Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Urbanization”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 415 records · Page 23Linked to original sources
PubMed2005

Urban health: evidence, challenges, and directions.

Urbanization is one of the most important demographic shifts worldwide during the past century and represents a substantial change from how most of the world's population has lived for the past several thousand years. The study of urban health considers how characteristics of the urban environment may affect population health. This paper reviews the empirical research assessing urban living's impact on population health and our rationale for considering the study of urban health as a distinct field of inquiry. The key factors affecting health in cities can be considered within three broad themes: the physical environment, the social environment, and access to health and social services. The methodologic and conceptual challenges facing the study of urban health, arising both from the limitations of the research to date and from the complexities inherent in assessing the relations among complex urban systems, disease causation, and health are discussed.

Causality↗
PubMed1990

Convergence in world urbanization? A quantitative assessment.

"Cross-national data are used to explore the question of whether world urban patterns and processes are converging or diverging. We compare tabular data on overall percent urban, urban primacy, overurbanization, and urban bias across world-system strata and global regions. The evidence suggests continuing differences and little evidence for convergence. To determine whether world-system effects have causal efficacy, we conclude with a regression analysis. These results provide strong evidence for a world-system explanation of continuing differences in overall level of urbanization and urban primacy, and a developmentalist approach seems to explain persisting divergence in levels of urban bias."

Demography↗
PubMed2005

Biosolids compost amendment for reducing soil lead hazards: a pilot study of Orgro amendment and grass seeding in urban yards.

In situ inactivation of soil Pb is an alternative to soil removal and replacement that has been demonstrated in recent years at industrial sites with hazardous soil Pb concentrations. Most children exposed to elevated soil Pb, however, reside in urban areas, and no government programs exist to remediate such soils unless an industrial source caused the contamination. Modern regulated biosolids composts have low Pb concentrations and low bioaccessible Pb fractions and can improve grass growth on urban soils. High Fe and P biosolids composts can reduce the bioavailability and bioaccessibility of soil Pb and can aid in establishing vegetation that would reduce soil transfer into homes. For these reasons, we conducted a field test of their use to reduce Pb bioaccessibility in urban soils in Baltimore, MD USA. We chose biosolids compost for its expected reduction in the bioaccessible Pb fraction of urban soils, ease of use by urban residents, and ability to beautify urban areas. Nine urban yards with mean soil Pb concentrations >800 mg Pb kg(-1) were selected and sampled at several distances from the house foundation before soil treatment. The soils were rototilled to 20 cm depth to prepare the sites, and resampled. The yards were then amended with 6-8 cm depth of Orgro biosolids compost (110-180 dry t/ha) rich in Fe and P, mixed well by rototilling, and resampled. Kentucky bluegrass (Poa pratensis) was seeded and became well established. Soils were resampled 1 year later. At each sampling time, total soil Pb was measured using a modified U.S. EPA nitric acid hotplate digestion method (SW 846 Method 3050) and bioaccessible Pb fraction was measured using the Solubility/Bioaccesibility Research Consortium standard operating procedure with modifications, including the use of glycine-buffered HCl at pH 2.2. Samples of untreated soils were collected from each yard and mixed well to serve as controls for the Pb bioaccessibility of field treated soils over time independent of positional variance within yards. At 1-year post-treatment, grass cover was healthy and reductions in bioaccessible Pb concentrations compared to pre-tillage were 64% (from 1655 to 595 mg kg(-1)) and 67% (from 1381 to 453 mg kg(-1)) at the sampling lines closest to the houses. Little or no reduction in bioaccessible Pb concentration was observed at sampling lines more remote from the house that also had the lowest bioaccessible Pb concentrations at pre-tillage (620 and 436 mg kg(-1), respectively). For the control soils, changes over time in total Pb and bioaccessible Pb concentrations and the bioaccessible Pb fraction were insignificant. This study confirms the viability of in situ remediation of soils in urban areas where children are at risk of high Pb exposure from lead in paint, dust and soil.

Biological Availability↗
PubMed2004

Comparative PM10-PM2.5 source contribution study at rural, urban and industrial sites during PM episodes in Eastern Spain.

In this study a set of 340 PM10 and PM2.5 samples collected throughout 16 months at rural, an urban kerbside and an industrial background site (affected by the emissions from the ceramic manufacture and other activities) were interpreted. On the regional scale, the main PM10 sources were mineral dust (mainly Al2O3, Fe, Ti, Sr, CaCO3, Mg, Mn and K), emissions derived from power generation (SO4=, V, Zn and Ni), vehicle exhausts (organic and elemental carbon, NO3- and trace elements) and marine aerosol (Na, Cl and Mg). The latter was not identified in PM2.5. At the industrial site, additional PM10 sources were identified (tile covering in the ceramic production, petrochemical emissions and bio-mass burning from a large orange tree cultivation area). The contribution of each PM source to PM10 and PM2.5 levels experiences significant variations depending on the type of PM episode (Local-urban mainly in autumn-winter, regional mainly in summer, African or Atlantic episode), which are discussed in this study. The results show that it would be very difficult to meet the EU limit values for PM10 established for 2010. The annual mean PM levels are 22.0 microg PM10/m3 at the rural and 49.5 microg PM10/m3 and 33.9 microg PM2.5/m3 at the urban site. The natural contribution in this region, estimated at 6 microg/m3 of natural mineral dust (resulting from the African events and natural resuspension) and 2 microg/m3 of marine aerosol, accounts for 40% of the 2010 EU annual limit value (20 microg PM10/m3). Mineral dust concentrations at the urban and industrial sites are higher than those at the rural site because of the urban road dust and the ceramic-production contributions, respectively. At the urban site, the vehicle exhaust contribution (17 microg/m3) alone is very close to the 2010 EU PM10 limit value. At the rural site, the African dust is the main contributor to PM10 levels during the highest daily mean PM10 events (100th-97th percentile range). At the urban site, the vehicle exhaust product is the main contributor to PM10 and PM2.5 levels during the highest daily mean PM events (100th-85th percentile range). Mineral dust concentrations during African dust events accounts for 20-30 microg/m3 in PM10 and 10-15 microg/m3 in PM2.5. During non-African dust events, mineral dust derived from anthropogenic activities (e.g. urban road dust) is also a significant contributor to PM10, but not to PM2.5.

Air Pollutants↗
PubMedDate not supplied

A comparison of rural and urban Emergency Medical System (EMS) personnel: a Texas study.

INTRODUCTION: In treating accident victims, actions by the Emergency Medical Personnel (EMP) at the scene may be the difference between life or death, full recovery or permanent disability. Development of selected profiles based on locale of services, tenure, and paramedic certification will provide valuable insight into the diversity within the Emergency Medical Services (EMS) profession. Not only will these profiles enable administrators to improve their recruitment, training, and retention of the emergency medical workforce, it potentially could enhance the quality of health care in the community. POPULATION: Emergency medical personnel attending a statewide conference in Texas in late 1996 (n = 425). HYPOTHESES: 1) There is no difference between the profiles of urban and rural EMP; 2) There is no difference between the profiles of urban EMP with < 9 years of experience and those with > or = 9 years of experience; 3) There is no differences between the profiles of rural EMP with < 9 years of experience and those with > or = 9 years of experience. 4) There is no difference between the profiles of urban EMP with paramedic certification and those without certification; and 5) There is no difference between the profiles of rural EMP with paramedic certification and those without certification. METHODS: EMP attending the conference completed 425 survey instruments measuring five demographic features, five work-related features, and two psychological features. Survey instruments were included in each registrant's conference package. Completed surveys were deposited anonymously in labeled receptacles throughout the statewide conference site. Data collection ceased at the end of the conference. Discriminant analysis identified distinct profiles for the urban and rural EMP. RESULTS: The urban EMP, more than rural subjects, was younger (mean = 36 years), more likely to be compensated 100% for their services, had a higher level of education (mean = 13.8 years), and reported a lower level of burnout. Urban EMP with < 9 years of experience tended to be younger, male, married, and reported less burnout. Urban paramedics were more likely to be compensated 100% for their services, and had achieved a higher level of education. The rural EMP with < 9 years of experience were less likely to be paramedic, reported lower burnout scores, and was younger. The rural EMP without paramedic certification was more likely to be a volunteer, and have had fewer years of service. CONCLUSIONS: In Texas, locale of service (urban or rural), length of tenure as an EMP (> or = 9 years), and paramedic certification appear to be significant factors that define the EMP population in Texas.

Adult↗
PubMed2005

Development and application of an urban tree air quality score for photochemical pollution episodes using the Birmingham, United Kingdom, area as a case study.

An atmospheric chemistry model (CiTTyCAT) is used to quantify the effects of trees on urban air quality in scenarios of high photochemical pollution. The combined effects of both pollutant deposition to and emission of biogenic volatile organic compounds (BVOC) from the urban forest are considered, and the West Midlands, metropolitan area in the UK is used as a case study. While all trees can be beneficial to air quality in terms of the deposition of O3, NO2, CO, and HNO3, some trees have the potential to contribute to the formation of O3 due to the reaction of BVOC and NOx. A number of model scenarios are used to develop an urban tree air quality score (UTAQS) that ranks trees in order of their potential to improve air quality. Of the 30 species considered, pine, larch, and silver birch have the greatest potential to improve urban air quality, while oaks, willows, and poplars can worsen downwind air quality if planted in very large numbers. The UTAQS classification is designed with practitioners in mind, to help them achieve sustainable urban air quality. The UTAQS classification is applicable to all urban areas of the UK and other mid-latitude, temperate climate zones that have tree species common to those found in UK urban areas. The modeling approach used here is directly applicable to all areas of the world given the appropriate input data. It provides a tool that can help to achieve future sustainable urban air quality.

Air↗
PubMed2003

Urban geochemistry: a multimedia and multielement survey of a small town in northern Europe.

The concentrations and distributions of chemical elements (Ag, Al, As, Au, Ba, Bi, Ca, Cd, Co, Cr, Cu, Fe, Ga, Hg, K, La, Mg, Mn, Mo, Na, Ni, P, Pb, S, Sb, Sc, Se, Sr, Te, Th, Ti, Tl, U, V, W and Zn) were studied in till, humus and urban soil in Jakobstad, a small town (20,000 inhabitants) in W. Finland. The analyses were performed with ICP-MS after aqua regia leaching of till (n = 37), urban topsoil (n = 32) and subsoil (n = 32), and HNO3 leaching of humus (n = 37). The till and humus samples, collected at the same sites, were divided into urban and rural samples. The urban till was not significantly enriched in metals. In contrast, a majority of the elements occurred in higher concentrations in the urban than the rural humus samples. Statistical and spatial interpretations of the humus data revealed that traffic (Pb, V and Ni), metal industry (Pb, Zn, Bi, Sb and Cr), an abandoned shooting range (Pb and Sb) and other sources contribute to higher metal levels in the urban humus. The urban soil samples were collected at parks, yards, abandoned industrial sites, roadsides, etc. The topsoil samples were enriched in most elements, also by elements not enriched in the urban humus (e.g. Cd). At several sites, the concentrations far exceeded the limit concentrations for contaminated soils in Finland. A large variety of sources were identified or indicated.

Cities↗
PubMed2004

Do students from rural backgrounds engage in rural family practice more than their urban-raised peers?

INTRODUCTION: In a previous prospective study, students from rural backgrounds were found to be significantly more likely to consider rural practice than their urban-raised peers. The purpose of this study was to determine whether the students with rural backgrounds who participated in the original investigation were more likely than their urban-raised peers to be currently engaged in rural family practice. METHOD: In Canada, family doctors have the greatest opportunity to practise in rural communities. Consequently, rural and urban background students from the original study who entered the discipline of family medicine as a career were identified for practice location follow-up. Participants were categorised as either rural (population less than 10 000) or urban practitioners according to the population of the community in which they practised. The proportion of rural and urban background students engaged in rural or urban practice was analysed using chi-square and relative risk probability. RESULTS: A total of 78 students from the original cohort were found to be practising family medicine; 22 of them had been rurally raised. Seven (32%) of the rural background students were practising in a rural community, compared to 7 (13%) of the 56 urban background students (RR = 2.55; P < 0.05). CONCLUSIONS: Rural background students who went on to complete family medicine residency training were approximately 2.5 times more likely to be engaged in rural practice than their urban-raised peers. Altering medical school admission policy to recruit more rural background applicants should be part of a multi-dimensional approach to increasing the number of rural practitioners.

Canada↗
PubMed2003

The city-fox phenomenon: genetic consequences of a recent colonization of urban habitat.

The red fox (Vulpes vulpes) is one of the best-documented examples of a species that has successfully occupied cities and their suburbs during the last century. The city of Zurich (Switzerland) was colonized by red foxes 15 years ago and the number of recorded individuals has increased steadily since then. Here, we assessed the hypothesis that the fox population within the city of Zurich is isolated from adjacent rural fox populations against the alternative hypothesis that urban habitat acts as a constant sink for rural dispersers. We examined 11 microsatellite loci in 128 foxes from two urban areas, separated by the main river crossing the city, and three adjacent rural areas from the region of Zurich. Mean observed heterozygosity across individuals and the number of detected alleles were lower for foxes collected within the city as compared with their rural conspecifics. Genetic differentiation was significantly lower between rural than between rural and urban populations, and highest value of pairwise FST was recorded between the two urban areas. Our results indicate that the two urban areas were independently founded by a small number of individuals from adjacent rural areas resulting in genetic drift and genetic differentiation between rural and urban fox populations. Population admixture and immigration analysis revealed that urban-rural gene flow was higher than expected from FST statistics. In the five to seven generations since colonization, fox density has dramatically increased. Currently observed levels of migration between urban and rural populations will probably erode genetic differentiation over time.

Alleles↗
PubMed1998

Effects of parental history of hypertension and urbanization on blood pressure in Zimbabweans.

The increasing prevalence of essential hypertension is a growing public health concern for Zimbabwe and other African countries. Two important risk factors for hypertension are urbanization and parental history of hypertension. The relations among parental history of hypertension, urbanization, and blood pressures (BPs) are poorly understood. The objective of this study is to clarify these relations in a population of urbanized, African, young adults. The relation between parental history of hypertension and urbanization on resting BP's and Bp responses to a mental arithmetic stressor was examined in a group of normotensive, Black medical students with (n = 36) and without (n = 34) a parental history of high BP, and with (n = 49) and without (n = 19) a parental history of urbanization. Results indicate that those with a positive parental history counterparts. Further, those with parents residing in urban areas had higher resting SBPs than those with parents residing in rural areas. However, no reactivity differences were apparent between the urban and rural parent groups. These data suggest that although parental history for hypertension influences both resting and reactivity BP's parental history of urbanization may influence only resting BP.

Journal Article↗
PubMedDate not supplied

Denitrification potential in urban riparian zones.

Denitrification, the anaerobic microbial conversion of nitrate (NO3-) to nitrogen (N) gases, is an important process contributing to the ability of riparian zones to function as "sinks" for NO3- in watersheds. There has been little analysis of riparian zones in urban watersheds despite concerns about high NO3- concentrations in many urban streams. Vegetation and soils in urban ecosystems are often highly disturbed, and few studies have examined microbial processes like denitrification in these ecosystems. In this study, we measured denitrification potential and a suite of related microbial parameters (microbial biomass carbon [C] and N content, potential net N mineralization and nitrification, soil inorganic N pools) in four rural and four urban riparian zones in the Baltimore, MD metropolitan area. Two of the riparian zones were forested and two had herbaceous vegetation in each land use context. There were few differences between urban and rural and herbaceous and forest riparian zones, but variability was much higher in urban than rural sites. There were strong positive relationships between soil moisture and organic matter content and denitrification potential. Given the importance of surface runoff in urban watersheds, the high denitrification potential of the surface soils that we observed suggests that if surface runoff can be channeled through areas with high denitrification potential (e.g., stormwater detention basins with wetland vegetation), these areas could function as important NO3- sinks in urban watersheds.

Bacteria, Anaerobic↗
PubMedDate not supplied

Urban-rural differences in amitriptyline use among nursing facility residents.

OBJECTIVE: To characterize patterns of amitriptyline use across the urban-rural continuum. DESIGN: Retrospective analysis of antidepressant drug codes and demographic and clinical data from the Minimum Data Set (MDS), 1994 to 1997. SETTING: Kansas nursing facilities. PARTICIPANTS: Facility residents aged 65 and older. MEASURES: A four-strata system was used to classify nursing facility location by county, from urban to frontier. We examined admission use and after-admission use of amitriptyline across strata for each year separately. Unadjusted and adjusted odds ratios were determined for each stratum, using the urban stratum as the point of reference. RESULTS: Admission use of amitriptyline occurred in 2.3 to 4% of all admissions, and although such use was highest in the most rural stratum, no clear urban-rural gradient was found. In contrast, amitriptyline use 30 days or more after admission demonstrated modest urban-rural gradients in unadjusted and adjusted analyses. In 1997, when adjusted for demographic factors, odds ratios for amitriptyline use were 2.10 (1.54-2.87), 1.68 (1.33-2.13), and 1.49 (1.17-1.90) for the Frontier, Rural, and Densely Settled Rural categories as compared with the Urban reference group. CONCLUSIONS: After admission to Kansas nursing facilities, rural practice patterns for amitriptyline use are less favorable than those in urban areas, and an urban-rural gradient is identified. Further work is needed to identify explanatory patient, facility, and prescriber factors.

Journal Article↗
PubMed2003

Urban drainage and highway runoff in cold climates: conference overview.

This overview of research findings presented at the conference on urban drainage and highway runoff in cold climates starts with generation of urban runoff and snowmelt, followed by snowmelt and winter runoff quality, best management practices for urban snowmelt and winter runoff, and snow management in urban areas. Research on the urban hydrological cycle is lagging behind the needs in this field, particularly in terms of data availability. The current studies of winter urban runoff quality focus on road salts in the urban environment and their environmental effects. The needs for better source controls in salt applications, improved management of chloride-laden runoff, and selective adoption of environmentally safer alternative de-icers were reported. Adaptation of the conventional stormwater best management practices (BMPs) for winter operation remains a challenge. The first step in refining the existing BMPs for winter operation is to advance the understanding of their operation, as reported for some cases at the conference. Finally, snow management in urban areas may require local storage of fresh (unpolluted) snow and disposal of more polluted snow at central snow disposal sites.

Cities↗
PubMed2003

[Ecological benefit assessment of urban vegetations by remote sensing and GIS].

As an important part of the urban ecosystem, urban vegetation plays an important role in improving urban environmental quality. The assessment of ecological benefits of urban or regional vegetations can help us more properly plan urban green space pattern, optimize urban vegetation structure, and further strengthen ecological construction. Through the discussion of the relevant researches at home and abroad, it's indicated that remote sensing and GIS could help as better evaluate the ecological effect of urban vegetations. This article introduced the UEA method adopted by AMERICAN FORESTS and CITYgreen software working with ArcView 3.2, as to make the best use of remote sensing and GIS in evaluating urban vegetation ecological effect quantitatively, and to promote sustainable development and ecological construction.

City Planning↗
PubMed2003

Identification of ecologically significant habitats for urban nature conservation: a case study in Turkey.

Given the rapid urbanization of Turkey, sustained productivity of natural resources should be an integral part of any urban development policy. The biogeochemical cycles and ecosystem services link urban and rural ecosystems. It is, therefore, essential that ecologically significant habitats along urban-rural continuum be protected to secure public and environmental health. This necessitates their identification and the establishment of administrative and legal foundations for urban nature conservation in the management of urban habitats, should be established Ecological analysis of urban habitats of Karşiyaka led to the identification of 19 ecologically significant habitats. Nature conservation priority was rated, using rarity, species richness, stratification, site age, and area of the habitats. Ecologically significant habitats made up about 54 ha of the total urban green space of 289 ha in Karşiyaka. The total number of plant species was estimated to be 273.

Animals↗
PubMed2005

Sustainable sanitation and water in small urban centres.

The objective of this paper is to review the global trends in urbanization with respect to availability of adequate sanitation and water supply services. Urbanization is unrelenting and rapid increase in the urban population in the less developed countries is of major global concern regarding this topic of sustainable sanitation and water. Most global urban growth is in the smaller cities and in the developing world. Half the urban developing world lacks adequate water and sanitation. Global urban access to waterborne sanitation is not affordable and thus is not a realistic option so alternative approaches are necessary. The treatment of drinking water cannot be a substitute for sanitation. In order to achieve sustainable sanitation, a change in attitude about human excreta and use of water is required. Essential features of a sustainable sanitation system are: containment, sanitisation and recycling. To improve water supply, we need to improve management practices, use full-cost pricing, introduce watershed approaches to protection and provide improved sanitation. Small urban initiatives need to go beyond the traditional sectors and new initiatives are required like on-site urban ecostations, source-separation of urine and faeces, decentralised greywater treatment and integration of sanitation into the cost of housing.

Cities↗
PubMed2006

Urban-rural differentials in child malnutrition: trends and socioeconomic correlates in sub-Saharan Africa.

This paper examines levels and trends of urban-rural differentials in child malnutrition, and investigates whether residual differences exist between urban and rural areas, given comparable measures of socioeconomic status (SES) of households and communities. Using data from Demographic and Health Surveys of 15 sub-Saharan African countries, and multilevel modelling, it shows that urban-rural differentials are considerable in all countries, that they have narrowed in most countries due primarily to an increase in urban malnutrition, and have widened in few countries as a result of sharp decline in urban malnutrition. These urban-rural gaps are abolished in almost all countries when SES is controlled. These results suggest that policies and programs contributing to the attainment of the MDGs should pay particular attention to the urban poor.

Africa South of the Sahara↗
PubMed2002

Rural-urban differences in health risks, resource use and expenditures within three state medicaid programs: implications for medicaid managed care.

This study uses Medicaid claims data for income-eligible enrollees in California, Georgia and Mississippi to compare expenditures, resource usage and health risks between residents of rural and urban areas of the states. Resource use is measured using the Resource Based Relative Value Scale (RBRVS) system for professional services, hospital days and outpatient facility visits; it also is valued at private insurance reimbursement rates for the states. Health risks are measured using the diagnosis-based Adjusted Clinical Group system. Resource use is compared on a risk-adjusted basis with the use of urban Medicaid enrollees as the benchmark. We find that actual expenditures for rural care users are lower than for urban care users. However, because the proportion of Medicaid enrollees who use care is higher in rural than in urban areas in all three states, expenditures per rural enrollee are not consistently lower. Case mix is more resource intensive for rural compared to urban residents in all three states. Although resource usage is not systematically lower overall for rural enrollees, on a risk-adjusted basis they tend to use less hospital resources than urban enrollees. Capitation rates based on historical per enrollee expenditures would not appear to under-reimburse managed care organizations for the care of rural as opposed to urban residents in the study states.

California↗