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151.
Since the 1980s, green purchasing/green procurement has increasingly been recognised as an effective means of addressing and reducing negative environmental impacts related to product production and consumption around the world. This paper reviews the procurement practices and policies of five Asian countries and Hong Kong, in the context of an international overview of green purchasing and practices. The extent of government involvement in green procurement is found to directly determine its overall effectiveness, and up-to-date information resources clearly enhance delivery and performance. A case study in Hong Kong demonstrates how public leadership on green procurement has advanced green procurement in the private sector.  相似文献   
152.
This study utilizes remote sensing derived forest aboveground biomass (AGB) estimates and ownership information obtained from the Protected Areas Database (PAD), combining landscape analyses and GIS techniques to demonstrate how different ownerships (public, regulated private, and other private) relate to the spatial distribution of AGB in New England states of the USA. “Regulated private” lands were dominated by lands in Maine covered by a Land Use Regulatory Commission. The AGB means between all pairs of the identified ownership categories were significantly different (P < 0.05). Mean AGB observed in public lands (156 Mg/ha) was 43% higher than that in regulated private lands (109 Mg/ha), or 30% higher than that of private lands as a whole. Seventy-seven percent of the regional forests (or about 9,300 km2) with AGB >200 Mg/ha were located outside the area designated in the PAD and concentrated in western MA, southern VT, southwestern NH, and northwestern CT. While relatively unfragmented and high-AGB forests (>200 Mg/ha) accounted for about 8% of total forested land, they were unevenly proportioned among the three major ownership groups across the region: 19.6% of the public land, 0.8% of the regulated private land, and 11.0% of the other private land. Mean disturbance rates (in absolute value) between 1992 and 2001 were 16, 66, and 19 percent, respectively, on public, regulated private, and other private land. This indicates that management practices from different ownerships have a strong impact on dynamic changes of landscape structures and AGB distributions. Our results may provide insight information for policy makers on issues regarding forest carbon management, conservation biology, and biodiversity studies at regional level.  相似文献   
153.

Purpose

This research is on the evaluation of biosorption capability of the core of Artocarpus odoratissimus (Tarap), grown in Brunei Darussalam, towards Cd(II) and Cu(II) ions present in synthetic solutions, and to characterize the surface of Tarap particles.

Methods

Thermogravimetric analysis and surface titrations were conducted to characterize the surface of dried Tarap core particles. Atomic absorption spectroscopic measurements were conducted to determine the extent of removal of Cd(II) and Cu(II) under different experimental conditions.

Results

Mass reductions associated with many exothermic reaction peaks were observed beyond 200°C up to 650°C indicating the combustion of organic matter in Tarap. Dried particles of core of Tarap bear a negative surface charge promoting strong interaction towards positively charged ions, such as Cu(II) and Cd(II). Biosorption of the two metal ions on Tarap, which is relatively high beyond pH?=?4, occurs within a short period of exposure time. The extent of biosorption is enhanced by acid treatment of the biosorbent, and further it does not significantly depend on the presence of nonreacting ions up to an ionic strength of 2.0?M.

Conclusion

Strong attraction between each metal ion and the biosorbent is attributed to the negative surface charge on the biosorbent within a broad pH range. Acid treatment of the biosorbent improves sorption characteristics, suggesting that ion exchange plays an important role in the metal ion??biosorbent interaction process.  相似文献   
154.
ABSTRACT

Particulate matter (PM) exposure data from the U.S. Environmental Protection Agency (EPA)-sponsored 1998 Baltimore and 1999 Fresno PM exposure studies were analyzed to identify important microenvironments and activities that may lead to increased particle exposure for select elderly (>65 years old) subjects. Integrated 24-hr filter-based PM2.5 or PM10 mass measurements [using Personal Environmental Monitors(PEMs)] included personal measurements, indoor and outdoor residential measurements, and measurements at a central indoor site and a community monitoring site. A subset of the participants in each study wore passive nephelometers that continuously measured (1-min averaging time) particles ranging in size from 0.1 to ~10 um. Significant activities and locations were identified by a statistical mixed model (p < 0.01) for each study population based on the measured PM2.5 or PM10 mass and time activity data. Elevated PM concentrations were associated with traveling (car or bus), commercial locations (store, office, mall, etc.), restaurants, and working.

The modeled results were compared to continuous PM concentrations determined by the nephelometers while participants were in these locations. Overall, the nephelometer data agreed within 6% of the modeled PM2.5 results for the Baltimore participants and within ~20% for the Fresno participants (variability was due to zero drift associated with the nephelometer). The nephelom-eter did not agree as well with the PM10 mass measurements, most likely because the nephelometer optimally responds to fine particles (0.3–2 um). Approximately one-half (54 ± 31%; mean ± standard deviation from both studies) of the average daily PM2.5 exposure occurred inside residences, where the participants spent an average of 83 ± 10% of their time. These data also showed that a significant portion of PM2.5 exposure occurred in locations where participants spent only 4–13% of their time.  相似文献   
155.
156.
‘Environmental cognitive stress’ a hybrid model combining environmental stress and cognitive determinants of pro-environmental behavior is explored among Australians living in contrasting ‘micro’ climates in the same river catchment system. Peoples’ climate risk perceptions are mediated by their connections to local environment, observations of environmental change and personal weather experiences. A longitudinal study randomly sampled 1,162 Hunter Valley coastal and rural residents in New South Wales. Telephone interviewers (2008) recruited lakeside homeowners ‘at risk’ of sea level rise, nearby ‘control’ residents and a comparable farming area group. Follow-up interviews (2011) located 81.5 % of the original sample. Fifty-six items based on the model asked about climate change observations, concerns, impacts and actions. Statistically significant rural–suburban and time differences were found. The rural sample was attuned to conditions affecting agricultural productivity: They worried about drought and heat, saw trees dying and changes to seasons and natural rhythms. They anticipate the impact of water scarcity, conserve water and value protecting plants and animals. Compared to higher elevation residents, lake dwellers observed marine life loss, worry about sea level rise and predict the decline of property values. Across time, all groups’ perceptions of warming indicators declined. Concerns and impacts were high and generally stayed high, as did actions related to energy use. No differences emerged in beliefs about climate warming. Climate change observations, along with concerns and actions, have important implications for the environmental cognitive stress model. Overall, dynamic changes in residents’ understandings are related to a changing policy environment, the vicissitudes of climate debates and weather experiences, including extreme swings from inundation to drought.  相似文献   
157.
The availability of wetlands and shallow water habitats significantly influences Gulf of Mexico (GOM) penaeid shrimp fishery productivity. However, the GOM region has the highest rate of wetland loss in the USA. Protection and management of these vital GOM habitats are critical to sustainable shrimp fisheries. Brown shrimp (Farfantepenaeus aztecus) are a major component of GOM fisheries. We present an approach for estimating the areal extent of suitable habitat for post-larval and juvenile brown shrimp in Mobile Bay, Alabama, using an existing habitat suitability index model for the northern GOM calculated from probabilistic survey of water quality and sediment data, land cover data, and submerged aquatic vegetation coverages. This estuarine scale approach is intended to support targeted protection and restoration of these habitats. These analyses indicate that approximately 60% of the area of Mobile Bay is categorized as suitable to near optimal for post-larval and juvenile shrimp and 38% of the area is marginally to minimally suitable. We identify potential units within Mobile Bay for targeted restoration to improve habitat suitability.  相似文献   
158.
Agriculture releases copious fertilizing pollutants to air sheds and waterways of the northwestern United States. To evaluate threats to natural resources and historic rock paintings in remote Hells Canyon, Oregon and Idaho, deposition of ammonia (NH3), nitrogen oxides (NOx), sulfur dioxide (SO2), and hydrogen sulfide (H2S) at five stations along 60 km of the Snake River valley floor were passively sampled from July 2002 through June 2003, and ozone data and particulate chemistry were obtained from the Interagency Monitoring of Protected Visual Environments (IMPROVE) station at Hells Canyon. NH3 concentrations were high; biweekly averages peaked at 5-19 ppb in spring and summer and the nutrient-laden Snake River is a likely source. Fine particulate ammonium nitrate (NH4NO3) averaged 2.6 microg/m3 during the 20% of worst visibility days with winter drainage of air masses from the Snake River Basin and possibly long distance transport from southern California. Other pollutants were within background ranges. NH3 is corrosive to clay-based pictographs; nitrogen deposition can alter natural biotic communities and terrestrial ecosystem processes at levels reported here.  相似文献   
159.
Just sustainabilities has emerged as a powerful discourse to guide local action towards sustainability. As an overarching discourse, it prescribes four policy principles: (1) addressing well-being and quality of life; (2) meeting the needs of present and future generations; (3) enabling justice and equity in terms of recognition, process, procedure, and outcome; and (4) living within ecosystem limits. Following previous calls for engaging public and private actors in just sustainabilities, this paper inquiries about the extent to which these principles can be realistically integrated in local environmental governance. A database of 400 sustainability initiatives in more than 200 cities in all world regions is analysed to examine whether just sustainabilities principles are already enshrined, explicitly or implicitly, in local sustainability initiatives. This analysis suggests that, in this sample, there is a significant deficit in terms of addressing the principles of justice and equity, and ecosystem limits. However, the data also suggest that local action may already be delivering some aspects of just sustainabilities, even if this is not always explicit. The paper concludes with a call for a coordinated effort to translate a just sustainabilities discourse to local actors leading action on the ground.  相似文献   
160.
Atmospheric particulate matter (PM) abundance, mass size distribution (MSD) and chemical composition are parameters relevant for human health effects. The MSD and phase state of semivolatile organic pollutants were determined at various polluted sites in addition to the PM composition and MSD. The distribution pattern of pollutants varied from side to side in correspondence to main particle sources and PM composition. Levels of particle-associated polycyclic aromatic hydrocarbons (PAHs) were 1–30 ng m?3 (corresponding to 15–35 % of the total, i.e., gas and particulate phase concentrations), of polychlorinated biphenyls (PCBs) were 2–11 pg m?3 (4–26 % of the total) and of DDT compounds were 2–12 pg m?3 (4–23 % of the total). The PM associated amounts of other organochlorine pesticides were too low for quantification. The organics were preferentially found associated with particles <0.45 μm of aerodynamic equivalent diameter. The mass fractions associated with sub-micrometer particles (PM0.95) were 73–90 %, 34–71 % and 36–81 % for PAHs, PCBs and DDT compounds, respectively. The finest particles fraction had the highest aerosol surface concentration (6.3–29.7)×10?6 cm?1 (44–70 % of the surface concentration of all size fractions). The data set was used to test gas-particle partitioning models for semivolatile organics for the first time in terms of the organics' MSD and size-dependent PM composition. The results of this study prove that at the various sites particles with diverse size, matrix composition, amount of contaminants and toxicological effects occur. Legislative regulation based on gravimetric determination of PM mass can clearly be insufficient for assessment.  相似文献   
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