Sulfur mustard long-term effects

Assennato G, Ambrose F and Sivo D (1997). Possibili effetti a lungo termine sull apparato esposizone ad iprite tra pescatori (Possible long-term effects on the respiratory tract of the sulfur mustard exposure... 

Sidell and Hurst have described the long-term effects produced from acute symptomatic clinical dose exposure to mustard, but less is known about the clinical effects from chronic, sometimes symptomatic, low-dose exposure. Acute is defined here as an exposure lasting less than 24 h. The term chronic refers to an exposure lasting for days, weeks, months, and even years. Clinical means producing a recognizable illness directly related to mustard exposure. Symptomatic means having either the acute or chronic clinical illness produced by sulfur mustard. Asymptomatic, of course, is without symptoms at all. 

The argument can be made that acute, subclinical asymptomatic injury causing long-term effects does not exist. The pros and cons will be considered in this chapter, and parallels will be drawn. Certainly chronic, snbclinical asymptomatic exposures do exist and there are parallels to other harmfnl sitnations. Obviously, workers in the mannfactnre of sulfur mustard, who were asymptomatic for part or aU of their employment, fall into this category. 

Roshan, R., Rahnama, R, Ghazanfari, Z., et al., 2013. Long-term effects of sulfur mustard on civilians mental health 20 years after exposure (The Sardasht-Iran Cohort Study). Health Qual. Life Outcomes 11, 69. 

Long-Term Effects of the Chemical Warfare Agent Sulfur Mustard... 

Table 6.1 Overview of sulfur mustard-induced long-term effects.

Considering all the above data, the U.S. EPA (1991) selected the unit risk of 8.5 x 10 per pg/m, derived from the Weibull time-to-tumor model, as the recommended upper bound estimate of the carcinogenic potency of sulfur mustard for a lifetime exposure to HD vapors. However, U.S. EPA (1991) stated that "depending on the unknown true shape of the dose-response curve at low doses, actual risks may be anywhere from this upper bound down to zero". The Weibull model was considered to be the most suitable because the exposures used were long-term, the effect of killing the test animals before a full lifetime was adjusted for, and the sample size was the largest obtainable from the McNamara et al. (1975) data. 

Studies of occupational exposures to sulfur mustard indicate an elevated risk of respiratory tract and skin tumors following long-term exposure to acutely toxic concentrations. Overall, several factors are important regarding the assessment of the carcinogenicity of sulfur mustard. Increased cancer incidence in humans appears to be associated only with exposures that caused severe acute effects, and occupational exposures tended to involve repeated exposures and repeated injury of the same tissues. Because the therapeutic use of the sulfur mustard analog nitrogen mustard is associated with an increased incidence of CML, the reports of CML in HD-exposed individuals appear to be relevant to the eareinogenicity of sulfur mustard. 

Smith, K.J., Hurst, C.G., Moeller, R.B., Skelton, H.G., Sidell, F.R. (1995). Sulfur mustard its continuing threat as a chemical warfare agent, the cutaneous lesions induced, progress in understanding its mechanism of action, its long-term health effects, and new developments for protection and therapy. J. Am. Acad. Dermatol. 32 16S-16. 

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