PULMONARY ASBESTOS BODIES AND ASBESTOS FIBERS AS INDICATORS OF EXPOSURE

Objectives The aim of the study was to analyze the correlation between pulmonary concentrations of asbestos bodies and asbestos fibers and t o characterize asbestos body counts from lung tissue of Finnish patien ts occupationally exposed and unexposed to asbestos. Methods Ninty-nin e surgically treated lung cancer patients were investigated. The numbe r of asbestos bodies in iron-stained 5-mu m histological lung tissue s ections was determined by optical microscopy, and the pulmonary concen tration of asbestos fibers was assessed by scanning electron microscop y. The correlation between asbestos body and asbestos fiber counts was calculated with linear regression. The asbestos body and asbestos fib er concentrations were also compared with exposure history according t o a personal interview of the patients.Results The average number of a sbestos bodies ranged from <0.1 to 750 asbestos bodies per tissue sect ion. All the cases with definite exposure showed an average of al leas t one asbestos body per tissue section. An average of at least one asb estos body per section was, however, detected in 34% of the patients w ith unlikely exposure. The regression equation log (AF) = -0.429 + 0.6 00 . log (AB) was found to predict the concentration of asbestos fiber s (AF, 10(6) fibers g(-1)) corresponding to a given number of asbestos bodies (AB) in a section of lung tissue. Conclusions The background l evel of asbestos bodies in the lungs of patients with no specific asbe stos exposure seems to be higher in Finland than in other countries. I n medicolegal cases, the methodological variation involved in asbestos fiber and asbestos body counting must be recognized and all available exposure data should be used to produce the best possible estimate of the exposure.