Columbia University has expelled a Chinese graduate student who officials say tainted a pillow in her apartment with a radioactive material in an attempt to force the school to let her switch majors from biology to business, according to the Associated Press in an article dated April 4.

This is an incident bizarre enough to baffle the administration of Columbia University and serious enough to get New York City and U.S. federal officials involved.

The incident began on February 8, when a routine check after the student did some laboratory work showed that she had radioactive contamination on her hands, chin, and hair. The next day the student borrowed a Geiger counter from the laboratory and surveyed her apartment and found that one spot on one pillow was "very hot."

Columbia’s Environment Health and Radiation Safety Department then launched a detailed and intensive investigation that lasted over a month. The Health Department of NYC and U.S. Nuclear Regulatory Commission also participated in the investigation.

The investigation has confirmed that the pillow was indeed contaminated with phosphorus-32, a common radioisotope used in research to tag cells and genes in the laboratory where the graduate student worked. The amount of radioactivity on the pillow also matched the typical activity stored in a single vial in that laboratory. This activity causes a dose rate at close range of about 2 mSv per hour (the annual dose limit for the public is 1 mSv per year), over 10000 times the normal background at NYC. This large amount of radioactivity leads officials to believe that the contamination was most likely a deliberate act.

Throughout the investigation, the graduate student and her recently married husband, another graduate student at Columbia, have denied any wrong doings, and claimed that they do not know how her pillow became tainted with the radioactive stain. The graduate student also suggested that, because of this incident, she may have to transfer her studies from biology to business.

But there are two important facts that remain to be explained. First, the couple’s apartment on the eighth floor is always locked and there is no sign of breaking in. The apartment building is also fairly secure and under the surveillance of a building superintendent and a security guard. Second, a detailed survey of the apartment showed that, other than the pillow, no place else in the apartment was contaminated. In other words, no one touched the pillow after it was contaminated. These two facts lead officials to believe that at least one of the two in the apartment is responsible for this incident.

Based on results of the investigation, Columbia has expelled the graduate student. She has continued to deny any involvement, and has appealed the expulsion. If she looses the appeal, she could forfeit her student visa and be forced to leave the United States. There is more trouble in store, for in NYC one needs a Health Department licence for radiation materials to possess phosphorus-32. The Health Department is deciding whether to refer this case to the NYC police to pursue it as a criminal act.

Lessons Learned

Radiation safety is a serious matter. The purchase, storage, use, and disposal of radioactive materials are governed by many legal requirements. These requirements are to ensure that the radiation worker, the public and the environment would not be exposed to unnecessary levels of radiation.

To satisfy legal requirements and to protect radiation workers, the public and the environment, the radiation safety program at HKUST was established to ensure a proper chain-of-custody of radioactive materials at all times. Safety procedures are set up and implemented so that at any time someone has custody of any radioactive material and is responsible for its safekeeping. Safety training is provided to all whose work involves radiation or radioactive materials to ensure this chain-of-custody.

In the Columbia case, someone abused the custody of radioactive materials. The phosphorus-32 should have never left the laboratory, except for an authorized transfer or for waste disposal. Intentional abuse of this kind may expose individuals and the environment to unacceptable levels of radiation, and must be prohibited. In addition to causing potentially grave consequences regarding one’s academic and professional career, there is also the very real possibility of criminal and civil liabilities.