Editor’s note: This is the second part of a two-part article that addresses the efforts of the People’s Liberation Army (PLA) to deal more effectively with the challenges of mental health, which can have serious impacts on the morale and readiness of individual service members—and therefore, on the combat readiness of the PLA as a whole. Part 1 of this article, which appeared in our last issue, provided a summary overview of psychological issues in the PLA as revealed by internal surveys and assessments by Chinese military medical personnel, as well as discussion of the policy responses under consideration by PLA leaders. This second part provides an examination of the stresses presented by particular physical operating environments, and the resulting impacts on the psychological health of PLA service members assigned to those environments.
Modern life can be quite stressful. One 2017 poll found that 78.4 percent of China’s young people aged 18 to 28 years reported feeling mentally fatigued, and 21.7 percent described themselves as heavily fatigued. Similar effects have been observed in the armed forces (Xinhua, May 15, 2017). Stress and fatigue are primary determinants of health, and physical environments, in turn, may significantly impact stress levels (Medical News Today, January 11, 2018). Chinese military medical researchers have identified four categories of environmental stressors:
- The natural environment (e.g., heat, cold, altitude and humidity);
- The artificial environment (e.g., acceleration, vibration, noise, and radiation);
- The social and psychological environment (e.g., loneliness, and living and working in confined spaces);
- The operational environment (e.g., continuous operation, inadequate sleep, and danger). 
The territory of the People’s Republic of China (PRC) includes vast regions of rugged terrain, particularly in China’s border regions. Today, PRC defense priorities focus on the southeastern seaboard opposite Taiwan; the South China Sea; and the Himalayan regions of the Sino-Indian frontier, where average elevations exceed 4,500 meters. The latter two regions have proven to be difficult operating environments in terms of soldiers’ mental wellbeing. Additionally, conditions specific to certain types of units present environmental factors that place further stressors on PLA service members.
The High-Altitude Plateau Environment
According to Chinese researchers, the high-altitude plateau environment takes the greatest toll on military mental health.  Such locations are difficult to endure because of a range of factors, including: strong ultraviolet radiation, thin air, scarce vegetation, unpredictable weather patterns, lack of water sources, and dramatic temperature fluctuations. Such harsh surroundings create vulnerabilities to disease and injury. One plateau unit reported its daily attrition rate due to diseases at 1.24 percent, with common illnesses including: upper respiratory tract infection, chapped skin, vitamin deficiencies, intestinal infection, and enterospasm. The daily attrition rate due to injuries was even higher at 3.42 percent; the leading injuries were skin and soft tissue injury, frostbite, spinal disc herniation, fatigue-related damages, and sciatica.  Sleep problems are also common: a 2017 study examining lowland troops participating in military maneuvers in Tibet described 25.3 percent experiencing poor sleep, and another study revealed that more than 50 percent of 326 service members deployed from lowlands to plateau environments suffered from sleep disorders. 
Furthermore, PLA soldiers experience loneliness and a lack of social support when stationed at these desolate locations. Although newly arrived enlistees show better results in mental health examinations, the plateau environment wears down service members over time: the longer one is deployed at high elevation, the more susceptible soldiers become to mental and physical health problems.  One study, measuring 4,631 service members of a unit posted on a high-altitude plateau, documents a 31.6 percent rate of depression.  Measuring 156 members of a transport unit at Qinghai Province’s Golmud City (average elevation 2,800 meters), researchers found obvious symptoms of somatization, anxiety, phobic anxiety, and psychoticism. 
A service member’s personality could change after prolonged deployment on the plateau. Noncommissioned officers (NCOs) posted at plateaus are more stubborn, sensitive, suspicious, worrisome, nervous, and easily agitated compared to counterparts elsewhere. They are more independent and can better cope with new environments; however, compared to lowland counterparts, plateau NCOs are less sociable, less imaginative, less willing to experiment, and lack self-regulation. 
In recent years, however, the PLA appears to be experiencing a positive turn in dealing with some of these issues. A 2017 study examining PLA Army service members from 46 units garrisoned on the Tibetan Plateau found that, with the exception of worsening somatization, the remaining eight symptoms dimensions on SCL-90/Symptom Checklist 90 (obsessive-compulsive tendencies, interpersonal sensitivity, depression, anxiety, hostility, phobic anxiety, paranoid ideation, and psychoticism) have improved, which the authors attributed to upgrades in the military mental health system.  A 2017 survey of 4,080 PLA service members based at positions 2,000 to 4,900 meters above sea level indicated that 7.8 percent of personnel showed symptoms of post-traumatic stress disorder—an 8.7 percent drop from a corresponding study published in 2006. 
Island Environments in the South China Sea
When viewed from afar, the South China Sea islets do not seem like stressful places. However, heat, humidity, isolation, and operating in a constant state of alert pose genuine challenges to service members in these locations. Island garrisons lack social support, according to one article that assessed a unit of 254 personnel defending an island in the South China Sea (SCS) under the jurisdiction of Sansha City.  One study suggests that the mental well-being of island defenders is worse than warship and submarine crews.  In 2016, an examination of 299 service members from seven SCS island defense units found that 108 (36.12 percent) had been sick in the prior two weeks; 160 (53.51 percent) had suffered injuries during training in the past two years; 22.41 percent of personnel had experienced heatstroke; 227 (75.92 percent) had suffered seasickness during training; and 80 (26.76 percent) believed they had some kind of mental illness.  Overall, these are not desirable numbers for troops stationed in the SCS, which the PRC leadership views as a critical front line of China’s national defense.
The installation of communications and radar jamming complexes on Chinese-held islands in early 2018 attracted criticisms from concerned parties about the militarization of the South China Sea. However, these developments also have implications for the health of service members. Exposure to electromagnetic radiation can have serious health consequences for those affected. Radiation can wear down troops constantly exposed to “high-density, high-intensity, multi-spectral electromagnetic waves released by various weapons and equipment,” especially when grassroots-level PLA officers and enlistees commonly lack basic knowledge on how to protect themselves (The Diplomat, April 18, 2018).  Colorless, tasteless, and odorless, the complex electromagnetic environment (复杂电磁环境, fuza dianci huanjing) can “cause headaches, dizziness, muscle aches, blurred vision and other symptoms. Prolonged exposure to hazardous radiation kills large amounts of cells, [with] different degrees of influence on nervous, cardiovascular, blood, endocrine and other systems.” 
In a study of 460 electronic countermeasures (ECM) personnel and 180 air defense communication specialists, one PLA researcher found a prevalence of depression significantly greater than the PLA norm: 196 members had slight depressive symptoms, 67 had mild symptoms, and 13 showed serious symptoms, for a total of 45.1 percent overall.  Another study of 89 members of an ECM regiment revealed higher than PLA average scores in somatization, anxiety and depression.  All in all, although new electronic warfare equipment could bolster Chinese capabilities in the SCS, it could further complicate the mental health environment for units operating in an already taxing natural setting.
Underground and Tunnel Environments
In a 2016 comprehensive study that surveyed 53,847 members from throughout the PLA, members of the PLA Rocket Force (PLARF) fared worst in terms of overall mental health (China Brief, July 31). As indicated by a June 2018 survey sampling 3,935 members of one PLARF unit, mental health problems of various degrees existed among 14.3 percent of participants.  In addition, the sample group had a higher total score than average on the PLA’s 2016 SCL-90 results, indicating below average mental well-being.  The PLARF’s sustained mental health challenges result from a combination of work-related stress and poor diet—as well as the enormous strain associated with handling radioactive materials, with eight out of every ten relevant personnel reporting feelings of “high psychological stress.” 
Among the biggest stressors for PLARF personnel are long periods spent underground. As keepers of China’s tactical and strategic missiles, PLARF units must spend considerable time training and living in underground military facilities that host China’s long-range precision strike weapons. Although portrayed as joyful places in PLA propaganda, the reality of tunnel living is decidedly different: besides significant temperature shift and prolonged isolation from the outside world, the lack of fresh air, food, and sunshine, as well as reduced oxygen levels, all make life difficult underground.  This is particularly true during training exercises, when the amount of oxygen is cut down to 80 percent of normal levels, and food rations are rolled back to one-third of normal supply (Sina News, July 22, 2017).
According to researchers from the PLARF Disease Prevention and Control Center, members of units stationed underground are 22 percent more likely to get sick than their counterparts posted above ground. A PLARF-sponsored survey of one underground military complex in southeastern China found it to be damp, cold and uncomfortable. Moreover, in this facility, the amount of formaldehyde—a highly toxic and inflammable gas that may cause skin, throat, lung, and eye irritation, myeloid leukemia, and rare cancers—exceeds the national health standard by 30 percent. 
While missile launch brigades are almost always the focus of public attention, it is the less-publicized engineering units (工程部队, gongcheng budui) that build and maintain the PLARF’s subterranean infrastructure. This group also experiences significant mental health impacts as a result of their workload and physical environment. One study of 651 construction workers in an unnamed engineering unit revealed a six-day workweek, with workers typically working 8 to 14 hours a day. However, those tasked with “frontline construction” (一线施工, yixian shigong) could work up to 13-14 hours daily. According to the study, 65 percent of 344 workers interviewed perceived their own health status as “okay or bad.” Seventy-four percent believed that, compared to one year before, their health had slightly or significantly declined. Seventy-five percent out of 632 workers surveyed indicated that their labor demands were somewhat or very tiring. 
There are a number of occupational hazards for tunnel construction workers. Ninety-seven percent of 640 workers identified dust as the leading hazard, followed by noise (87 percent), toxic and harmful gasses (79 percent), dampness (76 percent), poor ventilation (73 percent), and vibration (44 percent). With regards to noise, 64 percent of respondents are irritated by construction noise, while 28 percent feel very irritated. There are also shortages of personal protective equipment; and to make matters worse, 37 percent of correspondents were dissatisfied with the quality of the protective gear available. 
Under such working conditions, members of PLARF engineering units are exposed to a range of illnesses. Subjective symptoms reported by 533 workers surveyed include frequent coughing or coughing-up phlegm (65 percent), irritation (53 percent), sore throat (46 percent), joint pain (45 percent), dry eyes (41 percent), bad memory (40 percent), decline in physical health (38 percent), decrease in appetite (33 percent), tightness in chest (32 percent), ringing in the ears (31 percent), declining vision (30 percent), and feeling depressed (29 percent). 
Food also affects mood and mental health—and for service members, the quality and quantity of rations can impact morale and mental well-being. Yet a November 2017 report showed that PLARF personnel have an imbalanced diet that undercuts everyday performance. Consumption of vegetable oil, meat, eggs and dried vegetables were above the military limit, exceeding the official standards by 120.2 percent, 23.9 percent, 68.6 percent, and 24 percent, respectively.  By contrast, the intake of cereal, poultry, fish, shrimp, milk, sucrose, fresh vegetables, fruits and dried edible fungi were below standards. (Only soy intake aptly met the standard.) There is an excessive consumption of protein, sodium, phosphorus and iron, and insufficient intake of zinc and vitamin A, resulting in a high prevalence of deficiency symptoms. In addition, the survey found that 25 percent of participants were overweight or obese. 
While observers have witnessed positive changes regarding military life on the plateaus, high elevation still has the worst influence on service member mental health, followed by tropical maritime environments. In light of China’s security considerations on its southern and western flanks, improving the welfare of plateau and island troops should continue to be a concern of the PLA leadership. More attention should likewise be dedicated to the PLARF service members confronting mental health troubles due to a poor diet, stressful work environment, and long periods spent underground (Xinhua, March 29). Given the informational and psychological components prevalent in modern warfare, the role of morale and mental health in influencing combat effectiveness will become more and more consequential for a rapidly changing PLA. Military mental health will gain importance as China moves ahead with its military reforms, and the role of the PLA leadership in providing policy direction will be a pivotal factor.
Zi Yang is a Senior Analyst at the China Programme, S. Rajaratnam School of International Studies, Nanyang Technological University, Singapore. Follow him on Twitter @ZiYangResearch.
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 Ibid., p. 2200.
 Zongwu Liao and Peng Zhang, “Zhu gaoyuan budui weiqin baozhang shijian yu tihui” [Practice and Experience of Medical Support in the Plateau], Medical Journal of the Chinese People’s Armed Police Force No. 4 (2018), pp. 417–418.
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 Ibid., p. 482.
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 Jiajian Liu et al., “Huojianjun moubu guanbing shanshi diaocha” [Investigation of Diet of Officers and Enlistees in the PLARF], Journal of Preventive Medicine of Chinese People’s Liberation Army No. 11 (2017), p. 1391.
 Ibid., pp. 1390, 1392.