Despite fierce opposition, the National Academy of Sciences has published a report which says the U.S. milk supply is vulnerable to being poisoned with botulinum toxin.
The United States Department of Health and Human Services (HHS) had argued that the information might instruct would-be attackers.
The report by Lawrence Wein and Yifan Liu of California's Stanford University, outlines one way a small amount of the paralyzing poison could make as many as 500,000 people ill, and it recommends measures, such as better pasteurization and careful sampling, to reduce the threat.
The Proceedings of the National Academy of Sciences had originally scheduled publication of the paper in late May, but withdrew its embargoed release to reporters after the HHS objected.
This was an unusual move and the academy recommended that this be a test case for a debate over whether studies that could pertain to biological or chemical warfare be classified in the way studies related to nuclear weapons often are.
The academy, which is an independent body that advises the federal government on scientific and medical matters, met with officials to discuss concerns.
Academy president Bruce Alberts wrote in a commentary, that following the meeting, the Council of the National Academy of Sciences decided to publish the article as originally accepted, and accompanied it with an editorial to clarify their reasons for doing so.
Alberts argued that all of the information in the analysis was easily available on the Internet and open publication and debate can make the nation safer.
He added that because scientific advances are made through the combination of knowledge in unexpected ways, the discoveries of each individual scientist should be made available to a wide variety of other scientists, who can then either build upon or criticize them.
Christina Pearson of the Department of Health and Human Services says the department hotly disagrees and say they are concerned that if the academy is wrong, the consequences could be dire.
She says anything that publicizes vulnerabilities in the system that could facilitate an attack on the food supply, is a concern.
Botulinum toxin, made by bacteria, is the cause of botulism food poisoning and is considered a leading potential biological weapon, and milk, because it is so widely consumed, is considered a vulnerable target.
Wein and Liu set up a hypothetical scenario in which the toxin was put into milk early in the distribution process.
They say, because milk is pooled before being packaged and distributed, this would be an efficient way to try to poison many people, and other products such as fruit and vegetable juices, canned foods and some grains might be just as vulnerable.
Wein and Liu say if it was not detected, for every gallon of contaminated milk consumed, the mean number of people who would consume contaminated milk would be 568,000.
They say that less than 1 gram of toxin is required to cause 100,000 poisoned individuals, and 10 grams poison the great majority of the 568,000 consumers.
Better security and on-site testing could apparently foil such an attempt, and slightly better pasteurization would inactivate the toxin.