The Food and Drug Administration says scanners in airports used or security purposes pose only “miniscule” potential health risks.

A group of doctors and professors from the University of California had voiced concern in April that scanners that they could harm human bodies with radiation and cancer risks.

There are 385 scanners installed across 68 airports in the country by the Transportation Security Administration. The scanners emit low levels of radiation to scan passengers. The scanning resembles a nude image of the passenger and finds possession of any weapons or contraband hidden underneath.

More than 200 of the 385 image scanners is built by Torrance-based Rapiscan (it uses X-rays for scanning); while the remaining 174 scanners is by the New York based L3 Communications use millimeter wave radiation for the purpose.

In the letter to John P. Holden, President Obama's science and technology advisor, John L. McCrohan, deputy director for technical and radiological initiatives at the FDA, said the "concern that the dose to the skin may be dangerously high is not supported."

The letter also states that the X-ray scanners have been tested extensively by government and independent experts before approval for use at airports. ”As a result of these evidence-based, responsible actions, we are confident that full-body X-ray security products and practices do not pose a significant risk to the public health," the letter also stated.