1 应用统计学概览 辅助材料6 pierre 2013_svy ologit and hlm

1、Social Science & Medicine 80 (2013) 85e95Migration, environmental hazards, and health outcomes in ChinaJuan Chen a,*, Shuo Chen a, Pierre F. Landry ba Department of Applied Social Sciences, The Hong Kong Polytechnic University, Hong Kongb Department of Political Science, University of Pittsburgh, US

2、Aa r t i c l e i n f oa b s t r a c tArticle history:Available online 13 December 2012Chinas rapid economic growth has had a serious impact on the environment. Environmental hazards are major sources of health risk factors. The migration of over 200 million people to heavily polluted urban areas is

3、likely to be signicantly detrimental to health. Based on data from the 2009 national household survey “Chinese Attitudes toward Inequality and Distributive Injustice” (N 2866) and various county-Keywords:China MigrationEnvironmental hazards Environmental health Physical health Depressive distress Su

4、rveylevel and municipal indicators, we investigate the disparitiesubjective exposure to environmentalhazards and associated health outcomes in China. This study focuses particularly on migration-residency status and county-level socio-economic development. We employ multiple regressions that account

5、 for the complex multi-stage survey design to assess the associations between perceived environmental hazards and individual and county-level indicators and between perceived environmental hazards and health outcomes, controlling for physical and social environments at multiple levels. We nd that pe

6、rceived environmental hazards are associated with county-level industrialization and economic development: respondents living in more industrialized counties report greater exposure to environ- mental hazards. Rural-to-urban migrants are exposed to more water pollution and a higher measure of overal

7、l environmental hazard. Perceived environmental risk factors severely affect the physical and mental health of the respondents. The negative effects of perceived overall environmental hazard on physical health are more detrimental for rural-to-urban migrants than for urban residents. The research nd

8、ings call for restructuring the household registration system in order to equalize access to public services and mitigate adverse environmental health effects, particularly among the migrant population.2012 Elsevier Ltd. All rights reserved.Introductionincreasing population mobility, and changing re

9、sidential patterns all place tremendous strain on environmental health.Exposure to environmental hazards has deleterious effects on both physical and mental health. These effects can follow two routes: directly, through physical exposure that damages human health, or indirectly, through perception o

10、f risk and attendant chronic stress, which also have a detrimental effect on health (Peek, Cutchin, Freeman, Stowe, & Goodwin, 2009). Chronic exposure to environmental stressors can set in motion a complicated physio- logical response. The perceived risk of environmental threats can translate into c

11、hronic stress for exposed populations because of the uncertainty of the threat, lack of control, fear of potential health problems, and stigmatization (Hallman & Wandersman, 1992). These responses heighten the risk of chronic conditions such as diabetes and cardiovascular disease, and of psychologic

12、al condi- tions such as depressive distress and despair (Schulz & Northridge, 2004).Exposure to environmental hazards and the resulting health outcomes are associated with social and economic factors at both individual and community levels (Gee & Payne-Sturges, 2004). An awareness of the socio-econo

13、mic and environmental factors atChinas rapid economic development in the past few decades has been a double-edged sword: it has greatly improved the health and quality of life of the general population, but the associated industrialization has led to increasing energy use and industrial waste, which

14、 has rendered the air quality in Chinas cities among the worst in the world and has resulted in widespread industrial water pollution (Du & Zhang, 2007; Zhang et al., 2010). In addition to undergoing economic reforms, China is also experiencing a process of rapid urbanization. Following decades of s

15、trictly enforced rural-to-urban migration control through the household registration (hukou) system, there has been an internal migration of over 200 million people (Chan, 2013; Chan & Zhang, 1999). Economic development, the environment, migration, and health outcomes are closely linked (Holdaway, 2

16、010). Industrialization,* Corresponding author. Department of Applied Social Sciences, The Hong Kong Polytechnic University, Hung Hom, Kowloon, Hong Kong. Tel.: 852 3400 3689.E-mail address: .hk (J. Chen).0277-9536/$ e see front matter 2012 Elsevier Ltd. All rights reserved. http:/dx

17、./10.1016/j.socscimed.2012.12.002Contents lists available at SciVerse ScienceDirectSocial Science & Medicinejournal homepage: /locate/socscimed86J. Chen et al. / Social Science & Medicine 80 (2013) 85e95multiple levels is necessary, as well as an understanding of their complex

18、 relationships (Macintyre, Ellaway, & Cumm , 2002; Soobadera, Cubbin, Gee, Rosenbaum, Laurenson, 2006). Despite the considerable health risks arising from industrial pollution in China, researchers have not provided a good account of their scope and implications, the associated social and economic f

19、actors at various levels, the mechanisms by which these multi-level factors inuence exposure, and the consequences of exposure on physical and mental health (Holdaway, 2010).Our research addresses this gap. Using data from the second wave of the national household survey “Chinese Attitudes toward In

20、equality and Distributive Injustice” (2009) and various county- level and municipal indicators, we examine the subjective measure of perceived exposure to three types of environmental hazardsdair quality, water pollution, and industrial wastedand investigate disparities in perceived exposure and ass

21、ociated health outcomes. We focus on the role of migration and residency status, and of counties socio-economic development. Our analysis takes into account the potential inuence of municipal environ- mentalhazardmeasures. Provincial xed effectsfurtheraccountfor unobserved heterogeneity.water pollut

22、ion as a result of local industry and mining, which is often on a small scale and difcult to regulate (Wang, Webber,Finlayson, & Barnett, 2008). Fortance, Town and Village Enter-prises (TVEs) discharged high levels of heavy metals, industrialwaste, and other pollutants in the 1980s and 90s, which se

23、riously affected the environment (Wu, Maurer, Wang, Xue, & Davis, 1999). In addition, because environmental regulations are more strictly enforced in wealthier urban areas, some large industries have relocated to less afuent cities and rural locations and brought pollution with them to rural areas (

24、Holdaway, 2010).Rural-to-urban migrationDetermining the difference between urban and rural exposure to environmental hazards has been complicated by the largest-ever migration of a population from rural to urban areas (Chen, 2011; Hu, Cook, & Salazar, 2008). Rural-to-urban migration lies at the core

25、 of Chinas recent urbanization process. Chinas urban population has grown by about 440 million in the past thirty years, and half this growth is attributable to rural-to-urban migration (Chan, 2013). With this large-scale migration comes a complex tradeoff of environmental risks: migrants from rural

26、 areas often leave behind unsafe drinking water supplies that put them at risk of waterborne infectious diseases, but they are likely to be exposed to new risks, such as urban air pollution (Jia et al., 2008; Zhang et al., 2010). Their problems are compounded because they are not entitled to the sam

27、e labor protection and health-care benets as urban residents (Hesketh, Jun, Lu, & Mei, 2008; Mou et al., 2009; Peng, Chang, Zhou, Hu, & Liang, 2010; Zhao, Rao, & Zhang, 2011).Exposure to environmental hazards in ChinaChinese economic reforms have led to outstanding economic growth. From 1978 to 2010

28、, Chinas gross domestic product (GDP) grew at an average rate of 10% per year. A virtual industrial back- water in 1978, China is now the worlds biggest producer of concrete, steel, ships, and textiles, and has the worlds largest market for automobiles (Brandt, Rawski, & Sutton, 2008). The industria

29、l GDP increased approximately 80-fold from 1978 to 2009 (102.8 million to 3400 million). During the same period, the agri- cultural GDP increased 33-fold. Chinas rapid economic growth is primarily the result of industrial development (National Bureau of Statistics of China, 2010). The consequent env

30、ironmental hazards due to increased energy use and industrial waste, especially air and water pollution, are a major risk factors for health (Zhang et al., 2010). When examining the relationship between the environ- ment and health in China, one must take into account the chal- lenges of rapid indus

31、trialization and urbanization processes, the large-scale rural-to-urban migration, and the widening disparitiesocio-economic status.Socio-economic disparitiesEnvironmental health risks are not evenly distributed among the general population: as environmental justice research from developed countries

32、 shows, certain groups are particularly vulnerable (Holdaway, 2010). Racial, ethnic, and economic factors inuence the gure signicantly (Brown, 1995; Evans & Kantrowitz, 2002; Kohlhuber et al., 2006; Morello-Frosch & Lopez, 2006; Schulz & Northridge, 2004). Racial and ethnic minorities and low-wage e

33、arners tend to live closer to environmentally hazardous sites and industrial facilities (Faber & Krieg, 2002; ONeill et al., 2003; Perlin, Wong, & Sexton, 2001). High-polluting facilities are dispropor- tionately concentrated in low-income communities (Elliott, Wang, Lowe, & Kleindorfer, 2004).The e

34、xperience of developed countries will very likely be applicable to China, given the context of widening socio-economic inequality. Diseases associated with environmental factors are a major source of ill health, especially among disadvantaged pop- ulations. Zhang et al. (2010) argue that the conside

35、rable disparities in the health of the rich and poor are, at least partially, the result of higher exposure to polluted air and water in poor households and communities. Tang et al. (2008) maintain that exposure to envi- ronmental pollution is likely to be greater for poor people and that the situat

36、ion has worsened over the past decade. Occupation is another key factor: workersdmostly migrantsdemployed in mining, construction, and chemical industries suffer especially high rates of death and injury. Poor people are less likely to have the option of moving away from polluted areas or leaving da

37、ngerous jobs (Holdaway, 2010).Industrialization and urbanizationThe expansion of Chinese cities is historically unprecedented and as a result, the urban population has jumped from 18% of the total population in 1978 to 51.3% in 2011 (National Bureau of Statistics of China, 2011b). Urban residents ar

38、e more likely to be exposed to high levels of outdoor air pollution (Chan & Yao, 2008): the air quality of nearly 70% of Chinas urban areas does not meet the countrys national ambient air quality standards, and about three quarters of city dwellers are regularly exposed to air considered unsuitable

39、for inhabited areas (Shao, Tang, Zhang, & Li, 2006). Urbanization has also made it difcult to ensure clean drinking water, sewage treatment, and garbage disposal. According to the Ministry of Environmental Protection of China (2010), nearly one-quarter of Chinas 395 monitored drinking water sources

40、are substandard. The Report on the State of the Environment of China (2008) revealed that about one-third of urban sewage was not treated in 2008. The amount of industrial solid waste generatedSubjective exposure to environmental hazards and health outcomesnationwide was 1901.27 million tons, an inc

41、rease of 8.3% 2007.Rural environmental problems are also pressing andsinceThe links between poor air and water quality and adverse healthoutcomes are well established (Health Effectstitute, 2004; Prss-omestn & Corvaln, 2006). Substantial research has conrmed that exposure to industrial pollution has

42、 deleterious effects on both physiological and psychological well-being (Peek et al., 2009).respects even more serious (Ministry of Environmental Protection of China, 2008). Many rural communities are exposed to air andJ. Chen et al. / Social Science & Medicine 80 (2013) 85e9587Despite a growing bod

43、y of research in the eld of environmental health, one huge challenge rema : nding valid and reliable measures of environmental risk factors (exposures, susceptibilities, distribution of hazards) and health outcomes associated with environmental hazards that can be applied globally (Payne-Sturges & G

44、ee, 2006).Both “objective” and “subjective” indicators have been used to analyze problems of environmental health. An objective environ- mental hazard is “the potential for or occurrence of exposure to an environmental contaminant or hazardous condition” (Payne & Gee, 2006, p. 158), whereas a subjec

45、tive environmental hazard is the perception of exposure to any environmental contaminant or hazardous condition. Objective exposure is relatively easy to measure at the aggregate level. Measures of air pollution such as particulates (PM10) and sulfur dioxide (SO2) are regularly moni- tored in 471 Ch

46、inese cities. Drinking water quality is monitored in most cities (Ministry of Environmental Protection of China, 2010). Aggregate data at the municipal level, however, does not provide the targeted information necessary to determine the dispropor- tionate exposure of populations living close to majo

47、r pollutant sources, such as industries, highways, polluted rivers, or hazardous waste sites. Moreover, the quality of air and water in rural China is difcult to assess (Holdaway, 2010).Given the lack of valid and reliable data and measures of objective exposure to environmental hazards, we must rel

48、y on the subjective measure of perceived exposure to environmental hazards. The subjective measure can capture the perception of risk and the associated chronic stress, and therefore, be as important a predictor of health outcomes as objective measures. Peek et al. (2009) demonstrate that both objec

49、tive and subjective measures of exposure to environmental hazards are associated with poorer perceived physical health and increased psychological stress in Texas City. Their results suggest that subjective exposure (i.e., concern about environmental health risk) is more strongly asso- ciated with n

50、egative subjective measures of well-being than objective exposure (measured by the distance between ones residence and environmental hazard sites). The nding of the stronger effect of perceived exposure to environmental hazards in predicting health outcomes is intriguing; nonetheless, the research w

51、as conducted in one particular city in the US. The val-that the survey selects actual locations and then interviews local residents regardless of their registration status. The result is a high- quality representative sample that includes both migrants and formally registered respondents (Landry & S

52、hen, 2005).A total of 4279 household addresses were sampled and 2866 interviews were completed between October and December 2009 (a response rate of 67.0%). All the interviews were conducted in person by trained interviewers. The average interview length was approximately 45 min. To ensure quality c

53、ontrol, more than 40% of the participants were contacted either by phone or in person after the interview to validate the data. Due to missing data, 256 cases were excluded, resulting in a sample of 2610 for the present anal- ysis. Approval for ethical review of research project involving human subj

54、ects was granted to Martin K. Whyte by Harvard University for data collection and to Juan Chen by the Hong Kong Polytechnic University for data analysis.In order to identify how the communitys social and economic situation affects its residents exposure to environmental hazards and resulting health

55、outcomes, we collected data on the 56 counties over which the 39 primary sampling units (PSUs) of the national survey were spread. We rst retrieved indicators for the 56 counties based on the 2009 national survey. Additional contextual and titutional variables were then extracted from local gazet- t

56、eersand statistical yearbooks for each county (or city district).In addition to exploring socio-economic indicators, we used the titute of Public and Environmental Affairs website and the China City Statistical Yearbook (2010) to nd environmental hazard data aggregated at the municipal level. If dat

57、a were missing for 2009, we averaged the statistics reported for the same location in 2008 and 2010. When local data were unavailable, we computed the averageof reported statistics from the nearest municipalities.MeasuresPerceived environmental hazardsPerceived environmental hazards were assessed wi

58、th the following questions: “How would you evaluate the air quality of the place you live?” “How would you evaluate the water quality of the place you live?” and “How would you assess the degree of danger of exposure to toxic waste and other harmful pollutants in the place you live?” The answers to

59、the rst two questions were coded ona 5-point scale where 1 “very good”; 2 “good”; 3 “fair”;4 “poor”; and 5 “very poor.” The answers to the third question were coded on a 4-point scale where 1 “not at all”; 2 “not much”; 3 “somewhat”; and 4 “very much.” The measure of perceived overall environmental hazard was g