Acute Lethality

Most of our knowledge of the biological effects of petrolemn pollution is based on studying the acute effects of major spills or heavily contaminated sediments. These effects tend to be directly lethal. Acute toxicity has been foimd to be largely related to water solubility, with cmnulative toxicity reflecting the smn of the effects of each individual hydrocarbon. Relatively little is known about the effects of chronic exposures at lower concentrations, especially in the presence of other stressors, such as heavy metals. Effects of chronic inputs from land-based sources on populations, communities, and ecosystem structure and function are also not sufficiently known. 

In animals, information exists on lethality, acute systemic effects (respiratory), reproductive and developmental effects, and cancer following inhalation exposure, but none was found on other systemic effects after acute, intermediate, or chronic exposure. Much of the information in animals focused on oral exposure. Lethality, systemic effects after acute, intermediate and chronic exposures, immunotoxicity, developmental effects, reproductive effects, genotoxicity, and cancer have been evaluated. Reports on dermal exposure after direct application to the skin involved lethality, acute systemic effects (kidney, liver, dermal/ocular), and cancer. 

A 22-year-old man was found dead in a field. At autopsy, all organs were severely congested. Concentrations of metamfetamine in the heart, urine, and stomach were 0.8, 17, and 6.2 pg/ml respectively. Immunohistochemical tests on skeletal muscle showed lower than normal immunoreactivity of myoglobin, and 70-kDa heat shock protein was positive in the kidney. Because the concentration of metamfetamine in the blood was not lethal, acute intoxication was not deemed to have been the cause of death. Rather, based on the immunohistochemical findings, it was suggested that the patient had died of hyperthermia and metabolic acidosis. The patient s muscular hyperactivity had led to hyperthermia and metabolic acidosis. 

Lubricating oils have low acute toxicity. Their sub-lethal acute effects are generally limited to irritation of those tissues in contact with the oil. 

Figure IB The relationship between inoculum size and acute survivable sensitivity to LPS. For any mammalian species, a lethal effect will attend the inoculation of gramnegative organisms, given that the inoculum is large enough. The less sensitive the host is to LPS, the larger the lethal inoculum will be. If sensitivity to LPS is exquisite, even minute inocula may prove lethal acutely.

For humans (both workers and the public), the three potential consequences of the risk posed by either stockpile storage or agent destruction are acute lethality, acute and latent noncancerous health effects, and latent cancer. The potential adverse consequences for the environment are the contamination of land and water, and adverse effects suffered by native or endangered species. 

Microcystis, Nostoc, and Oscillatoria (Planktothrix). Cyanobacteria toxins (cyanotoxins) include cytotoxins and biotoxins (neurotoxins anatoxin-a, anatoxin-a(s) and saxitoxins, and the hepatotoxins microcystins MCs, and nodularins), with biotoxins being responsible for acute lethal, acute chronic, and subchronic poisonings of wild/domestic animals and humans. In most of the reported cases, afflicted animals consumed water from water bodies where there was an obvious presence of cyano-bacterial scum on the water surface. More recent measurements of cyanobacterial toxins using sensitive modem analytical methods have often revealed high frequencies of toxic blooms even when animal poisonings have not been reported. 

II. Toxic dose. The toxic oral dose in mammals is greater than 100-1000 mg/kg, and the potentially lethal acute oral dose is 10-100 g. Pyrethrins are not well absorbed across the skin or from the gastrointestinal tract. They have been used for many years as oral anthelminthic agents with minimum adverse effects other than mild gastrointestinal upset. 

In livestock, the consumption of aflatoxins in feed leads to a number of problems, which are then reflected in negative impacts on performance. Chronic exposure to aflatoxins leads to reduced growth and greater susceptibility to infections. This condition is often referred to as total failure to thrive. An extreme consequence of giving animals contaminated feed is lethal acute poisoning. 

Xia G, Kovochich M, Truitt RL, Johnson BD (2004) Tracking ex vivo-expanded CD4+CD25+ and CD8-hCD25+ regulatory T cells after infusion to prevent donor lymphocyte infusion-induced lethal acute graft-versus-host disease. Biol Blood Marrow Transplant 10 748-760... 

Reece and Burks (1985) observed that the 11 PAHs present in petroleum refinery effluents caused lethal acute effects in Daphnia magna and that these substances were acting in an additive or synergistic way. 

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