A National Academy of Sciences report says up to 20 parts per billion (ppb) of the rocket fuel chemical perchlorate in drinking water could be considered "safe." Perchlorate affects thyroid function, with children believed to be especially vulnerable. The Environmental Protection Agency [3] previously set 1 ppb as the "safe" perchlorate level; the Defense Department [4] suggested 200 ppb. The Natural Resources Defense Council [5] says the NAS report was compromised by "a brazen campaign" by White House and Defense Department officials and defense contractors "to downplay the hazards" of perchlorate. Through the Freedom of Information Act, NRDC obtained documents [6] suggesting politically-driven pressures on the scope of the NAS investigation, the composition of the NAS panel, and the report. Similar influence was exposed [7], when a member of the industry's Perchlorate Study Group [8] edited an article on adult perchlorate exposure, without the author's knowledge. The original version of the article, which appeared in Environmental Health Perspectives, a journal of the U.S. government's National Institute of Environmental Health Services, was deemed "potentially very damaging" by the group.