62 research outputs found

    The importance of primary data for life cycle assessment of construction products in Brazil

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    This work presents a study of six construction products: sand, gravel, clay block, concrete block, ready-mix concrete and mortar. National LCIs were developed using primary data collected at manufacturers located in the State of São Paulo, and upstream and downstream processes were based on the ecoinvent database. Datasets available in ecoinvent deemed representative of these six construction products were chosen for comparison. Four impact indicators were calculated: Global Warming Potential, Water Depletion, Cumulative Energy Demand and Resource Depletion. The differences between the national and the international impact results range from 10% to 255%, with an overall average difference of 69%. GWP was the indicator with the least average difference (53%); while Water Depletion had the highest (101%). Regarding the products, the differences considering all impact indicators range from 42% (gravel) to 109% (clay block). The results indicate the importance of national LCIs based on primary data in order to ensure reliable construction LCA studies in Brazi

    Adaptation of life-cycle inventories of sawn timber used in the structure of roofs in the state of São Paulo

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    Este trabalho teve como objetivo desenvolver o inventário de ciclo de vida para madeira empregada na estrutura de telhado de edificações populares do Estado de São Paulo, com base na adaptação de inventários existentes na base de dados ecoinvent (versão 3.1) para a realidade da produção madeireira no Brasil. Considerou-se como sistema de produto a produção de 1m3 de madeira serrada de cambará proveniente de manejo florestal sustentável na Amazônia, desde a extração das toras até a peça de madeira serrada estocada em São Paulo. As informações nacionais foram obtidas da literatura. A despeito das semelhanças entre o sistema de produto da base ecoinvent e a realidade nacional na extração das toras na floresta, há diferenças referentes ao transporte até a serraria, ao desdobro das toras e à geração e destinação de resíduos: no Brasil, todas as etapas são executadas próximas à região de exploração, resultando em alterações no modelo de transporte, máquinas empregadas e resíduos gerados. Além disso, os valores de consumo de diesel e eletricidade apresentaram ordens de grandeza diferentes dos ICVs de referência. Com base nessa análise, conclui-se que a estrutura de dados dos ICVs existentes na base ecoinvent auxilia a construção de inventários nacionais e que a adaptação dos inventários é imprescindível para a realização de estudos de avaliação do ciclo de vida condizentes com as condições do Brasil. Entretanto, considerando as diferenças observadas, é recomendada a apuração dos índices de consumo nacionais por meio de verificação e coleta de dados inloc

    Comparative analysis of procedures for the estimation of uncertainties in LCA: clay brick case study

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    O presente trabalho tem como objetivo discutir a estimativa de incertezas em ACV, utilizando três procedimentos de cálculo a partir de dados de inventários da produção de blocos cerâmicos de uma fábrica localizada no Estado de São Paulo (berço ao portão). O primeiro procedimento para a estimativa de incertezas consistiu na atribuição de modelos probabilísticos e seus parâmetros aos valores obtidos na fábrica. As distribuições de probabilidade foram selecionadas dentre as disponíveis no Simapro (versão 8.1.1.16). O segundo procedimento consistiu na aplicação das diretrizes do Ecoinvent versão 3.1 relativas a incertezas, adotandose valores padronizados de incerteza básica e incertezas adicionais da matriz Pedigree, com distribuição lognormal. O terceiro procedimento consistiu em uma mescla dos procedimentos prévios: adotou-se o primeiro procedimento para o cálculo da incerteza básica e a matriz Pedigree para a atribuição da incerteza adicional. Os ICVs foram inseridos com suas respectivas incertezas no Simapro e foram feitas simulações de Monte Carlo com parâmetros equivalentes para as três situações. Realizaram-se também análises de variância (ANOVA) para verificar a distribuição das incertezas entre o processo principal e os processos a montante. Observou-se que os procedimentos 1 e 2 são passíveis de adoção em estudos de ACV, a depender da disponibilidade de recursos e do nível de detalhamento do estudo em questão, sendo que o primeiro procedimento, que envolve o cálculo direto das incertezas associadas, tem potencial de agregar maior confiabilidade ao estudo de ACV, enquanto o segundo requer menor esforço para a estimativa de incertezas. Ambas as abordagens melhoram a qualidade do resultado final a ser comunicado em relação à divulgação de um valor determinístico único

    Anti-malarial prescriptions in three health care facilities after the emergence of chloroquine resistance in Niakhar, Senegal (1992–2004)

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    <p>Abstract</p> <p>Background</p> <p>In the rural zone of Niakhar in Senegal, the first therapeutic failures for chloroquine (CQ) were observed in 1992. In 2003, the national policy regarding first-line treatment of uncomplicated malaria was modified, replacing CQ by a transitory bi-therapy amodiaquine/sulphadoxine-pyrimethamine (AQ/SP), before the implementation of artemisinin-based combination therapy (ACT) in 2006.</p> <p>The aims of the study were to assess the evolution of anti-malarial prescriptions in three health care facilities between 1992 and 2004, in parallel with increasing CQ resistance in the region.</p> <p>Methods</p> <p>The study was conducted in the area of Niakhar, a demographic surveillance site located in a sahelo-sudanese region of Senegal, with mesoendemic and seasonal malaria transmission. Health records of two public health centres and a private catholic dispensary were collected retrospectively to cover the period 1992–2004.</p> <p>Results</p> <p>Records included 110,093 consultations and 292,965 prescribed treatments. Twenty-five percent of treatments were anti-malarials, prescribed to 49% of patients. They were delivered all year long, but especially during the rainy season, and 20% of patients with no clinical malaria diagnosis received anti-malarials. Chloroquine and quinine represented respectively 55.7% and 34.6% of prescribed anti-malarials. Overall, chloroquine prescriptions rose from 1992 to 2000, in parallel with clinical malaria; then the CQ prescription rate decreased from 2000 and was concomitant with the rise of SP and the persistence of quinine use. AQ and SP were mainly used as bi-therapy after 2003, at the time of national treatment policy change.</p> <p>Conclusion</p> <p>The results show the overall level of anti-malarial prescription in the study area for a considerable number of patients over a large period of time. Even though resistance to CQ rapidly increased from 1992 to 2001, no change in CQ prescription was observed until the early 2000s, possibly due to the absence of an obvious decrease in CQ effectiveness, a lack of therapeutic options or a blind follow-up of national guidelines.</p

    Evolution of malaria mortality and morbidity after the emergence of chloroquine resistance in Niakhar, Senegal

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    Background: Recently, it has been assumed that resistance of Plasmodium to chloroquine increased malaria mortality. The study aimed to assess the impact of chemoresistance on mortality attributable to malaria in a rural area of Senegal, since the emergence of resistance in 1992, whilst chloroquine was used as first-line treatment of malaria, until the change in national anti-malarial policy in 2003. Methods: The retrospective study took place in the demographic surveillance site (DSS) of Niakhar. Data about malaria morbidity were obtained from health records of three health care facilities, where diagnosis of malaria was based on clinical signs. Source of data concerning malaria mortality were verbal autopsies performed by trained fieldworkers and examined by physicians who identified the probable cause of death. Results: From 1992 to 2004, clinical malaria morbidity represented 39% of total morbidity in health centres. Mean malaria mortality was 2.4 parts per thousand and 10.4 parts per thousand among total population and children younger than five years, respectively, and was highest in the 1992-1995 period. It tended to decline from 1992 to 2003 (Trend test, total population p = 0.03, children 0-4 years p = 0.12 - children 1-4 years p = 0.04 - children 5-9 years p = 0.01). Conclusion: Contrary to what has been observed until 1995, mortality attributable to malaria did not continue to increase dramatically in spite of the growing resistance to chloroquine and its use as first-line treatment until 2003. Malaria morbidity and mortality followed parallel trends and rather fluctuated accordingly to rainfall

    Management of sulphur fertiliser to improve durum wheat production and minimise S leaching

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    Optimisation of S release from decomposing soil organic matter and S fertiliser related to plant S uptake is a central issue and goal in applied research in agricultural systems. Two lysimeter experiments were conducted in central Italy in two subsequent seasons on two commercial durum wheat cultivars to investigate the effects on yield, S and N uptake and leaching of different rates of N and S fertilisers, soil type and split applications of S. Sulphur fertiliser increased grain yield and N and S uptake of both varieties. Grain yield increase was mainly due to an increase of the number of kernels per spike, which was interpreted as a stimulation of the initiation of spikelets and/or florets, or to a reduction the floret mortality. As an average of the two seasons, S leaching during wheat cycle was 35 kg S ha−1. Sulphur fertiliser rate increased S concentration in drainage water and consequently S leached during wheat cycle. Compared to unfertilised control, S leached was by 13 kg ha−1 higher at 60 kg S ha−1 and by 19 kg ha−1 higher at 120 kg S ha−1. The splitting of sulphur fertiliser during crop cycle modified both grain yield and S leaching. The highest grain yield and S plant uptake was obtained with the splitting of S rate into 60 kg S ha−1 before seeding and 60 kg S ha−1 at stem elongation and the lowest amount of S lost by leaching occurred with the application of 36 kg S ha−1 before seeding and 84 kg S ha−1 at stem elongation. Sulphur output was equally accounted for by leaching and plant uptake. The input–output balance of S was positive in both experiments only when the higher S rate was applied, as more S was imported than removed. Thus, no substantial S deficit may be expected in short term, provided that high S fertiliser rate is applied and the availability of S is synchronised with plant needs
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