Experts say screening every piece of cargo impossible

Explosives found in airfreight shipped from Yemen Friday have put the spotlight on an aspect of air transit the federal government hasn't regulated as heavily as passenger transport.

In August, the Transportation Safety Administration required that all cargo carried by passenger airlines undergo screening or inspection.

But its 100 percent screening requirement for passenger airlines doesn't apply to cargo shipped on cargo-only airlines. And the Government Accountability Office estimated this summer that by August only 65 percent of all cargo coming into the United States would be screened.

Whether cargo aboard cargo-only flights gets "positively screened" - passes through X-ray machines, or is swabbed for chemicals used in explosives, or undergoes computer verification of the shipper's identity - depends on the shipper and the security program in place at the country of origin.

Without giving specifics, TSA officials said Friday that screening of freight would be beefed up in light of the new threats to security.

The process is growing more automated all the time with improvements in technology. Since the beginning of 2009, the TSA has approved dozens of new machines used to scan shipments for traces of explosive materials, chemicals and other substances. Screeners use everything from handheld wands to 12-foot-high X-ray machines to examine cargo.

The TSA is responsible for overseeing the safety of cargo shipments within the United States, but security measures differ from country to country.

Cargo airlines and companies that ship goods to the United States develop security plans. If those plans are approved by U.S. officials, cargo from those airlines and companies speeds through customs and is less likely to be screened.

The task of screening every piece of freight shipped by an airfreight company is virtually impossible to achieve, said Yossi Sheffi, professor of engineering systems and head of the Massachusetts Institute of Technology's Center for Transportation Logistics.

"There's nothing that's 100 percent secure," Sheffi said. "You want 100 percent secure? Lie in bed and cover your head."

Airfreight shipments represent a weakness in the U.S. screening efforts because "you cannot possibly inspect every last package that is sent across the globe," said Christopher Boucek, an analyst specializing in al-Qaida and the Middle East at the Carnegie Endowment for International Peace in Washington.

UPS and FedEx - which together own or lease 1,170 aircraft, according to the companies' most recent annual reports - said they are cooperating with authorities and declined to comment on whether or how they will change procedures in response to the incidents Friday.

Satish Jindel, president of SJ Consulting Group, estimated that Atlanta-based UPS and FedEx move about 20 million pieces a day.

With Keith Herbert