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1.
According to the United Nations population projections, the population of the elderly is expected to roughly triple in China from 2000 to 2050, particularly when the generations who were born between the 1950s and 1970s move through the age structure, and also because people are living longer and fertility rates have fallen, population aging is expected to put pressure on government's fiscal balance through higher old-age security benefits and health-care expenditures. This work draws together the broad range of elements involved within a consistent framework, based on a computable dynamic general equilibrium model with an overlapping generation structure. Further analysis using model simulation illustrates that the alternative schemes for the benefit rate, retirement age and technological progress are likely to be beneficial, and that an obvious slow-down in the growth of living standards is likely to be avoided.  相似文献   

2.
Abstract

The objective of social development is to construct a harmonious society. In China, the key to a harmonious society is the happiness of more than 900 million farmers living in the rural areas. This study aimed to measure rural residents’ subjective well-being (SWB) through the day reconstruction method, as well as to analyze SWB’s influencing factors through a variety of statistical methods. The results showed that the average U index was 12.79%, indicating that respondents were unhappy 12.79% of the time. Twenty-seven percent of the population had a U index greater than 0, with the average value being 47%, indicating that these people were unhappy 47% of the time. The study also found that SWB varied according to the characteristics of the respondents. Logistic regression analysis showed that social and demographic factors, including age, education, county, household size, generation number, per capita income, migration status and social networking, which significantly affected rural residents’ SWB. The size of the impact varied with the different factors.  相似文献   

3.
BackgroundMany cities across the world are beginning to shift their mobility solution away from the private cars and towards more environmentally friendly and citizen-focused means. Hamburg, Oslo, Helsinki, and Madrid have recently announced their plans to become (partly) private car free cities. Other cities like Paris, Milan, Chengdu, Masdar, Dublin, Brussels, Copenhagen, Bogota, and Hyderabad have measures that aim at reducing motorized traffic including implementing car free days, investing in cycling infrastructure and pedestrianization, restricting parking spaces and considerable increases in public transport provision. Such plans and measures are particularly implemented with the declared aim of reducing greenhouse gas emissions. These reductions are also likely to benefit public health.AimsWe aimed to describe the plans for private car free cities and its likely effects on public health.MethodsWe reviewed the grey and scientific literature on plans for private car free cities, restricted car use, related exposures and health.ResultsAn increasing number of cities are planning to become (partly) private car free. They mainly focus on the reduction of private car use in city centers. The likely effects of such policies are significant reductions in traffic-related air pollution, noise, and temperature in city centers. For example, up to a 40% reduction in NO2 levels has been reported on car free days. These reductions are likely to lead to a reduction in premature mortality and morbidity. Furthermore the reduction in the number of cars, and therefore a reduction in the need for parking places and road space, provides opportunities to increase green space and green networks in cities, which in turn can lead to many beneficial health effects. All these measures are likely to lead to higher levels of active mobility and physical activity which may improve public health the most and also provide more opportunities for people to interact with each other in public space. Furthermore, such initiatives, if undertaken at a sufficiently large scale can result in positive distal effects and climate change mitigation through CO2 reductions. The potential negative effects which may arise due to motorized traffic detouring around car free zone into their destinations also need further evaluation and the areas in which car free zones are introduced need to be given sufficient attention so as not to become an additional way to exacerbate socioeconomic divides. The extent and magnitude of all the above effects is still unclear and needs further research, including full chain health impact assessment modeling to quantify the potential health benefits of such schemes, and exposure and epidemiological studies to measure any changes when such interventions take place.ConclusionsThe introduction of private car free cities is likely to have direct and indirect health benefits, but the exact magnitude and potential conflicting effects are as yet unclear. This paper has overviewed the expected health impacts, which can be useful to underpin policies to reduce car use in cities.  相似文献   

4.
BackgroundPhthalates, reproductive toxicants in animals, are synthetic chemicals with ubiquitous human exposures because of their extensive use, with potential detrimental health effects. Infants are considered to represent a population at increased risk, as they are exposed early in life to several different sources of exposure to phthalates.Objectives and methodsLittle information exists on phthalate exposure through breast milk from different geographic areas. By means of a LC/LC–MS/MS method we tested the presence of several different phthalate metabolites in breast milk from 62 healthy mothers living in Southern Italy.ResultsThe simple monoesters mono-isobutyl phthalate (MiBP) (median 18.8 μg/l) and mono(2-ethylhexyl) phthalate (MEHP) (median 8.4 μg/l) were present in all milk samples, whereas mono-n-butyl phthalate (MnBP) (median 1.5 μg/l) and mono-benzyl phthalate (MBzP) (median < 0.3 μg/l) were found in 64.5% and 43.5% of the samples, respectively. Among the oxidative metabolites of DEHP and DiNP only mono(2-ethyl-5-carboxypentyl) phthalate (5cx-MEPP) and monoisononyl phthalate with one hydroxyl group (OH-MiNP) were detectable in one and 13 samples (21%), respectively.ConclusionsThese findings indicate that exposure to phthalates through breast milk in Southern Italian infants is comparable to that of other countries, thus confirming that human milk may represent an additional potential source of phthalate exposure in a population at increased risk. However, different milk concentrations of MiBP may suggest a different pattern of usage of di-iso-butyl phthalate in Europe, as compared to USA, whereas for the first time, we detected an oxidative DiNP metabolite, whose significance remains unclear.  相似文献   

5.
Abstract

In this paper, an approach to simulate the spatial distribution of urban population is proposed using urban land use and population statistical data through the geographical information systems (GIS). Then, the spatial population distribution of Urumqi as a case is simulated by the approach mentioned above and its varying patterns are analyzed by the raster population surface. As a result, producing raster population surface is more accurate and natural than the traditional choropleth map of population density. Concerning the spatial population distribution of Urumqi, the population density declines from south to north and the population distribution mainly presents “T-type”, the population distribution presents multi-centre agglomeration and the population distribution of the districts shows different features. The population density varies significantly with the increase in the distance from central business district (CBD). Finally, it is found in this paper that the development history of districts, terrain and traffic road are main factors that have an influence Urumqi's population distribution. This paper tries to provide more accurate population data for the plan and management of urban land, traffic and public facilities in order to enrich the researches on urban population distribution.  相似文献   

6.
Abstract

According to Statistical Yearbook of Jiangxi Province (2001~2006), We analyze the time-space variation of population distribution of Poyang Lake region from the two points of view. The former is quality of population, which involves culture structure, occupational structure, age structure and sex structure of population. The latter is quantity of population, which only involves the amount of population. Furthermore, we can reveal the internal relations and action mechanism of variation of population distribution by analyzing the regional economic development, population urbanization, land use and ecological landscape of Poyang Lake region. It is important to provide help for region planning, ecological landscape planning and environmental protection by correct understanding the man-land relationship of natural-human ecosystem in Poyang Lake region.  相似文献   

7.
Abstract

Based on the self-organizing modeling principle in the dissipative structure theory, the paper regards the migration coupling between the regions as the influence factor to create the model of regional urbanization simulation and prediction, which is more practical to simulate the space-time and dynamic evolvement characteristics of regional urbanization level. According to the historical data about the population and urbanization of Jiuquan, Jiayuguan and Yumen cities, the past 50 years' dynamic evolvement trend is simulated and the following 50 years' dynamic evolvement trend is predicted with the urbanization dynamic evolvement model based on the self-organizing model. The analysis of effective factors such as economic increase, resources exploitation, ecosystem construction, traffic location, national policies, population migration are given, then the reasons of the dynamic evolvement differences of the three cities' urbanization are drawn. The study suggests that the self-organizing model is fit for the simulation of Jiuquan-Jiayuguan-Yumen regional urbanization level in the past 50 years, and the departure between the stimulant and the actual data is under 5%, so it can be used to predict the urbanization future of the three cities. The predicted results show that the regional population will reach 1.074 million and the regional urbanization level will be 72.56%.  相似文献   

8.
Abstract

Floating population is a special population group in China resulting from the implementation of household registration system. This paper uses a set of floating population survey data, population censuses data and statistical data to analyze the increase and influence of floating population on the urban population situations in Beijing. It is found that Beijing has experienced a rapid increase of floating population since the 1990s and that the increase of this group has become the key factor of the current population expansion in the city. Its distribution in the urban regions intensified and extended the suburbanization process of the capital. In addition, the population structures of sex, age, education and employment in Beijing have changed to some extent due to the influx of floating population.  相似文献   

9.
Abstract

Nowadays the rising of opportunity cost of farm labor comes to the forefront of attention in China. In order to understand its impact on agricultural land-use structure, a theoretical framework of household economics is formulated drawn on Low’s model. Under the theoretical framework, the impact of the rising opportunity cost of on-farm on cropping structure is deduced in theory. And then, using statistic and survey data, taking mountain area of southern Ningxia as an example, the theoretical assumes are verified. The results show that the rise of opportunity cost of farm labor leads to less diversified cropping structure.  相似文献   

10.
ABSTRACT

This paper establishes a diagnostic model for assessing the rationality of size structure of urban agglomerations (UAs) in China. The model is designed to determine from a three-dimensional index including size distribution index (SDI), size compactness index (SCI), and size efficiency index (SEI). The spatio-temporal pattern of size structure involving the studied 19 UAs and its implications are explored. The results indicate that size structure of China’s UAs advanced from a low rationality development stage to a moderate rationality development stage in 1995–2015. Among them, the SDI and SEI were reasonably high, and the SCI was relatively low. Spatially, the high rationality UAs were distributed across eastern China, while the low rationality UAs were located in western China. UAs with positive size structure possessed typically a dual- or multicenter urban structure, while UAs with negative size structure usually presented as a single-center structure. The evolutionary trajectories of rationality of size structure of UAs can be summarized as four different stages. Our findings suggest that, in addition to consolidating the status of national-level UAs, the development of regional-level UAs should be promoted. Also, the fostering focus and direction should be oriented toward an UA with dual- or multicenter spatial structure.  相似文献   

11.
Abstract

Re-distributed manufacturing (RDM), broadly described as manufacturing done at a smaller-scale and locally, could be beneficial to business and urban society through creating jobs, reducing the environmental impacts of production, and improving resilience to future disturbances. Consideration of RDM within a city-region requires the consideration of a wide range of issues – societal, technical, economic and environmental. This paper presents the results of a study into the potential for RDM to contribute to a sustainable, resilient city in the face of a range of expected future disturbances on the city and on manufacturing sectors. The study took an integrated assessment approach which incorporated the development of a conceptual framework; a ‘strawman’ causal loop diagram which was reviewed by participants in a workshop; and a stock and flow system dynamics model that represents our understanding about the structure and behaviour of urban manufacturing. Several key themes emerged: similarities between RDM and traditional manufacturing, availability of physical space for RDM to be done, achieving urban resilience through RDM by enabling responsiveness to disturbances, changes in environmental impacts from production, additions or losses in jobs, the competitiveness of local manufacturing, and skills and innovation for RDM technologies. Further work is recommended.  相似文献   

12.
Abstract

The overlapping generation models the western scholars have designed from various perspectives to address different kinds of issues do not reflect Chinese emerging political and economic problems, and cannot be entirely and blindly applied to Chinese practical situation. In this paper the authors endeavor to incorporate some western scholars' research results into their own research findings to present overlapping generations model theory in a new perspective through establishing an overlapping generations theory on population including articulation of concepts and theorems of biological generation, economic generation and social generation and the overlapping periods in biological generation and two overlapping periods in economic generation among three generations. This management model with equilibrium distribution of resource wealth includes overlapping generations length model (δ), equilibrium transfer model (?) and a complete model on equilibrium distribution among generations (δ-?). The model provides quantitative basis for the creation of resource management system, and fills in a theoretical gap in this discipline in China. Besides, it furnishes a new methodology and manipulate tool for Chinese government to establish a comprehensive management information bank for many sectors such as economic trade, population, science and technology, education, human resource, natural resource and environment, agriculture, forestry, industry, mining and energy.  相似文献   

13.
Abstract

As a typical tropical agro-forestry ecosystem in Wenchang, Hainan Province, China, rational mechanisms of the rubber-tea-chicken eco-agricultural model were studied with the Solow technological level index, stability indicator, harmonizing coefficient, grey correlation coefficient and production dominance. This study focused on rational hierarchical structure, the limiting factors and optimal strategies of the model development based on model structure, resource conditions and external market demands. Results showed that rational mechanism of the rubber-tea-chicken ecosystem model mainly included technological contributions, leverage function of dominance component (livestock husbandry), stability of the model structure and harmony of its components, the model dominant product’s market demand and government’s supporting policies. The contributions of fund, technology, information and talent resources played an important role in improving sustainability and productivity of the agro-forestry model.  相似文献   

14.
IntroductionPerfluorinated alkylated substances (PFAS) are persistent industrial chemicals that have resulted in global environmental exposures. Previous epidemiological studies have reported possible effects on the immune system after developmental PFAS exposure, but the possible impact on childhood infectious disease is unclear.ObjectivesTo investigate the association between prenatal exposure to PFAS and symptoms of infections at age 1–4 years.MethodsThe Odense Child Cohort is an on-going prospective study on children's health, where serum concentrations of perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA), perfluorohexane sulfonic acid (PFHxS), perfluorodecanoic acid (PFDA) and perfluorononanoic acid (PFNA) were measured in 649 pregnant women before gestational week 16. Of these women, 359 reported on symptoms of infection in their child every two weeks for a one-year period. The association between prenatal exposure to PFAS and the symptoms was estimated using a logistic regression model and a negative binomial regression model. For the latter, the outcome was reported as an incidence rate-ratio (IRR), and all models were adjusted for maternal age, educational level, parity and child age.ResultsOn average, the children experienced symptoms of infection 23% of the time during one year. PFOS exposure in the high tertile compared to the low tertile was associated with a statistically significant increased proportion of days with fever (IRR: 1.65 (95% CI: 1.24, 2.18), P-trend < 0.001) and an increased odds of experiencing days with fever above the median (OR: 2.35 (95% CI: 1.31, 4.11). The latter tendency was also apparent for PFOA (OR: 1.97 (95% CI: 1.07, 3.62). Further, higher concentrations of PFOS and PFOA tended to increase the number of episodes of co-occurrence of fever and coughing and fever and nasal discharge during the one-year study period.ConclusionWe found a positive association between prenatal exposure to PFOS and PFOA and the prevalence of fever, which may be a sensitive marker of infection. This finding is in agreement with an immunotoxic effect of prenatal exposure to PFAS. The wider implications for childhood infectious disease deserve attention.  相似文献   

15.
IntroductionThe United Kingdom (UK) has one of the highest prevalence of asthma in the world, which represents a significant economic and societal burden. Reduced ventilation resulting from increased energy efficiency measures acts as a modifier for mould contamination and risk of allergic diseases. To our knowledge no previous study has combined detailed asset management property and health data together to assess the impact of household energy efficiency (using the UK Government's Standard Assessment Procedure) on asthma outcomes in an adult population residing in social housing.MethodsPostal questionnaires were sent to 3867 social housing properties to collect demographic, health and environmental information on all occupants. Detailed property data, residency periods, indices of multiple deprivation (IMD) and household energy efficiency ratings were also investigated. Logistic regression was used to calculate odds ratios and confidence intervals while allowing for clustering of individuals coming from the same location.ResultsEighteen percent of our target social housing population were recruited into our study. Adults had a mean age of 59 (SD ± 17.3) years and there was a higher percentage of female (59%) and single occupancy (58%) respondents. Housing demographic characteristics were representative of the target homes. A unit increase in household Standard Assessment Procedure (SAP) rating was associated with a 2% increased risk of current asthma, with the greatest risk in homes with SAP > 71. We assessed exposure to mould and found that the presence of a mouldy/musty odour was associated with a two-fold increased risk of asthma (OR 2.2 95%; CI 1.3–3.8). A unit increase in SAP led to a 4–5% reduction in the risk of visible mould growth and a mouldy/musty odour.DiscussionIn contrast to previous research, we report that residing in energy efficient homes may increase the risk of adult asthma. We report that mould contamination increased the risk of asthma, which is in agreement with existing knowledge. Exposure to mould contamination could not fully explain the association between increased energy efficiency and asthma. Our findings may be explained by increased energy efficiency combined with the provision of inadequate heating, ventilation, and increased concentrations of other biological, chemical and physical contaminants. This is likely to be modified by a complex interaction between occupant behaviours and changes to the built environment. Our findings may also be confounded by our response rate, demographic and behavioural differences between those residing in low versus high energy efficient homes, and use of self-reported exposures and outcomes.ConclusionEnergy efficiency may increase the risk of current adult asthma in a population residing in social housing. This association was not significantly modified by the presence of visible mould growth, although further research is needed to investigate the interaction between other demographic and housing characteristic risk factors, especially the impact of fuel poverty on indoor exposures and health outcomes.Study implicationsA multidisciplinary approach is required to assess the interaction between energy efficiency measures and fuel poverty behaviours on health outcomes prior to the delivery of physical interventions aimed at improving the built environment. Policy incentives are required to address fuel poverty issues alongside measures to achieve SAP ratings of 71 or greater, which must be delivered with the provision of adequate heating and ventilation strategies to minimise indoor dampness. Changes in the built environment without changes in behaviour of domicile residents may lead to negative health outcomes.  相似文献   

16.
Background and goalsAs part of the authorization process for the solid waste incinerator (SWI) in Modena, Italy, a human biomonitoring cross-sectional pilot study was conducted to investigate the degree to which people living and working in the proximity of the plant were exposed to SWI emissions.MethodsBetween May and June 2010, 65 subjects living and working within 4 km of the incinerator (exposed) and 103 subjects living and working outside this area (unexposed) were enrolled in the study. Blood, serum and urinary metals (Pb, Cd, Cu, Zn, Hg, Mn, Ni), urinary benzene, toluene, xylene (BTEX), S-phenylmercapturic acid (SPMA), and urinary polycyclic aromatic hydrocarbons (PAHs) were analysed. Information about lifestyle, anthropometric characteristics, residence, and health status was collected by a self-administered questionnaire. Exposure to particulate matter (PM) emitted from the SWI was estimated using fall-out maps from a quasi-Gaussian dispersion model. A multiple linear regression analysis investigated the relationship between biomarkers and the distance of a subject's place of residence from the SWI plant or the exposure to PM.ResultsUrinary BTEX and SPMA and blood, serum and urinary metals showed no differences between exposed and unexposed subjects. PAHs were higher in exposed than in unexposed subjects for phenanthrene, anthracene, and pyrene (median levels: 9.5 vs. 7.2 ng/L, 0.8 vs. < 0.5 ng/L and 1.6 vs. 1.3 ng/L, respectively, p < 0.05). Multiple linear regression analysis showed that blood Cd and Hg and urinary Mn, fluorene, phenanthrene, anthracene and pyrene were inversely correlated to the distance of a subject's residence from the SWI. Urinary Mn, fluorene and phenanthrene were directly correlated to PM exposure.ConclusionsThis study, although not representative of the general population, suggests that specific biomarkers may provide information about the degree of exposure the subjects working and living in the proximity of the SWI plant may have to emissions from that facility.  相似文献   

17.
BackgroundInfants are exposed to persistent environmental contaminants through breast milk, yet studies assessing the health effects of postnatal exposure are lacking. Existing postnatal exposure assessment is either too simple (lactation exposure model, LEM) or requires complex physiologically-based pharmacokinetic (PBPK) models.ObjectivesWe present equations for postnatal exposure calculations. We applied these equations to study the effect of hexachlorobenzene (HCB) on infant growth in the two first years of life.MethodsHCB was measured in breast milk samples in 449 mother-child pairs participating in the Norwegian birth cohort study HUMIS. We used these concentrations, mother's weight, height and age, together with child's weight at 8 age points, and proportion of milk consumed each month, to calculate HCB concentrations in the infant over age. We then estimated the association between HCB and infant growth using a linear mixed model.ResultsChildren exposed to HCB via mother's milk reached concentrations 1–5 times higher than the mother. HCB was associated with lower weight gain in the first 2 years (− 33 g per unit HCB and month, 95% CI: − 38, − 27 at 6 months). Associations were stronger during the first 3 months (− 57 g per unit HCB and month, 95% CI: − 67, − 49 at 1 month), indicating a critical window of effect. Our equations gave more precise estimates than the LEM.ConclusionOur equations for postnatal exposure of lipophilic environmental toxicants give better results than the LEM and are easier to implement than the complex PBPK models. HCB exposure, especially during the first three months of life, has a negative effect on infant growth up to 2 years.  相似文献   

18.
Abstract

A growing body of literature has documented the rapidly increasing income disparities that accompanied China's economic growth in the 1980s and 1990s, and the driving factors behind this. Growing income inequality in its turn may have important implications for the accumulation of physical capital, human capital, and natural capital and as a consequence for sustainable economic development. The purpose of this paper is to investigate the potential impact of income inequality on savings, human resources and the environment in China. It starts with an overview of the different causal mechanisms through which income inequality may affect the accumulation of physical capital, human capital, and natural capital, and discusses to what extent these causal relationships may be relevant in the case of China. Next, provincial data for the year 2002 are used to explore the relationship between income inequality and different elements of sustainable development in China. It is found that income inequality does not affect aggregate savings levels. Rising inequality, however, contributes to lower health and possibly also to higher fertility levels. It also lowers the use of chemical fertilizers in agriculture and therefore is likely to reduce water pollution. Other types of environmental degradation are not affected.  相似文献   

19.
The increased variability in weather as a manifestation of climate change is expected to have negative impacts on population survival in wildlife species, because it will likely lead to increased variation in vital demographic rates (mortality and reproduction) in these populations. For the effective protection of biodiversity, adaptation measures are needed to compensate for the expected increase in weather variability and the negative interaction with habitat fragmentation. As a case study, we studied the fluctuations in Great Bittern numbers (Botaurus stellaris) from 28 monitoring plots scattered over the Netherlands to explore the interaction between the effect of weather and possible remediating effects of the landscape structure. Great Bittern habitat surrounding these plots differs with respect to area, quality, and degree of isolation of this habitat. In western Europe, Great Bitterns are found to be susceptible to continuous loss of suitable habitat due to vegetation succession and fragmentation. Moreover, year-to-year fluctuations in local Great Bittern populations can be caused by severe winter weather or other weather extremes. Our results show that severe winter weather has indeed a significant negative impact on Great Bittern population growth rates. Furthermore, we found that an increased carrying capacity and spatial cohesion (i.e. inverse of habitat fragmentation) contribute to an increase in mean growth rates over the years. As growth rates are higher in large, well-connected habitats, we argue that recovery from negative effects of, e.g. severe winters on Great Bittern population numbers is enhanced in these less-fragmented habitats. We derived generic adaptation measures for enhancing the recovery rate of populations of species in general: one should invest in more large, well-connected nature areas, not only to diminish the negative effects of habitat fragmentation on wildlife populations, but additionally to reduce the impacts of climatic variability.  相似文献   

20.
Abstract

The health impacts of tobacco consumption are well documented and have gained acceptance worldwide. Today, a substantial, preventable burden of tobacco attributable diseases exists in most countries, though in most of the cases, unknown. Smoking accounts for almost half of the deaths in middle age in some regions. In Uganda, translating findings into policy action is slow and involves several stakeholders. It will continue to require support from tobacco control campaign groups. This paper analyses secondary literature on tobacco smoking and later provides an appropriate medium based communication strategy that can be adopted to counteract the persuasive smoking evil adverts of tobacco companies as well as creating awareness among the population of the health impacts caused by smoking.  相似文献   

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