Thallium poisoning case of Zhu Ling

Unsolved 1995 thallium poisoning case in China

This article is about the poisoning victim. For other uses, see Zhu Ling (disambiguation).

In this Chinese name, the family name is  Zhu (朱).

Thallium poisoning of Zhu Ling

Zhu Ling

Location| Tsinghua University, Beijing
Date| October 1994 - April 1995
Victim| Zhu Ling

Zhu Ling[a] (Chinese: 朱令; pinyin: Zhū Lìng, 24 April 1973 – 22 December 2023) was best known as the victim of an unsolved 1995 thallium poisoning case in Beijing, China. Her symptoms were posted to the Internet via a Usenet newsgroup by her friend from Peking University, Bei Zhicheng, and were subsequently proven to be caused by thallium poisoning. Her case was then reviewed by physicians in many different countries who examined her symptoms and made suggestions as to diagnoses and treatment. This effort was recognized as the first large-scale tele-medicine trial.[6] Her life was ultimately saved, but she suffered serious neurological damage along with permanent physical impairment, and died in December of 2023.[7]

This case drew great attention in the Chinese media, because the victim and the suspect were living in the same dormitory in the most prestigious university in the People's Republic of China, and in addition the case was never solved. Internet discussion of the crime has continued since then and became a hot topic on major online Chinese communities very frequently as a high-profile cold case.

## Poisoning case[edit]

### First hospitalization[edit]

In 1994, Zhu Ling was a sophomore in Class Wuhua2 (Class 2 majored in physical chemistry) at Tsinghua University in Beijing. Classmates described her as attractive, intelligent, and talented, with an interest in music. She began to show strange and debilitating symptoms starting from November 24, 1994, when she reported experiencing acute abdominal pain, and loss of appetite. Then (on December 5), discomfort in the stomach and her hair began to fall. On the night of December 11, 1994, despite her illness, Zhu Ling insisted on performing for the Tsinghua Chinese Orchestra at the Beijing Concert Hall, where she performed a solo of the Guqin piece "Guangling San".[8] Her hair was completely gone within a few days after the performance.

Following her hospitalization at Beijing Tongren Hospital on Dec 23, 1994, her condition gradually improved and she was allowed to return to school. She was discharged from the hospital on Jan 23, 1995.

### Second hospitalization[edit]

One Feb 20, 1995, a new semester started. On Feb 27, shortly after returning to school, Zhu Ling experienced intense pain in both legs. On Mar 6, Zhu Ling's condition deteriorated, experiencing severe leg pain and dizziness. Her parents took her to Peking University Third Hospital for treatment. Professor Chen Zhenyang (陈震阳), who was involved in the diagnosis and treatment, documented in his paper "Introduction to a Rare Case of Severe Thallium Poisoning" that on March 8, Zhu Ling "once again experienced intense foot pain, pain in the calves, so severe that she dared not touch any objects. This time it was more severe than the before, and the condition developed rapidly, extending to the lower back."[9]

On Mar 9, 1995, Zhu Ling's parents took her to the neurology specialist clinic in Peking Union Medical College Hospital (PUMCH). After being attended to by Professor Li Shunwei (李舜伟), he informed Zhu Ling's mother that her condition was "very similar to a case of Thallium poisoning at Tsinghua University in the 1960s. In the medical records for that day, Professor Li Shunwei described Zhu Ling's condition as follows: "(the patient is) mentally clear and articulate, experiencing significant hair loss, limbs hurt by touching, redness at the fingertips and soles which are not swollen but with elevated temperature. Reduced sensation in the fingertips and below the knees, symmetric knee reflex. Ankle reflex is slow. Highly suspicious of heavy metal poisoning, such as Thallium and Beryllium, consulted with Director Zhang Shoulin and professors including Ding Maobai". Upon admission, Zhu Ling "had clear Mees lines on her fingernails, raising suspicion of possible Thallium poisoning".[10] To further clarify the diagnosis, Professor Li Shunwei immediately contacted Professor Zhang Shoulin from the Chinese Academy of Medical Sciences Institute of Labor Health for Zhu Ling's diagnosis. On the same day, Zhu Ling, accompanied by her mother, went to Professor Zhang Shoulin for examination. Based on the symptoms, Zhang Shoulin suspected acute Thallium or Arsenic poisoning, but the institute was unable to conduct the necessary tests. Zhu Ling denied that she had had any contact with Thallium in class, a claim which was confirmed by Tsinghua's chemistry department. PUMCH also claimed the lack of equipment to perform such tests. As a result, the hospital, where the suspect Sun Wei's mother also works at, did not conduct any Thallium poisoning tests.[11]

### Diagnosis and treatment[edit]

On Mar 15, 1995, Zhu Ling was admitted to the neurology ward of PUMCH, complaining of "hair loss, abdominal pain, and joint and muscle pain for 3 months, pain in the distant ends of both lower limbs for 7 days, dizziness for 3 days. The patient had abdominal pain without obvious cause for the past 3 months before admission (December 8, 1994), characterized by continuous dull pain with intermittent colicky pain. Hair loss occurred 3 months later, accompanied by soreness in both shoulders and knee joints." The initial diagnosis was "peripheral neuropathy, cause of limb pain and redness to be determined". The lumbar puncture performed on the same day yielded normal results. The next day, a neurology consultation ruled out autoimmune diseases, poisoning, and metabolic diseases. Peking Union Medical College Hospital treated her according to the diagnosis of Guillain-Barré syndrome. After admission, her condition worsened rapidly, affecting her chest, her facial muscles became distorted, her speech was unclear. She was unable to drinking water which causes choking, and breathing difficulties emerged. Treatment involved broad-spectrum antibiotics, antiviral drugs, corticosteroids, immunosuppressants, and albumin injections, among other measures.

On Mar 20, Zhu Ling fell into a coma.

On Mar 23, Zhu Ling experienced central respiratory failure, and Peking Union Medical College Hospital performed a tracheotomy. On the same day, after a comprehensive neurology discussion, the diagnosis was revised to acute disseminated encephalomyelitis (ADEM), and treatment involved plasma exchange therapy.

On March 24th, Peking Union Medical College Hospital began plasma exchange therapy for Zhu Ling, and this continued until April 18th, totaling 7 sessions, with each session involving 1400-2000 milliliters of plasma, amounting to a total of 10,000 milliliters of plasma. Some believe that this played a crucial role in sustaining Zhu Ling's life in the absence of a confirmed diagnosis. However, during this process, Zhu Ling contracted hepatitis C.

On March 28th, Zhu Ling developed pneumothorax on the left lung and was transferred to the Intensive Care Unit (ICU) at Peking Union Medical College Hospital, where her breathing was supported by a ventilator.

On April 3rd, a comprehensive neurology consultation was held. Medical experts from Peking Union Medical College Hospital, PLA General Hospital 301, Boai Hospital, Beijing Hospital, and others participated. The final consensus from the consultation was that the current diagnosis and treatment were appropriate. Afterwards, Zhu Ling's parents spoke with some of the experts and learned that during the consultation at Peking Union Medical College Hospital, they considered that since Thallium poisoning had been ruled out, they had to explore other potential causes from different perspectives.

Zhu Ling remained in a coma for a prolonged period of five months, only awakening on August 31.

Peking Union Medical College Hospital conducted various tests on Zhu Ling, including HIV, lumbar puncture, magnetic resonance imaging (MRI), immune system evaluations, chemical poisoning assessments, anti-nuclear antibodies, nuclear antigen antibodies, Lyme disease, and urinary arsenic, among others. However, except for Lyme disease, all other test results were negative. During this period, the hospital informed Zhu Ling's family, explicitly stating that Thallium poisoning could be "ruled out".

## Diagnosis via Internet[edit]

Frustrated with local physicians' inability to help Zhu Ling, her friends Cai Quanqing and Bei Zhicheng, undergraduate students in Peking University, posted an "SOS" letter on a number of Internet Usenet groups on 10 April 1995, describing their friend's symptoms and asking for help with a diagnosis.[12][13][14] It was remarkable that by 1995 only a few research institutes in the People's Republic of China had Internet connections, including Cai's advisor. Responses began pouring in within a matter of hours,[15] and news reports hailed the event as a milestone in remote diagnosis by Internet, especially in the People's Republic of China. Of the more than 1,500 responses which Zhu Ling's friends received, roughly one-third proposed that she was suffering from thallium poisoning, the common antidote for which is Prussian blue.

Due to lack of internet infrastructure, Dr. Li Xin, a Chinese student at UCLA and Dr. John W. Aldis from the U.S. Embassy in Beijing collaborated to establish the UCLA Zhu Ling Thallium Poisoning Telemedicine Network. In 1996, Dr. Li Xin and his colleagues published a paper detailing the construction and operation of the remote medical diagnosis system during the Zhu Ling's Thallium poisoning incident, highlighting its significant role. Bei Zhicheng, Cai Quanqing, and others at Peking University uploaded Zhu Ling's case information, including photos at the onset of the illness, laboratory results, neurological examination findings, and radiographic images (chest X-rays, brain MRI, etc.). Dr. Li Xin and his colleagues at the UCLA School of Medicine set up servers to store Zhu Ling's medical data, collating and categorizing emails received from around the world. Medical experts worldwide could access information about Zhu Ling's medical condition through the network, sending emails to inquire about further details or provide relevant diagnostic or treatment suggestions.

According to the diagnostic and treatment logs in UCLA, as early as April 10th, the day Bei Zhicheng sent the email, there were doctors responding with a diagnosis of Thallium poisoning. Dr. Fink, a neurosurgeon in the United States, believed that heavy metal poisoning was highly probable. However, Peking Union Medical College Hospital replied at that time, stating that all laboratory tests related to heavy metal poisoning had been conducted. With further communication, American doctors eventually discovered that Peking Union Medical College Hospital had only performed screening tests for metal arsenic. As time went by, more medical experts believed that Thallium poisoning could NOT be ruled out and insisted that Peking Union Medical College Hospital should promptly conduct screening for metal thallium. Doctors from St. Jude Children's Research Hospital pointed out in their response, "Suspected Thallium poisoning can be nearly diagnosed based on symptoms such as hair loss, gastrointestinal problems, and neurological issues". Dr. Fink recalled that as Zhu Ling's condition worsened, they urged Peking Union Medical College Hospital through various channels to conduct Thallium poisoning screening for a quicker and more accurate diagnosis. At that time, in addition to leveraging connections at the U.S. Embassy in Beijing, they directly faxed relevant academic articles to Peking Union Medical College Hospital. Dr. Aldis also personally communicated with old friends who were healthcare professionals at Peking Union Medical College Hospital.

On Apr 18, 1995, Bei Zhicheng brought the translated emails to the ICU of PUMCH to provide to the doctors as a reference. There was no proactive response. Few people reviewed it, and the diagnosis of Thallium poisoning and the corresponding testing methods mentioned in the email were not adopted. This resulted in the delayed impact of the online remote diagnosis at that time.

When Zhu Ling's parents requested the doctors to consider the opinions presented in the email, Peking Union Medical College Hospital doctors responded with, "We have the ability to consult international medical databases". They also mentioned "Peking University students bring many problems". Many years later, when Bei Zhicheng had a heated online debate with Sun Wei in 2005 on Tianya BBS, he wrote, "The former director of the ICU at Peking Union Medical College Hospital refused to conduct further tests for heavy metal poisoning. Even after the misdiagnosis at Peking Union Medical College Hospital was discovered, he showed no remorse. Astonishingly, he said at a hospital meeting that 'This matter is an attempt by Western anti-China forces to discredit the Chinese medical community'".

Dr. Aldis documented in Zhu Ling's medical records: until May 16th, Bei received nearly 2000 emails. On the other hand, Bei and his friends at Peking University attempted to provide Peking Union Medical College Hospital with a modem, hoping to facilitate direct communication with overseas medical professionals. Unfortunately, due to some "non-technical reasons," all their attempts were unsuccessful. Dr. Aldis expressed deep regret at the limited communication channels between overseas doctors and Peking Union Medical College Hospital at that time, which hindered the exchange of information regarding Zhu Ling's diagnosis and treatment.

### Subsequent diagnosis and treatment[edit]

Due to suspicions raised in emails on the internet regarding Thallium poisoning, when Zhu Ling's parents learned that Professor Chen Zhenyang (陈震阳) from the Beijing Institute of Labor Protection could conduct Thallium poisoning tests, they received the discreet assistance of a Peking Union Medical College Hospital doctor. They obtained Zhu Ling's urine, cerebrospinal fluid, blood, nails, and hair samples. On April 28, 1995, Zhu's parents went to the Beijing Institute of Labor Protection for testing. The results indicated, "All specimens showed very high levels of Thallium, hundreds to thousands of times higher than that of a healthy person, confirming the diagnosis of Thallium poisoning." [16] For example, the results on April 28 for various samples were: urine Thallium 275 ug/L, blood Thallium 31 ug/L, hair Thallium 531 ug/kg, nail Thallium 22,824 ug/kg, and cerebrospinal fluid Thallium 263 ug/L. On the same day, Professor Chen Zhenyang issued a test report, stating that Zhu Ling had suffered from Thallium poisoning twice and suspecting intentional poisoning. He also recommended the administration of Prussian blue as an antidote. In a scholarly paper published in 1998, the doctors from Peking Union Medical College Hospital, responsible for diagnosis and treatment, emphasized that Zhu Ling had "no clear history of toxic substance exposure, early symptoms of abdominal pain and hair loss, self-relieved without specific treatment, and one month later suddenly developed peripheral neuropathy and signs of encephalopathy, not excluding the possibility of second poisonings".

On April 28, even with the test result of Thallium poisoning, Peking Union Medical College Hospital were prepared to issue Dimercaprol instead of Prussian blue. After multiple attempts of communication between Dr. Ivan Petrželka in Los Angeles Poison Control Center, Dr. Ashok Jain, Dr John Aldis and many other medial experts, Peking Union Medical College Hospital finally started treatment with Prussian blue on May 3, 1995.

On Aug 31, 1995, Zhu Ling woke up from a coma lasting for 5 months. Professor Chen Zhenyang believed that, "Although the patient started to wake up, due to severe poisoning and a prolonged period of unconsciousness, both the central and peripheral nervous systems of the patient were severely damaged." During the recovery phase, "the patient's symptoms improved, the upper limbs could move, and memory also showed some recovery. She could recall some events from earlier years, such as those from junior high school, and express simple questions in unclear language. Before falling ill, the patient used to play string instruments, but now, although she could make some movements resembling playing with her hands, she could not produce any sound from the strings. The coordination between the muscles of the tongue and mouth was impaired, making it impossible for her to express herself in correct language. The muscle strength in both legs was only at grade 1-2. There was a decline in vision, and partial atrophy of the optic nerve. CT scan results showed atrophy throughout the entire brain, including the cerebellum". Peking Union Medical College Hospital concluded in their paper titled "Clinical Analysis of Five Cases of Thallium Poisoning" that after treatment, "clinical symptoms and signs improved significantly, but due to the prolonged course of the disease, there were sequelae such as optic nerve atrophy, paralysis of both lower limbs, muscle atrophy, and intellectual impairment".

## Hair analysis[edit]

Zhu Ling's parents collected a small number of hairs from a blanket used by her during the poisoning period (1994–1995) and stored them in a plastic bag since. These samples were obtained by Min He, who, through collaboration with Richard Ash at the University of Maryland, reconstituted the original poisoning process using LA-ICP-MS. The results were published in Forensic Science International in 2018.[17] In summary, it appears that Zhu Ling had suffered roughly four months of repeated exposure to thallium with increased doses and frequency towards the end, as well as roughly two weeks of constant ingestion of large doses of thallium accompanied by an elevated amount of lead. The overall thallium distribution profiles in the analyzed hairs suggested both chronic and acute thallium exposures that correlated well with the sequential presentation of a plethora of symptoms originally experienced by Zhu Ling. Aligning the time-resolved thallium peaks in the hair with her symptoms also provided clues on possible routes of exposure at different poisoning stages.

## Police investigation[edit]

On the evening of April 28, 1995, when Zhu Ling was diagnosed for Thallium poisoning, Zhu Ling's parents immediately requested Professor Xue Fangyu (薛芳渝), then the Deputy Head of the Chemistry Department at Tsinghua University and in charge of student affairs, to report the case. Professor Xue Fangyu consulted He Meiying (贺美英), the Party Secretary of Tsinghua University at that time, and Tsinghua University President Wang Dazhong. After receiving approval, Professor Xue Fangyu immediately called the deputy director of the Tsinghua University Security Department, who also served as the deputy director of the Tsinghua University Police Station, to report the case. (Due to historical reasons, the Tsinghua University Security Department and the Tsinghua University Police Station was essentially the same). The next morning, Zhu Ling's aunt contacted Professor Xue Fangyu again, requesting the immediate relocation of students sharing the same dormitory to preserve the scene, seal Zhu Ling's belongings on campus, and conduct further examinations. However, Professor Xue Fangyu indicated that it would be difficult to relocate the students.

After the International Workers' Day holidays, Tsinghua University Security Department officially reported the case to the Beijing Municipal Public Security Bureau on May 5, 1995.

### Theft Case in Zhu Ling's Dormitory[edit]

Between April 28 and May 7, a "theft case" occurred in Zhu Ling's dormitory, where ONLY Zhu Ling's personal belongings were reported lost. Items included a contact lens case, lipstick, shampoo, shower gel, and a water cup.

### Investigation[edit]

On May 7, 1995, the Beijing Municipal Public Security Bureau officially initiated an investigation. On the same day, the Tsinghua University Police Station recorded a statement from Zhu Ling's family, informing them about the theft of Zhu Ling's personal belongings.

"According to relevant personnel from the Public Security Bureau, there are only more than twenty units in Beijing that need to use Thallium for work, and there are only more than two hundred people who can come into contact with Thallium." In 2006, Wang Bu (王补), a veteran police officer with decades of experience in solving cases, inferred, "The scope of suspects is very small," and further speculated based on the strict management of Tsinghua University's female dormitories that "the perpetrator must be someone close to Zhu Ling". Wang Bu was once hailed as the "pioneer of lie detection in the Chinese police force," and according to Zhu Ling's father, he was the director of the Research Department of the Public Security Bureau in Beijing.

Despite Tsinghua University claimed no undergraduate student could possibly be in contact with Thallium, the police found invoices for Thallium purchases from suspect Sun Wei's research group in Shijiazhuang.

In late 1995, the head of the Tsinghua University Police Station, Li Mucheng (李慕成), informed Zhu Ling's parents that there was a suspect, and after obtaining approval from higher authorities, they began to make progress, but details were kept confidential. In February 1996, leaders of the Beijing Municipal Public Security Bureau's fourteenth department informed Zhu Ling's family that the case was challenging, and efforts were ongoing.

It was not until January 2006 that police finally revealed to the media that their initial investigations had yielded a possible suspect. No explanation was given for the delay in releasing this information, and no one has yet been formally charged in connection with the case. The primary investigator, Li Shusen, told a correspondent from Southern People Weekly in a January 2006 phone interview that investigators have in fact reached some important conclusions regarding the case, but that the information is too sensitive to be released to the public at this time.[citation needed]

According to the official Weibo of the Beijing Municipal Public Security Bureau published on May 8, 2013, at 17:06, titled "Beijing Police Respond to 'Zhu Ling Ling Case,'" a special task force was formed to conduct the investigation. Based on Zhu Ling's daily activities, over 130 relevant individuals were investigated and interviewed. The work extended to all over 100 units in Beijing that were engaged in the production and use of Thallium.

## Suspect[edit]

The main suspect after police investigation is Sun Wei (孙维) (born (1973-08-10)10 August 1973), who was Zhu Ling's classmate and roommate at Tsinghua University from 1992 to 1997. Tsinghua University also said Sun Wei was the only student who would have had official access to thallium compound among the students with a close relationship to Zhu Ling, according to Zhu Ling's lawyer, Zhang Jie.[18] The authorities refused to release the results of their investigation to Zhu Ling's parents after they appealed.[19] However, Tsinghua University refused to issue Sun Wei's B.S. certificate and refused to provide her a document needed to get a passport or visa in 1997. It is believed Sun Wei has changed her name to Sun Shiyan (孙释颜) and her birthday from Aug 10, 1979 to Oct 12, 1979.[20]

The case began to draw extensive public attention near the end of 2005, after an ID named "skyoneline" posted on one of the largest Chinese online bulletin boards, Tianya Club, again questioning the innocence of the suspect and her family's role in blocking investigation and prosecution of the case.[21] In response, after over ten years of silence, on 30 December 2005, the main suspect Sun Wei released a statement proclaiming her innocence, which was confirmed by a weekly newspaper, Qingnian Zhoumo after interviewing Sun Wei's father in 2006.[22][23]

According to the statement, the suspect was identified as the only student with official access to thallium in her experiment for undergraduate research. She was detained by the police department on 2 April 1997, and signed a paper acknowledging she was a suspect. Sun Wei's family retrieved her from the police after eight hours of interrogation. In her statement, she also claimed that, according to the law, she was cleared as a suspect in August 1998. However, in a Morning News Post report dated March 2006, Zhu Ling's lawyer, Zhang Jie said of the suspect, "She was only exempted from the compulsory measure that she was subjected to as a suspect at that time, but not excluded from suspicion."

Internet discussion of the crime has continued since then, and has frequently become a hot topic on major online Chinese communities as a high-profile unsolved case. A hacker who claimed to have hacked into the email account of one of Sun Wei's classmates, revealed communications purporting to be between Sun and several of her classmates, showing Sun Wei was guiding them on how to post on forums to declare her innocence and they were preparing for Sun's statement in 2005.[24][25] Among the Internet users in the discussion, many people speculate that the main suspect has not been charged due to her family connections. Sun Wei's grandfather is Sun Yueqi, who was an important member of Chinese People's Political Consultative Conference as a senior leader of Revolutionary Committee of the Chinese Kuomintang and her first cousin once removed, Sun Fuling was deputy mayor of Beijing from 1983 to 1993 and Vice Chairperson of the Chinese People's Political Consultative Conference from 1998 to 2003.

### 2013 White House petition[edit]

An online White House Petition on the whitehouse.gov website was created on 3 May 2013, demanding investigation of the major suspect who was believed to be living in the U.S. at the time. The number of the signatures reached its 100,000 goal three days after it was created. This online campaign also drew great attention from U.S. and Chinese mainstream media towards Zhu Ling's family and the cold case.[26][27]

On 28 July 2015, the White House declined to comment on the petition's request, saying "Zhu Ling's poisoning in 1995 was a tragedy. No young person deserves to suffer as she has, and we can understand the heartbreak of those close to her. We decline, however, to comment on the specific request in your petition. As the We the People Terms of Participation explain, to 'avoid the appearance of improper influence, the White House may decline to address certain procurement, law enforcement, adjudicatory, or similar matters properly within the jurisdiction of federal departments or agencies, federal courts, or state and local government.'"

## Later life and death[edit]

Following her poisoning, Zhu's condition did not recover, with her eyesight, intelligence, and senses having been in a permanently degraded condition.[28] In an interview with Yangcheng Evening News, Zhu's parents revealed that she had to be hospitalized at least once a year following the poisoning. Following a flu in 2011, Zhu was hospitalized for ten months. The flu resulted in a lung infection, resulting in her only being able to eat liquid food from then on.[29]

On 18 November 2023, Zhu suffered a brain tumor attack, with a fever of 39 °C (102 °F) and fell into a severe coma. She died on 22 December 2023, at the age of 50.[30][31]

## Significance[edit]

Widespread awareness by the Chinese public and cynicism regarding the matter and the alleged whitewashing of it pose public relations problems for the government of the People's Republic of China. Information regarding the matter is too widespread to suppress, but, at the same time, evidence adequate to establish the guilt or innocence of the primary suspect is probably unavailable. Thus the matter serves as a vehicle for expression of public dissatisfaction with corruption and abuse of power by the political elite associated with the regime.[32]

## Notes[edit]

1. ^ Legal name: Zhu Ling-ling (Chinese: 朱令令; pinyin: Zhū Lìng-lìng).[1][2][3][4] Her family and herself[5] preferred the name Zhu Ling.

1. ^ 人民网 (8 May 2013). "北京警方回应朱令令案：证据灭失 无法破案". 人民网. Archived from the original on 31 December 2023. Retrieved 31 December 2023.
2. ^ 新华网北京 (Xinhua News Agency Website, Beijing Branch) (8 May 2013). "北京警方回应"朱令令案" [lit. Response on Zhu Lingling's Case by Beijing Police]". 中国共产党新闻网 (CPC News). Archived from the original on 31 December 2023. Retrieved 31 December 2023.
3. ^ BBC (8 May 2013). "北京警方首次就朱令中毒案作出回应 [lit. Beijing Police Responded On Zhu Ling's Poisoning Case For The First Time]". BBC. Archived from the original on 31 December 2023. Retrieved 31 December 2023. "北京公安发表的微博通篇都把朱令称为朱令令。" [lit. “Beijing Police called Zhu Ling as Zhu Ling-ling in the whole article of their Weibo post.”]
4. ^ 中华人民共和国公安部 (17 September 2007). 中华人民共和国公安部关于政协十届五次会议陈章立委员来信反映问题调查情况的复函. "朱令令，女，时年22岁，北京市人，清华大学化学系92级学生。"`{{cite book}}`: CS1 maint: url-status (link) Cited in: 王嘉宁 (20 April 2013). "铊中毒案结办？ 朱令家属称不知". 新京报. Archived from the original on 21 April 2013.
5. ^ 高敏 (24 December 2023). "与朱令最后的告别". 凤凰周刊. Archived from the original on 26 December 2023. Retrieved 31 December 2023. "后来，大家得知是她的姐姐出了事。等到朱令再回来时，沉默寡言了好一阵，还把自己的名字从"朱令令"改成了"朱令"。同学们私下推测原因，有种说法是，这是为了跟姐姐吴今的笔划一样，都是11划。"
6. ^ "Loonen J. (Rosas C&M, The Netherlands)Telemedicine--Telework in medicine and business" (PDF). TELESOL Newsletter Volume 2, pages 9–11. Archived from the original (PDF) on 21 July 2006.
7. ^ "Woman dies decades after unsolved China poisoning". BBC News. 23 December 2023. Retrieved 26 December 2023.
8. ^ "Zhu Ling's final performance on Youtube".
9. ^ "罕见的1例严重铊中毒情况介绍".
10. ^ ""朱令：十年一梦仍未醒"".
11. ^ ""朱令事件再起波澜"".
12. ^ Cai Quanqing (10 April 1995). "For Help". Newsgroup: sci.med. Retrieved 25 December 2018.[dead link]
13. ^ Cai Quanqing (10 April 1995). "For Help". Newsgroup: sci.med.transcription. Archived from the original on 25 November 2023. Retrieved 25 November 2023.
14. ^ Cai Quanqing (11 April 1995). "Urgent!!! Need diagnostic advice for sick friend". Newsgroup: sci.med. Retrieved 25 December 2018.
15. ^ Li, Xin; Aldis, John W. "Diagnosis through Internet". The First Large-Scale International Telemedicine Trial to China: ZHU Ling's Case. Archived from the original on 7 December 1998. Retrieved 25 December 2018.
16. ^ "Documentary: Zhu Ling's twelve years". CCTV. Archived from the original on 19 December 2021.
17. ^ Ash, Richard David; He, Min (1 November 2018). "Details of a thallium poisoning case revealed by single hair analysis using laser ablation inductively coupled plasma mass spectrometry". Forensic Science International. 292: 224–231. doi:10.1016/j.forsciint.2018.10.002. PMID 30343235. S2CID 53036754 - via ScienceDirect.
18. ^ Zhang Jie (20 April 2013). "Complete analysis of testimony in Zhu Ling's poisoning case" (in Chinese).
19. ^ "Zhu Ling's case unsolved after 19 years" (in Chinese). the Beijing News. 20 April 2013.
20. ^ Pasternack, Alex (9 May 2013). "Why Is China's Internet Turning to Obama To Solve a Decades-Old Poisoning Mystery?". VICE. Retrieved 23 December 2023.
21. ^ "天妒红颜：十年前的清华女生被毒事件". skyoneline. Retrieved 19 April 2013.
22. ^ "孙维的声明－－驳斥朱令铊中毒案件引发的谣言". Sun Wei Statement. Retrieved 19 April 2013.
23. ^ "我比任何人都想将真凶绳之于法". Southern Metropolis Daily. Archived from the original on 22 April 2013.
24. ^ "I want to restart Zhu Ling's case" (in Chinese). Southern Metropolis Daily. 20 April 2013. p. AA32. Archived from the original on 27 April 2013.
25. ^ "Sun Wei's guide for her friends revealed by hacked E-mail".
26. ^ Steven Jiang (8 May 2013). "Old poisoning case grips Chinese netizens worldwide". CNN.
27. ^ "Chinese Petition White House in Unsolved Poison Case". Bloomberg.com. Bloomberg Businessweek. 7 May 2013. Archived from the original on 10 May 2013.
28. ^ Wu, Hongfei (11 January 2006). "十年未结的清华投毒案". Southern People Daily. Archived from the original on 18 June 2013. Retrieved 9 May 2013.
29. ^ Yu, Shu; Yang, Jingjing; Ning, Jingjing (2 May 2013). "清华朱令"铊"中毒案悬疑重重 缘何不了了之？". Yangcheng Evening News. 金羊网. Archived from the original on 5 May 2013. Retrieved 7 May 2013.
30. ^ "清华大学铊中毒事件受害者朱令去世". Lianhe Zaobao (in Simplified Chinese). 23 December 2023. Retrieved 23 December 2023.
31. ^ "清华大学铊中毒受害者朱令去世，其父发声". Phoenix (in Chinese). Retrieved 23 December 2023.
32. ^ Andrew Jacobs (10 May 2013). "Poison Attack Revives Fury in China Over '95 Case". The New York Times. Retrieved 11 May 2013. "It's the lack of justice, the unfairness and the feeling that people with privilege can get away with anything," said Ms. He, an automotive engineer from China who now lives in Michigan. "People have just had enough."

## References[edit]

* SoS letter for Zhu Ling posted on Usenet 10 April 1995
* Bei Zhicheng, Cai Quanqing "For Help". Newsgroup: sci.med. 10 April 1995. Usenet: 3mbfii$v93@linuxguy.pku.edu.cn. Retrieved 12 June 2012.
* Cai Quanqing (10 April 1995). "For Help". Newsgroup: sci.med.transcription. Archived from the original on 25 November 2023. Retrieved 25 November 2023.
* Yu Chih-Ho, Huang Ning China - Mystery Ailment Diagnosed Via Internet Newsbytes News Network, 8 September 1995
* Yu Renfei Zhu Ling's lawyers involved to collect evidences News Morning Post, 14 March 2006
* Jessie Tao Campus poisoning mystery triggers debate China Daily: English Version, 13 January 2006
* Wu Hongfei, et al. Ten-year unresolved poisoning case: the suspect is said to have special background Southern People Weekly, 11 January 2006
* Ash, Richard David; He, Min (2018). "Details of a thallium poisoning case revealed by single hair analysis using laser ablation inductively coupled plasma mass spectrometry". Forensic Science International. 292: 224–231. doi:10.1016/j.forsciint.2018.10.002. ISSN 0379-0738. PMID 30343235. S2CID 53036754.
* Jennifer Ouellette (25 December 2018). "Study brings us one step closer to solving 1994 thallium poisoning case". Ars Technica. Retrieved 26 December 2018.
* "Mass spectrometry sheds new light on thallium poisoning cold case". sciencedaily.com. 13 December 2018. Retrieved 25 December 2018.

## External links[edit]

* Help Zhu Ling Foundation
* Youtube video: Who poisoned Zhu Ling? Documentation with English subtitle, made by huaren.us users, retrieved on 27 April 2013
* Annie Kai Ian Cheang (10 April 1995). "Docs in China unable to diagnose this disease. HELP!!". Newsgroup: misc.education.medical. Usenet: 3mce43$o40@geraldo.cc.utexas.edu. Retrieved 12 June 2012. One of the original Usenet posts asking for help
* Sun Wei's first statement on Tianya Club (in Chinese, "孙维的声明－－驳斥朱令铊中毒案件引发的谣言"), 30 December 2005, retrieved on 26 Jan 2020
* Sun Wei's second statement on Tianya Club (in Chinese, "声明:要求重新侦查，为"窃听器"错误向网友和公安道歉"), 13 January 2006, retrieved on 05 June 2020
* The whole story about the Poisoning of Zhu Ling (in Chinese, "朱令被投毒事件始末", PDF file)