Quantifying construction and demolition waste: An analytical review

Quantifying construction and demolition (C&D) waste generation is regarded as a prerequisite for the implementation of successful waste management. In literature, various methods have been employed to quantify the C&D waste generation at both regional and project levels. However, an integrated review that systemically describes and analyses all the existing methods has yet to be conducted. To bridge this research gap, an analytical review is conducted. Fifty-seven papers are retrieved based on a set of rigorous procedures. The characteristics of the selected papers are classified according to the following criteria - waste generation activity, estimation level and quantification methodology. Six categories of existing C&D waste quantification methodologies are identified, including site visit method, waste generation rate method, lifetime analysis method, classification system accumulation method, variables modelling method and other particular methods. A critical comparison of the identified methods is given according to their characteristics and implementation constraints. Moreover, a decision tree is proposed for aiding the selection of the most appropriate quantification method in different scenarios. Based on the analytical review, limitations of previous studies and recommendations of potential future research directions are further suggested.     

<Emphasis Type="Italic">Sargassum</Emphasis> on Santa Rosa Island,Florida: faunal use and beachgoer perception

The yearly influx of Sargassum onto the beaches of northwest Florida is considered a nuisance to some and a necessity to others. In Pensacola Beach, the Santa Rosa Island Authority rakes the wrack with mechanical beach cleaners to improve the aesthetic quality for beachgoers. The purpose of this study was three-fold: to evaluate the local faunal use of Sargassum wrack, to gauge public perception of Sargassum on the beach, and to test whether public perception of the beauty of the beach, the necessity of raking, and the likelihood of visiting could be influenced by a simple educational sign. A two-part methodology consisted of 1) systematic observation of faunal use, and 2) interviews of 200 beachgoers via a detailed pre-post/post only public use survey. Results showed that 11 of the 22 species of shorebirds documented, including two uncommon migrants, were observed using Sargassum wrack to forage, rest, and hide. Public survey results demonstrated that although beachgoers generally considered themselves to be “ecofriendly”, their perceptions of Sargassum wrack can be positively influenced through environmental education such as informative signage on the beach. In conclusion, Sargassum wrack provides valuable additional habitat to shorebirds and other critters, and that leaving the beach wrack to naturally become part of the ecosystem would not deter most beachgoers (70%) from visiting Pensacola Beach. This research contributes valuable information to coastal managers and other stakeholders for improved ecosystem protection and management.     

Driving self-restriction in high-risk conditions: how do older drivers compare to others?

Introduction

Many older drivers self-restrict or avoid driving under high-risk conditions. Little is known about the onset of driving self-restrictions or how widespread self-restrictions are among drivers of all ages.

Methods

The Second Injury Control and Risk Survey (ICARIS-2) was a nationwide cross-sectional, list-assisted random-digit-dial telephone survey from 2001 to 2003. National prevalence estimates and weighted percentages of those reporting driving self-restrictions were calculated. Multivariable logistic regression was used to explore associations between specific self-restrictions and age group, adjusting for other personal characteristics.

Results

More than half of all drivers reported at least one driving self-restriction. The most commonly reported restriction was avoidance of driving in bad weather (47.5%), followed by at night (27.9%) and on highways or high-speed roads (19%). A greater percentage of young adult women (18-24 years) reported self-restricting in bad weather compared to women in other age groups, and the percentage of drivers self-restricting at night, in bad weather, and on highways or high-speed roads increased steeply after age 64. We found that women, those in low income groups, and those who had driven low annual mileage were more likely to self-restrict.

Conclusions

In addition to assessing self-restrictions among older drivers, a new finding from our study is that self-restrictions are also quite prevalent among younger age groups. Driving self-restrictions may be better understood as a spectrum across ages in which drivers’ reasons for restriction change.

Impact on industry

Future research on the ability of driving self-restrictions to reduce actual crash risk and prevent injuries is needed.     

Factors influencing private and public environmental protection behaviors: results from a survey of residents in Shaanxi, China

Currently one of the largest and most rapidly developing countries, China also has some of the world's most severe environmental problems. China will most likely need to use all of the potential major strategies currently available to solve the country's huge environmental challenges, including promoting individual conservation behavior through educational campaigns and encouraging public environmental advocacy. This paper summarized the findings of a survey of 347 residents of Shaanxi province on environmental attitudes and behaviors. The survey found generally high levels of environmental knowledge and high recognition of the seriousness of environmental issues, moderate levels of individual actions supporting environmental resource conservation and low levels of public environmental behaviors, particularly for organized public advocacy. Further analysis indicated that the perceived importance of environmental protection is the most important factor influencing individual environmental resource conservation, but not public advocacy behaviors. Implications for environmental campaigns are discussed.     

Temporal and spatial variation in the δ<Superscript>15</Superscript>N and δ<Superscript>13</Superscript>C values of fish and squid from Alaskan waters

To test the hypothesis that stable isotope ratios from marine organisms vary, the δ¹⁵N and δ¹³C values from fish and squid collected in Alaskan waters were measured across years (1997, 2000, and 2005), seasons, geographic locations, and different size/age classes, and between muscle tissue and whole animals. Temporal, geographic, and ontogenetic differences in stable isotope ratios ranged from 0.5–2.5‰ (δ¹⁵N) to 0.5–2.0‰ (δ¹³C). Twenty-one comparisons of stable isotope values between whole organisms and muscle tissue revealed only four small differences each for δ¹⁵N and δ¹³C, making costly and space prohibitive collection of whole animals unnecessary. The data from this study indicate that significant variations of stable isotope values from animals in marine systems necessitates collection of prey and predator tissues from the same time and place for best interpretation of stable isotope analysis in foraging ecology studies.     

Sustainable urban community development from the grassroots: Challenges and opportunities in a pedestrian street initiative

Abstract

A local sustainable development initiative to establish a temporary pedestrian zone within a Canadian urban community served as a research study into the efficacy of social capital in the development of a network for community action. This community-based initiative used social capital to overcome campaign obstacles and the campaign itself generated new social capital within the neighbourhood through the creation of adaptive networks of participants. The campaign succeeded in creating a part-time pedestrian-only space that serves as an educational example of change for sustainable community development that is replicable in other communities, and provides an example of alternative occupation of community space. Contrary to other literature, little evidence of “core burnout” was found although the network does continue to expend a large amount of effort and time on fundraising. While social capital is a powerful tool for local grassroots action, the availability of a critical source of economic capital may prove vital to the long-term success and sustainability of the network.     

Comparison of total mercury and methylmercury cycling at five sites using the small watershed approach

The small watershed approach is well-suited but underutilized in mercury research. We applied the small watershed approach to investigate total mercury (THg) and methylmercury (MeHg) dynamics in streamwater at the five diverse forested headwater catchments of the US Geological Survey Water, Energy, and Biogeochemical Budgets (WEBB) program. At all sites, baseflow THg was generally less than 1ng L(-1) and MeHg was less than 0.2ng L(-1). THg and MeHg concentrations increased with streamflow, so export was primarily episodic. At three sites, THg and MeHg concentration and export were dominated by the particulate fraction in association with POC at high flows, with maximum THg (MeHg) concentrations of 94 (2.56)ng L(-1) at Sleepers River, Vermont; 112 (0.75)ng L(-1) at Rio Icacos, Puerto Rico; and 55 (0.80)ng L(-1) at Panola Mt., Georgia. Filtered (<0.7microm) THg increased more modestly with flow in association with the hydrophobic acid fraction (HPOA) of DOC, with maximum filtered THg concentrations near 5ng L(-1) at both Sleepers and Icacos. At Andrews Creek, Colorado, THg export was also episodic but was dominated by filtered THg, as POC concentrations were low. MeHg typically tracked THg so that each site had a fairly constant MeHg/THg ratio, which ranged from near zero at Andrews to 15% at the low-relief, groundwater-dominated Allequash Creek, Wisconsin. Allequash was the only site with filtered MeHg consistently above detection, and the filtered fraction dominated both THg and MeHg. Relative to inputs in wet deposition, watershed retention of THg (minus any subsequent volatilization) was 96.6% at Allequash, 60% at Sleepers, and 83% at Andrews. Icacos had a net export of THg, possibly due to historic gold mining or frequent disturbance from landslides. Quantification and interpretation of Hg dynamics was facilitated by the small watershed approach with emphasis on event sampling.     

Ten steps toward integrated environmental excellance

Environmental management is moving away from the traditional use of specialists to currect end-of-the-pipe problems and instead is moving back in the process to reduce the production of these waste materials. The author shows how integrating environmental responsiblity all the way down the production line might work in a practical application, including a ten-step formula for putting a total quality environmental program in place.