Recorded at AIHce EXP 2022
Naturally occurring asbestos (NOA) has been suspected as a carcinogenic agent affecting metallic and nonmetallic miners in the US and internationally. However, elongate mineral particles can belong to different morphological habits: asbestiform or nonasbestiform. The session will introduce the concept of particle habit as an important determinant of carcinogenic potency. The public health issue of elevated mesothelioma rates in taconite ore miners at the Mesabi Range, Minnesota, will be revisited, to illustrate the complexity of the determination of the type of particles responsible for specific health effects. In particular, the session will discuss: a) the role of fiber dimensions in determination of their carcinogenic potency; b) principles of risk assessment for the asbestiform and nonasbestiform impurities; c) approaches to evaluate the weight of evidence characteristics of the data; d) quantitative structure-activity relationship (QSAR) models that relate cancer mortality with various fiber characteristics; e) use of mineralogical information in site assessments and respiratory protection programs; and f) the need for updated occupational exposure limits for fibrous amphiboles.
Upon completion of the session, the participant will be able to:
• Describe the factors affecting the health of taconite ore miners.
• Recognize the characteristics of elongate mineral particles.
• Discuss current regulations related to fiber exposure and an OEL.
• Evaluate risk assessment methodology for the carcinogenic effects.
Daniel Hall, PE, CIH, PSE
Andrey Korchevskiy, PhD, DABT, CIH
Linda Dell, MS