Subclinical exposure

Needleman HL, Shapiro IM. 1974. Dentine lead levels in asymptomatic Philadelphia school children Subclinical exposure in high and low risk groups. Environ Health Perspect 7 27-31. 

Philadelphia School Children Subclinical Exposures in High and Low Risk Groups, EPA-NIEHS Conference on Low Level Lead Toxicity, Raleigh, North Carolina, October 1-2, 1973. 

Charleston et al. (1996) studied the effects of long-term subclinical exposure to methylmercury on the number of neurons, oligodendrocytes, astrocytes, microglia, endothelial cells and pericytes within the thalamus from the left side of the brain of the monkey Macaca fascicularis. These parameters were determined by use of the Optical Volume Fractionator stereological method. The accumulated burden of... 

Charleston JS, Body RL, Mottet NK, Vahter ME, Burbacher TM. (1995) Autometallographic determination of inorganic mercury distribution in the cortex of the calcarine sulcus of the monkey Macaca fascicularis following long-term subclinical exposure to ethylmercury and mercuric chloride. Toxicol Appl Pharmacol 132 325-333. 

We are not convinced that acnte, asymptomatic injuries that result in clinical disease truly exist. It is conceivable that certain synergistic situations can develop, such as would happen if co-factors or preexisting conditions (immunosuppression, genetic deficiency, or an additional chronic subclinical exposure) were triggered by some otherwise uneventful insult. This is certainly an unknown for mustard exposure at this time. The best that can be done is to draw analogies to other circumstances. 

Low-level SM exposure with or without symptoms but with delayed or long-term health effects has been described in detail (Mandel and Gibson, 1917 Hurst and Smith, 2001 Balali-Mood et al., 2005a,b Balali-Mood and Hefazi, 2006). Subclinical exposure to SM in some Iranian combatants induced delayed toxic effects (Ghanei et al., 2004a-c). Chronic SM exposure is usually occupational. Some factory workers in Japan and in the United Kingdom were reported to have had SM... 

More examples of chronic low dose, subclinical exposure to OPs in humans, leading to chronic neurotoxicity, are cited in a number of studies (e.g., Abou-Donia, 2003 Kamel and Hoppin, 2004). 

M. Ghanei, H. Fathi, M. M. Mohammad, J. Aslani and F. Nematizadeh, Long-term respiratory disorders of claimers with subclinical exposure to chemical warfare agents. Inhalation Toxicol, 2004,16, 491-495. 

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