Characterizing and Discriminating Airborne Amphibole Cleavage Fragments and Amosite Fibers: Implications for the NIOSH Method

Wylie, Ann G.; Virta, Robert L.; Russek, Estelle

doi:10.1202/0002-8894(1985)046<0197:cadaac>2.3.co;2

Cited by 15 publications

(28 citation statements)

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“…However, in many other environments, cleavage fragments might predominate. Amphibole cleavage fragments found in air and water samples have straight parallel sides, but also on average lower aspect ratios and much greater width than asbestos EMP of the same length (Siegrist and Wylie, 1980, Wylie and Schweitzer, 1982, Wylie et al, 1985, Harper et al, 2012. They may also exhibit stepped terminations.…”

Section: Is It An Asbestos Fiber or Is It A Cleavage Fragment?mentioning

confidence: 96%

“…Elongated serpentine fragments tend to be less regularly prismatic, although they can meet criteria for EMP (Wylie and Bailey, 1992). The differences in dimensional characteristics of asbestos relative to cleavage fragments have been used to discriminate these populations (Siegrist and Wylie, 1980;Virta et al, 1983;Wylie et al, 1985;Van Orden et al, 2008;Chatfield, 2013;Harper et al, 2012). These methods were developed from studies of populations that contain a large number of particles with lengths that extend over several orders of magnitude, and the problem of consistently identifying a single particle as a fiber or fragment is unresolved.…”

Section: Is It An Asbestos Fiber or Is It A Cleavage Fragment?mentioning

confidence: 97%

“…However, among natural populations, the dimensional overlap is small, occurring mainly among EMP less than a few micrometers (Wylie et al, 1985;Siegrist and Wylie, 1980;Wylie and Schweitzer, 1982) in length. These same dimensional studies demonstrated that in cleavage fragment populations, width increases with length, whereas in asbestos populations, widths are small, almost constant, and independent of length.…”

Section: Amphibole and Serpentine In Air And Watermentioning

confidence: 99%

“…The fiber concentration is expressed as f/cm 3 and termed PCM equivalent (PCME) because 0.25 µm approaches the lower limit of resolution following NIOSH 7400 procedures. The comparisons are not exact because visibility and resolution is often not the same (Wylie, 1985). The analytical TEM provide data on chemical composition and atomic structure that can be used to distinguish amphibole and serpentine EMP from other minerals.…”

Section: Airmentioning

confidence: 99%

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Methodologies for Determining the Sources, Characteristics, Distribution, and Abundance of Asbestiform and Nonasbestiform Amphibole and Serpentine in Ambient Air and Water

Wylie

Candela

2015

Journal of Toxicology and Environmental Health, Part B

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Anthropogenic and nonanthropogenic (erosion) processes contribute to the continuing presence of asbestos and nonasbestos elongated mineral particles (EMP) of amphibole and serpentine in air and water of urban, rural, and remote environments. The anthropogenic processes include disturbance and deterioration of asbestos-containing materials, mining of amphibole- and serpentine-bearing rock, and disturbance of soils containing amphibole and serpentine. Atmospheric dispersal processes can transport EMP on a global scale. There are many methods of establishing the abundance of EMP in air and water. EMP include cleavage fragments, fibers, asbestos, and other asbestiform minerals, and the methods employed do not critically distinguish among them. The results of most of the protocols are expressed in the common unit of fibers per square centimeter; however, seven different definitions for the term "fiber" are employed and the results are not comparable. The phase-contrast optical method used for occupational monitoring cannot identify particles being measured, and none of the methods distinguish amphibole asbestos from other EMP of amphibole. Measured ambient concentrations of airborne EMP are low, and variance may be high, even for similar environments, yielding data of questionable value for risk assessment. Calculations based on the abundance of amphibole-bearing rock and estimates of asbestos in the conterminous United States suggest that amphibole may be found in 6-10% of the land area; nonanthropogenic erosional processes might produce on the order of 400,000 tons or more of amphibole per year, and approximately 50 g asbestos/km(2)/yr; and the order of magnitude of the likelihood of encountering rock bearing any type of asbestos is approximately 0.0001.

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Section: Is It An Asbestos Fiber or Is It A Cleavage Fragment?mentioning

confidence: 96%

Section: Is It An Asbestos Fiber or Is It A Cleavage Fragment?mentioning

confidence: 97%

Section: Amphibole and Serpentine In Air And Watermentioning

confidence: 99%

Section: Airmentioning

confidence: 99%

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Methodologies for Determining the Sources, Characteristics, Distribution, and Abundance of Asbestiform and Nonasbestiform Amphibole and Serpentine in Ambient Air and Water

Wylie

Candela

2015

Journal of Toxicology and Environmental Health, Part B

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“…In general, the PCM technique is viewed as being unable to detect fibers less than 0.25 m in diameter [97]. However, thinner fibers are visible in the PCM, but their diameters cannot be measured.…”

Section: Analysis Of Airborne Fibers In Mixed Mineral Dustmentioning

confidence: 99%

Naturally occurring asbestos—A recurring public policy challenge

Lee

Strohmeier

Bunker

et al. 2008

Journal of Hazardous Materials

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Asbestos fibre identification vs. evaluation of asbestos hazard in ophiolitic rock mélanges, a case study from the Ligurian Alps (Italy)

et al. 2014

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In recent years, the high incidence of harmful health effects through inhalation of airborne asbestos from amphibole-bearing rock me´langes has been thoroughly documented. Here, we present a field-based, multi-scale\ud geological approach aimed at illustrating the occurrence of\ud amphibole fibrous mineralisation in an ophiolitic suite from\ud the Ligurian Alps (Italy) and discussing the implication on\ud in situ determination of the asbestos hazard. The rock\ud mélange is composed of plurimetre-sized blocks of different lithotypes (metagabbro, serpentinite, chloritoschist)\ud juxtaposed by the meaning of tectonic structures. The geological-structural survey revealed that the fibrous mineralisation is localised in specific structural sites of the rock volume, including veins and schistosity. Both microchemical and crystal structure analyses on selected fibrous samples revealed that actinolite fibres grow in veins within the metagabbro and in chloritoschists, while fibrous tremolite occurs in serpentinite schistosity. The morphological features of these amphibole fibres have been analysed in TEM images and used for classifying them as ‘‘asbestiform’’ or ‘‘non-asbestiform’’. The results show that the asbestos hazard determination is not unequivocally identified when different procedures for asbestos fibre identification and classification are applied. This may have impact on normatives and regulations in defining environmental hazards due to asbestos occurrence

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Characterizing and Discriminating Airborne Amphibole Cleavage Fragments and Amosite Fibers: Implications for the NIOSH Method

Cited by 15 publications

References 0 publications

Methodologies for Determining the Sources, Characteristics, Distribution, and Abundance of Asbestiform and Nonasbestiform Amphibole and Serpentine in Ambient Air and Water

Methodologies for Determining the Sources, Characteristics, Distribution, and Abundance of Asbestiform and Nonasbestiform Amphibole and Serpentine in Ambient Air and Water

Naturally occurring asbestos—A recurring public policy challenge

Asbestos fibre identification vs. evaluation of asbestos hazard in ophiolitic rock mélanges, a case study from the Ligurian Alps (Italy)

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