Elemental composition of ferruginous bodies and occupational categories: analyses and case studies in Mexico

Abstract

Inorganic fibers form part of the complex mixture of environmental pollutants in Mexico City and in general locations. Upon entering the lungs, some of those fibers are transformed into ferruginous bodies (FB) that can be used as biological markers of exposure to fibers. Hence, the objectives of this study were, first, to describe the most frequent types of FB found in the lungs, and second, to determine the elemental composition of the cores of some of those FB. A total of 264 lung samples collected from autopsies performed at the National Institutes of Health in Mexico City were analyzed. The FB were obtained by digesting the samples in commercial bleach and all the FB were then collected in 0.45 µm Millipore membranes. All the FB obtained from each case were counted directly under bright field microscopy, and then classified by morphology. Results showed from 14.5 FB/g in Category 1 (housewives), to 50.2 FB/g for samples from Category 5 (construction workers), and 152 FB/g for Category 6 (miners). Significant differences were found upon comparing samples from Categories 5/6 to Category 1 (p < 0.05). Type 1 FB were the most frequent ones seen in the samples from Categories 1 to 5. Elemental analyses of the cores of several FB found aluminosilicates, fiberglass, tremolite and amosite asbestos among others. In conclusion, residents of Mexico show exposures to a variety of fibers that induce FB including asbestos.

Identification of ferruginous bodies in the lungs of children and analyses of the elemental composition of fibers

“…The predominant morphological type of FB in the children's lungs was type-1, with a frequency of 84.3%. This figure is comparable to the 71% reported by Villeda-Cuevas et al (2012) for representatives of occupational category 1, which includes housewives. It also confirms to some degree the finding that in both children and housewives intramural exposure is a significant form of exposure to atmospheres with inorganic fibers.…”

“…The spectra of the X-rays of the FB from the positive cases were compared to mineralogical catalogues that report various types of particles, based primarily on the U.S. Geological Survey (www.usgs.gov). Furthermore, they were compared to the results obtained by Villeda-Cuevas et al (2012) in their elemental analysis of FB from adult patients. The EDXA revealed a significant presence of certain elements, including:…”

“…In Mexico, many reports have evaluated the presence, concentrations and distribution over time of ferruginous bodies (FBs) in diverse study groups. FBs are iron-covered inorganic fibers and particles in the lung characterized by a distinct morphological appearance and the presence of certain elements in their centers or fibers (Arenas-Huertero et al, 1994;Salazar-Flores et al, 2009;Villeda-Cuevas et al, 2012). However, existing studies have been carried out only in adult populations, both in Mexico (Arenas-Huertero et al, 2012) and abroad (Roggli, 2004), while aspects related to intramural contamination and its effects on children have been little explored.…”