Vehicles crossing the Canada-U.S. border will now be checked for radioactive material.
Monitors installed by U.S. Customs and Border Protection work like walk-through shoplifting detectors in stores.
The monitors, worth $250,000 each, have been ordered for all border crossings.
Agency Spokesman Mike Milne says Customs Officers can call a Central Lab anytime they want to talk to a Scientist.
Milne says other sources of radiation, like medical equipment, may trip the detector.
