Last week, our partners at PBS NewsHour ran a segment devoted to the Transportation Security Administration's controversial X-ray body scanners, and how despite health risks and a safer alternative, the TSA is proceeding to roll out these scanners in airports across the country.

ProPublica's Michael Grabell, in conjunction with NewsHour, has written a series of stories on these machines, which later led the head of the TSA, John Pistole, to testify that the agency will perform a new, independent study on the safety of body scanners. However, Pistole, much to the chagrin of Sen. Susan Collins, later changed his mind and may only rely on an internal inspector general's report to decide on their usage.

"Research suggests that anywhere from six to 100 U.S. airline passengers could get cancer each year from the machines," Grabell reported. "Still, the TSA has repeatedly defined the scanners as 'safe,' glossing over the accepted scientific view that even low doses of ionizing radiation — the kind beamed directly at the body by the X-ray scanners — increase the risk of cancer...there is an FDA safety regulation for X-ray scanning baggage — but none for X-rays scanning people at airports."

Watch the NewsHour report below, and see all of our airport X-ray scanner reporting here.

Watch For Frequent Fliers, How Big a Concern Is Backscatter Body Scan Radiation? on PBS. See more from PBS NEWSHOUR.