important. The carcinogenicity of blister agents is a second concern, and each of the other potential agents raises its own set of concerns. Understanding the pathogenesis of these chemical weapons is an important step in developing rational protocols for treatment of the casualties they produce.

Research in this area is complicated by the fact that it is not possible to work with human patients, and the most relevant tests are carried out with higher primates (which are both expensive and widely protected). Developing cellular models, or improved whole-animal models using rodents, will be an important part of this program.

Recommendation 4.22: Under the guidance of the NIH, there should be a program to develop improved treatments for injuries that result from exposures to chemical agents.

This program should have both an applied and a fundamental aspect: It should optimize existing protocols, using the most plausible threats, and it should increase our understanding of the general mechanisms of injury on exposure to toxic chemicals. The program should address treatment for both acute and chronic injury, and it should consider countermeasures and protective measures that embrace the full spectrum of threats. Because of the long time required to develop countermeasures, we should start now on important classes of weapons, even if they are not yet known to be ready for deployment.

The system used for developing drugs in the United States will require modification in order to support the development of treatments for chemical attacks. Several problems will have to be addressed:

• The markets are too small (unless dual-use applications can be developed) to make a serious effort by the pharmaceutical industry worthwhile.

• The system on which FDA clearance is based—the testing of new drugs in humans in carefully controlled trials—cannot be used, as these trials have no benefit for the subjects that would be involved.

• The best surrogates for humans in many studies—higher primates—are very carefully protected.

• Many of the chemical agents involved—especially nerve and blister agents—are difficult (or illegal) to use in universities.

The problems of carrying out this kind of research, and of clearing new drugs for use under appropriate circumstances, may require exceptions from current laws and regulations, along with indemnification of suppliers of materials in case of adverse reactions in humans. The FDA is well aware of these problems with regard to biological attacks, and it is trying to develop a suitable system for drugs that would be used in treating the resulting casualties; similar strategies will be applicable for drugs relevant to chemical attacks.