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NIH Record

NCI Scientist Cleared
NRC Vindicates NIH Response to Contamination Incident

The Nuclear Regulatory Commission on Sept. 17 denied a petition to revoke or suspend NIH's nuclear materials license that had been brought by two visiting fellows who were among 27 people apparently deliberately exposed to radioactive phosphorus-32 in an NCI laboratory in June 1995. The decision closes a 2-year investigation and leaves blameless NIH's rules for handling radioactive isotopes -- NRC determined NIH did all it could reasonably do to prevent misuse of the isotopes. It also finds that the accusations made by the fellows against their supervisor were groundless.

The petition was filed in October 1995 by Dr. Maryann Wenli Ma and her husband, Dr. Bill Wenling Zheng, visiting fellows in NCI scientist Dr. John Weinstein's lab who were expecting a child -- later born without complications -- at the time of the contamination. Ma was exposed to radiation in excess of NRC occupational limits, but a series of NRC investigations could not determine exactly how. Twenty-six others were exposed, at levels lower than Ma, from a contaminated water cooler. None of the exposed individuals is expected to suffer future adverse health consequences.

NRC decided not to pursue enforcement action against NIH on three grounds: there was no evidence that NIH contributed directly or indirectly to the deliberate misuse of licensed material; NIH couldn't have "reasonably foreseen that an employee would maliciously misuse licensed material as appears to have been done in this case"; and because NIH cooperated fully in the investigation.

Ma and Zheng had also made a variety of accusations against Weinstein, who was their supervisor at the time, including that he insisted they begin working with isotopes before being properly trained, and that once the contamination was discovered, he interfered with the NIH radiation safety response and delayed transport of Ma to the hospital for emergency treatment. NRC found all of the complaints to be baseless.

NRC had previously taken enforcement action against NIH, however, based on the findings of NRC inspections that followed the contamination incident. NIH was fined $2,500 for violating NRC security and control requirements and was cited for minor, isolated violations of NRC requirements related to radiation safety training, ordering radioactive materials, inventory control of such materials, monitoring, and the issuance, use and collection of dosimetry. (NIH contested these violations in May and September 1996.) The NRC concluded, however, that none of these violations contributed to the P-32 contamination incident.

Since the incident, NIH has "made significant efforts to improve its control of radioactive material," said NRC. "NIH has tightened its standards for the security and use of radioactive materials," noted NIH deputy director for intramural research Dr. Michael Gottesman. "As a result, NIH now has among the most stringent such standards found in research institutions."

Gottesman also credited Weinstein, a senior investigator in the Laboratory of Molecular Pharmacology, with cooperating fully with 2 years' worth of investigations not only by teams from NRC, but also by the FBI, the HHS inspector general's office, and the NIH Police. "[Weinstein] is an outstanding scientist and supervisor," he stated.

Ma and Zheng have applied several times to have their contracts as visiting fellows extended since the contamination occurred, and have received those extensions, but are scheduled to leave NIH early next year. Since the incident, they have been working off-campus in an NIDCD laboratory.


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