UBIQUITOUS FIBER EXPOSURE IN SELECTED SAMPLING SITES IN EUROPE

Objectives This study evaluates personal exposure to respirable inorga nic and organic fibers during normal human lifetimes and assesses the order of magnitude of the contribution of inorganic fibers other than asbestos to total fiber exposure from man-made and natural sources. Me thods Four groups (suburban schoolchildren, rural retired persons, off ice workers, and taxi drivers), with five persons per group, were moni tored for 24 h four times during one year. Personal sampling pumps col lected airborne dust on gold-precoated Nuclepore filters. The fibers w ere analyzed for fiber sizes specified by the World Health Organizatio n Results The geometric mean concentrations ranged from 9000 fibers . m(-3) (office workers) to 20 000 fibers . m(-3) (schoolchildren) for o rganic fibers, and from 600 fibers . m(-3) (taxi drivers) to 4000 fibe rs . m(-3) (schoolchildren) for gypsum fibers. For other inorganic fib ers the concentrations were around 5000 fibers . m(-3). The contributi on of fibers with an elemental composition similar to that of man-made vitreous fibers (MMVF) was less than about one-quarter of the content of other inorganic fibers. The fiber size distributions were uniform across the groups, and the organic fibers were the longest and thinnes t nonasbestos fibers. Conclusions Lifetime exposure to fibers can be r anked as organic fibers > other inorganic fibers > fibers with an elem ental composition similar to MMVF > MMVF. Information on the biologica l effects of fibers is difficult to interpret for use in assessing the health risk from exposure to low levels of ubiquitous fibers, and the re is a lack of knowledge on the effects of organic fibers.