Chrysotile Asbestos Fibers Detected in the Newborn Pups Following Gavage Feeding of Pregnant Mice

Abstract

Female pregnant mice were fed chrysotile asbestos suspension by gavage to determine whether there is transfer of fibers to the fetuses. Groups of mice were given 2 doses of either 50 microg chrysotile suspension in 0.2 ml sterile normal saline (treated), or 0.2 ml saline (control), and were allowed to mate 2 d later. After pregnancy was confirmed, the treated and control groups received 2 additional doses of chrysotile asbestos or saline on gestational d 7 and 12. Both groups were allowed to deliver naturally, and the pups were sacrificed at 8, 1, 19, or 20 d after birth. The lungs and liver of two pups from each mother were processed for fiber counts using electron microscopy and energy-dispersive x-ray analysis (EDXA). All pups of the treated group had chrysotile fibers, while none were present in pups from controls. The mean fiber count of the lungs of treated group of pups was 780 fibers/g, and the mean fiber count of the liver was 214 fibers/g. Mean length of the fibers in the lung and liver was 18.48 microm and 18.30 microm, respectively. The fibers were thin, measuring 0.42 microm and 0.33 microm in the lung and liver, respectively. There was no significant difference in the weight gain between the treated and control group of pups. The postnatal fetal mortality of the 2 groups, 8.2% for the treated and 4.5% for the control group, were not statistically significant. To our knowledge, this is the first animal study to demonstrate that oral ingestion of chrysotile asbestos during pregnancy results in transfer of asbestos fibers to the fetuses.

Occupational exposure to asbestos and risk of cholangiocarcinoma: a population-based case–control study in four Nordic countries

“…An experimental study demonstrated that, in mice, ingested asbestos fibres can cross the placenta and accumulate in the liver of the fetus. 35 This finding is in line with those from an epidemiological study that documented the presence of asbestos fibres in the liver of stillborn infants from mothers without a known occupational exposure to asbestos. 36 Due to the lack of information on established personal risk factors, we could not explore the role of asbestos in the initiation and/or promotion of CC.…”

Teratogenicity of asbestos in mice

“…It is thus likely to speculate that intraperitoneally administered asbestos fibers in the present study might at least partly be carried by lymphatic or blood flow from peritoneal cavity. Some literature indicates that transplacental distribution of asbestos from dam to fetus (Cunnibgham and Pontecraft, 1974;Haque et al, 1992Haque et al, and 2001. So, asbestos fibers might penetrate past the placenta to embryos in the present study.…”

“…On the other hand, during the course of toxicological evaluation for MWCNT, we have revealed the teratogenicity of MWCNT given intraperitoneally or intratracheally to mice . And we are strongly interested in the possible teratogenicity of other fibrous materials, especially of asbestos, because the transplacental transfer of asbestos fibers into embryos were evident in humans and experimental animals (Cunningham and Pontefract, 1974;Haque et al, 1992Haque et al, and 2001 Teratogenicity of asbestos in mice . To the best of our knowledge, there are no data available so far in the literature to describe either the presence or absence of the teratogenicity of asbestos.…”

Nonpulmonary Outcomes of Asbestos Exposure

“…In addition, oral administration of chrysotile asbestos to pregnant mice resulted in fibers detected in the lung and liver of pups by EDXA-EM (Haque et al, 2001). …”

“…“Unknown” exposures indicate the data came from occupational exposure matrices, including textiles, insulation, or cement workers. Sources: a Haque, 1992; 1996; 1998; Tsurikova, 1992. b Haque, 2001. c Schneider, 1977. d Saat, 1980; Dopp, 1997; Stevens, 1983. e Germani, 1999; Langseth, 2004; Magnani, 2008; Pira, 2005; Reid, 2009; Acheson, 1982; Newhouse, 1985; Wignall, 1982; Berry, 2000. f Millette, 1983. g Graham, 1967. h Attanoos, 2000. i Polissar, 1982.…”