Heiko J. Jahn

Particulate matter pollution in the megacities of the Pearl River Delta, China – A systematic literature review and health risk assessment

The exposure to ambient particulate matter (PM) pollution is a major threat to public health. Chinese megacities are coined by high levels of PM. Our aims were to examine the concentration levels of PM in megacities (Guangzhou, Hong Kong, and Shenzhen) of the Pearl River Delta (PRD), South China; to compare the results with international and national air quality guidelines; and to assess the health impact in terms of possible reductions in premature deaths due to PM reduction. The Medline(®) data base was used to identify published studies (systematic literature search). Based on our appraisal criteria 13 studies remained in the analysis. Additionally, publicly available data were extracted from data sources provided by municipal authorities of the cities under study. PM data reported in μg/m(3) were abstracted from single studies and municipal reports. If possible, the PM data were stratified for season of data collection (summer/winter half-year) and simple means were calculated for cities, seasons and months. Based on the abstracted data, a health impact assessment (HIA) was done in order to estimate potential preventable premature deaths due to PM pollution in the cities. Almost all PM data exceeded national and international air quality guidelines. Our HIA showed that in Guangzhou ten thousands of premature deaths could be prevented if the PM burden was reduced to these air quality limit values. We identified no suitable epidemiological study reporting PM according to our study protocol. Further epidemiological studies should be carried out to more precisely determine the spatial distribution of PM-related health risks in PRD. Environmental protection measures and public health interventions are required to reduce burden of PM-related diseases in PRD.

High HIV Prevalence and Risk of Infection Among Rural-to-Urban Migrants in Various Migration Stages in China: A Systematic Review and Meta-Analysis

Background Rural-to-urban migrants represent 17% of the total Chinese population and are considered a potential high-risk bridging population of HIV infection between urban and rural China. Method Based on a systematic review and meta-analysis, this study determined HIV prevalence among rural-to-urban migrants in different stages of migration. This review was conducted and reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Results We identified 54 studies reporting 59 HIV prevalence levels among rural-to-urban migrants in China. Overall, 53.4% (95% confidence interval, 33.5%–72.4%) of urban patients with HIV have migratory background. The floating-out population showed a higher HIV prevalence (0.15% [0.06%–0.34%]) than did the Chinese population (0.057%; odds ratio, 2.63 [1.35–5.14]). The floating-in population showed a higher HIV prevalence (0.38% [0.29%–0.50%]), corresponding to 6.70 (6.05–7.41) times greater odds of HIV infection. Higher prevalence levels were observed among female migrants (0.69% [0.51%–0.93%]), reflecting a much higher odds of HIV infection (12.18 [11.11–13.35]). Infection risk among returning migrants (0.18% [0.12%–0.29%]) was 3.16 (2.06–4.84) times higher than the overall Chinese population. Chinese internal migrants contribute to a substantial amount of the overall HIV epidemic in China. Conclusion Migrants are at greater risk for HIV infection than the general Chinese population and likely to facilitate the geographical spread of HIV in China. Targeted strategies for health promotion and HIV prevention for migrants in China should be developed.

Sexual dysfunction during methadone maintenance treatment and its influence on patient's life and treatment: A qualitative study in South China

Methadone maintenance treatment (MMT) has become an important modality of substitution treatment for opioid addicts in China since 2006. However, data are limited regarding the change in sexual function from heroin use to MMT and the influence of sexual dysfunction (SD) during MMT on patients life and treatment. Face-to-face in-depth interviews were conducted with 13 male and 14 female MMT patients, five of their partners, and three clinicians. The interviews took place in four MMT clinics in Guangdong Province between August 2010 and February 2011. The patients and their partners were asked separately for their perceptions of patients sexual function during MMT, and the influence of SD on personal/family life and treatment. The main SD problems patients perceived were libido inhibition and decreased sexual pleasure. Methadone was thought to have a stronger inhibition effect on sexual desire than heroin. SD decreased quality of patients sexual life and damaged intimate relationships. There was a gender difference in coping with SD. Men generally tended to refuse, escape, or alienate their partners. Women tended to hide sexual listlessness, endure sexual activity and tried to satisfy their partners. SD might increase risk of voluntary dropout from treatment and illicit drug use during treatment. Patients with SD did not get any effective therapy from clinicians and they also lacked skills on coping with SD-related problems. Sexual dysfunction prevented patients from reconstructing a normal intimate relationship, and affected stability of maintenance treatment. Response to patients SD and SD-related problems from clinicians was inadequate. There is a need to develop a clinical guide to deal with both SD itself and SD-related problems.

A research agenda for aging in China in the 21st century

Abstract China is encountering formidable healthcare challenges brought about by the problem of aging. By 2050, there will be 400 million Chinese citizens aged 65+, 150 million of whom will be 80+. The undesirable consequences of the one-child policy, rural-to-urban migration, and expansion of the population of ‘empty nest’ elders are eroding the traditional family care of the elders, further exacerbating the burden borne by the current public healthcare system. The challenges of geriatric care demand prompt attention by proposing strategies for improvement in several key areas. Major diseases of the elderly that need more attention include chronic non-communicable diseases and mental health disorders. We suggest the establishment of a home care-dominated geriatric care system, and a proactive role for researchers on aging in reforming geriatric care through policy dialogs. We propose ideas for preparation of the impending aging burden and the creation of a nurturing environment conducive to healthy aging in China.

Assessing spatial associations between thermal stress and mortality in Hong Kong: A small-area ecological study

AIMS Physiological equivalent temperature (PET) is a widely used index to assess thermal comfort of the human body. Evidence on how thermal stress-related health effects vary with small geographical areas is limited. The objectives of this study are (i) to explore whether there were significant patterns of geographical clustering of thermal stress as measured by PET and mortality and (ii) to assess the association between PET and mortality in small geographical areas. METHODS A small area ecological cross-sectional study was conducted at tertiary planning units (TPUs) level. Age-standardized mortality rates (ASMR) and monthly deaths at TPUs level for 2006 were calculated for cause-specific diseases. A PET map with 100 m × 100 m resolution for the same period was derived from Hong Kong Urban Climatic Analysis Map data and the annual and monthly averages of PET for each TPU were computed. Global Morans I and local indicator of spatial association (LISA) analyses were performed. A generalized linear mixed model was used to model monthly deaths against PET adjusted for socio-economic deprivation. RESULTS We found positive spatial autocorrelation between PET and ASMR. There were spatial correlations between PET and ASMR, particularly in the north of Hong Kong Island, most parts of Kowloon, and across New Territories. A 1°C change in PET was associated with an excess risk (%) of 2.99 (95% CI: 0.50-5.48) for all natural causes, 4.75 (1.14-8.36) for cardiovascular, 7.39 (4.64-10.10) for respiratory diseases in the cool season, and 4.31 (0.12 to 8.50) for cardiovascular diseases in the warm season. CONCLUSIONS Variations between TPUs in PET had an important influence on cause-specific mortality, especially in the cool season. PET may have an impact on the health of socio-economically deprived population groups. Our results suggest that targeting policy interventions at high-risk areas may be a feasible option for reducing PET-related mortality.

Public Health in Megacities and Urban Areas: A Conceptual Framework

In this chapter, first, we will briefly discuss worldwide urbanisation processes with major dimensions of public health challenges in megacities and urban areas. Second, we present some empirical findings from public health surveys conducted in the megacity of Dhaka, Bangladesh. Third, a conceptual framework is proposed based on our research on megacities within the framework of the German Research Foundation’s priority programme “Megacities – Megachallenge: Informal Dynamics of Global Change” and forth, a description of the burden of disease – classified as group I, II and III diseases – in urban areas including their determinants are presented. Lastly, strategies to improve the quality of life in megacities and urban areas are discussed.

Characterization of ambient-generated exposure to fine particles using sulfate as a tracer in the Chinese megacity of Guangzhou

Total personal exposures can differ from the concentrations measured at stationary ambient monitoring sites. To provide further insight into factors affecting exposure to particles, chemical tracers were used to separate total personal exposure into its ambient and non-ambient components. Simultaneous measurements of ambient and personal exposure to fine particles (PM2.5) were conducted in eight districts of Guangzhou, a megacity in South China, during the winter of 2011. Considerable significant correlations (Spearmans Rho, rs) between personal exposures and ambient concentrations of sulfate (SO42-; rs>0.68) were found in contrast to elemental carbon (EC; rs>0.37). The average fraction of personal SO42- to ambient SO42- resulting in an adjusted ambient exposure factor of α=0.72 and a slope of 0.73 was determined from linear regression analysis when there were minimal indoor sources of SO42-. From all data pooled across the districts, the estimated average ambient-generated and non-ambient-generated exposure to PM2.5 were 55.3μg/m3 (SD=23.4μg/m3) and 18.1μg/m3 (SD=29.1μg/m3), respectively. A significant association was found between ambient-generated exposure and ambient PM2.5 concentrations (Pearsons r=0.51, p<0.001). As expected, the non-ambient generated exposure was not related to the ambient concentrations. This study highlights the importance of both ambient and non-ambient components of total personal exposure in the megacity of Guangzhou. Our results support the use of SO42- as a tracer of personal exposure to PM2.5 of ambient origin in environmental and epidemiological studies.

Sense of coherence and associated factors among university students in China: cross-sectional evidence

BackgroundSense of Coherence (SOC) is considered as a health-promoting resource; it is mainly developed before the age of 30. The multiple demands university students face, such as study-related stress and financial difficulty, could challenge their SOC development. This study aimed to: 1) investigate the association between SOC, socio-demographic and lifestyle-related characteristics; 2) assess the effect of perceived stress on SOC controlling for other variables among the Chinese university students. Analyses were done to derive a better view on possible strategies to strengthen students’ SOC and with that to promote their health.MethodsThe data used were from a Chinese university student health survey (N = 1,853). Logistic regression analyses were used to explore the effects of varied socio-demographic, lifestyle-related variables on students’ level of SOC, as well as the association between perceived stress and SOC controlling for other variables in the analysis.ResultsBoth social support (OR = 2.56 [1.87–3.50]) and better performance compared with peers (OR = 1.64 [1.15–2.34]) were associated with a stronger SOC. Not feeling isolated at university (OR = 1.60 [1.04–2.47]) and satisfaction with the political situation (OR = 2.05 [1.57–2.67]) were also associated with a stronger SOC. This counts also for high health awareness (OR = 1.40 [1.05–1.87]) and nutrition importance (OR = 1.67 [1.04–2.69]). Perceived stress (OR = 0.81 [0.79–0.83]) was negatively associated with a strong SOC when controlling for socio-demographic and lifestyle-related variables.ConclusionWe suggest integrating stress coping, emotion management training programmes as well as measures promoting social integration for students and teachers at campus, promoting healthy behaviours, and creating a supportive learning environment as strategies for enhancing the SOC level of university students in China.

Only-Child Status in Relation to Perceived Stress and Studying-Related Life Satisfaction among University Students in China: A Comparison with International Students.

Objectives University students in general face multiple challenges, which may affect their levels of perceived stress and life satisfaction. Chinese students currently face specific strains due to the One-Child Policy (OCP). The aim of this study was to assess (1) whether the levels of perceived stress and studying-related life satisfaction are associated with only-child (OC) status after controlling for demographic and socio-economic characteristics and (2) whether these associations differ between Chinese and international students. Materials and Methods A cross-sectional health survey based on a self-administrated standardised questionnaire was conducted among 1,843 (1,543 Chinese, 300 international) students at two Chinese universities in 2010–2011. Cohen’s Perceived Stress Scale (PSS-14) and Stock and Kraemer’s Studying-related Life Satisfaction Scale were used to measure perceived stress and studying-related life satisfaction respectively. Multivariable logistic regression analyses were used to examine the associations of OC status with perceived stress and studying-related life satisfaction by sex for Chinese students and international students separately. Results The Chinese non-only-children (NOCs) were more likely to come from small cities. Multivariable regression models indicate that the Chinese NOCs were more stressed than OCs (OR = 1.39, 1.11–1.74) with a stronger association in men (OR = 1.48, 1.08–2.02) than women (OR = 1.26, 0.89–1.77). NOCs were also more dissatisfied than their OC fellows in the Chinese subsample (OR = 1.37, 1.09–1.73). Among international students, no associations between OC status and perceived stress or studying-related life satisfaction were found. Conclusions To promote equality between OCs and NOCs at Chinese universities, the causes of more stress and less studying-related life satisfaction among NOCs compared to OCs need further exploration.

Migration and Health in Megacities: A Chinese Example from Guangzhou, China

Migration has influence on health in various aspects. It affects public health in home and host countries and can cause severe health consequences for the migrants. Within this paper, general migration patterns and processes will be introduced and the various associations to health will be discussed. We describe the situation of internal migration in China and emphasise the importance of the Chinese household registration (hukou) system. Using the example of first results of a public health field study, we describe different urban life-world dimensions and their influences on health of working migrants in the megacity of Guangzhou, South China.