Airports in the US are testing cargo screening systems, following the recent passing of a law requiring the screening of all cargo on passenger planes. The law is to be implemented within three years.

At present, there is no single technology available to screen all cargo and many airports rely on fi ltering, such as paying attention to packages sent with unusual payment methods.

Three airports are testing various screening technology at a cost of $30m, according to US media reports. San Francisco International Airport is testing x-rays and trace explosives detectors.

Seattle-Tacoma Airport is focussing on detecting stowaways in boxes using ultra-sensitive sound monitors to detect an intruder’s heartbeat, and Cincinnati/Northern Kentucky International Airport is working on improving cargo screening using existing technology and making sure freight is moved in a timely fashion.