Asbestos in soil and water: A review of analytical techniques and methods

Examining the Environmental Ramifications of Asbestos Fiber Movement Through the Water-Soil Continuum: A Review

The environmental pollution potential of asbestos products is a worldwide health issue, but their dissemination through the water-soil continuum is often an overlooked aspect. Similarly, the behavior of asbestos fibers released from the products is still not fully understood, although our knowledge is based on studies concerning their mineralogical characteristics, health effects, and waste disposal. It has been claimed and contradicted that asbestos harm is only found in air and humans. Asbestos fibers are found not only in industrial settings but also through the industrial use of asbestos cement products, which has contributed to asbestos emissions and its movement in water and soil. Asbestos fibers are diverse in their physicochemical properties, and this diversity has a significant influence on their behavior in the environment. Recent research has confirmed that asbestos can be transported by water and spread to other parts of the environment. However, the mechanisms underlying this, such as the settling of fibers, their attachment to soil particles, or their movement in groundwater, as well as the environmental and health implications, require further investigation. This paper examines the process and impact of asbestos contamination in the interconnected water, soil, and plant environmental sectors, providing a systematic review of the latest literature.

Assessing potentially toxic elements (PTEs) content in asbestos and related groundwater: A review of the levels detected

This article provides a review of published literature on the concentration levels of potentially toxic elements (PTEs) in asbestos minerals like chrysotile, actinolite, amosite (asbestiform grunerite), anthophyllite, crocidolite (asbestiform riebeckite) and tremolite and their potential to release PTEs into groundwaters worldwide. A large number of PTEs, such as Fe, Cr, Ni, Mn, Co and Zn, may be hosted by asbestos minerals, and their release in the lung environment can cause different health problems as well as their intake via drinking water. The review highlights that amosite is the phase with the highest PTEs content, followed by crocidolite, actinolite, anthophyllite, tremolite and chrysotile. Chrysotile, tremolite, and anthophyllite contain higher levels of Cr, Ni, and Co, while Fe and Mn are more enriched in amosite and crocidolite. Actinolite contains a high concentration of all considered PTEs. High levels of Cr, Fe, Zn, Mn, and Ni were also detected in groundwater interacting with ophiolite rocks containing asbestos minerals. The three main recognized hydro-geochemical facies (Mg-HCO3, Ca-HCO3 and Ca-OH), characterizing the ophiolite aquifers, show high levels of Cr and Ni, with values sometimes above the World health Organization (WHO) thresholds for drinking waters, which can cause adverse health effects in short and long term. The knowledge emerging from this work is a significant contribution to the already wide frame of understanding asbestos-related diseases and provide a strong scientific basis for further mineralogical and geochemical studies.

Evaluation of asbestos dispersion during laser ablation of rocks containing Naturally Occurring Asbestos (NOA)

Health risks are often overlooked when the short-term consequences are not immediately apparent. During restoration work, cleaning actions can generate particles that pose health risks to workers through inhalation. This is particularly true in the case of asbestos fibres that might be spread out from the laser cleaning of buildings or heritage artifacts made of stone, such as serpentinite and other ultramafic rocks, that have a high probability of containing asbestos (e.g., chrysotile, tremolite asbestos, actinolite asbestos). To show workers the importance of wearing proper protection to prevent health injuries, several serpentinite samples, ascertained to contain asbestos minerals by specific investigations, have been laser ablated using ad hoc modified equipment in order to collocate a HEPA filter prone to collect all dust emitted during ablation. The powder deposited on the surface of these filters after laser ablation was analyzed, by Powder X -ray Diffraction (PXRD), Transmission Electron Microscopy combined with Energy Dispersive Spectroscopy (TEM/EDS), micro-Raman spectroscopy (μ-Raman) and Fourier-transform infrared spectroscopy (FTIR/ATR). The results confirmed the presence of asbestos fibres during the laser ablation of rocks containing Naturally Occurring Asbestos (NOA), emphasizing the importance of wearing appropriate personal protective equipment (PPE) during these procedures. Noteworthy, approximately 33 % of the analyzed fibres met the WHO criteria in size for respirable fibres. Furthermore, through our experiments, we also demonstrated that using tools that integrate filters into working tools would definitively further decrease the risk of fibres inhalation to workers.

The aftermath of asbestos prohibition in industry and its association with malignant mesothelioma in the south of Iran: An enduring predicament yet to be resolved

Purpose

Malignant Mesothelioma (MM) is a rare malignancy of the serosa membranes with a high mortality rate and long latent period. The relationship between a group of mineral fibers known as asbestos and mesothelioma is now well accepted in which people can be exposed to these fibers by various means during their lifetime and has been its usage has banned in many countries, such as Iran, which announced its gradual elimination from 1999 over a period of 7 years by using safe substitutes. However, the mineral particles are able to sustain itself in the environment, air, water, and soil and on the other hand, symptoms may take up to half a century to develop in exposed individuals. Also, there remains a shortage of comprehensive investigation on the effects of asbestos exposure within the familial context (household or domestic exposure) or on individuals residing in proximity to asbestos mines or factories (environmental exposure). Based on the high number of MM cases in Iran, and also our hypothesis that residuals of asbestos in the environment and petroleum products may be the etiological factor for MM, we conducted this study to evaluate the clinic epidemiological features of MM in the south of Iran its relation to possible asbestos exposure.

Methods

In this study, we analyzed the demographic features and occupations of confirmed cases of MM in Shiraz, southern Iran along with the follow-up of the patients' disease from 2008 to 2018, while also comparing the features of our patients with a control group compromising of 105 non-MM patients.

Results

Among the 35 confirmed cases of MM, with an average age of 61 years, 9 (25.7%) were female, and 26 (74.3%) were male. During our assessment, 12 patients had already died, with a mean time of 11.26 months post-diagnosis. Our findings revealed a higher prevalence of MM among housekeepers and employees of oil companies. In comparison to the control group, individuals with occupational exposure and those residing near refinery locations were at a heightened risk of developing MM. However, based on regression analysis, only occupations associated with refineries exhibited a significant correlation with MM (p = 0.028; OR: 14.602; 95% CI: 1.328-160.499).

Conclusion

Both occupational and para-occupational exposure demonstrated a significant correlation with MM, whereas our regression analysis did not affirm geographical and environmental factors as contributors to MM. Despite the industry's prohibition of direct asbestos usage, the persistent existence of asbestos particles in the environment for decades, coupled with the long latency period of MM, warrants further investigation. Health authorities and policymakers should recognize this potential hazard, prompting an enhancement of early detection within at-risk groups.

Thermally-treated asbestos-cement wastes as supplementary precursor for geopolymeric binders: CO2 emission and properties

This article explores the impact of thermally treated asbestos-cement waste (ACWT) on metakaolin-based geopolymers, using liquid sodium silicate (LSS) and liquid potassium silicate (LKS) as alkali activators. Through statistical mixture design, various formulations were tested for rheological parameters, mineralogical composition, efflorescence mass, electrical conductivity, compressive strength, and CO2 emissions. Formulations with sodium silicate exhibited higher yield stress compared to those with potassium silicate, while flash setting occurred in LKS-activated mixtures with high ACWT content. Alkali activator content significantly affected mechanical strength and leachate electrical conductivity. CO2 emissions were higher for LKS-activated formulations but lower for those with more ACWT. Finally, by incorporating ACWT, it was possible to optimize the formulations, resulting in high compressive strength, reduced free ions, and reduced negative environmental impact.

Mapping soil trace metal distribution using remote sensing and multivariate analysis

Trace metal soil contamination poses significant risks to human health and ecosystems, necessitating thorough investigation and management strategies. Researchers have increasingly utilized advanced techniques like remote sensing (RS), geographic information systems (GIS), geostatistical analysis, and multivariate analysis to address this issue. RS tools play a crucial role in collecting spectral data aiding in the analysis of trace metal distribution in soil. Spectroscopy offers an effective understanding of environmental contamination by analyzing trace metal distribution in soil. The spatial distribution of trace metals in soil has been a key focus of these studies, with factors influencing this distribution identified as soil type, pH levels, organic matter content, land use patterns, and concentrations of trace metals. While progress has been made, further research is needed to fully recognize the potential of integrated geospatial imaging spectroscopy and multivariate statistical analysis for assessing trace metal distribution in soils. Future directions include mapping multivariate results in GIS, identifying specific anthropogenic sources, analyzing temporal trends, and exploring alternative multivariate analysis tools. In conclusion, this review highlights the significance of integrated GIS and multivariate analysis in addressing trace metal contamination in soils, advocating for continued research to enhance assessment and management strategies.

Mobility of crocidolite asbestos in sandy porous media mimicking aquifer systems

Asbestos is widely recognized as being a carcinogen when dispersed in air, but very little is known about its exposure pathways in water and its subsequent effects on human health. Several studies have proved asbestos presence in groundwater but failed to assess its mobility in aquifer systems. This paper aims to fill this gap by studying the transport of crocidolite, an amphibole asbestos, through sandy porous media mimicking different aquifer systems. To this purpose, two sets of column test were performed varying the crocidolite suspension concentration, the quartz sand grain size distribution, and the physicochemical water parameters (i.e., pH). The results proved that crocidolite is mobile in quartz sand due to the repulsive interactions between fibres and porous media. The concentration of fibres at the outlet of the column were found to decrease when decreasing the grain size distribution of the porous medium, with a bigger impact on highly concentrated suspensions. In particular, 5-to-10-µm-long fibres were able to flow through all the tested sands while fibres longer than 10 µm were mobile only through the coarser medium. These results confirm that groundwater migration should be considered a potential exposure pathway while implementing human health risk assessment.

From field analysis to nanostructural investigation: A multidisciplinary approach to describe natural occurrence of asbestos in view of hazard assessment

The environmental impact of natural occurrences of asbestos (NOA) and asbestos-like minerals is a growing concern for environmental protection agencies. The lack of shared sampling and analytical procedures hinders effectively addressing this issue. To investigate the hazard posed by NOA, a multidisciplinary approach that encompasses geology, mineralogy, chemistry, and toxicology is proposed and demonstrated here, on a natural occurrence of antigorite from a site in Varenna Valley, Italy. Antigorite is, together with chrysotile asbestos, one of the serpentine polymorphs and its toxicological profile is still under debate. We described field and petrographic analyses required to sample a vein and to evaluate the NOA-hazard. A combination of standardized mechanical stress and automated morphometrical analyses on milled samples allowed to quantify the asbestos-like morphology. The low congruent solubility in acidic simulated body fluid, together with the toxicity-relevant surface reactivity due to iron speciation, signalled a bio-activity similar or even greater to that of chrysotile. Structural information on the genetic mechanism of antigorite asbestos-like fibres in nature were provided. Overall, the NOA site was reported to contain veins of asbestos-like antigorite and should be regarded as source of potentially toxic fibres during hazard assessment procedure.

Waterborne asbestos: Good practices for surface waters analyses

Asbestos occurrence has been mainly monitored in air so far and only limitedly considered in other matrices, such as water. Waterborne asbestos could originate from natural or anthropogenic sources, leading to non-conventional exposure scenarios. It could be a secondary source of airborne asbestos in case of water-to-air migration, particularly in case of surface moving water, such as in rivers and streams. The scarce attention dedicated to waterborne asbestos has led to a considerable fragmentation in regulatory approaches regarding the study of water samples possibly contaminated by mineral fibres. In this context, this study has been designed to test the reliability of an existing analytical method devoted to natural waters investigations. Following the operational protocol issued by the Piedmont (Italy) Environmental Protection Agency, Scanning Electron Microscopy analyses have been performed on a standard sample of waterborne chrysotile, mimicking stream water. The investigations have been performed by different operators and using different analytical setups, to verify whether the method applied has a good interlaboratory reproducibility and which could be the most error-prone analytical steps. Three data sets have been obtained on the same sample, showing a low reproducibility among each other. Possible reasons causing this discrepancy have been discussed in detail and good practices to perform reliable analyses on surface water samples containing asbestos have been proposed to help the regulatory organs to better define analytical protocols.

Environmental Assessment of Friable Asbestos from Soil to Air Using the Releasable Asbestos Sampler (RAS)

The objectives of this study are to examine the feasibility of the releasable asbestos sampler (RAS) equipment for laboratory tests as an alternative to activity-based sampling (ABS), and to apply the equipment controlled by wind velocity and water contents in the field to asbestos-contaminated soils. Two asbestos-contaminated mines (the Jecheon mine and the Jongmin-ri mine) were selected. At each mine, 21 surface soils (0~15 cm) were sampled, the asbestos concentrations were analyzed, and then three representative sites, containing 0.25%, 0.50%, and 0.75% of asbestos in soils, were chosen to evaluate the amount of releasable asbestos by the modified RAS with wind velocity and water contents. The results showed that the levels of releasable asbestos from soil to air increased with higher wind velocities and lower water content. In addition, the application of risk assessment of releasable asbestos in the soils as an alternative to the activity-based sampling (ABS) method was established at each site, and an estimation of the excess lifetime cancer risk (ELCR) was also calculated. According to the calculation, the estimated ELCR values did not exceed the threshold value (1 × 10^-4) in the Jecheon mine for all the soils, while some samples from the Jongmin-ri mine exceeded the threshold value. Therefore, proper remediation work is needed to control friable asbestos from soils to air in the vicinity of the mines.