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1.
Urban community gardens provide affordable, locally grown, healthy foods and many other benefits. However, urban garden soils can contain lead (Pb) that may pose risks to human health. To help evaluate these risks, we measured Pb concentrations in soil, vegetables, and chicken eggs from New York City community gardens, and we asked gardeners about vegetable consumption and time spent in the garden. We then estimated Pb intakes deterministically and probabilistically for adult gardeners, children who spend time in the garden, and adult (non-gardener) household members. Most central tendency Pb intakes were below provisional total tolerable intake (PTTI) levels. High contact intakes generally exceeded PTTIs. Probabilistic estimates showed approximately 40 % of children and 10 % of gardeners exceeding PTTIs. Children’s exposure came primarily from dust ingestion and exposure to higher Pb soil between beds. Gardeners’ Pb intakes were comparable to children’s (in µg/day) but were dominated by vegetable consumption. Adult household members ate less garden-grown produce than gardeners and had the lowest Pb intakes. Our results suggest that healthy gardening practices to reduce Pb exposure in urban community gardens should focus on encouraging cultivation of lower Pb vegetables (i.e., fruits) for adult gardeners and on covering higher Pb non-bed soils accessible to young children. However, the common practice of replacement of root-zone bed soil with clean soil (e.g., in raised beds) has many benefits and should also continue to be encouraged.  相似文献   

2.
Fifty-two samples of surface soils were taken in the urban area of Seville, to assess the possible influence of different land uses on their metal contents and their relationship with several soil properties. The samples corresponded to five categories or land uses: agricultural, parks, ornamental gardens, riverbanks, and roadsides. Sequential extraction of metal according to the procedure proposed by the former Community Bureau of Reference (BCR) was carried out, and pseudo-total (aqua regia soluble) metal contents were determined. Lower organic C, total N and available P and K contents were found in riverbank samples, probably due to the lack of manuring of those sites, left in a natural status. In contrast, significantly higher electrical conductivity was found in those sites, due to the tidal influence of the nearby Atlantic Ocean. Other land uses did not show significant differences in the general properties. Concentrations of Cu, Pb and Zn, both aqua-regia soluble and sequentially extracted, were clearly higher in soils from ornamental gardens, whereas the concentrations in the riverbank samples were slightly lower than the other categories. In contrast, other metals (Cd, Cr, Fe, Mn, Ni) were uniformly distributed throughout all land uses. A strong statistical association is found among the concentrations of Cu, Pb, Zn and organic C, suggesting that the larger contents of these metals in ornamental gardens are partly due to organic amendments added to those sites more frequently than to other kinds of sites. Considering the conclusions of previous studies, heavy traffic can also contribute to those `urban’ metals in urban soils. Periodic monitoring of the concentrations of urban metals in busy city centres and of the quality of amendments added to soils of recreational areas are recommended.  相似文献   

3.
Previous studies evaluating the welfare cost of air pollution have not paid much attention to its potential effect on mental health and subjective well-being (SWB). This paper attempts to fill the gap by investigating the impact of air pollution on several key dimensions, including mental health status, depressive symptoms, moment-to-moment happiness, and evaluative happiness. We match a nationwide longitudinal survey in China with local air quality and rich weather conditions according to the exact time and place of survey. By making use of variations in exposure to air pollution for the same individuals over time, we show that air pollution reduces hedonic happiness and increases the rate of depressive symptoms, while life satisfaction has little to do with the immediate air quality. Our results shed light on air pollution as an important contributor to the Easterlin paradox that economic growth may not bring more happiness.  相似文献   

4.
Global insect pollinator declines have prompted habitat restoration efforts, including pollinator-friendly gardening. Gardens can provide nectar and pollen for adult insects and offer reproductive resources, such as nesting sites and caterpillar host plants. We conducted a review and meta-analysis to examine how decisions made by gardeners on plant selection and garden maintenance influence pollinator survival, abundance, and diversity. We also considered characteristics of surrounding landscapes and the impacts of pollinator natural enemies. Our results indicated that pollinators responded positively to high plant species diversity, woody vegetation, garden size, and sun exposure and negatively to the separation of garden habitats from natural sites. Within-garden features more strongly influenced pollinators than surrounding landscape factors. Growing interest in gardening for pollinators highlights the need to better understand how gardens contribute to pollinator conservation and how some garden characteristics can enhance the attractiveness and usefulness of gardens to pollinators. Further studies examining pollinator reproduction, resource acquisition, and natural enemies in gardens and comparing gardens with other restoration efforts and to natural habitats are needed to increase the value of human-made habitats for pollinators.  相似文献   

5.
The generation of ecosystem services depends on both social and ecological features. Here we focus on management, its ecological consequences, and social drivers. Our approach combined (1) quantitative surveys of local species diversity and abundance of three functional groups of ecosystem service providers (pollinators, seed dispersers, and insectivores) with (2) qualitative studies of local management practices connected to these services and their underlying social mechanisms, i.e., institutions, local ecological knowledge, and a sense of place. It focused on the ecology of three types of green areas (allotment gardens, cemeteries, and city parks) in the city of Stockholm, Sweden. These are superficially similar but differ considerably in their management. Effects of the different practices could be seen in the three functional groups, primarily as a higher abundance of pollinators in the informally managed allotment gardens and as differences in the composition of seed dispersers and insectivores. Thus, informal management, which is normally disregarded by planning authorities, is important for ecosystem services in the urban landscape. Furthermore, we suggest that informal management has an important secondary function: It may be crucial during periods of instability and change as it is argued to promote qualities with potential for adaptation. Allotment gardeners seem to be the most motivated managers, something that is reflected in their deeper knowledge and can be explained by a sense of place and management institutions. We propose that co-management would be one possible way to infuse the same positive qualities into all management and that improved information exchange between managers would be one further step toward ecologically functional urban landscapes.  相似文献   

6.
Municipal solid waste management was studied for 1 year in a representative urban area of Lahore city for environmental sustainability. The effects of financial status of the household and the seasonal variations on generation rate and compositions of municipal solid waste (MSW) were determined. MSW generation rate and the economic status of the households were positively correlated (p < 0.05). Seasonal variations observed were significant only for organics (p = 0.001), plastics (p = 0.008) and food waste fractions (p = 0.009) in MSW. Response surface regression model developed and analysed by Minitab-15® showed that the interaction of season and different economic zones of the town on the MSW generation rate was non-significant (p = 0.334). Elemental and heating value analyses of the mixed organic fractions in kitchen waste had carbon 47.93%, hydrogen 6.20%, nitrogen 2.24%, sulphur 0.23%, oxygen 39.01%, and C and N ratio 27.78. Findings concluded that food waste was 56% of total MSW with 71.03% moisture content and a modest heating value of 5566 J/g. Existing temporary storage capacity of MSW is 51% of the total MSW generated considering the weighted MSW generation rate of 0.57 kg/person/day calculated in this study. Composting could be a possible final disposal option due to high moisture and organic content and can be studied in future research. Development of a transfer station, introduction of home composting programmes and awareness towards proper segregation and reduction of waste at the household level is suggested to attain sustainability in the MSW management system.  相似文献   

7.
Many conservation interventions are hypothesized to be beneficial for both the environment and people's well-being, but this has rarely been tested rigorously. We examined the effects of adoption or nonadoption of a conservation intervention on 3 dimensions of people's well-being (material, relational, and subjective) over time. We focused on a fisheries bycatch management initiative intended to reduce environmental externalities associated with resource extraction. We collected panel data from fishers (n = 250) in villages with (adopters and nonadopters) and without (control) the conservation intervention 3 times over 2 years. We found no evidence that adoption reduced any of the 3 dimensions of well-being in the local populations affected by the intervention. There were modest improvements in material (t = –1.58) and subjective livelihood well-being (p = 0.04) for adopters relative to nonadopters over time. The variations in well-being experiences (in terms of magnitude of change) among adopters, nonadopters, and controls across the different domains over time affirmed the dynamic and social nature of well-being.  相似文献   

8.
Mercury as a toxic element and its associated health hazard has been an important topic of research for urban pollution for many years. In this paper, the spatial distribution, pollution assessment, and health risk associated with Hg in roadside dust 96 street dust samples, representing differing land-uses, have been investigated. Land-uses included residential areas (RA), industrial areas (IA), public gardens (PG), roadside areas (RS), and suburban areas (SA) in the city of Ahvaz, Iran were investigated. Compared with other cities, the concentration of Hg in Ahvaz was considerably higher with a mean value of 2.53 mg kg?1, ranging from 0.02 to 8.75 mg kg?1. Residential areas exhibited higher Hg in street dust than other areas, as demonstrated by spatial mapping illustrating hot spots associated with old urban areas with high residential density, high volume traffic of roadside areas, and industrial districts: including oil-drilling activities, steel smelting-related industries, and small industrial towns around Ahvaz. However, Hg concentrations in street dust near to the public gardens (PG) and suburban areas (SA) were not at elevated levels compared other land-uses investigated in this study. A health risk assessment model of non-carcinogenic effects was evaluated for both children and adults. The HQ values also revealed that the main exposures route for children and adults decreased as follows: vapour > ingestion > dermal contact > inhalation. The hazard index (HI) in each area is less than the safe level (HI ≤ 1) for children and adults, but higher for children. The HI value decreases as the following order: RS > IA > RA > SA > PG, which indicates potentially serious health hazards for children in the study areas.  相似文献   

9.
Coastal systems are characterized by high geophysical and biophysical sensitivity as being their massive occupation a serious issue concerning their self-regulation. Worldwide coastal areas are exposed to problems such as coastal erosion, degradation and destruction of marine habitats, pollution and rising sea level. Thus, it is crucial to design models of coastal vulnerability assessment to ensure a better management of coastal areas. This study characterizes the vulnerability of the coastal stretch between the beaches of Porto de Mós and Falésia in the Algarve, corresponding to 52?km of the south coast of Portugal. The expansion of urban areas was modelled using a Cellular Automata (CA) based approach. Results show that 65% of the coastal stretch has high and very high vulnerability caused by both physical and human factors. Results further indicate that urban growth may interfere with the natural evolution of the coastal geomorphology. The scenario of urban expansion for the year 2015 highlights the need to develop effective urban planning processes to ensure a correct balance between the geophysical resilience of coastal systems and the promotion of the coastal sector as a strategic asset for the regional and national economy.  相似文献   

10.
Surface sediments were collected from the shore and lagoons of Kavaratti, Kadamat and Agatti islands of Lakshadweep Archipelago during May 2015 and analysed for the spatial distribution of the micronutrient element, phosphorus. Phosphorus was separated by sequential extraction procedure into five fractions – exchangeable (Ex-P), iron bound, (Fe-P), calcium bound (Ca-P), organic and residual fractions (OP) and total phosphorus (TP). The average relative contribution of each P species to TP was: OP?>?Ca –P?>?Ex – P?>?Fe – P. The high concentration of organic and residual phosphorus (87–96%) compared to inorganic phosphorus is particularly evident at stations characterised by higher total phosphorus concentrations. Among the three forms of IP in the sediments, Ca-P was dominant at all stations. The OC/OP ratio ranged from 3 to 163 in the sediments, suggesting that the organic matter in sediments had been subjected to degradation. Hence, the major contribution towards organic and residual phosphorus form is from the residual fraction comprising biologically resistant or non-available phosphorus form composed of refractory materials. The concentration of phosphorus reported in the present study is higher than that of the earlier studies in Lakshadweep, indicating a terrestrial and anthropogenic in?uence on the sediment.  相似文献   

11.
ABSTRACT

Rural communities worldwide face a decrease of critical ecosystem services caused by replacement of native forests by commercial plantations. Replacement of native forest by commercial plantations decreases water provisioning, with possible negative impacts over well-being. We tested this hypothesis in Central Chile. We assessed subjective well-being (SWB) and local perceptions of changes in forest cover and water provision among 78 rural families. We also assessed if the Shifting Baseline Syndrome (SBS) affects the perceptions of environmental changes and their implications in SWB. Individuals perceived less forest cover than 20 years ago, and this is seen as a factor of decreased livelihood, availability of forest products, and water provisioning for households. People also reported less water available than 20 years ago. The main drivers associated with decreased water provision were the establishment of pine plantations (44% of individuals) and drought (44%). A better-off SWB was associated with perception of lower rate of deforestation. The perceptions of forest degradation and its association to SWB are affected by SBS. Paradoxically, a better-off SWB was also associated with an improvement of water quality, although the quantity and quality of water have decreased according to biophysical data, which ought to decrease the SWB. Impacts of environmental degradation in SWB are masked by factors such as more infrastructure for drinking water, assisted by governments. This masking of environmental degradation reduces the opportunity to avoid negative impacts over well-being among rural communities that are dependent on assistance around the world.  相似文献   

12.
As part of a harmonised assessment of urban soils (), we investigated the variability of metal content in soils from Aveiro (Portugal) and Glasgow (UK). Samples were collected from parks and other public open spaces in each city. Metal content (Al, Ca, Cr, Cu, Fe, Mn, Ni, Pb and Zn) and basic soil parameters (texture, CEC, pH, organic matter) were determined and data investigated using principal component analysis (PCA). The two cities differ in absolute levels of metal content reflecting industrial and historical development. Factors identified by PCA included anthropogenic (Cu, Pb, Zn), soil properties and geology, which explain variability when data were assessed based on metal content, soil properties and land use. This study highlights the contribution from geological background even in strongly urbanised environments.  相似文献   

13.
Abstract: By 2050, 70% of the world's population will live in urban areas. In many cases urbanization reduces the richness and abundance of native species. Living in highly modified environments with fewer opportunities to interact directly with a diversity of native species may adversely affect residents’ personal well‐being and emotional connection to nature. We assessed the personal well‐being, neighborhood well‐being (a measure of a person's satisfaction with their neighborhood), and level of connection to nature of over 1000 residents in 36 residential neighborhoods in southeastern Australia. We modeled these response variables as a function of natural features of each neighborhood (e.g., species richness and abundance of birds, density of plants, and amount of vegetation cover) and demographic characteristics of surveyed residents. Vegetation cover had the strongest positive relations with personal well‐being, whereas residents’ level of connection to nature was weakly related to variation in species richness and abundance of birds and density of plants. Demographic characteristics such as age and level of activity explained the greatest proportion of variance in well‐being and connection to nature. Nevertheless, when controlling for variation in demographic characteristics (examples were provided above), neighborhood well‐being was positively related to a range of natural features, including species richness and abundance of birds, and vegetation cover. Demographic characteristics and how well‐being was quantified strongly influenced our results, and we suggest demography and metrics of well‐being must be considered when attempting to determine relations between the urban environment and human well‐being.  相似文献   

14.
The Ria Formosa lagoon, Portugal, receives organic matter from many natural and anthropogenic sources. This paper presents an overview of the contribution these sources made through the use of lipid biomarkers. Sixty-one surface sediment samples were collected and analysed for a range of lipids. Sewage materials were confined to regions within 2 km of discharge points; phytoplankton biomarkers (sterols and fatty acids) suggest production was greatest in the inner parts of the lagoon that also have greatest inorganic nutrient enrichment; terrestrial organic matter was present in relatively low concentrations as shown by both sterol and fatty alcohols; bacteria were widespread although the Sulphate Reducing Bacteria (SRBs, shown by the presence of 3-OH fatty acids) were located near but not adjacent to sewage discharge points.  相似文献   

15.
Raising chickens for eggs in urban areas is becoming increasingly common. Urban chickens may be exposed to lead, a common urban soil contaminant. We measured lead concentrations in chicken eggs from New York City (NYC) community gardens and collected information on factors that might affect those concentrations. Lead was detected between 10 and 167 μg/kg in 48 % of NYC eggs. Measures of lead in eggs from a henhouse were significantly associated (p < 0.005) with lead concentrations in soil. The association between soil and egg lead has been evaluated only once before, by a study of a rural region in Belgium. In our study, the apparent lead soil-to-egg transfer efficiency was considerably lower than that found in Belgium, suggesting that there may be important geographic differences in this transfer. We developed models that suggested that, for sites like ours, lead concentrations in >50 % of eggs from a henhouse would exceed store-bought egg concentrations (<7–13 μg/kg; 3 % above detection limit) at soil lead concentrations >120 mg/kg and that the concentration in one of six eggs from a henhouse would exceed a 100 μg/kg guidance value at soil lead concentrations >410 mg/kg. Our models also suggested that the availability of dietary calcium supplements was another influential factor that reduced egg lead concentrations. Estimates of health risk from consuming eggs with the lead concentrations we measured generally were not significant. However, soil lead concentrations in this study were <600 mg/kg, and considerably higher concentrations are not uncommon. Efforts to reduce lead transfer to chicken eggs and associated exposure are recommended for urban chicken keepers.  相似文献   

16.
The Ria Formosa lagoon, Portugal, receives organic matter from many natural and anthropogenic sources. This paper presents an overview of the contribution these sources made through the use of lipid biomarkers. Sixty-one surface sediment samples were collected and analysed for a range of lipids. Sewage materials were confined to regions within 2 km of discharge points; phytoplankton biomarkers (sterols and fatty acids) suggest production was greatest in the inner parts of the lagoon that also have greatest inorganic nutrient enrichment; terrestrial organic matter was present in relatively low concentrations as shown by both sterol and fatty alcohols; bacteria were widespread although the Sulphate Reducing Bacteria (SRBs, shown by the presence of 3-OH fatty acids) were located near but not adjacent to sewage discharge points.  相似文献   

17.
The concentrations of organic carbon (Corg), inorganic carbon (Cinorg), organic nitrogen (Norg) and total aromatic (AromT) were determined in 25 samples of bottom sediments from the Lake Valencia, Venezuela, as a contribution to the knowledge about pollution by organic compounds in tropical lakes. Results demonstrate that the Corg and Norg concentrations do not show the pollution indexes by themselves. This is a consequence of the masking effect of naturally derived organic matter from the decay of algae and organisms in the water column and terrestrial plants, which are transported to the lake. Nevertheless, the AromT concentrations and the normalised AromT (normalized to organic carbon) make it possible to detect organic matter of anthropogenic origin, in the AromT levels are about nine times higher than those natural. The variation in the band intensity of the IRFT spectra for some functional groups present in the saturate and aromatic hydrocarbon fractions gives an indication of anthropogenic contribution for some zones of the lake. With the 1H NMR spectra it was not possible to differentiate a natural source from an anthropogenic one in the lake. Naturally occurring organic compounds (eicosane, pentacosane, and hexacosane) were detected with GC technique in the saturated hydrocarbon fraction. The presence of an unresolved complex mixture (UCM) in the GC chromatograms indicates pollution by branched and cyclic hydrocarbons. These compounds are probably produced by the incomplete combustion of oil products. Potentially toxic organic compounds such as anthracene, phenanthrene and chrysene were found in the aromatic hydrocarbon fraction, which despite presenting low concentrations (ppb order) accumulate in the lake sediments along with the natural source organic matter. The main access paths of organic pollutants to the lake are the rivers which cross the two urban and industrial areas (Maracay and Valencia cities). The mixture of polluted sediments with bottom natural sediments and the autochthonous contribution of organic matter mitigate the pollution levels progressively towards the center of the lake.  相似文献   

18.
Coastal zones in Portugal, as interface areas between land and sea, have problems related to the growing human pressure in terms of changes in land use associated with urban and industrial occupation, new accessibility (ports, motorways) and traffic flows, intensification of recreational use (beaches, water sports) and excessive fishing. Impacts include deterioration of water quality and sediments; alteration and degradation of natural habitats; new hydrodynamic situations; major landscape changes: and rapid changes in habits and way of life of the local populations and increased exposure of populations and assets to natural and induced risks (storms, accidents, spills, explosions). Plans for the Management of the Coastal Zone (POOC) have been developed and seven of them have been approved, while two similar plans are at a final stage of preparation. Together they cover the entire coast of Portugal. Their implementation and assessment could be a first step towards an integrated management of the Portuguese coastal zones. River Basin Management Plans (PBH) have been concluded and recently approved for the whole country. However, these plans do not consider estuarine systems and some other issues related to coastal systems. The National Water Plan (PNA) is under public presentation and discussion. Several ‘key messages’ are presented in this paper as a contribution for assessment of the proposals of this plan on issues related with coastal waters.  相似文献   

19.
基于RS和GIS的长沙城市热岛效应与TSP污染耦合关系   总被引:2,自引:0,他引:2  
城市热岛效应反映了城市化发展对城市环境的影响,是影响城市生态环境的一个重要因素。文章以长沙市为例,利用3S技术与传统技术相结合对大气中总悬浮颗粒物(TSP)在城市热岛中的作用与贡献进行了研究。结果表明,长沙城市热岛效应与TSP污染在空间与时间分布上都具有耦合关系。采用RS和GIS技术可以从空间上对TSP在城市热岛中的贡献进行研究。长沙市TSP污染的分布特征和热岛强度分布状况基本一致,都是由市中心往外逐渐减轻。TSP高值区,城区呈高温区;TSP低值区,城区呈低温区。采用长沙市TSP高值区、TSP低值区的两个监测点2002年逐月TSP监测数据及相应气象统计数据,从时间上对TSP污染与城市热岛效应进行了相关性研究,长沙市TSP污染与热岛强度在年度分布上存在正相关关系。随着长沙城市建设和城市化速度的加快,城市热岛强度有逐年增强的趋势。3S技术与传统技术相结合,使科学研究更客观、准确。3S技术用于中尺度的区域环境质量调查,可实现空间区域的定量表达,而传统技术获取的环境背景数据,则从微观上对空间数据的准确性进行验证。  相似文献   

20.
Until the last decade, protecting the environment was seen as a factor contributing to human well-being, and conservation of natural ecosystems was considered to be one of the most important factors of environmental protection. Numerous studies have dealt with the benefits of natural ecosystems and in recent years even more so with ecosystem services, as well as interactions of ecosystem services with each other and with the urban and peri-urban environment. This paper suggests an approach to the spatial unity of the Florina region using basic ecosystem services identified by land use. The aim was, first, to describe the spatial distribution of basic ecosystem services and their interactions and, second, to investigate whether they form important statistical correlations with the basic features of the prefecture. A 1 km × 1 km analysis of 10 ecosystem services covering the surface of the prefecture was carried out.  相似文献   

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