Lung asbestos fiber burden analysis: effects of the counting rules for legal medicine evaluations

Abstract

Objectives

The work shows the effect of counting rules, such as analysis magnification and asbestos fiber dimension to be count (with length ≥5 µm or also asbestos fibers with length <5 µm) in the lung asbestos fiber burden analysis for legal medicine evaluations.

Methods

On the same lung tissue samples, two different analyses were carried out to count any asbestos fibers with length ≥1 µm and with length ≥5 µm. Results of the amphibole burden of the two analyses were compared by linear regression analysis on log10-transformed values.

Results

The analysis should be carried out at an appropriate magnification and on samples prepared in such a way as they allow the counting of very fine fibers. If the analysis is limited to the asbestos fibers with length ≥5 µm, there is a high risk of not detecting possible residual chrysotile fiber burden and thinner crocidolite asbestos fibers.

Conclusions

On average we estimated that 1 amphibole fiber with length ≥5 µm corresponds to ∼8 amphibole fibers with length ≥1 µm in the lung. The values of the Helsinki criteria should be updated taking this into account.

Keywords:

• Asbestos
• SEM
• fibre length
• lung burden analysis
• Helsinki Consensus Report

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

Fiber dimensions and identification for each fiber can be made available on request.

Additional information

Funding

This work has been carried out without grants or external funding.