Portable Raman Spectrometer for In Situ Analysis of Asbestos and Fibrous Minerals

Toxicological and epidemiological approaches to carcinogenic potency modeling for mixed mineral fiber exposure: the case of fibrous balangeroite and chrysotile

CONTEXT

Excess mesothelioma risk was observed among chrysotile miners and millers in Balangero, Italy. The mineral balangeroite has been identified in an asbestiform habit from the Balangero chrysotile mine (Italy). Previous studies did not contain a detailed description of the fiber dimensions, thus limiting possible approaches to estimating their carcinogenic potential.

OBJECTIVES

To reconstruct excess mesothelioma risk based on characteristics of mixed fiber exposure.

METHODS

The lengths and widths of particles from a sample of balangeroite were measured by transmission electron microscopy (TEM). Statistical analysis and modeling were applied to assess the toxicological potential of balangeroite.

RESULTS

Balangeroite fibers are characterized as asbestiform, with geometric mean length of 10 μm, width of 0.54 μm, aspect ratio of 19, and specific surface area of 13.8 (1/μm). Proximity analysis shows dimensional characteristics of balangeroite close to asbestiform anthophyllite. Modeling estimates the average potency of balangeroite as 0.04% (95% CI 0.0058, 0.16) based on dimensional characteristics and 0.05% (95% CI-0.04, 0.24) based on epidemiological data. The available estimate of the fraction of balangeroite in the Balangero mine is very approximate. There were no data for airborne balangeroite fibers from the Balangero mine and no lung burden data are available. All estimates were performed using weight fractions of balangeroite and chrysotile. However, based on reasonable assumptions, of the seven cases of mesothelioma in the cohort, about three cases (43%) can be attributed to fibrous balangeroite.

CONCLUSION

The presence of different types of mineral fibers in aerosolized materials even in small proportions can explain observed cancer risks.

Distinguishing asbestos cement from fiber-reinforced cement through portable µ-Raman spectroscopy and portable X-ray fluorescence

It is now widely acknowledged that asbestos can adversely affect human health; accordingly, in recent decades, fiber-reinforced cement (FRC) has been used as a substitute for asbestos cement (AC). This manuscript focuses on portable micro-Raman spectroscopy coupled with portable microscopy (p-µR) and portable X-ray fluorescence (p-XRF) as a means to identify chrysotile fibers in AC (Eternit) and fibers present in the asbestos-free FRC used as a substitute. Our results show that the simultaneous use of portable devices such as p-µR and p-XRF may be useful in quickly identifying fibrous chrysotile asbestos in Eternit, as well as polyvinyl fibers in new material FRC used as substitutes for Eternit. Chrysotile shows bands in the 800-200 cm^-1 range, whereas polyvinyl alcohol fibers show bands in the 3000-800 cm^-1 range. The p-XRF data on the two types of cement could possibly be used as a chemical fingerprint for the two different materials. Given that exposure to asbestos is a serious health hazard, its rapid and reliable detection in situ on residential buildings is important both for citizens and for administrative bodies charged with safeguarding public health. We believe that our study provides valuable insight into the potential use of portable devices for identifying asbestos and asbestos-free materials.

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

In this review the main standard and novel analytical techniques and methods for sampling, sample preparation, detection and quantification of asbestos in soil and water are described, compared and discussed in terms of advantages and limitations. An overview of common analytical methods applied for identification and quantification of airborne asbestos is preliminary provided, as they have been widely studied, due to the well-known human pathologies related to fibers inhalation. Despite the presence of asbestos in soil and water may also constitute a health risk, it has been less investigated and regulated. For these environmental matrices, the methods adopted at international and national scale, covering the whole analytical process, from sampling to management of data, are reported in depth, highlighting their limitations like sensitivity, reliability and reproducibility. Finally, different promising novel/unconventional methods, that may substitute or support traditional ones for asbestos detection both in environmental and anthropic matrices, are presented and critically evaluated.