Veterans at Risk: The Health Effects of Mustard Gas and Lewisite


World War II (WWII) has been called “the unfought chemical war.” Both sides had produced millions of tons of chemical weapons and had made massive preparations for their use, yet the weapons were never used. These preparations included the establishment of secret research programs to develop better weapons and better methods of protecting against those weapons. In the United States, some of this research was focused on the development of protective clothing and skin ointments, which could prevent or lesson the severe blistering effects of mustard agents (sulfur and nitrogen mustard) and Lewisite (an arsenic-containing agent).

By the time the war ended, over 60,0000 U.S. servicemen had been used as human subjects in this chemical defense research program, in a wide range of exposures from mild to quite severe. All those undergoing the latter exposure. and some undergoing the former were told at the time that they should never reveal the nature of the experiments. Almost to a man, they kept this secret for the next 40 years.

Public attention was drawn to these experiments when some of the WWII human subjects began to seek compensation from the Department of Veterans Affairs (VA) for health problems that they believed were caused by their exposures to mustard agents or Lewisite. Resolution of these cases was complicated by a lack of records documenting individual participation in the experiments, and uncertainty as to which health problems were in fact the result of these exposures.

In June 1991 the VA announced guidelines for the handling of these cases, including the loosening of normal requirements for documenting individual participation in the experiments, and the identification of seven diseases to be considered as caused by mustard agents or Lewisite. In addition, the VA requested that the Institute of Medicine (IOM) convene a committee to assess the strength of association between  exposure to these agents and the development of specific diseases. The committee was also charged with identifying the gaps in the literature, and making recommendations as to closing them.

General Conclusions

  • The lack of follow-up health assessments of the human subjects in the WWII gas chamber and field tests severely diminished the amount and quality of information that could be applied in the assessment of long-term health consequences of exposure to mustard agents and Lewisite.
  • The levels of exposure to mustard agents and Lewisite may have been much higher than inferred in the summaries of the gas chamber and field tests.
  • There were no epidemiologic studies done of mustard-agent exposed U.S. chemical weapons productions workers, war gas handlers and trainers, or combat casualties from WWII.