Factors and values of willingness to pay for improved construction waste management--a perspective of Malaysian contractors

Malaysia is facing an increase in the generation of waste and of accompanying problems with the disposal of this waste. In the last two decades, extensive building and infrastructure development projects have led to an increase in the generation of construction waste material. The construction industry has a substantial impact on the environment, and its environmental effects are in direct relation to the quality and quantity of the waste it generates. This paper discusses general characteristics of the construction contractors, the contractors' willingness to pay (WTP) for improved construction waste management, determining factors which affect the amount of their willingness to pay, and suggestions and policy implications in the perspective of construction waste management in Malaysia. The data in this study is based on contractors registered with the construction industry development board (CIDB) of Malaysia. Employing the open ended contingent valuation method, the study assessed the contractors' average maximum WTP for improved construction waste management to be RM69.88 (1US$=3.6 RM) per tonne of waste. The result shows that the average maximum WTP is higher for large contractors than for medium and small contractors. The highest average maximum WTP value is RM88.00 for Group A (large contractors) RM78.25 for Group B (medium-size contractors) and RM55.80 for Group C (small contractors). One of the contributions of this study is to highlight the difference of CIDB registration grade in the WTP for improved construction waste management. It is found that contractors' WTP for improved waste collection and disposal services increases with the increase in contractors' current paid up capital. The identified factors and determinants of the WTP will assist the formulation of appropriate policies in addressing the construction waste problem in Malaysia and indirectly improve the quality of construction in the country.     

Carbofuran toxicity on total lipids and free fatty acids in air breathing fish during exposure and cessation of exposure--in vivo

Clarias batrachus, fish were exposed to sublethalconcentration of commercial carbofuran for 144 hr. After 144 hrof exposure period, fish were transferred to fresh water and kept inthe same for 144 hr in order to study the effect of carbofuranafter cessation of intoxication. Total lipids and free fattyacids were determined in liver, muscle kidney and ovary at aninterval of 24, 72 and 144 hr during exposure and after therelease into toxicant free water. Total lipids increased in allthe tissues throughout the exposure period, followed by decreaseduring depuration period. The results showed an alteration infree fatty acid content in different tissues of the fish. Theelevated levels returned to almost control values after transferof fish into carbofuran free water.     

An investigation of lifting operations on UK construction sites

Lifting operations and associated equipment have become commonplace within the UK construction industry. However, recent high profile accidents involving lifting equipment have shown that the result of its misuse can have serious cost and health implications.The main aim of the research was to investigate lifting operations on construction sites exploring different options, their effectiveness, and their effect on safety. This research looked into the processes in place; the factors that have to be taken into consideration when placing and using lifting equipment; and the competent persons required when operating equipment. With these aims, literature review was conducted. This was followed by investigation on three construction sites. These case studies were enhanced through interviews with general site staff, managerial staff, and appointed persons.The findings revealed six main points to improve safety in lifting operations. These are: through planning; training; equipment selection, use and inspection; feedback/communication; appointed person’s role; and database. Thorough planning of lifting operations has positive effects on safety. There is need for tighter accreditation of all qualifications in the lifting operations field. The charter of major lifting equipment from specialist contractors should be considered as industry best practise. Companies should avoid authoritarian working culture to facilitate efficient feedback to improve safety. The appointed person should have site based role. Site inspections and maintenance should be monitored on a national database form.Practitioners can benefit from this paper as it provides information on experiences from three construction sites. Furthermore, researchers can use the findings for their future studies.     

Social constraints before sanitation improvement in tea gardens of Sylhet, Bangladesh

Sylhet, the northeastern divisional city of Bangladesh, is the major tea-producing region of the country where a large number of low-income workers completely depending on extremely labor-intensive economic activity for their bread and butter, live in and around the tea gardens. The living conditions of these communities are remarkably meager due to the lack of proper utility facilities, especially in water supply and sanitation sectors. A study was conducted at Lakkatura and Ali Bahar Tea Estates to assess the deteriorated sanitation condition of the tea garden workers community and to determine the constraints before the improvement of the condition. It was found that the existing sanitary condition of both of the tea garden slums is very poor because of the same topographical condition and socioeconomic and cultural status of the dwellers. About 50% to 60% tea garden workers still are used to open defecation causing various excreta related diseases and not practiced with washing hand after defecation. Lack of knowledge and awareness about health and hygiene, unwillingness, poverty, superstitions, etc. are responsible for the deteriorated condition of the sanitation system. Based on the analysis, providing latrines free of costs, undertaking extensive motivational and awareness programs and publicity, regular consultation of tea garden workers with the health specialists, and vector control staff of concerned utilities as well as an integrated water supply, sanitation, and hygiene promotion programs should be considered as the priority in order to improve the deteriorated sanitary conditions in two tea gardens.     

Exogenous melatonin reduces water deficit-induced oxidative stress and improves growth performance of Althaea rosea grown on coal mine spoils

Environmental Science and Pollution Research - Coal mining activities are responsible for significant land degradation and often long-term irreversible effects on ecosystem functioning. To better...     

In vitro effects of erythromycin and florfenicol on primary cell lines of Unio crassus and Cyprinus carpio

Environmental Science and Pollution Research - The ubiquitous use of antibiotics leads exposure of these chemicals on non-target aquatic species, while the toxicity assays for these chemicals are...     

An automated solid waste bin level detection system using a gray level aura matrix

An advanced image processing approach integrated with communication technologies and a camera for waste bin level detection has been presented. The proposed system is developed to address environmental concerns associated with waste bins and the variety of waste being disposed in them. A gray level aura matrix (GLAM) approach is proposed to extract the bin image texture. GLAM parameters, such as neighboring systems, are investigated to determine their optimal values. To evaluate the performance of the system, the extracted image is trained and tested using multi-layer perceptions (MLPs) and K-nearest neighbor (KNN) classifiers. The results have shown that the accuracy of bin level classification reach acceptable performance levels for class and grade classification with rates of 98.98% and 90.19% using the MLP classifier and 96.91% and 89.14% using the KNN classifier, respectively. The results demonstrated that the system performance is robust and can be applied to a variety of waste and waste bin level detection under various conditions.     

Environmental effects of shipping imports from China and their economic valuation: the case of metallic valve components

This paper aims to consider the total cost, including polluting environmental emissions, of imports from China to Europe of five valve components in aluminium, steel and iron. These are compared with locally produced alternatives to investigate whether internalising such external costs affects their price competitiveness. Seaborne trade represents 90% of international trade and is growing faster than the world’s economy, but marine pollution emissions are not reflected in market prices. Chinese aluminium, iron and steel production are about 2.5 times more polluting than their European counterparts, but this is also not reflected in prices. In this paper both types of extra emissions are calculated, valued and added to the cost of the components analysed, for comparison with locally produced alternatives. The locally produced components generally remain uncompetitive with Chinese imports for all likely values of external cost, except for heavy aluminium components under high external cost assumptions. The Chinese iron components analysed are simply too low in cost for European (in this case Spanish) equivalents to be competitive even allowing for environmental costs; while the stainless steel ones are so small and light that transport cost, even including externalities, is not significant. While these specific results are of limited generalizability, they provide insight into an issue of considerable and growing importance. Some suggestions are offered for further research.     

Evaluation of Extracted Chitosan from Portunus Pelagicus for the Preparation of Chitosan Alginate Blend Scaffolds

In recent years there is a growing need in generating a biocompatible and cost effective porous scaffold for tissue engineering purposes. Therefore, this study focused on conversion of the shell waste of locally available crab variety P.pelagicus (Blue swimming crab) into the chitosan scaffold. As the poor mechanical strength of chitosan limits its usage in tissue engineering, it was blended with alginate. The scaffolds were prepared by the freeze gelation method which requires less time and minimum energy, with fewer residual solvent and easier to scale up. To the best of our knowledge there are no reports on scaffold preparation from the extracted chitosan, blended with alginate by freeze gelation method. The biological properties of chitosan-alginate scaffolds (Cts–Alg) were evaluated and compared with those of chitosan scaffolds. The prepared scaffolds were characterized by SEM, swelling property, in vitro enzymatic degradation, and hemo, biocompatibility properties. Chitosan-alginate scaffolds had an average pore size of 40 μm and tensile strength of 0.564 ± 0.0.018 % MPa. Its swelling ratio was 27.5 ± 0.28 %, with mass loss percentage of 10 ± 0.33 % after 4 weeks of degradation. It has exhibited good hemocompatible properties too. Mouse fibroblast 3T3 cells were able to adhere and proliferate well in the blended scaffold. All these results indicated that chitosan-alginate scaffold is a suitable alternative substitute for tissue engineering.