In 1995, a researcher at the Massachusetts Institute of Technology (MIT) noticed something amiss. Yuqing Li’s Geiger counter alarm started blaring. The radiation source? Him. But how did he become so radioactive? How did anything hazardous get inside his body?

What Happened?

Unsolved to this day, the question remains: who attempted to poison Li? Radiation Protection Officer, Frank Masse, failed to determine how approximately 600 microcuries of Phosphorus-32 (P-32) ended up in the researcher’s food. As a reference, 530 microcuries can be considered detrimental. The post-doctoral researcher had a full year’s exposure limit, which he got during his lunch break. Multiple MIT officials checked over his procedures and logs: Li secured his radioactive materials appropriately and followed safety protocols. As the investigation continued, it became apparent the P-32 originated outside his laboratory. On December 15, 1995, the Nuclear Radiation Commission (NRC) said the poisoning was a deliberate act by a third party. But, who put it there?

P-32

Phosphorus-32 (P-32) is an easily accessible isotope used in biomedical research and diagnostics. It has a half-life of approximately two weeks. It naturally occurs at low levels and can be used to study plant and animal nucleic acids. Despite being one of the safer radioactive isotopes, researchers must adhere to strict safety protocols, including wearing a dosimeter to track their radiation exposure over time and lead-lined clothing for additional protection.

Full Recovery and Future Prevention

Luckily, after sixty days, Li suffered no long-term adverse health effects and fully recovered. Today, Yuqing Li is a prestigious neuroscience researcher from the University of Florida, where he joined the Department of Neurology at their School of Medicine in 2010. Continuing his earlier work, he examines neuroplasticity and neurodevelopment, sometimes using animal models, which is often unavoidable in this field.  His work benefits children born with neurodevelopmental disorders, aging populations struggling with neurodegenerative disorders, and those in recovery from opioid addiction.

While not affecting the long-term use of P-32 or other radioactive tracers in research at the institution, the incident remained puzzling. Those assigned to investigate, such as the NRC, compared it to other domestic and international incidents involving iodine and P-32 isotopes at other universities. Many instances were self-ingestion, a cause mitigated by appropriate safety protocols. However, this differed for Li and at least one other P-32 victim. While investigators did not solve this mystery, we must consider these risks to human health as we continue to use radiotracers in laboratory research.

Editor: Lucy Cafiero