Abstract: A cargo shipment security system includes a flexible body configured to completely enclose and contain cargo within an internal environment having a predetermined pressure. The system includes a sealable vacuum port disposed on and through the body and configured to couple with a vacuum source for creating a vacuum within the internal environment. The system includes one or more sealable ports disposed on and through the body, positioned to cause a turbulent flow through a predetermined volume of the internal environment of the body when the vacuum source is applied at the vacuum port and fluid is caused to enter the internal environment. The system includes one or more detectors positioned to intercept fluid flowing from the internal environment to an external environment outside the body, in such a way as to enable detection of the presence of a substance exiting from the internal environment.