Poisoning long-term effects

Most of the materials used in the manufacture of chemicals are poisonous, to some extent. The potential hazard will depend on the inherent toxicity of the material and the frequency and duration of any exposure. It is usual to distinguish between the short-term effects (acute) and the long-term effects (chronic). A highly toxic material that causes immediate injury, such as phosgene or chlorine, would be classified as a safety hazard. Whereas a material whose effect was only apparent after long exposure at low concentrations, for instance, carcinogenic materials, such as vinyl chloride, would be classified as industrial... 

The long-term effects of carbon monoxide poisoning for victims who recover are less clear. Those who recover from exposure to high levels, especially if they have been unconscious, can suffer effects on the memory and the brain and heart which may last some time or even be permanent. Some victims may suffer heart attacks some time after apparent recovery or succumb to pneumonia, especially the elderly. Similarly, despite an apparent full recovery, some weeks after the poisoning the victim may suffer from effects on the brain (for example, encephalopathy) which can cause symptoms similar to Parkinson s disease or personality changes (irritability, for example) which can persist for some time. Loss of short-term memory is common. Muscle damage sometimes occurs, which can lead to renal failure. This is because the breakdown products of the muscle are excreted into the urine and overload the kidneys. These effects are most likely in those who are victims of severe poisoning. 

There are several forms of the toxin which are now marketed as Botox (type A toxin) and Myobloc (type B toxin). Botox has recently been used in cosmetic medicine as a way of reducing lines and wrinkles in the face due to ageing. There have, however, been cases of unwanted long-term effects after its repeated cosmetic use. The toxin must be used with great care. Here again we have an example of the principle of Paracelsus and the poison paradox all substances are poisons, and it is the right dose that differentiates a poison from a remedy. 

Unfortunately, there are no data on the long-term effects of nerve agent poisoning in children, and the effects must be extrapolated from what has been discovered in the adult population (Rotenberg and Newmark, 2003). Surveillance studies performed on victims of the sarin attacks in Japan revealed a wide range of sequelae, such as continued respiratory problems, vision disturbances, headache, and fatigue. Neuropsychiatric problems were also reported as a delayed effect. 

Lead nephropathy is important because it is one of the few renal diseases that is preventable. Moreover, lead-induced acute renal dysfunction can sometimes be reversed by chelation therapy [19, 28, 63]. The salutary effect of chelation therapy appears to be on the acute reduction in GFR and the acute elevation of blood pressure associated with elevated blood lead concentration rather than on the long-term effects of cumulative exposure associated with endothelial dysfunction, hypertension, and interstitial nephritis. There is no evidence that such therapy reverses established interstitial nephritis. The partial remission achieved among moonshiners and lead workers appears to represent reversal of the physiologic effects of acute poisoning superimposed on chronic lead nephropathy. No improvement in renal function has been observed once advanced interstitial nephritis is present and the steady-state serum creatinine concentration exceeds about 3 mg/ dL [64]. 

There are few studies of the health effects from rhodium or its common compounds. Powdered rhodium metal is considered to be an irritant to the skin, eyes, and respiratory system. There has been no research on the long-term effects of exposure to rhodium or its compounds. Elements without information about toxicity are usually treated as if they are poisonous. 

Renal tubular dysfunction with itai-itai disease is irreversible and progressive even if the cadmium exposure is reduced. There is no specific treatment for renal tubular dysfunction by chronic cadmium poisoning. Long-term administration of vitamin D could be useful in the treatment of osteomalacia however, its effectiveness is limited, and the reappearance of osteomalacia could be observed due to the latent renal tubular dysfunction. 

Grauer, E. and J. Kapon. 2004. Stress exposure and sarin poisoning interaction of long-term effects. Israel J Psychiatry 41(1) (abstract). 

Long-term effects of sarin poisoning need to be monitored more closely in the future and a well-designed large-scale study needs to be carried out. 

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