this is that if you were scanned with a backscatter scanner every day of your life, you would still only receive a tenth of the dose of a typical CT scan ... By comparison, the amount of radiation from a backscatter scanner is equivalent to about 10 minutes of natural background radiation in the United States ... I believe that the general public has nothing to worry about in terms of the radiation from airline scanning ... For moms-to-be, no evidence supports an increased risk of miscarriage or fetal abnormalities from these scanners ... A pregnant woman will receive much more radiation from cosmic rays she is exposed to while flying than from passing through a scanner in the airport". In May 2010 the National Council on Radiation Protection and Measurements issued a press release in response to the health risk claims from UCSF and Columbia University (claims of excessive skin dose and risks to large populations vs. individuals). The NCRP claims that cancer risks cited by opponents are completely inaccurate, stating that: the summation of trivial average risks over very large populations or time periods into a single value produces a distorted image of risk, completely out of perspective with risks accepted every day, both voluntarily and involuntarily. and that general-use systems should adhere to an effective dose of 0.1 microsievert (μSv) (0.01 millirem) or less per scan, and can be used mostly without regard to the number of individuals scanned or the number of scans per individual in a year. An effective dose of 0.1 μSv (0.01 mrem) per scan would allow 2,500 scans of an individual annually [i.e., if each scan required 0.1 μSv (0.01 mrem)] without exceeding the administrative control of 0.25 mSv (25 mrem) to a member of the general public for a single source or set of sources under one control. Assuming 250 workdays per year, this would correspond to an average of 10 scans each day, a frequency that is unlikely to be encountered. All the same the Inter-Agency Committee on Radiation Safety which includes the International Atomic Energy Agency, Nuclear Energy Agency and the World Health Organization, reported that, "Pregnant women and children should not be subject to scanning, even though the radiation dose from body scanners is 'extremely small'". It has also been suggested that defects in the machines, damage from normal wear-and-tear, or software errors could focus an intense dose