David Xu: Toxic Workplace

0:28Shopify's point of sale system helps you sell at every stage of your business. You may have heard of the sex cult NXIVM and the famous actress who went to prison for her involvement, Allison Mack. But she's never told her side of the story, until now. People assume that I'm like this pervert. My name is Natalie Rubamed, and in my new podcast, I talk to Allison to try to understand how she went from TV actor to cult member, and what she thinks of it all now. How do you feel about having been involved in bringing sexual trauma to other people? I mean, I don't even know how to answer that question.

0:58Allison after NXIVM from CBC's Uncover is available now wherever you get your podcasts.

1:13On the eastern side of the San Francisco Bay, just a few blocks from the water, sit the offices of Berkeley Engineering and Research, also known by the acronym B-E-A-R, or BEAR. Inside the company's humble buildings are state-of-the-art labs and workshops where some of the country's brightest scientific minds do their work, analyzing data, conducting experiments. These are some of the smartest, most accomplished minds in the world. One of those super-intelligent, super-competent engineers was David Zhu. One day in March 2019, the then 34-year-old Zhu slipped into one of the company's offices. But it wasn't his office.

1:59It belonged to his colleague, Rong Yuan. Zhu crossed to Yuan's desk and picked up her water bottle. He unscrewed the cap and poured something inside. Then he put the water bottle back down. He started to leave, but then turned back and adjusted the bottle slightly, making sure it was in the exact same position he'd found it. For months, Zhu had repeated the same movement. It was a near daily task. He must have thought no one was looking or paying attention. Little did he know that his window of opportunity was about to come crashing down around him.

2:47this is the opportunist an original podcast from podcast one you're listening to a story told in one episode called david jew toxic workplace i'm sarah james mclaughlin in this episode we dive into the story of david jew a brilliant engineer who used his chemical knowledge to escalate a workplace rivalry to the point of life or death.

3:54By just about any objective measure, David Zhu is a pretty smart guy. He went to UC Berkeley. The Northern California School is one of the top science and engineering universities in the world. There, Zhu earned a bachelor's, a master's, and a doctoral degree in various sciences including chemical, electrical, and mechanical engineering. You could say he was a triple threat. Zhu started his career at Berkeley Engineering and Research back in 2009. The company is located in the East Bay, an area known for attracting and producing smart, progressive-minded folks. It's also just a stone's throw from Silicon Valley.

4:36We spoke to Rachel Swan, a reporter for the San Francisco Chronicle, who provided context on Zhu's case. Berkeley, it's essentially like a college, a bit of a college town, you could say, you know, as well as a, you know, city that's pretty famous for hippies and free speech protests, stuff like that. But right now, you know, it is kind of dominated by the university, UC Berkeley. So there's a big kind of science tech industry around there. UC Berkeley has Lawrence Labs, Livermore Labs. And so he worked in a consulting engineering firm that's in the west part of Berkeley, sort of more industrial.

5:35So he's among this community of, you know, probably Berkeley educated, very elite engineers who have actually a lot of high profile contracts with businesses. He's at a pretty high profile engineering firm that, you know, secures like these big, big contracts to do testing and consulting and such. Zhu's employer, Berkeley Engineering and Research, provides consulting services to corporate and government agencies, as well as expert witnesses to law firms. Basically, it's a small group of people who are very smart and knowledgeable in their fields. The company's website describes its mission like this.

6:24The engineers at Berkeley Engineering and Research are some of the best specialists in their fields. With over 85 years of combined experience, our team brings a unique scientific perspective to investigate and analyze complex failures. From product and mechanical failures to class action lawsuits, Bayer utilizes multiple engineering disciplines and scientific methods to deliver the perfect solution to your specific solution. By all appearances, Zhu's expertise seemed to be a good fit for the company. His specialty was metallurgy, the science and technology of producing and purifying metals. Over the years, Zhu worked his way up to senior materials engineer.

7:10Just as a personal note, like I've talked to, this was actually after I wrote the article, but I've talked to people who have contracted with this guy in various industries. So clearly, like, the firm he worked for had quite a lot of reach, you know. So he's in this community that, you know, they're drawing from the huge brain trust of UC Berkeley. And, you know, there's these extremely high profile labs where they're making like Nobel worthy discoveries. In other words, you're talking about a very elite sector of scientists and engineers. At Bayer, Zhu distinguished himself not just professionally, but also philanthropically.

7:53Outside of the lab, he sought to make a positive impact. One thing that jumped out at me, too, is he was one of the engineers who helped design the suicide barrier at the Golden Gate Bridge. And he also helped with some of the analyses related to the San Bruno pipeline. So there was an explosion back in San Bruno in 2010. You'd almost call it humanitarian work from an engineering angle as well. So this is someone who's like pretty well regarded. And as if being a genius philanthropist wasn't enough, he was also a family man and a whiz at home repair. Was also at the same time this suburban dad.

8:42You know, people wrote about how he could he was the guy who could like fix your computer. He could really fix anything. He could fix anything around the house. So I guess on the one hand, like very decorated in academia and engineering and also had, you know, he had kids. He lived in Lafayette, which is like a hilly, beautiful, picturesque suburb outside Berkeley. He was kind of a family man and took his daughter to gymnastics and ballet. And so in addition to being this elite engineer, he's like very much a suburban dad. It seemed like Zhu had everything going for him. Like he could do no wrong.

9:33And people who knew him well backed that up. Yeah. I'll admit, like most of what I know comes from voluminous letters that people have written about him. But, you know, it was like a testament that he had so many letters in support. It was dozens, you know, I mean, it was quite a lot. You don't always see that in a case like this. But I've talked to people who have had business relationships with him. And there was, I did ask, was there any kind of inkling of, you know, violence beneath the surface? And absolutely not, you know. So from what I could see as an outside observer, this really took everybody by surprise.

10:16eyes.

10:20By 2017, eight years after starting at Bayer, he had worked his way up until he was third in line to take over the company when the principal senior engineer retired. He was set up for a big promotion, which likely would have come with a significant raise, not to mention the prestige of heading up such a well-regarded firm. But then, in early 2017, someone came along who threw a wrench into the works of Zhu's best laid plans. Her name was Rong Yuan.

10:53Like Zhu when he started out, Yuan was a promising young engineer. And also like Zhu, she specialized in metals. Maybe Zhu saw something of himself in Yuan and realized she could be a threat to his rise. Right away, Zhu expressed concern that he and Yu Wang would be in competition for the same work. He had a co-worker, also a person who studied metals at the firm, who was in a similar position. Both of them were kind of jockeying to possibly take over the company after one of the principals. According to the court filings, he had voiced misgivings about this person and expressed to other people that this person, Rong Yuan, was a competitor.

11:48She's really kind of stayed out of the public eye, but also clearly a very decorated, highly educated engineer who was also in line to have a leadership position at this prestigious consulting firm. So Yuan joins the company and Zhu decides they are on a collision course. He's put in almost a decade of work and climbed to the top of the ladder. But now, there's a young upstart who he feels is gunning for the top spot. But, just a few months after Yuan started working at Bear, she began having strange health issues. It started in October of 2017. Various forms of stomach upset, nausea, vomiting, diarrhea, cramps.

12:40Could it just be the stress of a new job? Or was there something else going on? Whatever was happening to her, on some level at least, it seemed to be connected to work. Specifically, her bouts of illness tended to happen shortly after eating meals at the office. And more than once, her symptoms were so extreme that she had to be rushed to the hospital for emergency treatment. There didn't seem to be any rhyme or reason to when her sickness would pop up again. Even a bright scientist like Yuan couldn't get to the bottom of her symptoms. The mystery illness continued for over a year. In November of 2018, Zhu expressed concern for his co-worker.

13:30He offered his own hypothesis on her condition, saying it might be caused by mold or poor air quality. Zhu took quite an interest in Yuan's health urging her to see a doctor and even asking if anything had come up in her blood and urine tests and as she was getting sick he was expressing concern and telling her she needed to go to a doctor and remember these two people are co-workers Yeah, even thinking about it makes me kind of crazy. Later that month, something strange happened. Yuan's peculiar sickness seemed to spread. Her mother and father also fell ill. This was after Yuan's mother made the family a rice porridge with the water from her water bottle.

14:28The same water bottle that Yuan took with her to work. She at one point brought the water home and her parents used it to cook with and also got sick. So there was definitely signs from which she could infer that, okay, there's something in the water that is making me sick, you know, and not making anybody else sick at the office. The next month, December 2018, the same thing happened again. All three of the family members got sick after consuming water from Yuan's bottle. At this point, Yuan's mother made a suggestion. There might be something wrong with the water.

15:19Up next, Yuan discovers the shocking reason that she and her family have been getting sick. Now, back to the story. By the end of 2018, Rong Yuan had been working at the prestigious firm of Berkeley Engineering and Research for nearly two years. But for more than half of that time, she had been afflicted by a mysterious illness. Her symptoms would pop up intermittently. After eating a meal at the office or drinking from a water bottle she took with her to work. When her parents both became sick after drinking water from the same bottle, Yuan started to suspect that something was happening to the water when she took it to the office.

16:06After more than a year of this, and a suggestion from her mother, Yuan finally decided to get to the bottom of what was going on. So she did what scientists do, and she set up an experiment. Her research question might have gone something like this. What will I observe if I set up a secret surveillance camera in my office? I guess I would keep an open mind and say, you know, she put out the camera because she suspected that this illness was being generated by her water. It took a couple of months, but finally her experiment bore fruit. In February of 2019, Yuan played back the secret camera footage and saw something truly alarming.

16:54Her co-worker, David Zhu, a family man and fellow metal specialist with whom just about everyone held in high regard, snuck into her office. Why would he do something like that? The camera angle wasn't quite right, so she couldn't see exactly what he had done, but But he appeared to move something on her desk near her water bottle.

17:22Could it be that he was tampering with her water somehow? Was he putting something in it that was making her and her parents sick? The data was suggestive, but not conclusive. So Yuan made sure to collect a sample from her water bottle. And then she adjusted the camera angle and ran her experiment again. The next month, she finally got the undeniable evidence she was looking for. She caught Zhu on camera, red-handed, clearly entering her office, unscrewing her water bottle, and pouring something inside. I guess it's fair to say she wanted to see what is happening with my water at work. and on the video she captured him coming into her office and tampering with the water.

18:20Whether that was a complete surprise, I don't know. It certainly seemed shocking. Shocking to say the least. Yuan's co-worker, a leading scientist in his field, had been caught on camera intentionally putting something in her water bottle. When she had drunk from that water bottle on several occasions, she had become seriously ill. Here is Rachel Swan describing what she saw when she viewed the video. Had I not known the story, I guess it would have been hard for me to know what was going on. I mean, what I saw was a person in close-up, you know, kind of like at the water. whether they were putting something into it.

19:07You know, with my untrained eye, it was hard to tell. Now, there's a common saying in the sciences, correlation does not equal causation. Another way of putting that is just because two variables seem to be connected, it doesn't mean that one causes the other. But the evidence that Yuan had uncovered was one heck of a correlation. It was kind of grainy, but she, I believe, was able to catch this at multiple times and from multiple angles. So it was definitive enough that when she presented it to police, they had probable cause. They were able to develop probable cause to arrest him and search his house.

19:54Greeny footage or not, one thing seemed undeniably clear. Yuan's co-worker was poisoning her. Yuan went to the police with the surveillance footage and the water supply she'd taken from her bottle after Zhu had tampered with it. She told the authorities that she was afraid of Zhu, that he was highly intelligent, and that he would know how to poison someone. As it turned out, Yuan was right to be scared. Authorities were finally able to close the loop and establish the causation. The water from Yuan's bottle tested positive for dangerously high levels of a heavy metal called cadmium. A brief note on cadmium, since it's not something one generally comes across in day-to-day life.

20:42Cadmium is a soft, silvery, whitish, bluish material, solid at room temperature with similar properties to zinc and mercury. We spoke to Joe Zagorski, a professor at Michigan State University's Center for Research on Ingredient Safety, to provide some helpful information on heavy metals like cadmium and their potential impact on the body. Heavy metals are naturally occurring elements that have high densities or in chemistry you might hear that referred to as high atomic weights. And some examples are lead, arsenic, and mercury. And because of that, they are naturally part of our environment. There are some areas that might have higher levels than others just because, you know, the Earth's not the same everywhere on its surface, but they're all naturally part of the Earth.

21:41Cadmium specifically is mainly used in batteries, certain pigments, and as a corrosion-resistant plating on steel objects like cars. The metal is a solid at room temperature, but it also forms certain salts, like cadmium chloride and cadmium sulfate, that dissolve in water, like inside a co-worker's water bottle. The metal doesn't have any odor or taste and is very poisonous at a high enough dose. But it's important to note that just coming into contact with a small amount of cadmium isn't enough to cause serious side effects. So actually, this kind of touches on something that is really the central dogma of toxicology, and that is the idea that everything, every chemical in existence, it has the ability to be both safe and dangerous if in the right amount.

22:36We refer to it as the dose makes the poison. And so naturally, the vast majority of people that come in contact with these heavy metals in the environment are coming into contact with them at such low levels that there's really no major health concern. That will depend on the amount you ingest, how frequently you ingest. And a lot of times these metals are bound to other things. And so it really kind of depends on what type of mixture they're in. So basically, if you consume a large enough dose of cadmium over a long enough period, then like Rong Yuan, you can be in for a very bad time. What you're referring to is something that we refer to as a chronic exposure.

23:24So over, it's not, if it were just a one-time exposure, we refer to that as being acute. And then there's some exposures that are a little bit longer. We refer to those as subchronic. And then these very, very long-term exposures are called chronic exposures. And the difference here is that a lot of these metals have a relatively long half-life, which is the amount of time it takes for the amount of that chemical, in this case metal, to decrease by half. And so if they have a long half-life, essentially that means it's staying in your body a long time. And if you have one single exposure and then you have no exposure after that, your body has time to take care of itself and detoxify itself because it will naturally take care of itself.

24:12It's what our bodies are made to do. But if you have continual exposure, now we have the possibility that these things can start to continue to build up and get higher and higher and higher in terms of concentration in our bodies. So our bodies can't get rid of it fast enough. And what you see is if you have small amounts, relatively small amounts, but you have them at very frequent or very regular intervals, ultimately, long term, you can end up with toxicity. Whereas if you took that same amount and exposed somebody to it one time, or even a couple of times, and then stop, you don't get the toxicity because your body is able to take care of it and get rid of it.

25:02The ability for our bodies to get rid of harmful chemicals is mostly thanks to our kidneys. They do the lion's share of the detoxing. But there's only so much and so fast that they can detox. If the kidneys can't keep up with the chronic exposure, all sorts of nasty health effects can pop up. There are definite, very negative outcomes that can occur from chronic exposure to some chemicals. There are instances where chronic exposure to something can result in a lot of different toxicities, from kidney issues to cardiovascular issues and high risk of heart attack to increased risk of diabetes to the development of cancer.

25:50As Yuan experienced, high levels of cadmium can cause severe stomach issues. It can also negatively affect the skeletal system, causing osteoporosis, which can increase the risk of broken bones. The metal also impacts the body on a cellular level. It can alter your DNA and cause mutations and potential chromosomal deletions. Without doing a full recap of high school biology, let's just say DNA is really important and deleting it is really bad. So bottom line, in high chronic doses, too much cadmium can cause organ failure, cancer, and even death. And when Yuan finally got tested, her blood levels were consistent with being exposed to heavy metal poisoning over weeks or months.

26:45By this point, it seemed pretty clear what had happened. Yuan and her parents had been poisoned. But then the question became, why? Shockingly, this extraordinary attack seemed to be born out of a garden-variety professional jealousy. There was definitely this sense of, you know, did this person snap, you know? Did this person have this kind of extremely competitive instinct that was sort of just lurking beneath the surface? In some office environments, I mean, there is a lot of, like, rivalry within an office. One can only imagine, especially once you get into the upper echelons. A lot of, it's interesting because a lot of us can kind of, like, in some ways it's such a familiar story in a weird sense, like reading through the documents, you know.

27:46I think a lot of us could totally, if not relate to, at least understand this dynamic of two powerful people sort of seething, or at least one of them seething, and really wanting to undo each other. I think what stuck out most to me was actually that kind of parable of jealousy. And it's laid out in pretty stark detail that a guy is, you know, sort of, you definitely get the sense of this person who's worked very hard all his life, who's kind of worked his way up. who sees another co-worker also rising and also potentially threatening to take his spot, you know, and I mean, that's just, again, that's something that I think a lot of us have seen before or could relate to.

28:59I mean, that's so basic in human relationships, you know, So I think that parable of just like, I have to stop this person, whatever it takes. It could have really been that simple. Zhu saw Yuan as a threat to his position and the promotion that he'd been working toward for years. He wanted to eliminate the threat. And he saw poisoning her as his opportunity to remove her. As an engineer, he may have taken a calculated, dispassionate approach. He had a problem, so how could he solve it? Lucky for him, he had a laboratory full of chemicals at his disposal. And as a chemical engineer and metal specialist, he knew them inside and out.

29:52He knew their properties. And he knew that certain metals, like cadmium, could be snuck into his co-workers' food and drink to solve his problem. He had the motive, he had the means, he had the opportunity, and he took it.

30:19Up next, David Zhu pays the price for his actions somewhat, but he gets a pretty sweet deal. Now, back to the story. All right, a California engineer accused of trying to kill a co-worker by slowly poisoning her over more than a year is in custody this morning. Prosecutors say 34-year-old David Hsu added toxic metal to the woman's food and water until she finally caught him on camera. While Hsu's move is shocking, he's certainly not the first person to use heavy metals to try and take out an opponent. It wouldn't surprise me if there are instances throughout history where people have used heavy metals in general to cause toxicity and try to poison people, especially because compared to some other chemicals, they can be relatively potent in terms of toxicity.

31:23So you can get away with using less of that than another chemical and still get the desired outcome. In this case, the desired outcome would be poisoning. As it turns out, Zhu could be in the same company as the likes of the Russian government. In 2023, the wife of the head of Ukraine's Defense Intelligence Agency was diagnosed with heavy metals poisoning. Russia and Ukraine, of course, have been at war since 2021. and it was determined that the poison may have been intended for her husband. Though it wasn't exactly clear who attacked the official's wife or why, experts in the area pointed the finger at Russia as the obvious suspect.