VOLUNTEERS taking part in tests of the Pentagon's "less-lethal" microwave weapon were banned from wearing glasses or contact lenses due to safety fears. The precautions raise concerns about how safe the Active Denial System (ADS) weapon would be if used in real crowd-control situations.

The ADS fires a 95-gigahertz microwave beam, which is supposed to heat skin and to cause pain but no physical damage (New Scientist, 27 October 2001, p 26). Little information about its effects has been released, but details of tests in 2003 and 2004 were revealed after Edward Hammond, director of the US Sunshine Project - an organisation campaigning against the use of biological and non-lethal weapons - requested them under the Freedom of Information Act.

The ADS weapon's beam causes pain within 2 to 3 seconds and it becomes intolerable after less than 5 seconds. People's reflex responses to the pain is expected to force them to move out of the beam before their skin can be burnt. One person suffered a burn in a previous test when the beam was accidentally used on the wrong power setting.

The US marines and police are both working on portable versions, and the US air force is building a system for controlling riots from the air.

Read the full Details of US microwave-weapon tests revealed article at New Scientist