Abstract
Background: Determination of background levels of lung retention of nonfibrous mineral particles (NFMP) in control populations is a key issue for a correct use of mineralogical analysis of lung samples as a tool for the identification of the occupational or environmental origin of some pulmonary disorders.
Aims: The objective of the study was to characterize the level of retention of NFMP in the lung in 2 series of subjects free of occupational exposure to such particles and undergoing lung surgery, recruited over a 20 years period, to study the evolution of background levels.
Methods: Mineralogical analysis of lung tissue for quantification of NFMP was performed in these 2 series : 35 subjects recruited in 1994-1999 (G1: 17 females, 18 males, mean age: 58.7 years), and 36 subjects in 2009-2014 (G2: 19 females, 17 males, mean age: 63.2 years). Analytical transmission and scanning electron microscope equipped with an energy dispersive X-ray device was used to quantify and characterize NFMP greater than 0.1 μm. Non parametric tests were used to compare results of the quantification in the two series.
Results: Median concentration of all NFMP was 21.2 x 107 particles/gram of dry lung (p/g) and 43.5 x 107 p/g in G1 and G2, respectively (p=0.02). The most significant change when comparing G1 and G2 was the increase in the level of titanium particles (median: 5 x 107 p/g and 8.8 x 107 p/g in G1 and G2, respectively; p= 0.005).
Conclusions: The increase between 1994-1999 and 2009-2014 concerning the level of retention of titanium particles in the lung of subjects free of specific occupational exposure warrants further investigation to identify possible new environmental or household sources.
- Copyright ©ERS 2015
