17 research outputs found

    Oil Contaminated Soil as Potential Applicable Material in Civil Engineering Construction

    Get PDF
    Subsurface and ground water contamination with chemicals from industrial and agricultural sources poses environmental problems. Apart from constituting health risk to both human and animals (terrestrial and aquatic), it is a source of deterioration to physical, chemical and geotechnical properties of the soil. The reuse of contaminated soil as civil engineering materials is seeing as one of the effective alternative methods of disposing contaminated soil. However, this is subject to either the containment of the agent of contamination in soil or effective remediation of the contaminated soil. The geomechanic and geotechnical behaviour of oil contaminated soil is therefore reviewed to ascertain their potential reuse as engineering material. This is explored in relation to the current state of oil contamination in Nigeria. It is was reported that there was reduction in shear strength and stress-strain behaviour of low plastic and high plastic clays, significant reduction in permeability, strength and compressibility of the contaminated soil, reduction in maximum dry density (MDD) and optimum moisture content (OMC) and increase in liquid and plastic limits of the soil. It is also revealed that the maximum dry density and thus the compaction characteristics of the oil contaminated soil structure depend on the type and viscosity of the pore fluid. Other factors include the nature of the soil particles in relation to its mechanical and physicochemical properties and the presence of any organic or inorganic materials. However, irrespective of these constraints, contaminated soil can still be applied as reused materials as discussed especially in hot-mix asphalt production, concrete production and sandcrete block production. Keywords: Soil, Oil, Contamination, Reuse, Geotechnical properties

    Solid Waste Management in a Leprosarium in Southwestern Nigeria

    Get PDF
    Waste from healthcare institutions generally ought to be treated and disposed hygienically. However, the type of institution normally determines the material component and the nature of the waste generated whether it is hazardous or non-hazardous, infectious or non-infectious waste. Also health status of an individual or community is a function of standard of living, medical services available, social amenities and hygienic environment normally determined through impact assessment. These have been examined in relation to the leprosarium in Ogbomosho, Southwestern Nigeria. The leprosarium under study consists of a clinic and three camps located at about 1000m from the clinic. The leprosarium housed 30 patients, while the camps served as home for about 140 people under rehabilitation together including their children. As one of the health institutions, it is apparent that the waste generated is heterogeneous mixture of both general municipal waste and bio-medical waste. The percentage of biomedical waste which is hazardous in nature is low about 1.0% with average generation rate of 0.13kg/day while that of non-hazardous, non-infectious general waste is 0.288kg/person/day. The average waste generation rate in term of mass is determined to be between 0.084 – 0.095kg/person/day which reveals the poor status and rural nature of these leper settlements. The waste components consist of bandages and swabs, paper, nylon and plastic, domestic waste, animal waste (mostly goat manure), wood ash and yard trimmings which are being disposed on open dump sites and sometimes by open burning which are unhygienic causing health hazards. Accumulation of these waste components without proper disposal initiates its putrefaction which produces offensive odour. In addition, absence of adequate sanitary facilities has promoted open defecation which is a source of infectious, diseases. As an economical, appropriate and useful method of waste disposal, composting was proposed since it is found relevant and acceptable  for the leprosarium and the settlements around as the waste generated is predominantly biodegradable and decomposable materials. Key words: Solid waste, bio-medical waste, characterization, waste disposal, compostin

    Large expert-curated database for benchmarking document similarity detection in biomedical literature search

    Get PDF
    Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe

    Global, regional, and national life expectancy, all-cause mortality, and cause-specific mortality for 249 causes of death, 1980-2015 : a systematic analysis for the Global Burden of Disease Study 2015

    Get PDF
    Background Improving survival and extending the longevity of life for all populations requires timely, robust evidence on local mortality levels and trends. The Global Burden of Disease 2015 Study (GBD 2015) provides a comprehensive assessment of all-cause and cause-specific mortality for 249 causes in 195 countries and territories from 1980 to 2015. These results informed an in-depth investigation of observed and expected mortality patterns based on sociodemographic measures. Methods We estimated all-cause mortality by age, sex, geography, and year using an improved analytical approach originally developed for GBD 2013 and GBD 2010. Improvements included refinements to the estimation of child and adult mortality and corresponding uncertainty, parameter selection for under-5 mortality synthesis by spatiotemporal Gaussian process regression, and sibling history data processing. We also expanded the database of vital registration, survey, and census data to 14 294 geography-year datapoints. For GBD 2015, eight causes, including Ebola virus disease, were added to the previous GBD cause list for mortality. We used six modelling approaches to assess cause-specific mortality, with the Cause of Death Ensemble Model (CODEm) generating estimates for most causes. We used a series of novel analyses to systematically quantify the drivers of trends in mortality across geographies. First, we assessed observed and expected levels and trends of cause-specific mortality as they relate to the Socio-demographic Index (SDI), a summary indicator derived from measures of income per capita, educational attainment, and fertility. Second, we examined factors affecting total mortality patterns through a series of counterfactual scenarios, testing the magnitude by which population growth, population age structures, and epidemiological changes contributed to shifts in mortality. Finally, we attributed changes in life expectancy to changes in cause of death. We documented each step of the GBD 2015 estimation processes, as well as data sources, in accordance with Guidelines for Accurate and Transparent Health Estimates Reporting (GATHER). Findings Globally, life expectancy from birth increased from 61.7 years (95% uncertainty interval 61.4-61.9) in 1980 to 71.8 years (71.5-72.2) in 2015. Several countries in sub-Saharan Africa had very large gains in life expectancy from 2005 to 2015, rebounding from an era of exceedingly high loss of life due to HIV/AIDS. At the same time, many geographies saw life expectancy stagnate or decline, particularly for men and in countries with rising mortality from war or interpersonal violence. From 2005 to 2015, male life expectancy in Syria dropped by 11.3 years (3.7-17.4), to 62.6 years (56.5-70.2). Total deaths increased by 4.1% (2.6-5.6) from 2005 to 2015, rising to 55.8 million (54.9 million to 56.6 million) in 2015, but age-standardised death rates fell by 17.0% (15.8-18.1) during this time, underscoring changes in population growth and shifts in global age structures. The result was similar for non-communicable diseases (NCDs), with total deaths from these causes increasing by 14.1% (12.6-16.0) to 39.8 million (39.2 million to 40.5 million) in 2015, whereas age-standardised rates decreased by 13.1% (11.9-14.3). Globally, this mortality pattern emerged for several NCDs, including several types of cancer, ischaemic heart disease, cirrhosis, and Alzheimer's disease and other dementias. By contrast, both total deaths and age-standardised death rates due to communicable, maternal, neonatal, and nutritional conditions significantly declined from 2005 to 2015, gains largely attributable to decreases in mortality rates due to HIV/AIDS (42.1%, 39.1-44.6), malaria (43.1%, 34.7-51.8), neonatal preterm birth complications (29.8%, 24.8-34.9), and maternal disorders (29.1%, 19.3-37.1). Progress was slower for several causes, such as lower respiratory infections and nutritional deficiencies, whereas deaths increased for others, including dengue and drug use disorders. Age-standardised death rates due to injuries significantly declined from 2005 to 2015, yet interpersonal violence and war claimed increasingly more lives in some regions, particularly in the Middle East. In 2015, rotaviral enteritis (rotavirus) was the leading cause of under-5 deaths due to diarrhoea (146 000 deaths, 118 000-183 000) and pneumococcal pneumonia was the leading cause of under-5 deaths due to lower respiratory infections (393 000 deaths, 228 000-532 000), although pathogen-specific mortality varied by region. Globally, the effects of population growth, ageing, and changes in age-standardised death rates substantially differed by cause. Our analyses on the expected associations between cause-specific mortality and SDI show the regular shifts in cause of death composition and population age structure with rising SDI. Country patterns of premature mortality (measured as years of life lost [YLLs]) and how they differ from the level expected on the basis of SDI alone revealed distinct but highly heterogeneous patterns by region and country or territory. Ischaemic heart disease, stroke, and diabetes were among the leading causes of YLLs in most regions, but in many cases, intraregional results sharply diverged for ratios of observed and expected YLLs based on SDI. Communicable, maternal, neonatal, and nutritional diseases caused the most YLLs throughout sub-Saharan Africa, with observed YLLs far exceeding expected YLLs for countries in which malaria or HIV/AIDS remained the leading causes of early death. Interpretation At the global scale, age-specific mortality has steadily improved over the past 35 years; this pattern of general progress continued in the past decade. Progress has been faster in most countries than expected on the basis of development measured by the SDI. Against this background of progress, some countries have seen falls in life expectancy, and age-standardised death rates for some causes are increasing. Despite progress in reducing age-standardised death rates, population growth and ageing mean that the number of deaths from most non-communicable causes are increasing in most countries, putting increased demands on health systems. Copyright (C) The Author(s). Published by Elsevier Ltd.Peer reviewe

    Global, regional, and national comparative risk assessment of 79 behavioural, environmental and occupational, and metabolic risks or clusters of risks, 1990-2015: a systematic analysis for the Global Burden of Disease Study 2015

    Get PDF
    Forouzanfar MH, Afshin A, Alexander LT, et al. Global, regional, and national comparative risk assessment of 79 behavioural, environmental and occupational, and metabolic risks or clusters of risks, 1990-2015: a systematic analysis for the Global Burden of Disease Study 2015. LANCET. 2016;388(10053):1659-1724.Background The Global Burden of Diseases, Injuries, and Risk Factors Study 2015 provides an up-to-date synthesis of the evidence for risk factor exposure and the attributable burden of disease. By providing national and subnational assessments spanning the past 25 years, this study can inform debates on the importance of addressing risks in context. Methods We used the comparative risk assessment framework developed for previous iterations of the Global Burden of Disease Study to estimate attributable deaths, disability-adjusted life-years (DALYs), and trends in exposure by age group, sex, year, and geography for 79 behavioural, environmental and occupational, and metabolic risks or clusters of risks from 1990 to 2015. This study included 388 risk-outcome pairs that met World Cancer Research Fund-defined criteria for convincing or probable evidence. We extracted relative risk and exposure estimates from randomised controlled trials, cohorts, pooled cohorts, household surveys, census data, satellite data, and other sources. We used statistical models to pool data, adjust for bias, and incorporate covariates. We developed a metric that allows comparisons of exposure across risk factors-the summary exposure value. Using the counterfactual scenario of theoretical minimum risk level, we estimated the portion of deaths and DALYs that could be attributed to a given risk. We decomposed trends in attributable burden into contributions from population growth, population age structure, risk exposure, and risk-deleted cause-specific DALY rates. We characterised risk exposure in relation to a Socio-demographic Index (SDI). Findings Between 1990 and 2015, global exposure to unsafe sanitation, household air pollution, childhood underweight, childhood stunting, and smoking each decreased by more than 25%. Global exposure for several occupational risks, high body-mass index (BMI), and drug use increased by more than 25% over the same period. All risks jointly evaluated in 2015 accounted for 57.8% (95% CI 56.6-58.8) of global deaths and 41.2% (39.8-42.8) of DALYs. In 2015, the ten largest contributors to global DALYs among Level 3 risks were high systolic blood pressure (211.8 million [192.7 million to 231.1 million] global DALYs), smoking (148.6 million [134.2 million to 163.1 million]), high fasting plasma glucose (143.1 million [125.1 million to 163.5 million]), high BMI (120.1 million [83.8 million to 158.4 million]), childhood undernutrition (113.3 million [103.9 million to 123.4 million]), ambient particulate matter (103.1 million [90.8 million to 115.1 million]), high total cholesterol (88.7 million [74.6 million to 105.7 million]), household air pollution (85.6 million [66.7 million to 106.1 million]), alcohol use (85.0 million [77.2 million to 93.0 million]), and diets high in sodium (83.0 million [49.3 million to 127.5 million]). From 1990 to 2015, attributable DALYs declined for micronutrient deficiencies, childhood undernutrition, unsafe sanitation and water, and household air pollution; reductions in risk-deleted DALY rates rather than reductions in exposure drove these declines. Rising exposure contributed to notable increases in attributable DALYs from high BMI, high fasting plasma glucose, occupational carcinogens, and drug use. Environmental risks and childhood undernutrition declined steadily with SDI; low physical activity, high BMI, and high fasting plasma glucose increased with SDI. In 119 countries, metabolic risks, such as high BMI and fasting plasma glucose, contributed the most attributable DALYs in 2015. Regionally, smoking still ranked among the leading five risk factors for attributable DALYs in 109 countries; childhood underweight and unsafe sex remained primary drivers of early death and disability in much of sub-Saharan Africa. Interpretation Declines in some key environmental risks have contributed to declines in critical infectious diseases. Some risks appear to be invariant to SDI. Increasing risks, including high BMI, high fasting plasma glucose, drug use, and some occupational exposures, contribute to rising burden from some conditions, but also provide opportunities for intervention. Some highly preventable risks, such as smoking, remain major causes of attributable DALYs, even as exposure is declining. Public policy makers need to pay attention to the risks that are increasingly major contributors to global burden. Copyright (C) The Author(s). Published by Elsevier Ltd

    Wastewater management in a Nigerian leper colony

    Get PDF
    Wastewater from infected leprosy patients is expected to contain considerably higher concentrations of pathogens than standard domestic wastewater and, therefore, is more infectious. Isolation of lepers' is thought to prevent the spread of a wide range of infectious diseases that could potentially be contacted through direct or indirect exposure from an infected person's wastewater in the surrounding environment. However, inappropriate management of wastewater and sewage from these camps has led to contamination of the surrounding environment, typical in Nigeria. This study aims to recommend safe, efficient and sustainable management of wastewater and sewage in a lepers' colony in Ogbomosho, south west Nigeria. The case study is privately owned, with three camps and a leprosarium. Information and data (primary and secondary) were collected from medical personnel (doctors, matrons and nurses), management staff and lepers in each camp, through hand- delivered and orally explained questionnaires and physical observations. Wastewater samples could not be collected for analysis because there were no septic tanks or drainage for sewage and wastewater disposal. Two of the camps have no sanitary disposal system, with the remaining camp occupying one pit latrine, which is inadequate in prevention of environmental pollution. The leprosarium itself uses the pit latrine as an improvised bathroom and for defecation. Therefore, a further aim of this work is to provide a sewage treatment facility to cope with the problem of unsanitary disposal of excreta. The majority of wastewater is generated from bathing, personal washing, ward clean-ups, patients' services and general house-keeping activities. The approximate quantity of water being used per head per day was found to be 64-79 litres, resulting in ~60 litres of wastewater that was discharged without treatment. To ameliorate environmental risks that leper colonies are responsible for, the pour-flush toilet was recommended based on its suitability for the physical condition of lepers, its ease of operation, maintenance and sustainability, minimum water usage for flushing and low construction costs. However, this must be fed into a well designed and sited septic tank and soak-away pit to receive foul sewage and sullage, respectively. Ideally, construction of a proper in-built bathroom is recommended for both the leprosarium and camps. © 2011 Vilnius Gediminas Technical University (VGTU) Press Technika
    corecore