Joaquin Sapien of ProPublica reports that the CDC's original report on the safety of FEMA trailers dispensed to Hurricane Katrina victims was fundamentally flawed. While an agency standard states that formaldehyde exposure for two-weeks or more at levels measuring 30 parts per billion (ppb) can lead to health problems — the FEMA trailers all measured above this level — the study used a measure of 300 ppb. At this level, the CDC proclaimed the trailers fit for residents as long as they kept the windows open. An investigation by ProPublica shows flawed science and failed communication between government agencies allowed conflicting information about the trailers' safety to continue to circulate. "The story that emerged is of a government bureaucracy that remained silent as the formaldehyde crisis mounted, straying from its mission to serve the public by 'providing trusted health information to prevent harmful exposures and disease related to toxic substances.'"