Depleted uranium (DU) is an emerging environmental pollutant that is introduced into the environment primarily by military activity. While depleted uranium is less radioactive than natural uranium, it still retains all the chemical toxicity associated with the original element. In large doses the kidney is the target organ for the acute chemical toxicity of this metal, producing potentially lethal tubular necrosis. In contrast, chronic low dose exposure to depleted uranium may not produce a clear and defined set of symptoms. Chronic low-dose, or subacute, exposure to depleted uranium alters the appearance of milestones in developing organisms. Adult animals that were exposed to depleted uranium during development display persistent alterations in behavior, even after cessation of depleted uranium exposure. Adult animals exposed to depleted uranium demonstrate altered behaviors and a variety of alterations to brain chemistry. Despite its reduced level of radioactivity evidence continues to accumulate that depleted uranium, if ingested, may pose a radiologic hazard. The current state of knowledge concerning DU is discussed.

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Salvinorin A is a unique hallucinogen that is seeing increased use in humans. It is not currently a controlled substance and is used as a legal alternative to controlled substances. Usually smoked or buccally absorbed by chewing, doses of approximately 200 mcg can produce profound hallucinogenic effects of short duration. The mechanism of action of salvinorin A is at the kappa-opioid receptor. Little data is available on the medical effects of this substance so animal studies were undertaken to explore the acute toxic effects of this substance in rats and the chronic effects in mice. Rats were anesthetized and administered salvinorin A at 1600 mcg/kg or vehicle. Recordings were made of galvanic skin response, EKG, temperature, and pulse pressure for 100 minutes. Mice were chronically exposed to vehicle or 400, 800, 1600, 3200, or 6400 mcg/kg of salvinorin A for two weeks. After exposure the animals were sacrificed and brain, heart, kidney, bone marrow, blood and spleen were removed, fixed, sectioned, stained and examined by light microscopy. No effects were seen on cardiac conduction, temperature, or galvanic skin response. A nonsignificant rise was seen in pulse pressure. Histologic studies of spleen, blood, brain, liver, kidney, and bone marrow did not find any significant histologic changes at any of the doses examined. These data suggests that the toxicity of salvinorin A is relatively low, even at doses many times greater than what humans are exposed to. However, further studies should be done on blood pressure effects. The psychological impact of this potent hallucinogen should also be investigated.

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Depleted uranium (DU) is used in both civilian and military applications. Civilian uses are primarily limited to ballast and counterweights in ships and aircraft with limited risk of environmental release. The very nature of the military use of DU releases DU into the environment. DU released into the environment from military use takes the form of large fragments that are chemically unchanged and dust in the form of oxides. DU dust is nearly insoluble, respirable and shows little mobility in the soil. Exposure to DU occurs primarily from inhalation of dust and possible hand to mouth activity. Toxicity of DU is believed to be primarily chemical in nature with radiological activity being a lesser problem. DU has been shown to have a variety of behavioral and neurological effects in experimental animals. DU has been used the Balkans, Afghanistan, and both Iraq wars and there is a high probability of its use in future conflicts. Further, other nations are developing DU weaponry; some of these nations may use DU with a greater radiological risk than those currently in use. The toxicity of DU has been studied mostly as an issue of the health of military personnel. However, many tons of DU have been left in the former theater of war and indigenous populations continue to be exposed to DU, primarily in the form of dust. Little epidemiological data exists concerning the impact of DU on these groups. It may be possible to extrapolate what the effects of DU may be on indigenous groups by examining the data on similar metals. DU has many similarities to lead in its route of exposure, chemistry, metabolic fate, target organs, and effect of experimental animals. Studies should be conducted on indigenous groups using lead as a model when ascertaining if DU has an adverse effect.