Teratogenicity of depleted uranium aerosols: A review from an epidemiological perspective

We reviewed toxicological data on both natural and depleted uranium. We included peer reviewed studies and gray literature on birth malformations due to natural and depleted uranium. Our approach was to assess the "weight of evidence" with respect to teratogenicity of depleted uranium.Animal studies firmly support the possibility that DU is a teratogen. While the detailed pathways by which environmental DU can be internalized and reach reproductive cells are not yet fully elucidated, again, the evidence supports plausibility. To date, human epidemiological data include case examples, disease registry records, a case-control study and prospective longitudinal studies.The two most significant challenges to establishing a causal pathway between (human) parental DU exposure and the birth of offspring with defects are: i) distinguishing the role of DU from that of exposure to other potential teratogens; ii) documentation on the individual level of extent of parental DU exposure. Studies that use biomarkers, none yet reported, can help address the latter challenge. Thoughtful triangulation of the results of multiple studies (epidemiological and other) of DU teratogenicity contributes to disentangling the roles of various potentially teratogenic parental exposures. This paper is just such an endeavor.In aggregate the human epidemiological evidence is consistent with increased risk of birth defects in offspring of persons exposed to DU.Depleted uranium (DU) is a man-made, radioactive, heavy metal derived from uranium ore. Naturally occurring uranium ore (rock in which the uranium concentration is approximately 1,000 or more parts per million) is mined and processed to yield a much more concentrated substance, one that is virtually pure uranium. Natural uranium exists in three isotopic forms and contains 99.274% U238, 0.72% U235, and 0.0057% U234 by weight. DU, a byproduct of uranium enrichment, has an isotopic content of 99.75% U238, 0.25% U235, and 0.005% U234. As part of