Non-Communicable Diseases in China

China is currently experiencing a rapid epidemiological transition. The incidence of chronic diseases—cancer, cardiovascular disease, diabetes, arthritis, cerebrovascular disease, mental illness, and others—has increased dramatically as a result of societal changes, especially those related to diet, physical activity, and tobacco use. China’s growing rates of chronic diseases have been attributed to the aging of the Chinese population, in addition to increases in high-risk behaviors.[1] Our class reading regarding this topic (Yang et al., 2008) points to the importance of prevention in curbing the rise of chronic diseases in China. This blog focuses further on a particularly susceptible group: rural-to-urban migrant workers.

China’s accelerated epidemiological transition parallels the tremendous economic growth and development China has seen in recent decades. As is expected, such growth has brought with it rapid urbanization. From 1978 to 2004, the percentage of the population living in cities increased from 17.9% to 41.8%.[2] Internal migration of rural residents to urban areas has certainly contributed to this rapid urbanization. It is estimated that the number of rural-urban migrant workers in China was 11 million in 1982, and presently the number of rural-urban migrant workers stands at 120 million.2 This number is expected to increase by about 10 million every year.[3]

There are a number of reasons for the massive influx of rural residents into urban areas. First, there is a great disparity in the income that can be earned in the countryside versus the city. Second, China’s transition to a modernized market economy has in many ways favored migration from rural to urban areas. With a market economy has come the collapse of state-owned farms. Furthermore, the Chinese government introduced the Household Responsibility System in agricultural reform, under which government-owned farmland is entrusted to individual households, which pay taxes, keeping all other proceeds. Together, the collapse of state-owned farms and the contracting of individual households to manage government farmland have led to the disintegration of collective farms and a surplus of rural labor.[3]

There are many driving forces for rural-urban migration in China, yet there are also other forces aiming to contain such migration. Most notable is the hukou system, or the Household Registration System. The Chinese register as residents of their birthplace under the hukou system, and only residents are eligible for social services such as low-income housing, education, and health care benefits.[3] Thus, rural-urban migrants and their families are ineligible for such social services upon migration to the city. For example, a migrant worker’s children would not be able to enjoy the same public education available to their urban-resident counterparts. But although the hukou system acts as a deterrent of sorts, it certainly has not hindered the 120 million Chinese rural residents who have chosen to migrate to urban areas.

Rural-urban migrants are a vulnerable group, due in large part to China’s hukou system. Migrant workers are also likely to live in unsanitary and overcrowded conditions, take up physically demanding jobs, and receive low wages.[3] Moreover, there are other government restrictions that make legitimate employment difficult for migrant workers in urban areas[4]—though the Chinese government has been gradually relaxing its control on rural-urban migration. For example, some municipal governments have restricted migrant workers to certain industries and corporations.[5] Indeed, most migrants hang on the lowest rung of the urban socio-economic ladder.

Given the difficulties faced by rural-urban migrants, they are particularly susceptible to poor mental health.[6] In fact, Yang & Luo (2008) showed a statistically significant difference in psychosocial characteristics between migrants and non-migrants, with migrants faring far worse than non-migrants. Mental disorders are an often-overlooked non-communicable disease, particularly in low- and middle-income countries. Mental disorders in general are responsible for 10% DALYs lost in low- and middle-income countries; depression alone is responsible for 3.4% of DALYs lost.[7]

Migrants are also more susceptible to other chronic conditions than the general Chinese population. The process of migration and the status of migrants make them prone to psychological distress and anxiety, which is associated with greater levels of alcohol consumption and intoxication.[8] High-risk drinking is associated with several chronic conditions, including hypertension, heart disease, and hormonal problems, as well as damage to the liver and pancreas.[7]

Susceptibility of migrants to chronic conditions is also related to level of education. Migrants are generally less educated than non-migrants, and rural residents less educated than urban residents.[2] Level of education—as well as socioeconomic status[7]—has many repercussions for health behaviors. For example, less educated, poor people are more likely to smoke than more educated, wealthy people. Exacerbating the situation is certainly China’s role as the largest producer of cigarettes in the world.[9] Finally, level of education may also influence individuals’ diet and physical activity behaviors, affecting their risk for cardiovascular disease and diabetes.

It is clear that non-communicable diseases are a growing problem in China, and that rural-urban migrants are particularly susceptible to chronic conditions. As is emphasized in the class reading on the topic (Yang et al., 2008), prevention is key to curbing the rise of non-communicable diseases. However, in order to effectively addresses non-communicable diseases in China, more attention must be shifted to rural-urban migrants. Specifically, given the ever-increasing countryside-to-city migration, the hukou system must be reassessed so that migrants can receive the same health care and other social benefits available to urban residents. This would be an important step in addressing non-communicable diseases among a large and vulnerable group in China. Bringing about change in the hukou system policy, however, may take many years. In the meantime, migrant communities should be the target of interventions to prevent and treat non-communicable diseases.

References
[1] Yang G, Kong L, Zhao W, Wan X, Zhai Y, Chen L, & Koplan J (2008). Emergence of chronic non-communicable diseases in China. The Lancet, 372: 1697-1705.
[2] Yang X & Luo H (2008). Migration, urbanization, and drug use and casual sex in China: A multilevel analysis. Environment and Planning (Advance online publication). Retrieved February 26, 2009, from http://www.envplan.com/epa/fulltext/aforth/a40297.pdf.
[3] Wong D & Leung G (2008). The functions of social support in the mental health of male and female migrant workers in China. Health & Social Work, 33(4), 275-285.
[4] Hong Y et al. (2006). Rural-to-urban migrants and the HIV epidemic in China. AIDS and Behavior, 10(4), 421-430.
[5] Li X et al. (2006). Health indicators and geographic mobility among young rural-to-urban migrants in China. World Health & Population, 8(2), 5-21.
[6] Wong D & Son HX (2008). The resilience of migrant workers in Shanghai China: the roles of migration stress and meaning of migration. International Journal of Social Psychiatry, 54(2), 131-143.
[7] Skolnik R (2008). Essentials of global health. Sudbury, MA: Jones and Bartlett Publishers.
[8] Lin D et al. (2005). Alcohol intoxication and sexual risk behaviors among rural-to-urban migrants in China. Drug and Alcohol Dependence, 79, 103-112.
[9] Hesketh T et al. (2007). Smoking, cessation and expenditure in low income Chinese: cross sectional survey. BioMed Central Public Health, 7(29).