Urbanisation and Disease Patterns in Shanghai

Shanghai is in many aspects at the leading edge of China’s urbanisation, modernisation and economic development, factors which have serious consequences for the quality of life and well-being of the city’s 23 million people. With almost 90 per cent of its population living in officially defined urban areas within its municipal boundaries, Shanghai has the highest level of urbanisation among all large cities in China. With a total fertility rate of only 0.89 in 2010, much lower than the widely accepted replacement level of 2.1, Shanghai has the lowest level of fertility among all large Chinese cities and one of the lowest among world cities. In addition, Shanghai’s proportion of older inhabitants (aged 60 and over) made up 22.5 per cent of the overall population in 2009, a figure that is almost double the national average. The ‘greying’ of Shanghai, pre-maturely relative to China’s overall development (getting old before getting rich), is associated with and reflected in the city’s changing pattern of diseases, especially those leading causes of death. Since the composition of diseases has a direct bearing on health and well-being in a dense urban environment, understanding the transition of disease pattern in connection to rapid urban restructuring in Shanghai provides valuable insights into what we can expect for other large and dense cities in China and beyond.

To address this topic, I confine the period of study to the last ten years for which comparable data are available and which have witnessed continued rapid urban growth and noticeable shifts in the disease pattern. The data pertains to the cause-specific death rates of the top ten killer diseases and measures of urbanisation, including population density, percentage of non-agriculture population, percentage of service sector output and public urban green space (see Table 1). Using the main findings, I will discuss the effects of urbanisation on population health in general and the pattern of diseases in particular, and highlight policy implications.

During the past decade, Shanghai underwent a dramatic change in its city form and other urban characteristics. With more than 20 million people packed into fixed municipal boundaries, the population density of Shanghai reached 3,030 people per square kilometre in 2009, up by 19.5 per cent from 2000. This indicator rises to 16,000–44,000 people per square kilometre in central Shanghai, making the city one of the most crowded megacities in the world. While this level of human density used to be associated with dense industrial activities, especially in the central city, Shanghai has gradually moved away from manufacturing and has been enlarging its service sector. Over the past two decades it has relocated many of its factories to its outlying areas and neighbouring provinces. As a result, manufacturing as a share of Shanghai’s GDP dropped from 60.1 per cent in 1990 to 41.9 per cent in 2000 and then down to 35.9 per cent in 2009, while the service sector’s percentage of GDP rose from 31.9 to 52.1 and then to 59.4 in 2009.

With the transformation of industry structures, the composition of the population changed greatly. The percentage of non-agricultural population increased from 74.6 per cent in 2000 to 88.3 per cent in 2009 (Table 1). Alongside the demographic and economic restructuring, Shanghai’s government focused on increasing green infrastructure, raising the coverage of urban green spaces in the city from 22.2 per cent in 2000 to 38.1 per cent in 2009. These urban changes may have some effect on the health and well-being in Shanghai.

Life expectancy at birth is a general indicator of urban health or health in general. While life expectancy for China doubled from around 35 right after the Communist Revolution of 1949 to about 70 in 1980, the already high life expectancy for Shanghai, relative to the rest of China, rose further through the reform era and again from 73.4 in 1978 to 78.8 in 2000 to then 81.7 in 2009, a figure which was approaching that of Western industrialised countries. Beyond life expectancy, the top ten killer diseases account for more than 90 per cent of the all deaths annually in Shanghai. From 2000 to 2009, the top ten killers were circulation diseases, cancer, respiratory system diseases, damnification and poisoning, endocrine-immunity-metabolic diseases, digestive system diseases, infectious and parasitic diseases, mental system diseases, nervous system diseases and genitourinary diseases. While this pattern was quite stable for the last decade, the top three, namely circulation diseases, cancer and respiratory system diseases caused over three-quarters of all deaths. Cancer-related death per 100,000 rose 16 per cent during the study period, while the death rates of both nervous system diseases and endocrine-immunity-metabolic diseases registered increases of over 60 per cent and became the most significant of increases among the top ten killers in the past decade. Both infectious and parasitic diseases and mental system diseases declined by 30 per cent, respectively. Respiratory system disease rate decreased 16.1 per cent during the past decade. It is clear that chronic diseases have replaced infectious and acute diseases to become major causes of death in Shanghai, which is a much more similar disease pattern to that of Western industrialised countries.

To analyse the direct association between the diseases and measures of urbanisation, specifically density, I have conducted a stepwise regression analysis using limited data and summarise the key findings here (see Table 2). Population density is positively related to the death rates of circulation diseases, cancer and nervous system diseases. While the data did not allow a causal analysis that would include other factors, the evidence suggests that density has something to do with two of the top three killing diseases in Shanghai. To the extent that density reflects the negative effect of a crowded living environment on certain health conditions, the findings point to areas of further research and policy discussion on the mechanisms that transmit the effect of density on critical health outcomes in Shanghai. The analysis also indicates a negative statistical association between the percentage of non-agriculture population and death rates of respiratory system diseases, endocrine-immunity-metabolic diseases and infectious diseases, with the relationship being the strongest for respiratory system diseases. Not being able to control for the potential influence of other factors, it appears that a higher level of industrial activity makes a difference to less people dying from respiratory system diseases. This is consistent with the two parallel trends of more industrialisation and lower death rates from respiratory system diseases in Shanghai over time. The percentage of tertiary industry product of GDP and the percentage of coverage of urban green areas demonstrate mixed effects on some diseases (see Table 2 below).

As Shanghai has been leading all Chinese cities in building skyscrapers, creating wealth and raising the standard of living, the challenge of making the city healthier has risen to the fore and will continue to stay high on the policy agenda. In this essay, I have provided a limited empirical assessment of where Shanghai is in becoming a healthier city in terms of its recent disease profile. One thing is clear, however: Shanghai has become similar to Western cities in terms of the same chronic diseases overtaking acute diseases as the leading causes of death. Since there is some evidence that chronic diseases are related to population density and levels of industrial activity in the expected directions, it calls for more systematic research, using better data, to probe the underlying causal connections. This should facilitate a more informed policy discussion on how to build Shanghai up not only as a wealthy city but also how to turn it into a healthy one as a model for more balanced urban development.

The author would like to acknowledge the comments and editorial support of Professor Xiangming Chen.

Youde Guo is Associate Professor in the School of Social Development and Public Policy at Fudan University, Shanghai.