilitating efficient responses, and curtailing potential long-term effects of the disaster. The paper underscores the necessity for continuous health monitoring of the affected population to mitigate possible adverse impacts on human health. These strategies play a pivotal role in reducing the likelihood of air pollution, supporting emergency response and recovery initiatives, and fostering new dedicated scientific studies.

Assessment of asbestos-cement roof distribution and prioritized intervention approaches through hyperspectral imaging

The discernment of asbestos-cement (AC) roofs within urban areas stands as a pivotal concern pertinent to communal well-being and ecological oversight, particularly in emerging nations where asbestos continues to be extensively employed. Conventional methodologies entailing the recognition of asbestos-cement roofs and the characterization of their degradation status, such as tangible examinations and laboratory assays, prove to be temporally protracted, financially demanding, and arduous to extrapolate comprehensively across expansive urban domains. In this paper, it is presented a novel approach for identifying asbestos-cement roofs in urban areas using hyperspectral airborne acquisition and carry out a diagnosis that allows to identify the state of asbestos-cement roofs and thus provide a tool for the competent authorities to develop and prioritize intervention strategies to mitigate the problem. Four different methodologies were implemented and compared, three of which are new in the literature, to identify the deterioration of asbestos-cement (AC) roof state in large urban areas. This, in turn, furnishes a tool for competent authorities to identify the state of AC roofs, develop and prioritize intervention strategies to mitigate the problem. The control points in field allowed validating the classification and the proposed methodology for the prioritization of intervention in AC roofs. Some neighborhoods in the city showed peaks in the area of asbestos-cement roofs of 47% of the total area of the neighborhood, representing practically all of the roofs present in the neighborhood. On average around 20% of the total area of a neighborhood in Cartagena is covered by AC. Furthermore, it was found a total area of AC roofs throughout the city of more than 9 km2 (9 million square meters). On the other hand, two of the 4 methods used showed encouraging results that demonstrate their ability to identify covers in poor and good condition at a large scale from hyperspectral images. This academic novelty suggests that there is a possibility of practical application of these methods in other urban contexts with high concentrations of AC roofs, helping in the planning and optimization of intervention strategies to mitigate the risk in public and environmental health due to the presence of asbestos.

Global, regional, and national burden of asbestosis from 1990 to 2019 and the implications for prevention and control

BACKGROUND

Asbestosis is a common pneumoconiosis caused by long-term asbestos exposure. Analysis of the burden of asbestosis would help in creating informed public health strategies.

METHODS

Data on asbestosis were analyzed using the Global Burden of Disease study 2019. The estimated annual percentage change (EAPC) was calculated to demonstrate temporal trends in the age-standardized rate (ASR) of asbestosis from 1990 to 2019.

RESULTS

Globally, 36,339 incident cases of asbestosis, led to 3572 deaths and 71,225 disability adjusted life years (DALYs) in 2019. During 1990-2019, the overall ASRs of incidence and DALYs declined by an annual average of 0.29 % and 0.27 %, with the respective EAPCs being -0.29 (95 % confidence interval [CI]: -0.43, -0.14) and -0.27 (95%CI: -0.53, -0.01). The ASRs of mortality increased with EAPC of 0.65 (95%CI: 0.34, 0.96). Trends in incidence and prevalence rose in females, but declined in males. The asbestosis burden was heterogeneous across regions and countries. The heaviest burden of asbestosis was observed in the United States, India, and China. Trends in ASRs of asbestosis varied across countries/territories. Pronounced increasing trends in incidence and prevalence occurred in Georgia, Iran, and Croatia.

CONCLUSIONS

Decreasing incident trend of asbestosis was observed globally over the past three decades. However, the ongoing asbestosis burden highlighted that asbestosis remained a challenge to public health, and cost-effective measures were required to reduce the asbestosis burden.