Sir

David Whitlock, in Correspondence (“Bioterror killed five in US; guns kill 30,000 a year” Nature 436, 460; 200510.1038/436460b), is right about the number of people killed each year by firearms in the United States. But in fact suicide accounts for more than half of these deaths. The annual rate of firearm murder and non-negligent homicide is less than 10,000, and is overwhelmingly more often due to handguns than to military-style firearms (Federal Bureau of Investigation Crime in the United States: Uniform Crime Report 2003, Washington DC; 2004).

The firearm is designed for use against individual targets and is incapable of having the same large-scale effect as a well-dispersed biological agent. Almost 3,000 people perished in the 9/11 attacks, but a systematic biological release could conceivably claim 30,000 lives or more. We did not realistically anticipate commercial airliners being used as massively destructive devices, and are now in the difficult position of trying to determine how other major attacks could reasonably be prevented.

The firearm should not be considered in the same context as the potential nuclear, biological or chemical threat.