This study employed contingent valuation method to estimate the willingness to pay (WTP) of the households to improve the waste collection system in Kuala Lumpur, Malaysia. The objective of this study is to evaluate how household WTP changes when recycling and waste separation at source is made mandatory. The methodology consisted of asking people directly about their WTP for an additional waste collection service charge to cover the costs of a new waste management project. The new waste management project consisted of two versions: version A (recycling and waste separation is mandatory) and version B (recycling and waste separation is not mandatory). The households declined their WTP for version A when they were asked to separate the waste at source although all the facilities would be given to them for waste separation. The result of this study indicates that the households were not conscious about the benefits of recycling and waste separation. Concerted efforts should be taken to raise environmental consciousness of the households through education and more publicity regarding waste separation, reducing and recycling.
The purpose of this paper is to investigate the links between renewable energy (RE), non-renewable energy (NRE), capital, labour and economic growth, using the nonlinear autoregressive distributive lag (NARDL) model in Malaysia for the period of 1980-2018. The results of NARDL confirm the asymmetric effect of RE and NRE consumption on the economic growth in the long run as well as the short run in Malaysia. The findings also show that in the long and short run, positive shocks of NRE are greater than the positive shocks of RE. It indicates that Malaysia's economic growth is highly dependent on NRE which is not a good indication as NRE consumption increases carbon dioxide (CO2) emission in the country. Moreover, the empirical results of this study demonstrated that RE consumption reduction accelerates economic growth, whereas NRE consumption reduction decreases economic growth. It can have claimed that in Malaysia, RE is still more expensive than NRE. In conclusion, this study offered a variety of measures to develop RE to reduce the dependency on NRE consumption.
Information on waste generation, socioeconomic characteristics, and willingness of the households to separate waste was obtained from interviews with 402 respondents in Dhaka city. Ordinary least square regression was used to determine the dominant factors that might influence the waste generation of the households. The results showed that the waste generation of the households in Dhaka city was significantly affected by household size, income, concern about the environment, and willingness to separate the waste. These factors are necessary to effectively improve waste management, growth and performance, as well as to reduce the environmental degradation of the household waste.
In the early days of abundant resources and minimal development pressures, little attention was paid to growing environmental concerns in Malaysia. The haze episodes in Southeast Asia in 1983, 1984, 1991, 1994, and 1997 imposed threats to the environmental management of Malaysia and increased awareness of the environment. As a consequence, the government established Malaysian Air Quality Guidelines, the Air Pollution Index, and the Haze Action Plan to improve air quality. Air quality monitoring is part of the initial strategy in the pollution prevention program in Malaysia. Review of air pollution in Malaysia is based on the reports of the air quality monitoring in several large cities in Malaysia, which cover air pollutants such as Carbon monoxide (CO), Sulphur Dioxide (SO2), Nitrogen Dioxide (NO2), Ozone (O3), and Suspended Particulate Matter (SPM). The results of the monitoring indicate that Suspended Particulate Matter (SPM) and Nitrogen Dioxide (NO2) are the predominant pollutants. Other pollutants such as CO, O(x), SO2, and Pb are also observed in several big cities in Malaysia. The air pollution comes mainly from land transportation, industrial emissions, and open burning sources. Among them, land transportation contributes the most to air pollution. This paper reviews the results of the ambient air quality monitoring and studies related to air pollution and health impacts.
This paper examines the factors that might influence recycling behaviour of the households in Dhaka city, Bangladesh. Information on recycling activity, socio-economic characteristics, and attitudes of the households towards recycling were obtained from interviews with 456 households in Dhaka. Logistic regression analysis was used to determine the dominant factors that might influence the recycling behaviour of the households. The results showed that environmental consciousness, the availability of storage space, and age (25-35 years) are significant positive predictors of recycling behaviour (at the 1% level). Another variable Income 2 (TK3,000-15,000) is also positively correlated with recycling (at the 5% level). Establishment of a recycling programme could be an effective strategy in implementing sustainable waste management in Bangladesh. For this strategy to succeed, however, active partnership between households and the waste management service department is required. The households' attitudes toward recycling should, therefore, be taken into consideration as should the results of this study, which are important indicators of households' positive attitudes toward sustainable waste management in Dhaka.
The focus of this study is to analyze the level of knowledge, awareness, and attitude toward plastic waste and to distinguish the key drivers that encourage the households in Kuala Lumpur, Malaysia, to participate in "No plastic campaign," This study used the logistic regression model to explain the factors that may affect the willingness to participate (WTP) of households in the campaign. In this study, it is found that 35 % of households are willing to participate in the campaign. The results of the study also indicate that people who are more informed and more convinced of their knowledge have a more positive attitude toward recycling than their counterparts do. Furthermore, this study provides additional evidence of the level and classification of importance of motivating factors for plastic recycling, using the modified average and coefficient of variation of the models. From the analysis, the factor "helps reduce landfill use" is found as the most important factor and the factor of "raising money for charity" is found as the least important factor that motivates households to participate in recycling. The determinations of the study suggest some strategies that could hold implications for government and households to boost them to participate in the campaign "No Plastic Bag."
This paper examines whether attitudes towards electric vehicles (ATEVs), subjective norms (SNs) and perceived behavioural control (PBC) have significant associations with consumer purchase intention (PI) and the purchase behaviour of environmentally friendly vehicles (EFVs). The results from the survey questionnaires are analysed using confirmatory factor analysis (CFA) and structural equation modelling (SEM). The findings of this paper indicate that ATEV, SN and PBC significantly influence PI. This finding also indicates that environmental consequence and individual preferences do not influence the PI of the respondents. We found that Malaysian car owners are largely unaware of the greenhouse effects on the environment or attach to it little importance, which is reflected in their PI towards EFVs. The outcomes of this study could help policymakers design programmes to influence attitudes, subjective norms, perceived behavioural control and purchase behaviour to prevent further air pollution and reduce CO2 emissions from the transportation sector.
This study investigated the main target sites of chlorpyrifos (CPF), its effect on biochemical indices, and the pathological changes observed in rat liver and kidney function using gas chromatography/mass spectrometry. Adult female Wistar rats (n = 12) were randomly assigned into two groups (one control and one test group; n = 6 each). The test group received CPF via oral gavage for 21 days at 5 mg/kg daily. The distribution of CPF was determined in various organs (liver, brain, heart, lung, kidney, ovary, adipose tissue, and skeletal muscle), urine and stool samples using GCMS. Approximately 6.18% of CPF was distributed in the body tissues, and the highest CPF concentration (3.80%) was found in adipose tissue. CPF also accumulated in the liver (0.29%), brain (0.22%), kidney (0.10%), and ovary (0.03%). Approximately 83.60% of CPF was detected in the urine. CPF exposure resulted in a significant increase in plasma transaminases, alkaline phosphatase, and total bilirubin levels, a significant reduction in total protein levels and an altered lipid profile. Oxidative stress due to CPF administration was also evidenced by a significant increase in liver malondialdehyde levels. The detrimental effects of CPF on kidney function consisted of a significant increase in plasma urea and creatinine levels. Liver and kidney histology confirmed the observed biochemical changes. In conclusion, CPF bioaccumulates over time and exerts toxic effects on animals.
We investigated the protective role of Withania somnifera leaf extract (WSLEt) on isoproterenol- (ISO-) induced myocardial infarction (MI) in rats. Subcutaneous injection of ISO (85 mg/kg body weight (b.w.)) administered to rats for two consecutive days caused a significant increase in cardiac troponin I (cTnI) levels and serum lipid profiles, as well as the activities of some marker enzymes. In addition to these diagnostic markers, there were increased levels of lipid peroxidation (LPO) and decreased activities of enzymatic antioxidants (superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione reductase (GRx), and glutathione-S-transferase (GST)) in the myocardium. However, oral pretreatment (100 mg/kg b.w.) with WSLEt for 4 weeks elicited a significant cardioprotective activity by lowering the levels of cTnI, lipid profiles, and marker enzymes. The levels of LPO products were also significantly decreased. Elevated activities of antioxidant enzymes were also observed in rats pretreated with WSLEt. As further confirmed histopathologically, our findings strongly suggest that the cardioprotective effect of WSLEt on myocardium experiencing ISO-induced oxidative damage may be due to an augmentation of the endogenous antioxidant system and an inhibition of LPO in the myocardial membrane. We conclude that WSLEt confers some protection against oxidative damage in ISO-induced MI in rats.
The present study was designed to investigate the cardioprotective effects of Sundarban honey (SH) in rats with isoproterenol- (ISO-) induced myocardial infarction. Adult male Wistar Albino rats were pretreated with Sundarban honey (5 g/kg) daily for a period of 6 weeks. After the treatment period, ISO (85 mg/kg) was subcutaneously injected into the rats at 24 h intervals for 2 days. ISO-induced myocardial damage was indicated by increased serum cardiac specific troponin I levels and cardiac marker enzyme activities including creatine kinase-MB, lactate dehydrogenase, aspartate transaminase, and alanine transaminase. Significant increases in serum total cholesterol, triglycerides, and low-density lipoprotein-cholesterol levels were also observed, along with a reduction in the serum high-density lipoprotein-cholesterol level. In addition to these diagnostic markers, the levels of lipid peroxide products were significantly increased. The activities of antioxidant enzymes such as superoxide dismutase, glutathione peroxidase, and glutathione reductase were significantly decreased in the hearts after ISO-induced myocardial infarction. However, pretreatment of ischemic rats with Sundarban honey brought the biochemical parameters to near normalcy, indicating the protective effect of Sundarban honey against ISO-induced ischemia in rats. Histopathological findings of the heart tissues further confirmed the biochemical findings, indicating that Sundarban honey confers protection against ISO-induced oxidative stress in the myocardium.
The present study was designed to investigate the cardioprotective effects of Malaysian Tualang honey against isoproterenol- (ISO-) induced myocardial infarction (MI) in rats by investigating changes in the levels of cardiac marker enzymes, cardiac troponin I (cTnI), triglycerides (TG), total cholesterol (TC), lipid peroxidation (LPO) products, and antioxidant defense system combined with histopathological examination. Male albino Wistar rats (n = 40) were pretreated orally with Tualang honey (3 g/kg/day) for 45 days. Subcutaneous injection of ISO (85 mg/kg in saline) for two consecutive days caused a significant increase in serum cardiac marker enzymes (creatine kinase-MB (CK-MB), lactate dehydrogenase (LDH), and aspartate transaminase (AST)), cTnI, serum TC, and TG levels. In addition, ISO-induced myocardial injury was confirmed by a significant increase in heart lipid peroxidation (LPO) products (TBARS) and a significant decrease in antioxidant enzymes (SOD, GPx, GRx, and GST). Pretreatment of ischemic rats with Tualang honey conferred significant protective effects on all of the investigated biochemical parameters. The biochemical findings were further confirmed by histopathological examination in both Tualang-honey-pretreated and ISO-treated hearts. The present study demonstrates that Tualang honey confers cardioprotective effects on ISO-induced oxidative stress by contributing to endogenous antioxidant enzyme activity via inhibition of lipid peroxidation.
Honey, a supersaturated natural product of honey bees, contains complex compounds with antioxidant properties and therefore has a wide a range of applications in both traditional and modern medicine. In the present study, the protective effects of Sundarban honey from Bangladesh against acetaminophen- (APAP-) induced hepatotoxicity and nephrotoxicity in experimental rats were investigated. Adult male Wistar rats were pretreated with honey (5 g/kg) for 4 weeks, followed by the induction of hepatotoxicity and nephrotoxicity via the oral administration of a single dose of APAP (2 g/kg). Organ damage was confirmed by measuring the elevation of serum alkaline phosphatase (ALP), alanine transaminase (ALT), aspartate transaminase (AST), total protein (TP), total bilirubin (TB), urea, creatinine, and malondialdehyde (MDA). Histopathological alterations observed in the livers and the kidneys further confirmed oxidative damage to these tissues. Animals pretreated with Sundarban honey showed significantly markedly reduced levels of all of the investigated parameters. In addition, Sundarban honey ameliorated the altered hepatic and renal morphology in APAP-treated rats. Overall, our findings indicate that Sundarban honey protects against APAP-induced acute hepatic and renal damage, which could be attributed to the honey's antioxidant properties.
Increases in the incidence of cardiovascular disease (CVD) have aroused strong interest in identifying antioxidants from natural sources for use in preventive medicine. Citrus macroptera (C. macroptera), commonly known as "Satkara", is an important herbal and medicinal plant reputed for its antioxidant, nutritious and therapeutic uses. The aim of the present study was to investigate the cardio-protective effects of ethanol extracts of C. macroptera peel and pulp against isoproterenol (ISO)-induced myocardial infarction (MI) in rats. Male albino Wistar rats (n=36) were pre-treated with peel and pulp extracts (500mg/kg) for 45days. They received a challenge with ISO (85mg/kg) on the 44th and 45th days. Our findings indicated that subcutaneous injection of ISO induced severe myocardial injuries associated with oxidative stress, as confirmed by elevated lipid peroxidation (LPO) and decreased cellular reduced glutathione (GSH) and anti-peroxidative enzymes, including glutathione peroxidase, glutathione reductase and glutathione-S-transferase, compared with levels observed in control animals. Pre-treatment with C. macroptera peel and pulp extracts prior to ISO administration however, significantly improved many of the investigated biochemical parameters, i.e., cardiac troponin I, cardiac marker enzymes, lipid profile and oxidative stress markers. The fruit peel extract showed stronger cardio-protective effects than the pulp extract. The biochemical findings were further confirmed by histopathological examinations. Overall, the increased endogenous antioxidant enzyme activity against heightened oxidative stress in the myocardium is strongly suggestive of the cardio-protective potential of C. macroptera.
Atherosclerosis commences with the trapping of low density lipoproteins (LDLs) in blood vessels by modified proteoglycans (PGs) with hyperelongated glycosaminoglycan (GAG) chains. GAG chain synthesis and growth factor mediated hyperelongation regulates the composition and size of PGs in a manner that would cause low density lipoprotein (LDLs) retention in vessel wall. Galactosaminoglycans are a class of GAGs, commonly observed on PGs. Multiple enzymes are involved in galactosaminoglycan biosynthesis. Galactosaminoglycan synthesis is regulated by various signalling pathways which are amenable to pharmacological manipulation to treat atherosclerosis. Receptor mediated signalling pathways including protein tyrosine kinase receptors (PTKRs), serine/threonine kinase receptors (S/TKRs) and G-protein coupled receptors (GPCRs) pathways regulate galactosaminoglycan synthesizing enzyme expression. Increased expression of these enzymes modify galactosaminoglycan chain structure by making them hyperelongated. This review focuses on the signalling pathways regulating the expression of genes involved in galactosaminoglycan synthesis and modification. Furthermore, there are multiple other processes for inhibiting the interactions between LDL and galactosaminoglycans such as peptide mimetics of ApoB100 and anti-galactosaminoglycan antibodies and the therapeutic potential of these strategies is also addressed.
Propolis contains high concentrations of polyphenols, flavonoids, tannins, ascorbic acid, and reducing sugars and proteins. Malaysian Propolis (MP) has been reported to exhibit high 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical-scavenging activity and ferric reducing antioxidant power (FRAP) values. Herein, we report the antioxidant properties and cardioprotective properties of MP in isoproterenol- (ISO-) induced myocardial infarction in rats. Male Wistar rats (n = 32) were pretreated orally with an ethanol extract of MP (100 mg/kg/day) for 30 consecutive days. Subcutaneous injection of ISO (85 mg/kg in saline) for two consecutive days caused a significant increase in serum cardiac marker enzymes and cardiac troponin I levels and altered serum lipid profiles. In addition significantly increased lipid peroxides and decreased activities of cellular antioxidant defense enzymes were observed in the myocardium. However, pretreatment of ischemic rats with MP ameliorated the biochemical parameters, indicating the protective effect of MP against ISO-induced ischemia in rats. Histopathological findings obtained for the myocardium further confirmed the biochemical findings. It is concluded that MP exhibits cardioprotective activity against ISO-induced oxidative stress through its direct cytotoxic radical-scavenging activities. It is also plausible that MP contributed to endogenous antioxidant enzyme activity via inhibition of lipid peroxidation.