Symptoms prevalence among office workers of a sealed versus a non-sealed building: Associations to indoor air quality

ObjectivesAn increasing number of complaints related to time spent in artificially ventilated buildings have been progressively reported and attributed, at least in part, to physical and chemical exposures in the office environment. The objective of this research was to investigate the association between the prevalence of work-related symptoms and the indoor air quality, comparing a sealed office building with a naturally ventilated one, considering, specially, the indoor concentration of TPM, TVOCs and the main individual VOCs.MethodsA cross-sectional study was performed to compare the prevalence of sick building syndrome (SBS) symptoms among 1736 office workers of a sealed office building and 950 of a non-sealed one, both in Rio de Janeiro's downtown. The prevalence of symptoms was obtained by a SBS standardized questionnaire. The IAQ of the buildings was evaluated through specific methods, to determine the temperature, humidity, particulate matter and volatile organic compound (VOC) concentrations.ResultsUpper airways and ophthalmic symptoms, tiredness and headache were highly prevalent in both buildings. Some symptoms were more prevalent in the sealed building: “eye dryness” 33.3% and 27.1% (p: 0.01); “runny nose” 37.3% and 31.3% (p: 0.03); “dry throat” 42% and 36% (p: 0.02); and “lethargy” 58.5% and 50.5% (p: 0.03) respectively. However, relative humidity and indoor total particulate matter (TPM) concentration as well as total volatile organic compounds (TVOCs) were paradoxically greater in the non-sealed building, in which aromatic compounds had higher concentration, especially benzene. The analysis between measured exposure levels and resulting symptoms showed no association among its prevalence and TPM, TVOCs, benzene or toluene concentration in none of the buildings.ConclusionsOther disregarded factors, like undetected VOCs, mites, molds and endotoxin concentrations, may be associated to the greater prevalence of symptoms in the sealed building.     

Future climate and adverse health effects caused by fine particulate matter air pollution: case study for Poland

Ground level air pollution, especially fine particulate matter (PM_2.5), has been associated with a number of adverse health effects. The dispersion of PM_2.5 through the atmosphere depends on several mutually connected anthropogenic, geophysical and meteorological parameters, all of which are affected by climate change. This study examines how projected climate change would affect population exposure to PM_2.5 air pollution in Poland. Population exposure to PM_2.5 in Poland was estimated for three decades: the 1990s, 2040s and 2090s. Future climate conditions were projected by Regional Climate Model RegCM (Beta), forced by the general atmospheric circulation model ECHAM5. The dispersion of PM_2.5 was simulated with chemical transport model CAMx version 4.40. Population exposure estimates of PM_2.5 were 18.3, 17.2 and 17.1 μg/m³ for the 1990s, 2040s and 2090s, respectively. PM_2.5 air pollution was estimated to cause approximately 39,800 premature deaths in the population of Poland in the year 2000. Our results indicate that in Poland, climate change may reduce the levels of exposure to anthropogenic particulate air pollution in future decades and that this reduction will reduce adverse health effects caused by the air pollution.     

Small island developing states: coastal systems, global change and sustainability

The intent of this paper is to place the concepts of exposure, vulnerability, resilience and risk in the context of the consequences of global change for the sustainable development of small island developing states (SIDS). Many such states face a number of global climate change risks, such as an increase in the proportion of more intense storms, along with other global change threats that include energy security and costs. All these threats come on top of local development threats, such as increased run-off, often with increasing levels of contaminants due to unsustainable agricultural and industrial practices. When taken together, the resulting pressures on islands and their communities lead to significant increases in vulnerability to change due to reduced resilience to these changes. Vulnerability is also increasing as a result of contemporary processes that heighten the exposure of material and other assets. The capacity to address hazard risk also influences vulnerability. This includes the level of awareness of coastal hazards and exposure, and access to critical life support infrastructure, especially for people living in hazard-prone areas. Vulnerability and resilience are considered to be important integrating concepts when managing the local consequences of global changes. There are many initiatives that will help reduce the vulnerability and enhance the resilience of SIDS to such changes. These include improving risk knowledge and coastal resource and land use management, while also strengthening socio-economic systems and livelihoods. In this way, managing global change can be closely aligned with local development and humanitarian processes, thereby enhancing the overall sustainability of development processes and outcomes.     

Pollutant exposures and health symptoms in aircrew and office workers: Is there a link?

Sensory effects in eyes and airways are common symptoms reported by aircraft crew and office workers. Neurological symptoms, such as headache, have also been reported. To assess the commonality and differences in exposures and health symptoms, a literature search of aircraft cabin and office air concentrations of non-reactive volatile organic compounds (VOCs) and ozone-initiated terpene reaction products were compiled and assessed. Data for tricresyl phosphates, in particular tri-ortho-cresyl phosphate (ToCP), were also compiled, as well as information on other risk factors such as low relative humidity.A conservative health risk assessment for eye, airway and neurological effects was undertaken based on a “worst-case scenario” which assumed a simultaneous constant exposure for 8 h to identified maximum concentrations in aircraft and offices. This used guidelines and reference values for sensory irritation for eyes and upper airways and airflow limitation; a tolerable daily intake value was used for ToCP. The assessment involved the use of hazard quotients or indexes, defined as the summed ratio(s) (%) of compound concentration(s) divided by their guideline value(s).The concentration data suggest that, under the assumption of a conservative “worst-case scenario”, aircraft air and office concentrations of the compounds in question are not likely to be associated with sensory symptoms in eyes and airways. This is supported by the fact that maximum concentrations are, in general, associated with infrequent incidents and brief exposures. Sensory symptoms, in particular in eyes, appear to be exacerbated by environmental and occupational conditions that differ in aircraft and offices, e.g., ozone incidents, low relative humidity, low cabin pressure, and visual display unit work. The data do not support airflow limitation effects. For ToCP, in view of the conservative approach adopted here and the rareness of reported incidents, the health risk of exposure to this compound in aircraft is considered negligible.     

Development of a personal exposure monitor for two sizes of inhalable particulates

Measurement of personal exposure to ambient level particulate concentrations is often extremely difficult because of a lack of personal exposure monitors capable of collecting measurable quantities within a meaningful sampling period. A new personal exposure monitor for two fractions of inhalable particulates (i.e., the 3–15 μm aerodynamic diameter and the < 3 μm or respirable fraction) has been developed and characterized. This monitor is capable of collecting a sample of each fraction that is quantifiable with ambient concentrations of inhalable/respirable particulates as low as 25 μg/m³ in a 24-h sampling period. Wind tunnel tests have been made on the particulate personal exposure monitor to determine sampling efficiency as a function of relative wind speed and orientation with respect to the sampler.     

Lymphatic transport of inhaled diesel particles in the lungs of rats and guinea pigs exposed to diluted diesel exhaust

Factors influencing the disposition of the inhaled diesel particles were studied by analyzing the deposition of radioactively labelled diesel particles in the respiratory system, by determining the specific function of alveolar cellular mechanisms in the primary defense against inhaled particles and by identifying the important role of the lymphatic system in the lung clearance of experimental animals exposed to diluted emissions from a diesel engine. Radioactive ¹³¹Barium was used as a tracer of diesel particles and the deposition efficiency was determined to be 15%±6% of the inhaled dose in the Fischer 344 rat strain. The number of cells obtained by bronchial lavage increased significantly after a prolonged exposure to a concentration of 1500 μg/m³ of diesel particles. The increased cell number was more than twofold, contained two distinct cell populations (alveolar macrophages and neutrophils) and represented a reactive mobilization of the defense mechanisms in the organism. Light microscopy studies investigated the role of lymphatic transport of the particulate matter and revealed that the peribrochial and perivascular aggregates of lymphoid tissue contained diesel particles even after short exposure periods at low dose levels. With the increasing burden of particles in the respiratory system, the coloration of hilar and mediastinal lymph nodes continuously changed to gray and finally to dark black, depending upon the dose level and exposure. However, at all exposure levels, most of the diesel particles in the alveoli were phagocytized by an increased alveolar cellular defence and particle-containing macrophages were actively moving towards the mucociliary escalator or towards lymphatic channels leading to peribronchial lymphoid aggregates and bronchial or mediastinal lymph nodes. In the lymph nodes, alveolar macrophages containing diesel particles were found mostly in the afferent subcapsular lymphatic vessels and marginal sinuses. In the later stages, cellular structure disintegrated and large aggregates of particulate matter were dispersed throughout the medullary cords with increasing accumulation towards the hilus. It is concluded that the lymphoid aggregates and lymphatic nodes play an important role in sequestering diesel particles or particle-containing phagocytizing cells and provide a pathway, in addition to the mocociliary clearance for particulate removal from the deep pulmonary region.     

Never smoker lung cancer risks from exposure to particulate tobacco smoke

The average particulate environmental tobacco smoke (ETS) exposure of never and current smokers and the average lung cancer mortality rate for current smokers is estimated from empirical data. These estimates are used in a linear downward extrapolation of the lung cancer risk/mg of particulate ETS exposure for current smokers to calculate the average lung cancer risk for never smokers and the number of never smoker lung cancer deaths (LCD) in the U.S. in 1980 from exposure to particulate ETS. The estimated average daily inhaled particulate ETS exposure for never smokers is 0.62 mg/day for men and 0.28 mg/day for women. The average never smoker is estimated to retain 11% of the inhaled exposure, for a daily retained exposure of 0.07 mg for men and 0.03 mg for women. Other estimates are: a daily retained exposure for current smokers of 310 mg for men and 249 mg for women, a smoking-attributable lung cancer risk for current smokers in 1980 of 284 LCD/100,000 men and 121 LCD/100,000 women, and an annual retained-exposure lung cancer risk for never smokers of 0.64 LCD/100,000 men and 0.015 LCD/100,000 women. These risks and exposures estimate 12 lung cancer deaths among never smokers from exposure to particulate ETS: 8 among the 11.96 million male never smokers and 4 among the 28.85 million female never smokers in the U.S. in 1980. Conversely, between 655 and 3,610 never smoker lung cancer deaths are estimated from methods based on the average lung cancer risk observed in epidemiological studies of exposure to ETS. Three possible reasons for the discrepancy between the exposure and risk-based estimates are discussed: the excess risks observed in epidemiological studies are due to bias, the relationship between exposure and risk is supralinear, or sidestream tobacco smoke is substantially more carcinogenic than an equivalent exposure to mainstream smoke.     

The radiological impact of atmospheric emissions from oil shale retorts

The radionuclide content of various oil shales, shale oils, and retorting waste products has been studied to determine the extent to which the development of this energy resource may perturb the natural radiation environment. Nearly all of the radioactivity in the raw shale is found in the spent shale after retorting. A primary exposure pathway to the public from this radioactivity will be through the release of particulate matter to the atmosphere during various mining, crushing, and retorting operations. Since the activity of this material is close to that of normal soil, however, the expected radiological impact is small.     

Applicability of a noise-based model to estimate in-traffic exposure to black carbon and particle number concentrations in different cultures

Several studies show that a significant portion of daily air pollution exposure, in particular black carbon (BC), occurs during transport. In a previous work, a model for the in-traffic exposure of bicyclists to BC was proposed based on spectral evaluation of mobile noise measurements and validated with BC measurements in Ghent, Belgium. In this paper, applicability of this model in a different cultural context with a totally different traffic and mobility situation is presented. In addition, a similar modeling approach is tested for particle number (PN) concentration.Indirectly assessing BC and PN exposure through a model based on noise measurements is advantageous because of the availability of very affordable noise monitoring devices. Our previous work showed that a model including specific spectral components of the noise that relate to engine and rolling emission and basic meteorological data, could be quite accurate. Moreover, including a background concentration adjustment improved the model considerably. To explore whether this model could also be used in a different context, with or without tuning of the model parameters, a study was conducted in Bangalore, India. Noise measurement equipment, data storage, data processing, continent, country, measurement operators, vehicle fleet, driving behavior, biking facilities, background concentration, and meteorology are all very different from the first measurement campaign in Belgium. More than 24 h of combined in-traffic noise, BC, and PN measurements were collected. It was shown that the noise-based BC exposure model gives good predictions in Bangalore and that the same approach is also successful for PN. Cross validation of the model parameters was used to compare factors that impact exposure across study sites. A pooled model (combining the measurements of the two locations) results in a correlation of 0.84 when fitting the total trip exposure in Bangalore. Estimating particulate matter exposure with traffic noise measurements was thus shown to be a valid approach across countries and cultures.     

气候变化经济学研究综述

对近10 a来国内外有关气候变化经济学研究成果作了综述。气候变化经济学是一门研究人类干预气候变化过程中涉及经济过程的学科。当前的研究热点包括气候变化的经济影响、适应措施的成本和收益、国际合作机制和涉及代际公平的折现率选取。 在研究方法上,对得到广泛运用的成本收益分析法和碳税机制作了详细的评述。在应用层面上,欧美发达国家在城市气候变化经济评估系统建立和碳税征收方面都有成功的应用,但我国在这方面的实践还处于起步阶段。对于我国气候变化经济学领域的研究来说,比较适合在发达省份以市域或省域为单位开展成本收益评估,发展中省份则应将更多关注放在评估气候变化可能造成的经济损害及相应的防范措施。此外,我国也应关注在欧盟地区实施较为成功的碳税政策,虽然目前在中国开征碳税的可能性较低,但是对碳税在中国实施的可行性、税率选取及立法保障机制等方面的探讨和研究仍是必要的     

Innovation for sustainable development: from environmental design to transition management

Society needs to adapt in order to provide the wealth that an increasing part of the world population is getting used to. We are on a track to ecological and resource collapse if actions are not taken soon. Technology will have to play a key role in the process of changing industrial society. But innovation has to be embedded in social and organizational innovation. We need sociotechnical change. Environmentally conscious design has been practiced in engineering design for more than a decade. Its merits are sometimes blamed as futile, as the world has not witnessed a significant contribution to the solution of the larger (global) problems. This paper first sketches a scheme of the various levels of technological change, ranging from: (1) incremental optimizations of single artifacts, to (2) major change of artifacts, (3) systems change, and (4) technological transitions (involving changes in production and consumption). It outlines the stakeholders involved in these types of innovations and the parties that could orchestrate the innovation process. In this paper, It is argued that the most encompassing level of technological innovation, the level of transition, is crucial for achieving long-term sustainable development, as it has the largest potential for improvement. However, transition is not very well manageable. The paper contains a review of the literature regarding the occurrence of technological transitions. After a transition has occurred, the new system is often not efficient. Its gains in terms of diminished resource consumption or pollution have to be enlarged by less encompassing innovation strategies, such as systems innovations and product optimization. Transitions for sustainable development are often impossible, as the new systems have to compete with fully developed and optimized systems that have far advanced at the learning curve, i.e., are optimized by various systems and incremental innovations. Less encompassing levels of innovation, even those that aim at more sustainability, can counteract transitions that have more potential for sustainable development by improving the competing (unsustainable) technology. The paper will give several examples of this dilemma and some guidelines for developing government policies as well as corporate strategies. On the policy level, it is argued that it is especially important to develop (scope for) market niches for new sustainable systems and products as they create scope for experiments that could lead to transitions.

Obstetrical outcomes and biomarkers to assess exposure to phthalates: A review

Studies of the effects on pregnancy outcomes of in utero exposure to phthalates, contaminants that are widely present in the environment, have yielded conflicting results. In addition, the mode of assessment of exposure varies between studies. The aim of this review was therefore to establish a current state of knowledge of the phthalates and metabolites involved in unfavorable pregnancy outcomes. Extant data were analyzed to determine which biomarker is the best suited to assess the relation between in utero exposure to phthalates and pregnancy outcomes.This review of the literature was conducted using the database of PubMed. A search was made of studies investigating exposure to phthalates and the following birth outcomes: preterm birth (gestational age < 37 weeks), change in gestational age, change in body size at birth (birth weight, length, head circumference), anti-androgenic function, decreased anogenital distance, cryptorchidism, hypospadias and congenital malformation. The methodological approach adopted in each study was examined, in particular the methods used for exposure assessment (biomarkers and/or questionnaire).Thirty-five studies were included. Premature birth and decreased anogenital distance were the most commonly reported outcomes resulting from a moderate level of exposure to phthalates. The principal metabolites detected and involved were primary metabolites of di-2(ethylhexyl)-phthalate (DEHP) and di-n-butyl-phthalate (DnBP). No clear conclusion could be drawn with regard to gestational age at birth, body size at birth and congenital malformations. In epidemiological studies, maternal urine is the most suitable matrix to assess the association between in utero exposure to phthalates and pregnancy outcomes: in contrast to other matrices (cord blood, amniotic fluid, meconium and milk), sampling is easy, non-invasive and, can be repeated to assess exposure throughout pregnancy. Oxidative metabolites are the most relevant biomarkers since they are not prone to external contamination.Further epidemiological studies are required during pregnancy to i) determine the role of phthalates other than DEHP [currently replaced by various substitution products, in particular diisononyl-phthalate (DiNP)]; ii) establish the effect of phthalates on other outcomes (body size adjusted for gestational age, and congenital malformations); iii) determine the pathophysiological pathways; and iv) identify the most suitable time for biomarker determination of in utero exposure to phthalates.     

Prenatal exposure to substance of abuse: A worldwide problem

Substance abuse during pregnancy is an important public health issue affecting the mother and the growing infant. Preterm labor, miscarriage, abruption and postpartum hemorrhage are obstetric complications which have been associated with women who are dependent on abused substances. Moreover, women are also at an increased risk of medical problems such as poor nutrition, anemia, urinary tract infections as well as sexually transmitted infections, hepatitis, HIV and problems related to infection. Intrauterine growth restriction, prematurity, stillbirth, neonatal abstinence syndrome, and Sudden Infant Death Syndrome represent only some of fetal effects. Later on, during childhood, it has been shown that in utero exposure to substances of abuse is associated with increased rates of respiratory infections, asthma, ear and sinus infections. Moreover, these children are more irritable, have difficulty focusing their attention, and have more behavioral problems. Therefore, the assessment of in utero exposure to abused substance is extremely necessary and is relevant for the care of the mother and the offspring. In this sense, several approaches are possible; however, recently the evaluation of in utero exposure to abused drugs has been achieved by testing biological specimens coming from fetus or newborn, pregnant or nursing mother, or from both the fetus and the mother. Maternal and neonatal biological materials reflect exposure in a specific time period and each of them has different advantages and disadvantages in terms of accuracy, time window of exposure and cost/benefit ratio.The methodology for identification and determination of abused substances in biological materials are of great importance. Consequently, sensitive and specific bioanalytical methods are necessary to accurately measure biomarkers. Different immunoassays methods are used as screening methods for drug testing in the above reported specimens, however, the results from immunoassays should be carefully interpreted and confirmed by a more specific and sensitive chromatographic methods such as GC–MS or LC–MS. The interest in the development and optimization of analytical techniques to detect abused substances in different specimens is explained by the several possibilities and information that they can provide.     

Assessment of environmental tobacco smoke and respirable suspended particle exposures for nonsmokers in Hong Kong using personal monitoring

One hundred and ninety-four randomly selected nonsmoking subjects collected air samples in their breathing zone by wearing personal monitors for 24 h. The study was centered in Hong Kong, and comprised housewives in one group, primarily for assessing exposures in the home, and office workers in a second group to assess the contribution of the workplace to overall exposure. Samples collected were analysed for respirable suspended particles (RSP), nicotine, 3-ethenylpyridine, and environmental tobacco smoke (ETS) particles using ultraviolet absorbance (UVPM), fluorescence (FPM), and solanesol measurements (SolPM). Saliva cotinine analyses were also undertaken to confirm the nonsmoking status of the subjects and to investigate their correlation with ETS exposure measurements. Approximately 6% of the subjects in Hong Kong misclassified their nonsmoking status. Median time-weighted average (TWA) RSP concentrations varied from 43 to 54 μg m⁻³ with no significant differences detected between any of the groups investigated. Office workers who lived and worked with smokers were exposed to 2.6 μg m⁻³ ETS particles (SolPM) and 0.44 μg m⁻³ nicotine, based on median TWA concentrations. Median concentrations of ETS particles and nicotine were below the limits of quantification for housewives living with smokers and were not significantly different from those for housewives living with nonsmokers. It would therefore be unreliable in Hong Kong to use a smoking spouse as a marker for assessing health risks related to ETS exposure. The office workers in this study were significantly more exposed to ETS than housewives from either smoking or nonsmoking homes, and the workplace was estimated to contribute over 33% of the annual exposure to ETS particles and nicotine. Exposure estimates suggest that the most highly exposed office workers in this study receive between 11 and 50 cigarette equivalents per year, based upon upper decile levels for ETS particles and nicotine, respectively.     

Downscaling nonclimatic drivers for surface water vulnerabilities in the Elbe river basin

Aggregated consideration of both climate and socio-economic change in a coarse spatial resolution is a central feature for scenario development in global change research. Downscaling of the supposed aggregated changes is a necessary prerequisite for the assessments of global change at the regional scale. The present paper describes the method and results of an approach to develop and to apply scenarios of socio-economic change at a sub-national level, which are consistent with global change scenarios. National and regional models of economic and demographic development are used to regionalise drivers of socio-economic change. Scenario results are subsequently applied in order to analyse the impacts of socio-economic and climatic changes on water management issues in the Elbe river basin. Starting from global IPCC-Emissions Scenarios and taking up their key points, we formulate two scenarios for the German and Czech parts of the Elbe catchment areas. We present a system of demographic and economic models, designed to consistently project socio-economic developments at a national and sub-national level and, thus, to quantitatively illustrate our scenarios. The results show that in a scenario that assumes continued globalisation and emphasis on economic growth, export orientation will result in a comparatively high share of manufacturing. Growth spreads from centres to peripheral regions. Still, at the national level, the increase in population and employment will be modest and create little additional pressure, but water stress will be considerably stronger on a regional basis, namely in metropolitan areas such as Prague, Berlin and Hamburg. In a scenario where economic goals are balanced with ecologic and social ones, growth is weaker and the weight of the service sector increases more rapidly, thus easing the driving forces for overall water demand and pollution. However, as in this scenario regional metropolitan centres develop at the cost of peripheral regions, regional development is more selective and the driving forces for potential water stress will diverge spatially.     

A review of traffic-related air pollution exposure assessment studies in the developing world

Exposure assessment studies in the developing world are important. Although recent years have seen an increasing number of traffic-related pollution exposure studies, exposure assessment data on this topic are still limited. Differences among measuring methods and a lack of strict quality control in carrying out exposure assessment make it difficult to generalize and compare findings between studies. In this article, exposure assessment studies carried out in the developing world on several traffic-related air pollutants are reviewed. These pollutants include particulate matter (PM), carbon monoxide (CO), nitrogen dioxide (NO(2)), volatile organic compounds (VOCs), and polycyclic aromatic hydrocarbons (PAHs). In addition, it discusses advantages and disadvantages of various monitoring methods (ambient fixed-site monitoring, microenvironment monitoring, and personal exposure assessment using portable samplers) for these pollutants in exposure assessment studies. Also included in this paper is a brief introduction of standards for these pollutants in ambient air or in occupational settings established by the United States Environmental Protection Agency (USEPA), the United States Occupational Safety and Health Administration (OSHA) and the World Health Organization (WHO). The review ends with a summary of the limitations and gaps in recent studies and suggestions for future research in the developing world.     

Critical factors in assessing exposure to PBDEs via house dust

Assessment of indoor exposure to polybrominated diphenyl ethers (PBDEs) requires a critical examination of methods that may influence exposure estimates and comparisons between studies. We measured PBDEs in residential dust collected from 20 homes in Boston, MA, to examine 5 key questions: 1) Does the choice of dust exposure metric-e.g., concentration (ng/g) or dust loading (ng/m2)-affect analysis and results? 2) To what degree do dust concentrations change over time? 3) Do dust concentrations vary between rooms? 4) Is the home vacuum bag an acceptable surrogate for researcher-collected dust? 5) Are air and dust concentrations correlated for the same room? We used linear mixed-effects models to analyze the data while accounting for within-home and within-room correlations. We found that PBDE dust concentration and surface loading were highly correlated (r=0.86-0.95, p<0.001). Average dust concentrations did not significantly differ over an 8-month period, possibly because home furnishings changed little over this time. We observed significant differences between rooms in the same home: PBDE concentrations in the main living area were 97% higher than the bedroom for decaBDE (p=0.02) and 72% higher for pentaBDE (p=0.05). Home vacuum bag dust concentrations were significantly lower than researcher-collected dust and not strongly correlated. Air (vapor and particulate phase) and dust concentrations were correlated for pentaBDE (p=0.62, p<0.01), but not for decaBDE (p=0.25). In addition, potential markers of BDE 209 debromination (BDE 202 and the BDE197:BDE201 ratio) were also observed in household dust samples. One vacuum bag sample contained the highest concentrations of BDE 209 (527,000 ng/g) and total PBDEs (544,000 ng/g) that have been reported in house dust.     

Assessing relative vulnerability to sea-level rise in the western part of the Mekong River Delta in Vietnam

The Mekong River Delta in Vietnam plays a crucial role for the region in terms of food security and socioeconomic development; however, it is one of the most low-lying and densely populated areas in the world. It is vulnerable to seawater incursion, flood risk, and shoreline change, exacerbated as a consequence of sea-level rise (SLR) related to climate change. This study examined the Kien Giang coast in the western part of the delta, comprising seven coastal districts (namely Ha Tien, Kien Luong, Hon Dat, Rach Gia, Chau Thanh, An Bien, and An Minh), the economy of which is important in terms of agriculture and aquaculture. The analytical hierarchical process (AHP) method of multi-criteria decision making was integrated directly into geographic information systems (GIS) to derive a composite vulnerability index that indicated areas most likely to be vulnerable to SLR. The hierarchical structure comprised three key components: exposure (E), sensitivity (S), and adaptive capacity (A), at level 1. At the next level, 8 sub-components were mapped: seawater incursion, flood risk, shoreline change, population characteristics, land use/land cover, and socioeconomic, infrastructure, and technological capability, beyond which a further 22 variables (level 3) and 24 sub-variables (level 4) related to vulnerability were also mapped. Variables were assigned weights for incorporation into AHP pairwise comparisons after discussion with stakeholders. Maps were generated to visualise areas where the relative vulnerability was very low, low, moderate, high, and very high. Societal data were generally only available at district level; however, several regional patterns emerged. Relatively high exposure to flooding and inundation, salinity, and moderate loss of mangroves occurred along the coastal fringe of each district. This western section of the delta, which is low-lying and remote from the distributaries that carry sediment to the coast, appears to be particularly vulnerable. The most sensitive areas tended to be ethnic households engaged in rice cultivation and with moderate population density. The least adaptable areas consisted of high numbers of poor households, with low income, and moderate densities of transport, irrigation and drainage systems. Most coastal districts were determined to be moderately to relatively highly vulnerable, with scattered hotspots along the coast.     

努鲁儿虎贫困山区生态环境综合治理方略探讨

努鲁儿虎贫困山区虽经多年治理,生态环境仍恶化,严重地制约当地经济的发展。为改善生态环境,必须正视本区缺粮食、缺资本、缺人才的区情,绿化工程建设必须紧紧围绕解决当地人民脱贫致富这一中心才有生命力,才有持久的后劲;必须营造适合当地具有生态经济效益的树(草)种;必须坚持谁种谁有,谁经营谁得利的政策;必须改变以往造林中“输血”型投资,为“造血”型投资等一系列方略。