Is There Transplacental Transfer of Asbestos? A Study of 40 Stillborn Infants

Abstract

An autopsy study was conducted to investigate whether there is transplacental transfer of asbestos in humans. The asbestos burden of lung, liver, skeletal muscle, and placenta digests of 40 stillborn infants was determined using a bleach digestion method. The fibers detected in the tissue digests were characterized as to the type of asbestos, using electron microscopy, energy-dispersive x-ray analysis, and selected-area diffraction analysis. Placental digests of 45 full-term, liveborn infants were similarly processed as controls. Low levels of small, thin, uncoated asbestos fibers were detected in the placentas and organs of 37.5% of the stillborn infants (15 of 40). The fiber sizes ranged from 0.05 to 5.0 microns in length and 0.03 to 0.3 micron in width, with a mean length of 1.15 microns and a mean width of 0.069 micron. Maximum numbers of fibers were found in the lungs (mean 235,400 fibers/g; n = 10), followed by liver (mean 212,833 fibers/g; n = 6), placenta (mean 164,500 fibers/g; n = 4), and skeletal muscle (80,000 fibers/g; n = 1). The fibers were detected at all stages of gestation and showed no association with gestational age. A significant association was found between fiber presence and working mothers, and positive but nonsignificant associations were found with maternal history of drug abuse, previous abortions, and fetal maceration. No association was found between premature rupture of membranes and fiber presence. No fibers were detected in the 45 placentas of the liveborn control infants. There was a highly significant difference in the asbestos fiber counts of the placentas of the stillborn and liveborn infants (P < .001). Our studies demonstrate the presence of short and thin asbestos fibers in stillborn infants and their positive association with working mothers.

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

“…The lung is particularly likely to retain fibers, since it is one of the first organs to be exposed to the maternal blood carrying the fibers from the placenta, and has a rich capillary network that may trap more fibers. Additionally, in our previous studies, fibers were found in the liver and lung of stillborn infants (Haque et al, 1996.…”

“…There are reports of childhood mesotheliomas, particularly in children of asbestos workers (Fraire et al, 1988;Cooper et al, 1989). Recent autopsy studies have documented the presence of asbestos, not only in children but also in stillborn infants, with the latter suggesting transplacental transfer of asbestos fibers (Haque et al, 1990(Haque et al, , 1996. The uptake and circulation of asbestos fibers after ingestion and their distribution to various organs have been demonstrated in several adult human as well as animal studies (Carter & Taylor, 1980;Cook & Olson, 1979;Cunningham & Pontefract, 1973;Hallenbeck & Patel-Mandlik, 1979).…”

Nonpulmonary Outcomes of Asbestos Exposure

“…Tissue digests were characterized as to the type of asbestos using EDXA-EM and selected-area diffraction analysis. Small, thin, uncoated asbestos fibers were found in 15 of the 40 stillborn infants, while no fibers were found in the placental tissue of any live-born controls (Haque et al, 1996). Interestingly, in a larger third study by Haque et al (1998) using the same methods, low numbers of asbestos fibers were also found in 15% of the live-born placental controls.…”

“…An asbestos fiber burden ranging from 71,000 to 357,000 fibers/g wet weight was detected in at least one organ of all five infants (Haque et al, 1992). Haque et al (1996) continued by examining the organs from 40 stillborn infants and comparing them to the placenta from liveborn controls. Tissue digests were characterized as to the type of asbestos using EDXA-EM and selected-area diffraction analysis.…”

Revision of French Occupational Exposure Limits of Asbestos and Recommendation of Measurement Method: Can the Dimensional Characteristics of the Asbestos Fibers (Long, Thin, Short) Be Taken Into Account?

“…In humans, asbestos fibers have been particularly identified in samples of lymphatic ganglions (Dodson et al, 1990;Sebastien et al, 1979), in healthy or diseased parietal pleura (Boutin et al, 1996;Dodson et al, 1990;LeBouffant et al, 1976;Sebastien et al, 1980;Suzuki and Kohyama, 1991;Suzuki et al, 2005), omentum and radix mesenteri (Dodson et al, 2001;Dodson et al, 2000) and in the placenta and tissue samples of stillborn infants (Haque et al, 1996;Haque et al, 1992;Haque et al, 1998).…”