Scientist Outraged After Co-Worker's Poisoning Conviction Dismissed

A California engineer, Rong Yuan, 50, expressed outrage and a sense of systemic failure after a judge dismissed the felony poisoning conviction of her former coworker, David Xu, 41. Xu was convicted in 2019 for secretly pouring cadmium, a toxic heavy metal, into Yuan's water bottle at their workplace, Berkeley Engineering and Research (BEAR), starting in January 2017.

Yuan began experiencing severe health issues in 2017, including nausea, hair loss, and frequent emergency room visits. Her parents, who came from China to care for her, also ingested the contaminated water and tested positive for cadmium poisoning. Yuan's father died last year from heart failure, which she believes may have been exacerbated by the cadmium exposure.

Using a hidden camera, Yuan captured Xu pouring a white substance into her water bottle. Police identified the substance as cadmium. Despite the evidence, Xu, who allegedly resented Yuan's arrival at the company and did not want to share laboratory space, was not incarcerated. His case progressed under former Alameda County District Attorney Pamela Price, who had pledged criminal justice reform.

In 2023, Xu accepted a no-contest plea deal for one felony poisoning count, receiving no additional jail time. The judge doubled his probation to two years, making him eligible to seek dismissal of his conviction under California law. On Monday, a judge granted Xu's petition over the objections of the Alameda District Attorney's office. The dismissal means Xu's conviction will no longer appear on background checks for employers, though it can still be used if he faces new charges.

"The system failed me," Yuan told The Los Angeles Times. "He didn't stay in jail." She added that she does not believe Xu deserves a second chance after his actions, which she described as planned and cowardly. "Poisoning is not something like you suddenly got angry and lose control. It's planned," she stated.

Yuan, a metallurgical engineer, continues to suffer from liver and gastrointestinal problems. Cadmium is a toxic metal with a long half-life in the human body, capable of causing significant long-term organ damage and cancer. The dismissal of Xu's conviction raises concerns for Yuan, who fears he could obtain employment at another company without his past actions being easily discoverable.

Pamela Price, the former district attorney under whom Xu's case unfolded, was recalled by voters in 2024, with critics citing her perceived leniency with criminals. The current Alameda District Attorney's office stated that they opposed the motion for dismissal but that the court granted it over their objections.