To understand the variations in the decomposability of tropical peat soil following deforestation for an oil palm plantation, a field incubation experiment was conducted in Sarawak, Malaysia. Peat soils collected from three types of primary forest, namely Mixed Peat Swamp (MPS; Gonystylus-Dactylocladus-Neoscrotechinia association), Alan Batu (ABt; Shorea albida-Gonstylus-Strenonurus association), and Alan Bunga (ABg; Shorea albida association), were packed in polyvinyl chloride pipes and installed in an oil palm plantation. Carbon dioxide (CO2) and methane (CH4) fluxes from soil were monthly measured for 3years. Environmental variables including soil temperature, soil moisture content, and groundwater table were also monitored. The pH, loss on ignition, and total carbon (C) content were similar among the three soils, while total N content was larger in the MPS than in the ABg soils. Based on13C nuclear magnetic resonance (NMR) spectroscopy, C composition of the MPS and ABg soils was characterized by the largest proportion of C present as alkyl C and O-alkyl C, respectively. The C composition of the ABt soil was intermediate between the MPS and ABg soils. The CO2fluxes from the three soils ranged from 78 to 625mgCm-2h-1with a negative correlation to groundwater level. The CH4fluxes ranged from -67 to 653μgCm-2h-1. Both total CO2and CH4fluxes were larger in the order ABg>ABt>MPS (P<0.05). Annual rate of peat decomposition as was estimated from cumulative C loss differed up to 2 times, and the rate constant in exponential decay model was 0.033y-1for the MPS soil and 0.066y-1for the ABg soil. The field incubation results of the three forest peat soils seem to reflect the difference in the labile organic matter content, represented by polysaccharides.
The impact of global warming has received much international attention in recent decades. To meet climate-change mitigation targets, environmental policy instruments have been designed to transform the way goods and services are produced as well as alter consumption patterns. The government of Malaysia is strongly committed to reducing CO2gas emissions as a proportion of GDP by 40% from 2005 levels by the year 2020. This study evaluates the economy-wide impacts of implementing two different types of CO2emission abatement policies in Malaysia using market-based (imposing a carbon tax) and command-and-control mechanism (sectoral emission standards). The policy simulations conducted involve the removal of the subsidy on petroleum products by the government. A carbon emission tax in conjunction with the revenue neutrality assumption is seen to be more effective than a command-and-control policy as it provides a double dividend. This is apparent as changes in consumption patterns lead to welfare enhancements while contributing to reductions in CO2emissions. The simulation results show that the production of renewable energies is stepped up when the imposition of carbon tax and removal of the subsidy is augmented by revenue recycling. This study provides an economy-wide assessment that compares two important tools for assisting environment policy makers evaluate carbon emission abatement initiatives in Malaysia.
Plastic waste is a global issue of an increasing concern in aquatic ecosystems. Microplastics form a large proportion of plastic pollution in marine environments. Although microplastics are prevalent, their distribution along the coasts of tropical regions is not well studied. Microplastic pieces (1-5 mm) were collected from two distinct regions along the coastlines of Singapore, from the northern coast in the Johor Strait and the southern coast in the Singapore Strait. Microplastics were present in concentrations ranging from 9.20-59.9 particles per kg of dry sand sediment. The majority of microplastics identified were foam particles (55%) and fragments (35%). Microplastics were significantly more abundant on heavily populated beaches compared to pristine beaches. High throughput sequencing was used to profile the communities of bacteria on the surfaces of microplastic particles. The structure of the microbial communities was primarily characterised by Proteobacteria and Bacteroidetes and were distinct across sites. Hydrocarbon-degrading genera such as Erythrobacter were dominant in areas with heavy shipping and pollution. Potential pathogenic genera such as Vibrio and Pseudomonas were also identified. This study highlights the diverse bacterial assemblages present on marine microplastic surfaces and the importance of understanding the bacterial plastisphere.
The quantification of microplastics in environmental samples often requires an observer to determine whether a particle is plastic or non-plastic, prior to further verification procedures. This implies that inconspicuous microplastics with a low natural detection may be underestimated. The present study aimed at assessing this underestimation, looking at how colour (white, green and blue), size (large; ~1000 μm and small; <400 μm) and grain size fraction may affect detection. Sediment treatments varying in grain size were inoculated with known quantities of low-density polyethylene microbeads extracted from commercially bought facial scrubs. These microbeads varied in colour and size. Once extracted using a density separation method microbeads were counted. An overall underestimation of 78.59% may be a result of observer error and/or technical error. More specifically, the results suggested that microbeads varying in colour and size have a different detection probability and that these microbead features are more important in underestimation likelihoods than grain sizes.
The rapid depletion of fossil fuels and ever-increasing environmental pollution have forced humankind to look for a renewable energy source. Microalgae, a renewable biomass source, has been proposed as a promising feedstock to generate biofuels due to their fast growth rate with high lipid content. However, literatures have indicated that sustainable production of microalgae biofuels are only viable with a highly optimized production system. In the present study, a cradle-to-gate approach was used to provide expedient insights on the effect of different cultivation systems and biomass productivity toward life cycle energy (LCEA), carbon balance (LCCO2) and economic (LCC) of microalgae biodiesel production pathways. In addition, a co-production of bioethanol from microalgae residue was proposed in order to improve the economic sustainability of the overall system. The results attained in the present work indicated that traditional microalgae biofuels processing pathways resulted to several shortcomings, such as dehydration and lipid extraction of microalgae biomass required high energy input and contributed nearly 21 to 30% and 39 to 57% of the total energy requirement, respectively. Besides, the microalgae biofuels production system also required a high capital investment, which accounted for 47 to 86% of total production costs that subsequently resulted to poor techno-economic performances. Moreover, current analysis of environmental aspects of microalgae biorefinery had revealed negative CO2 balance in producing microalgae biofuels.
Food waste is a universal problem in many countries. In line with Sustainable Development Goals 7 and 12, it is crucial to identify a cost-effective food waste valorization management framework with the least human health and environmental impacts. However, studies on the synergistic effect of life cycle assessment and mathematical optimization interconnected with human health, environment, and economic are relatively few and far between; hence they cannot provide holistic recommendations to policymakers in developing environmental and economic feasibility of food waste management frameworks. Taking Malaysia as a case study, this study proposes a simple and deterministic model that integrates life cycle assessment and multi-objective mathematical optimization to unpack the health-environment-economic wellbeing nexus in food waste management sector. The model evaluates the life cycle human health, environmental, and economic impacts of five food waste disposal and valorization technologies: open landfill, sanitary landfill, aerated windrow composting, high-temperature drying sterilization, and anaerobic digestion, and identifies the optimal food waste valorization configuration solution in Malaysia. Based on the results modeled by SimaPro 9.0 and General Algebraic Modeling System with augmented ε-constraint, valorization of food waste into electricity via anaerobic digestion is the most favorable option, with 146% and 161% reduction of human health and ecosystems, respectively, as compared with open landfill. If cost is combined as an objective function with human health and ecosystems, high-temperature drying sterilization is the most attractive scenario due to the high livestock feed revenue. Among the 10 Pareto-optimal solutions, 9% sanitary landfill, 3% aerated windrow composting, 30% high-temperature drying sterilization, 30% anaerobic digestion to electricity, and 28% anaerobic digestion to cooking gas, is recommended as future food waste management configuration. The sensitivity results demonstrate that prices of electricity, cooking gas, and livestock feed affect the optimal configuration food waste management system.
The stakeholders' perceptions on the impacts of Urban Heat Island (UHI) are critical for reducing exposure and influencing their response to interventions that are aimed at encouraging a behaviour change. A proper understanding of the UHI impacts on the society, economy and environment is deemed an essential motivating factor for the stakeholders to work towards UHI mitigations in the local context. This study adopted an inductive qualitative approach using Stakeholder Dialogue Sessions (SDSs) to assess the perceived impacts of UHI among various stakeholders, comprising policy makers, academicians, developers and Non-Governmental Organizations (NGO), in a tropical metropolitan city. The results revealed five themes such as deterioration of public health, acceleration of urban migration patterns and spending time in cooler areas, reduction of workers' productivity, increased energy consumption by the households and deterioration of environmental quality and natural resources that were categorized into social, economic and environmental impacts. Although most of the stakeholders were quite unfamiliar with the term UHI, they still display a good understanding of the potential impacts of UHI due to their posteriori knowledge and ability to rationalize the physical condition of the environment in which they live. The findings provide useful insights and valuable information to the local authorities to tailor necessary actions and educational campaigns to increase UHI awareness among the stakeholders. Being among the earlier studies to use a qualitative approach to attain the aforementioned objective, the findings are crucial to determine the level of understanding of the stakeholders on the impact of UHI. Through this study, the authors have highlighted the gaps and needs for knowledge improvements aimed at behaviour change among the stakeholders.
Wood-based panels provide efficient alternatives to materials such as plastics derived from traditional petroleum sources and thereby help to mitigate greenhouse gas emissions. Unfortunately, using indoor manufactured panel products also results in significant emissions of volatile organic compounds including olefins, aromatic and ester compounds, which negatively affect human health. This paper highlights recent developments and notable achievements in the field of indoor hazardous air treatment technologies to guide future research toward environmentally friendly and economically feasible directions that may have a significant impact on the improvement of human settlements. Summarizing and synthesizing the principles, advantages, and limitations of different technologies can assist policymakers and engineers in identifying the most appropriate technology for a particular air pollution control program based on criteria such as cost-effectiveness, efficiency, and environmental impact. In addition, insights into the development of indoor air pollution control technologies are provided and potential areas for innovation, improvement of existing technologies, and development of new technologies are identified. Finally, the authors also hope that this sub-paper will raise public awareness of indoor air pollution issues and promote a better understanding of the importance of indoor air pollution control technologies for public health, environmental protection, and sustainable development.
Life cycle assessment was used to evaluate the environmental impacts of phytoplanktonic biofuels as possible sustainable alternatives to fossil fuels. Three scenarios were examined for converting planktonic biomass into higher-value commodities and energy streams using the alga Scenedesmus sp. and the cyanobacterium Arthrospira sp. as the species of interest. The first scenario (Sc-1) involved the production of biodiesel and glycerol from the planktonic biomass. In the second scenario (Sc-2), biodiesel and glycerol were generated from the planktonic biomass, and biogas was produced from the residual biomass. The process also involved using a catalyst derived from snail shells for biodiesel production. The third scenario (Sc-3) was similar to Sc-2 but converted CO2 from the biogas upgrading to methanol, which was then used in synthesizing biodiesel. The results indicated that Sc-2 and Sc-3 had a reduced potential (up to 60 % less) for damaging human health compared to Sc-1. Sc-2 and Sc-3 had up to 61 % less environmental impact than Sc-1. Sc-2 and Sc-3 reduced the total cumulative exergy demand by up to 44 % compared to Sc-1. In conclusion, producing chemicals and utilities within the biorefinery could significantly improve environmental sustainability, reduce waste, and diversify revenue streams.
Although Ca transport in plants is highly complex, the overexpression of vacuolar Ca(2+) transporters in crops is a promising new technology to improve dietary Ca supplies through biofortification. Here, we sought to identify novel targets for increasing plant Ca accumulation using genetical and comparative genomics. Expression quantitative trait locus (eQTL) mapping to 1895 cis- and 8015 trans-loci were identified in shoots of an inbred mapping population of Brassica rapa (IMB211 × R500); 23 cis- and 948 trans-eQTLs responded specifically to altered Ca supply. eQTLs were screened for functional significance using a large database of shoot Ca concentration phenotypes of Arabidopsis thaliana. From 31 Arabidopsis gene identifiers tagged to robust shoot Ca concentration phenotypes, 21 mapped to 27 B. rapa eQTLs, including orthologs of the Ca(2+) transporters At-CAX1 and At-ACA8. Two of three independent missense mutants of BraA.cax1a, isolated previously by targeting induced local lesions in genomes, have allele-specific shoot Ca concentration phenotypes compared with their segregating wild types. BraA.CAX1a is a promising target for altering the Ca composition of Brassica, consistent with prior knowledge from Arabidopsis. We conclude that multiple-environment eQTL analysis of complex crop genomes combined with comparative genomics is a powerful technique for novel gene identification/prioritization.
Remote sensing and geographic information system techniques are significant and popular approaches that have been used in recent years to measure and map urban growth patterns. This paper primarily aims to provide a basis for a literature review of urban growth measurement and mapping by using different methods. For this purpose, the general characteristics of measuring and mapping urban growth patterns are described and classified. The strengths and weaknesses of the various methods have been identified from an analysis and discussion of the characteristics of the techniques. Results of reviews confirm that combining quantitative and qualitative techniques, such as Shannon approach and change detection, to measure and map urban growth patterns will improve understanding of the phenomenon of urban growth. Moreover, using social and economic data such as population and income data will improve understanding of the relationships between causes and effects. The integration of social and economic factors with quantitative and qualitative techniques will contribute to a perfect evaluation of urban growth patterns and land use changes, taking technical, social, economic, spatial, and temporal factors into account.
The aim of this paper is to review the potentialities and major methodological challenges
of integrating remote sensing (RS) and geographic information system (GIS) with socioeconomic data
from published articles or book chapters. RS and GIS combined with social science (SS)(termed as
geoinformation technology) serve many applications for sustainable management and monitoring of
the environment. This combined approach gives more accurate results than the single one. It makes
information available about the trend and pattern of land use and land cover change (LUCC) with
socioeconomic variables like population, demographic or income. This combined study which links
RS and GIS with socioeconomic data can also be used successfully for monitoring transmission rate
of disease and mapping or preparing vulnerability index. For impact assessment and modelling, this
combined technology provides better results than the single one. There are some methodological
problems for the researchers to link completely two different disciplines as the object of study and
observational unit is completely different. However, this interdisciplinary study is gaining popularity
day by day to researchers from different disciplines as well as decision makers.
The distribution patterns of tropical ectomycorrhizal (ECM) fungi along altitudinal gradients remain largely unknown. Furthermore, despite being an iconic site for biodiversity research, virtually nothing is known about the diversity and spatial patterns of fungi on Mt Kinabalu and neighbouring mountain ranges. We carried out deep DNA sequencing of soil samples collected between 425 and 4000 m above sea level to compare richness and community composition of ECM fungi among altitudinal forest types in Borneo. In addition, we tested whether the observed patterns are driven by habitat or by geometric effect of overlapping ranges of species (mid-domain effect). Community composition of ECM fungi was strongly correlated with elevation. In most genera, richness peaked in the mid-elevation montane forest zone, with the exception of tomentelloid fungi, which showed monotonal decrease in richness with increasing altitude. Richness in lower-mid- and mid-elevations was significantly greater than predicted under the mid-domain effect model. We provide the first insight into the composition of ECM fungal communities and their strong altitudinal turnover in Borneo. The high richness and restricted distribution of many ECM fungi in the montane forests suggest that mid-elevation peak richness is primarily driven by environmental characteristics of this habitat and not by the mid-domain effect.
Shewanella spp is a facultatively anaerobic, motile, gramnegative bacillus and can be found throughout the world mainly in marine environments and soil. It is a rare pathogen in human and infection by it is usually associated with underlying severe morbidities. We report a case of a 69- years old woman who presented with Shewanella putrefaciens dysentery and who was subsequently found to have underlying malignancy.
An emerging infection is defined as an infection which has newly appeared in a population while a re-emerging infection is one which has existed in the past but its incidence is rapidly increasing. The reasons for the emergence and re-emergence of infections are not well understood but appear to be associated with factors that involve the pathogen, the host and the environment. These factors are often inter-related and act together in a complex manner to bring about changes in patterns of infection. Pathogens are extremely resourceful and possess mechanisms to adapt to new hosts and environments as well as to acquire new virulence traits. Host factors include herd immunity, social behaviour and demographics. Environmental factors like the climate, deforestation and new technologies have an impact on the emergence of infections. The challenge is to contain an infection when it emerges but more importantly to prevent its emergence in the first place. As the emergence of an infection is complex and multifactorial, a multidisciplinary approach is required. Health based strategies alone are insufficient. Social, economic and environmental measures and the political will to implement appropriate policies are equally important.
A cross sectional study was conducted among 1007 children aged 1-2 years, from padi farming area. The percentage of male children was 51.4%. The prevalence of at least one of the chronic respiratory symptoms was 12.81%, and the prevalence of chronic cough, chronic sputum, wheezing and bronchial asthma as diagnosed by doctors were 9.33%, 3.87% 5.36% and 3.38% respectively. The overall prevalence of bronchial asthma was 6.26%. The prevalence of asthma was highest among children aged 11-12 years (8.9%) and higher among males (6.95%). No significant relationship was found between the prevalence of either chronic respiratory disease symptoms of bronchial asthma, and selected environmental factors, namely exposure to cigarette smoke, use of mosquito coil and wood stove. However there was a significant relationship between prevalence of asthma in children and history of asthma among parents and grandparents.
Study site: Two villages in Tg. Karang (Kg. Sawah Sempadan and Kg Sri Tiram Jaya), Selangor, Malaysia
A child's growth achievement depends on his genetic endowment and the environment in which he lives; Comparative studies of children of similar racial origin but growing under different environmental conditions have shown differences in their body size and shape. In general higher income families produce offspring with higher mean birth weight. This is largely due to better nutrition and care of mothers during pregnancy and childhood. Children from higher socioeconomic groups are on an average larger in size in terms of weight, height, head circumference, midarm circumference, crown-rump length and leg length. This is largely due to a better home environment including sanitation, nutrition, health and care enjoyed by the better-off children. .Generally urban children are larger than rural children mainly due to economic differences between the two areas. In most countries the secular trend to children getting larger still continues reflecting an improvement of living conditions with time. Unlike body size, body shape is less influenced by the environment and the change in body proportion brought about by environment is not permanent. In developing countries, children from higher socioeconomic families have generally thicker skinfolds. On the average, infants and preschool children of European ancestry have thicker triceps skinfolds compared with Negroes and Asians living in comparable environments. It is possible that this is due to long term adaptation to different climatic conditions.