A comparison of parallel dust and fibre measurements of airborne chrysotile asbestos in a large mine and processing factories in the Russian Federation

Abstract

Our study shows that dust to fibre conversion is possible by unit but extrapolations are needed. The patterns for exposure by dust and fibre will be similar but estimated fibre levels will show less contrast due to the conversion factor being smaller at higher dust concentrations.

Relationships of Lower Lung Fibrosis, Pleural Disease, and Lung Mass with Occupational, Household, Neighborhood, and Slate Roof-Dense Area Residential Asbestos Exposure

“…The ORs of LLF, PD, and LM in two categories, neighborhood factory exposure >20 years and slate roof exposure in a slate roof-dense area, were increased in all models (Table 5). of asbestos-containing materials was associated with higher prevalence rates of LLF and PD, compared to the occupational use of asbestos products [17]. The previous finding that low levels of occupational, household, and neighborhood exposure may induce pleural plaques [18] is consistent with our results.…”

Temporal Trends in Airborne Dust Concentrations at a Large Chrysotile Mine and its Asbestos-enrichment Factories in the Russian Federation During 1951–2001

“…Fiber concentration is generally the preferred metric for assessing health outcomes from asbestos exposure because dust encompasses other airborne materials in addition to asbestos fibers ( Harries, 1971 ; Dement et al , 2008 ). A limited number of parallel dust and fiber measurements available for The Asbest Study have been used to derive dust-to-fiber conversion factors that may be applied to estimate fiber levels for the planned risk analyses ( Feletto et al , 2017 ). In Brazil, Bagatin et al (2005) reported the annual fiber concentrations throughout a chrysotile asbestos mine and mills between 1977 and 1993.…”

Occupational cohort study of current and former workers exposed to chrysotile in mine and processing facilities in Asbest, the Russian Federation: Cohort profile of the Asbest Chrysotile Cohort study

“…Since the late 1800s, there have been 7 asbestos-enrichment processing mills (called factories) operated by JSC Uralasbest, each of which conducted the same chrysotile-enrichment process, but with varying technology and machinery used. Over time, the degree of mechanization has advanced and technologies have improved, permitting the enrichment of ore with lower chrysotile content and resulting in reduced exposures to airborne dust and fibres in the work environment [ 20 , 21 ]. All factories used the dry milling technique, which consists of repeated cycles of crushing the raw ore, drying, and then screening through vibrating screeners so that chrysotile fibres rise to the surface and are removed by vacuum suction.…”

“…For each job, an annual average dust concentration was estimated, which was derived from measurements taken at the measurement points applicable to that job (note that jobs with mobility of workers may have involved several measurement points). In the mine, the annual average was weighted by season, by calculating first averages for the winter and the summer period and weighing them 2:1 to reflect the relative length of winter versus summer in this area [ 21 ]. Estimated annual average concentrations were linked to each cohort member based on the job performed in each calendar year and adjusted for the proportion of the year that the worker had actually worked.…”

“…Exposure to asbestos fibres was estimated using dust-to-fibre conversion factors derived from three series of parallel measurements of dust and fibre concentrations conducted in 1995, 2007, and 2013–2014; these conversion factors were used to assign modelled fibre concentrations to each annual average dust concentration [ 21 ]. Estimated fibre concentrations were then assigned to each cohort member by job and by calendar year.…”