Full Breakdown
Berkeley Engineer’s Co-worker Conviction Expunged After Cadmium Poisoning Case
By Drooid · · How we work
Core Event: Cadmium Poisoning and Conviction Expungement
In a case that began with unexplained vomiting and hair loss for Rong Yuan, a Berkeley engineer, video surveillance captured co-worker David Xu pouring a toxic substance into Yuan’s water bottle. Laboratory testing identified the substance as cadmium, with the water containing levels 3.5 million times the federal limit. Yuan, her parents, and other family members tested positive for cadmium poisoning. Xu pleaded guilty to poisoning in a 2019 plea agreement and received two years of probation. On October 12, a judge granted Xu’s request to have his felony conviction expunged, despite objections from prosecutors.
Background & Context
Yuan’s health problems started in 2017 and persisted despite extensive medical consultations. The breakthrough came when her mother noticed an odd odor from Yuan’s water bottle, prompting Yuan to install a small desk-top camera. The footage revealed Xu’s deliberate act, leading to criminal charges. The case drew attention to workplace safety and the challenges of detecting covert chemical attacks.
Official Statements & Responses
Prosecutors argued that expungement would undermine accountability, but the judge ruled in Xu’s favor. Yuan publicly criticized the decision, noting that she had sought $500,000 in restitution but received only $7,000. She also highlighted the broader impact on her family, stating that her father died last year from heart failure and that the poisoned water contaminated meals prepared at home.
Verbatim Quotes
- “I never expected that I can capture anybody. It's a just an engineer's routine. If you have some issue, you think about the root cause,” — Rong Yuan
- “I don't think he deserves a second chance. A second chance for a lot to hurt other people, to make other people turning into victims,” — Rong Yuan
- “If I don't ask you to come to the U.S., they will be poisoned. If I don't bring the water back home, they won't be poisoned,” — Rong Yuan
Impact and Ongoing Consequences
Nearly a decade after the initial exposure, Yuan continues to experience health issues and works only part-time. She expressed guilt over the water’s return to her household, fearing further harm to relatives. Yuan’s decision to speak publicly stems from a desire to expose systemic failures and to honor her father’s memory. The expungement has left her questioning the justice system’s capacity to protect victims of covert workplace attacks.
