Impact of exposure to cooking-generated air pollution on human respiratory health: A case study of different microenvironments of India

Cooking is a significant source of indoor air pollution (IAP) and is associated with significant morbidity and mortality. Liquefied petroleum gas (LPG; predominant cooking fuel of urban India), though safer than solid fuels, emits significant concentration of fine particles, NO_x and several other pollutants, which may trigger respiratory ailments. Effect of exposure to pollutants, generated from fuel combustion and cooking activities, on subjects of different microenvironments has been assessed by carrying out a health survey using a questionnaire and by conducting spirometry. A significant increase in prevalence of cough and impairment of lung functions has been found among cooks compared to non-cooks. A significant difference in prevalence of cough between smoker and non-smoker non-cooks but no such difference in cooks suggests that kitchen pollutants and smoking have similar effects on respiratory system. Comparison of lung functions (average FEV1% predicted and average FVC% predicted) of cooks (90.6% and 82.6%) and non-cooks (93.7% and 86.2%) shows a significant difference in certain categories. The study brings out a close association between different kitchen microenvironments and specific respiratory parameters, signifying short- and long-term impairment. The impairment is prevalent in both rural and urban Indian cooks, signifying that fuel usage (biomass and LPG) and cooking practices play a prominent role in affecting respiratory health.     

A Cost-Benefit Analysis of Leaves of Eight Australian Savanna Tree Species of Differing Leaf Life-Span

Cost-benefit analysis of foliar construction and maintenance costs and of carbon assimilation of leaves of differing life-span were conducted using two evergreen, three semi-deciduous, and three deciduous tree species of savannas of north Australia. Rates of radiant-energy-saturated CO₂ assimilation (P _max) and dark respiration were measured and leaves were analysed for total nitrogen, fat, and ash concentrations, and for heat of combustion. Specific leaf area, and leaf N and ash contents were significantly lower in longer-lived leaves (evergreen) than shorter-lived leaves (deciduous) species. Leaves of evergreen species also had significantly higher heat of combustion and lower crude fat content than leaves of deciduous species. On a leaf area basis, P _max was highest in leaves of evergreen species, but on a leaf dry mass basis it was highest in leaves of deciduous species. P _max and total Kieldahl N content were linearly correlated across all eight species, and foliar N content was higher in leaves of deciduous than evergreen species. Leaf construction cost was significantly higher and maintenance costs were lower for leaves of evergreen than deciduous species. Maintenance and construction costs were linearly related to each other across all species. Leaves of evergreen species had a higher cost-benefit ratio compared to leaves of deciduous species but with longer lived leaves, the payback interval was longer in evergreen than deciduous species. These results support the hypotheses that longer lived leaves are more expensive to construct than short-lived leaves, and that a higher investment of N into short-lived leaves occurs which supports a higher P _max over a shorter payback interval. This revised version was published online in June 2006 with corrections to the Cover Date.     

Comparative LCAs for Curbside Recycling Versus Either Landfilling or Incineration with Energy Recovery (12 pp)

Background This article describes two projects conducted recently by Sound Resource Management (SRMG) – one for the San Luis Obispo County Integrated Waste Management Authority (SLO IWMA) and the other for the Washington State Department of Ecology (WA Ecology). For both projects we used life cycle assessment (LCA) techniques to evaluate the environmental burdens associated with collection and management of municipal solid waste. Both projects compared environmental burdens from curbside collection for recycling, processing, and market shipment of recyclable materials picked up from households and/or businesses against environmental burdens from curbside collection and disposal of mixed solid waste. Method logy. The SLO IWMA project compared curbside recycling for households and businesses against curbside collection of mixed refuse for deposition in a landfill where landfill gas is collected and used for energy generation. The WA Ecology project compared residential curbside recycling in three regions of Washington State against the collection and deposition of those same materials in landfills where landfill gas is collected and flared. In the fourth Washington region (the urban east encompassing Spokane) the WA Ecology project compared curbside recycling against collection and deposition in a wasteto- energy (WTE) combustion facility used to generate electricity for sale on the regional energy grid. During the time period covered by the SLO study, households and businesses used either one or two containers, depending on the collection company, to separate and set out materials for recycling in San Luis Obispo County. During the time of the WA study households used either two or three containers for the residential curbside recycling programs surveyed for that study. Typically participants in collection programs requiring separation of materials into more than one container used one of the containers to separate at least glass bottles and jars from other recyclable materials. For the WA Ecology project SRMG used life cycle inventory (LCI) techniques to estimate atmospheric emissions of ten pollutants, waterborne emissions of seventeen pollutants, and emissions of industrial solid waste, as well as total energy consumption, associated with curbside recycling and disposal methods for managing municipal solid waste. Emissions estimates came from the Decision Support Tool (DST) developed for assessing the cost and environmental burdens of integrated solid waste management strategies by North Carolina State University (NCSU) in conjunction with Research Triangle Institute (RTI) and the US Environmental Protection Agency (US EPA)1. RTI used the DST to estimate environmental emissions during the life cycle of products. RTI provided those estimates to SRMG for analysis in the WA Ecology project2. For the SLO IWMA project SRMG also used LCI techniques and data from the Municipal Solid Waste Life- Cycle Database (Database), prepared by RTI with the support of US EPA during DST model development, to estimate environmental emissions from solid waste management practices3. Once we developed the LCI data for each project, SRMG then prepared a life cycle environmental impacts assessment of the environmental burdens associated with these emissions using the Environmental Problems approach discussed in the methodology section of this article. Finally, for the WA study we also developed estimates of the economic costs of certain environmental impacts in order to assess whether recycling was cost effective from a societal point of view. Conclusions Recycling of newspaper, cardboard, mixed paper, glass bottles and jars, aluminum cans, tin-plated steel cans, plastic bottles, and other conventionally recoverable materials found in household and business municipal solid wastes consumes less energy and imposes lower environmental burdens than disposal of solid waste materials via landfilling or incineration, even after accounting for energy that may be recovered from waste materials at either type disposal facility. This result holds for a variety of environmental impacts, including global warming, acidification, eutrophication, disability adjusted life year (DALY) losses from emission of criteria air pollutants, human toxicity and ecological toxicity. The basic reason for this conclusion is that energy conservation and pollution prevention engendered by using recycled rather than virgin materials as feedstocks for manufacturing new products tends to be an order of magnitude greater than the additional energy and environmental burdens imposed by curbside collection trucks, recycled material processing facilities, and transportation of processed recyclables to end-use markets. Furthermore, the energy grid offsets and associated reductions in environmental burdens yielded by generation of energy from landfill gas or from waste combustion are substantially smaller then the upstream energy and pollution offsets attained by manufacturing products with processed recyclables, even after accounting for energy usage and pollutant emissions during collection, processing and transportation to end-use markets for recycled materials. The analysis that leads to this conclusion included a direct comparison of the collection for recycling versus collection for disposal of the same quantity and composition of materials handled through existing curbside recycling programs in Washington State. This comparison provides a better approximation to marginal energy usage and environmental burdens of recycling versus disposal for recyclable materials in solid waste than does a comparison of the energy and environmental impacts of recycling versus management methods for handling typical mixed refuse, where that refuse includes organics and non-recyclables in addition to whatever recyclable materials may remain in the garbage. Finally, the analysis also suggests that, under reasonable assumptions regarding the economic cost of impacts from pollutant emissions, the societal benefits of recycling outweigh its costs.     

内蒙古大兴安岭森林可燃物燃烧释放PM2.5中水溶性离子排放特性

研究森林可燃物燃烧释放的细颗粒物(PM_2.5)的排放因子对于揭示森林火灾对大气和生态系统的影响至关重要,而水溶性离子是细颗粒物的重要化学成分,对颗粒物的形成具有重要意义。利用自主设计的生物质燃烧系统,模拟内蒙古大兴安岭5种典型乔木(蒙古栎、白桦、兴安落叶松、黑桦、山杨)的3种组成部分(树干、树枝、树皮)及其地表死可燃物(凋落物层、半腐殖质层、腐殖质层)以及3种典型灌木(平榛、二色胡枝子、兴安杜鹃)树枝燃烧,采用ISC1100离子色谱分析仪测定2种燃烧状态(阴燃和明燃)下PM_2.5中水溶性离子(Na⁺、NH₄⁺、K⁺、Mg²⁺、Ca²⁺、F^-、Cl^-、NO₃^-、NO₂^-、SO₄^2-)的排放因子。结果表明:乔木所有组成部分及其地表死可燃物和灌木树枝燃烧所排放PM_2.5中检测到的水溶性离子,阴燃以K⁺、Cl^-和Na⁺为主要组分,明燃以K⁺、Cl^-和SO₄^2-为主要组分。不同燃烧状态下相同乔木树种及其地表死可燃物和相同灌木排放PM_2.5中检测到的水溶性离子总量均存在显著差异。灌木树枝在阴燃期间PM_2.5中水溶性无机离子的排放因子比明燃更高。乔木释放的PM_2.5中阳离子与阴离子的比率为1.26,地表死可燃物为1.12,灌木为2.0,表明颗粒物呈碱性。内蒙古大兴安岭的森林大火不会通过释放水溶性离子导致生态系统的酸化。     

兴安落叶松人工林腐殖质阴燃燃烧温度变化特征

森林地下火是发生在腐殖质层的一种缓慢、无焰、低温、持久的阴燃燃烧,整个燃烧过程都是靠自身所释放的热量所维持。所以地下火发生时产生的温度是研究其火行为特征的重要指标,更是森林地下火监测和扑救过程中的重要依据。以大兴安岭地区5种地类下人工种植的兴安落叶松林为研究对象,以室内控制点烧实验为基础,研究不同地类和腐殖质粒径阴燃燃烧的温度变化特征。结果表明：不同粒径的腐殖质阴燃燃烧最高温度之间不存在显著差异（P>0.05）,而不同地类和二者的交互作用对阴燃燃烧最高温度的影响则存在显著差异（P<0.05）;4种腐殖质粒径下不同地类之间的阴燃燃烧最高温度都存在显著差异（P<0.05）。任意一种腐殖质粒径下塔头甸子的阴燃燃烧温度都是最高的,最高可达897.53℃,其次是水湿地,有坡山地、无坡山地、农用地的腐殖质阴燃燃烧温度较低。不同地类的腐殖质燃烧地表温度较高,最高温度可达618.83℃;随着燃烧时间的增加,腐殖质燃烧的地表温度随之降低,二者之间关系可以用y=a×x^b方程拟合,并且拟合程度高（R²>0.9,P<0.01）。相关研究成果可以为该地区森林地下火监测扑救提供科学有效的理论依据。     

大兴安岭小尺度草甸火燃烧效率研究

燃烧效率是进行生物质燃烧温室气体释放量计算的关键因子,以大兴安岭典型草甸区为研究区域,通过样地调查和采样,应用GIS和地统计学的方法对燃烧格局和燃烧效率进行计算。结果表明:研究区域内草甸可燃物的平均载量为37.3t/hm²,草本层、枯落物层和腐殖层载量平均所占比例分别为18.50%,28.95%和52.55%。样地的块金系数分别在80.84%-97.88%之间变化,过火迹地的燃烧深度具有弱的空间相关性。研究区域内平均燃烧效率为64.51%,根据不同的火烧强度,研究区域的燃烧效率在44.35%-90.6%之间变化。     

Product specific emissions from municipal solid waste landfills

This paper presents and verifies the computer tool LCA-LAND for estimation of emissions from specific waste products disposed in municipal solid waste landfills in European countries for use in the inventory analysis of LCA. Examples of input data (e.g. distribution of the waste product in different countries, composition of the product and physical/chemical/biological properties of waste product components) and output data (e.g. estimated emissions to atmosphere and water) are given for a fictive waste product made of representative types of components (toluene, cellulose, polyvinylchloride (PVC), copper and chloride). Since waste products from different processes in the product system may be disposed at different landfills where they are mixed with waste originating outside the product system, the estimated emissions from specific waste products cannot be compared with measured emissions from true landfills. Hence, the computer tool is verified in terms of mass balances and sensitivity analyses. The mass balances agree exactly and the sensitivity analyses show that different types of waste product components behave differently in different types of landfills. Emission of e.g. toluene is significantly reduced in the presence of landfill top-cover, landfill gas combustion units and leachate treatment units. Generally, the sensitivity analysis shows good agreement between the relative proportions of various types of emissions (based on properties of the waste and properties of landfills) and good agreement with emission levels that would be expected based on a general understanding of landfill processes.     

High‐Performance Planar Perovskite Solar Cells Using Low Temperature,Solution–Combustion‐Based Nickel Oxide Hole Transporting Layer with Efficiency Exceeding 20%

NiO_x hole transporting layer has been extensively studied in optoelectronic devices. In this paper, the low temperature, solution–combustion‐based method is employed to prepare the NiO_x hole transporting layer. The resulting NiO_x thin films show better quality and preferable energy alignment with perovskite thin film compared to high temperature sol–gel‐processed NiO_x. With this, high‐performance perovskite solar cells are fabricated successfully with power conversion efficiency exceeding 20% using a modified two‐step prepared MA_1?yFA_yPbI_3?xCl_x perovskite. This efficiency value is among the highest values for NiO_x‐based devices. Various characterizations and analyses provide evidence of better film quality, enhanced charge transport and extraction, and suppressed charge recombination. Meanwhile, the device exhibits much better device stability compared to sol–gel‐processed NiO_x and poly(3,4‐ethylenedioxythiophene):poly(styrenesulfonate)‐based devices.     

Temperature and efficiency of development during endogenous feeding in herring embryos and yolk-sac larvae

Oxygen uptakes, dry weights and energy contents of herring Clupea harengus were measured periodically from the time of egg fertilization to the end of the yolk-sac stage (without added food). Temperature of incubation (3·5–17° C) had little effect on efficiency of conversion of egg reserves to body material.     

Sedimentary records of carbonaceous particles from fossil fuel combustion

Carbonaceous particles produced by fossil fuel combustion can be found in considerable amounts in recent lake sediments. As these particles contain elemental carbon they are resistant to chemical decomposition and therefore both well preserved in sediments and possible to quantify. Sediment samples can be oxidized with H₂O₂ and digested with HF without the particles being destroyed. The pioneers in studying carbonaceous particles in lake sediments in relation to fossil fuel combustion were J. J. Griffin and E. D. Goldberg. They measured elemental carbon concentrations in Lake Michigan sediments, mainly by infrared assay. On the basis of these analyses, size distribution measurements and also morphological studies of single particles they concluded that the carbonaceous particle record reflected the onset of industrial activity and the increased intensities of fossil fuel combustion during the twentieth century. Similar results have been obtained from another lake in the USA by B. K. Kothari and M. Wahlen. We have counted spherical carbonaceous particles (larger than 5–10 µm), which are characteristic for oil and coal burning, in several lake sediments. In Swedish lakes, the annual accumulation of coarse carbonaceous spheres in varved sediments and the concentration stratigraphy in non-varved sediments, follow the same main pattern as statistical data for the Swedish coal and oil combustion over the last two centuries. Coarse carbonaceous spheres in two sediment profiles from Scottish lakes have also been counted. As for the USA and Sweden the sedimentary record was found to reflect the history of fossil fuel combustion.