Evaluaci��n de la exposici��n laboral a material particulado en empresas pertenecientes a diferentes sectores econ��micos en Colombia, 2014

Introducci��n El material particulado son part��culas s��lidas y l��quidas emitidas al aire, las cuales pueden generar diferentes alteraciones en la salud, variando desde cuadros respiratorios al��rgicos, a episodios asm��ticos, dermatitis o inclusive llegar a facilitar la g��nesis de enfermedades de tipo neopl��sico. Estos pueden tener origen natural e industrial, encontrandose en diferentes actividades econ��micas. Objetivo Evaluar la exposici��n laboral a material particulado en empresas pertenecientes a diferentes sectores econ��micos afiliadas a una ARL en Colombia, en el periodo comprendido entre 2011 al 2014 Metodolog��a Es un estudio de corte transversal, analizando una base de datos de 257 empresas con 1108 mediciones de material particulado, recolectados entre 2011 ��� 2014. Las variables usadas fueron: regi��n, actividad econ��mica, ��rea, oficio, tiempo de exposici��n y concentraci��n de material particulado. Se realiz�� distribuciones de frecuencia, medidas de tendencia central y de dispersi��n. Se evaluaron las diferencias de las distribuciones de los tiempos de exposici��n y el porcentaje de exposici��n entre los grupos con y sin riesgo (los que sobrepasaban o no los l��mites permisibles), con la prueba asint��tica no param��trica de Mann Whitney. Resultados Las principales mediciones ambientales en las empresas fueron en la industria qu��mica con un 31%, siendo 2 de cada 3 datos pertenecientes a la regi��n andina, las cuales tienen como principales contaminantes qu��micos las part��culas no fraccionadas con el 70,9%. Respecto a las concentraciones ambientales de material particulado en las empresas participantes, se encontr�� un promedio de 1,72 mg/m3 �� 3,613, con una mediana de 0,480 mg/m3 y un coeficiente de variaci��n de 210,05%. El 2,9% sobrepasaron los valores l��mites establecidos por la ACGIH (American Conference of Governmental Industrial Hygienists) y el 92,5% seg��n los l��mites de la EPA (Agencia de Protecci��n del Ambiente), presentando mayor riesgo en el personal operativo con 93,3% (p= 0,002). Conclusi��n El riesgo seg��n los l��mites establecidos por la ACGIH para las mediciones realizadas en Colombia fue bajo, aunque al utilizar los par��metros de la EPA, el riesgo fue alto, por lo cual se requiere hacer un seguimiento espec��fico a estas empresas y fomentar la implementaci��n del sistema de gesti��n en seguridad y salud en el trabajo.

Aerial image analysis using spiking neural networks with application to power line corridor monitoring

Trees, shrubs and other vegetation are of continued importance to the environment and our daily life. They provide shade around our roads and houses, offer a habitat for birds and wildlife, and absorb air pollutants. However, vegetation touching power lines is a risk to public safety and the environment, and one of the main causes of power supply problems. Vegetation management, which includes tree trimming and vegetation control, is a significant cost component of the maintenance of electrical infrastructure. For example, Ergon Energy, the Australia���s largest geographic footprint energy distributor, currently spends over $80 million a year inspecting and managing vegetation that encroach on power line assets. Currently, most vegetation management programs for distribution systems are calendar-based ground patrol. However, calendar-based inspection by linesman is labour-intensive, time consuming and expensive. It also results in some zones being trimmed more frequently than needed and others not cut often enough. Moreover, it���s seldom practicable to measure all the plants around power line corridors by field methods. Remote sensing data captured from airborne sensors has great potential in assisting vegetation management in power line corridors. This thesis presented a comprehensive study on using spiking neural networks in a specific image analysis application: power line corridor monitoring. Theoretically, the thesis focuses on a biologically inspired spiking cortical model: pulse coupled neural network (PCNN). The original PCNN model was simplified in order to better analyze the pulse dynamics and control the performance. Some new and effective algorithms were developed based on the proposed spiking cortical model for object detection, image segmentation and invariant feature extraction. The developed algorithms were evaluated in a number of experiments using real image data collected from our flight trails. The experimental results demonstrated the effectiveness and advantages of spiking neural networks in image processing tasks. Operationally, the knowledge gained from this research project offers a good reference to our industry partner (i.e. Ergon Energy) and other energy utilities who wants to improve their vegetation management activities. The novel approaches described in this thesis showed the potential of using the cutting edge sensor technologies and intelligent computing techniques in improve power line corridor monitoring. The lessons learnt from this project are also expected to increase the confidence of energy companies to move from traditional vegetation management strategy to a more automated, accurate and cost-effective solution using aerial remote sensing techniques.

Role of traffic in atmospheric accumulation of heavy metals and polycyclic aromatic hydrocarbons

Traffic related emissions have been recognised as one of the main sources of air pollutants. In the research study discussed in this paper, variability of atmospheric total suspended particulate matter (TSP), polycyclic aromatic hydrocarbons (PAH) and heavy metal (HM) concentrations with traffic and land use characteristics during weekdays and weekends were investigated. Data required for the study were collected from a range of sampling sites to ensure a wide mix of traffic and land use characteristics. The analysis undertaken confirmed that zinc has the highest concentration in the atmospheric phase during weekends as well as weekdays. Although the use of leaded gasoline was discontinued a decade ago, lead was the second most commonly detected heavy metal. This is attributed to the association of previously generated lead with roadside soil and re-suspension to the atmosphere. Soil related particles are the primary source of TSP and manganese to the atmosphere. The analysis further revealed that traffic sources are dominant in gas phase PAHs compared to the other sources during weekdays. Land use related sources become important contributors to atmospheric PAHs during weekends when traffic sources are at their minimal levels.

Sustainability in road transport : an integrated life cycle analysis for estimating emissions

Despite of a significant contribution of transport sector in the global economy and society, it is one of the largest sources of global energy consumption, green house gas emissions and environmental pollutions. A complete look onto the whole life cycle environmental inventory of this sector will be helpful to generate a holistic understanding of contributory factors causing emissions. Previous studies were mainly based on segmental views which mostly compare environmental impacts of different modes of transport, but very few consider impacts other than the operational phase. Ignoring the impacts of non-operational phases, e.g., manufacture, construction, maintenance, may not accurately reflect total contributions on emissions. Moreover an integrated study for all motorized modes of road transport is also needed to achieve a holistic estimation. The objective of this study is to develop a component based life cycle inventory model which considers impacts of both operational and non-operational phases of the whole life as well as different transport modes. In particular, the whole life cycle of road transport has been segmented into vehicle, infrastructure, fuel and operational components and inventories have been conducted on each component. The inventory model has been demonstrated using the road transport of Singapore. Results show that total life cycle green house gas emissions from the road transport sector of Singapore is 7.8 million tons per year, among which operational phase and non-operational phases contribute about 55% and about 45%, respectively. Total amount of criteria air pollutants are 46, 8.5, 33.6, 13.6 and 2.6 thousand tons per year for CO, SO2, NOx, VOC and PM10, respectively. From the findings, it can be deduced that stringent government policies on emission control measures have a significant impact on reducing environmental pollutions. In combating global warming and environmental pollutions the promotion of public transport over private modes is an effective sustainable policy.

Respiratory health effects of diesel particulate matter

Particulate matter (PM) emissions involve a complex mixture of solid and liquid particles suspended in a gas, where it is noted that PM emissions from diesel engines are a major contributor to the ambient air pollution problem. Whilst epidemiological studies have shown a link between increased ambient PM emissions and respiratory morbidity and mortality, studies of this design are not able to identify the PM constituents responsible for driving adverse respiratory health effects. This review explores in detail the physico-chemical properties of diesel particulate matter (DPM), and identifies the constituents of this pollution source that are responsible for the development of respiratory disease. In particular, this review shows that the DPM surface area and adsorbed organic compounds play a significant role in manifesting chemical and cellular processes that if sustained can lead to the development of adverse respiratory health effects. The mechanisms of injury involved included: inflammation, innate and acquired immunity, and oxidative stress. Understanding the mechanisms of lung injury from DPM will enhance efforts to protect at-risk individuals from the harmful respiratory effects of air pollutants.

Airborne concentration of Volatile Organic Compounds in school environment in Brisbane

Traffic emissions are considered as a major source of pollutants, particularly ultrafine particles, in the urban environment. There is an increased concern about airborne particles not only because of their environmental effects but also due to their potential adverse health effects on humans. There have been a number of studies related to the number concentration and size distribution of these particles but studies on the chemical composition of aerosols, especially in the school environment, are very limited. Mejia et. al (2011) reviewed studies on the exposure to and impact of air pollutants on school children and found that there were only a handful of studies on this topic. Therefore, the main focus of this research is on an analysis of the chemical composition of airborne particles, as well as source apportionment and the quantification of ambient concentrations of organic pollutants in the vicinity of schools, as a part of ���Ultrafine Particles from Traffic Emissions on Children���s Health��� (UPTECH) project. The aim of the present study was to find out the concentrations of different Volatile Organic Compounds (VOCs) in both outdoor and indoor locations from six different schools in Brisbane.

Atmospheric deposition as a source of heavy metals in urban stormwater

Atmospheric deposition is one of the most important pathways of urban stormwater pollution. Atmospheric deposition which can be in the form of either wet or dry deposition have distinct characteristics in terms of associated particulate sizes, pollutant types and influential parameters. This paper discusses the outcomes of a comprehensive research study undertaken to identify important traffic characteristics and climate factors such as antecedent dry period and rainfall characteristics which influences the characteristics of wet and dry deposition of solids and heavy metals. The outcomes confirmed that Zinc (Zn) is correlated with traffic volume whereas Lead (Pb), Cadmium (Cd), Nickel (Ni), and Copper (Cu) are correlated with traffic congestion. Consequently, reducing traffic congestion will be more effective than reducing traffic volume for improving air quality particularly in relation to Pb, Cd, Ni, and Cu. Zn was found to have the highest atmospheric deposition rate compared to other heavy metals. Zn in dry deposition is associated with relatively larger particle size fractions (>10 ��m), whereas Pb, Cd, Ni and Cu are associated with relatively smaller particle size fractions (<10 ��m). The analysis further revealed that bulk (wet plus dry) deposition which is correlated with rainfall depth and contains a relatively higher percentage of smaller particles compared to dry deposition which is correlated with the antecedent dry period. As particles subjected to wet deposition are smaller, they disperse over a larger area from the source of origin compared to particles subjected to dry deposition as buoyancy forces become dominant for smaller particles compared to the influence of gravity. Furthermore, exhaust emission particles were found to be primarily associated with bulk deposition compared to dry deposition particles which mainly originate from vehicle component wear.

Environmental sustainability of urban road transport : an integrated analysis for life cycle emission impact

Despite of significant contributions of urban road transport to global economy and society, it is one of the largest sources of local and global emission impact. In order to address the environmental concerns of urban road transport it is imperative to achieve a holistic understanding of contributory factors causing emissions which requires a complete look onto its whole life cycle. Previous studies were mainly based on segmental views which mostly studied environmental impacts of individual transport modes and very few considered impacts other than operational phase. This study develops an integrated life cycle inventory model for urban road transport emissions from a holistic modal perspective. Singapore case was used to demonstrate the model. Results show that total life cycle greenhouse gas emission from Singapore���s road transport sector is 7.8 million tons per year. The total amount of criteria air pollutants are also estimated in this study.

Prediction of CO concentrations based on a hybrid Partial Least Square and Support Vector Machine model

Due to the health impacts caused by exposures to air pollutants in urban areas, monitoring and forecasting of air quality parameters have become popular as an important topic in atmospheric and environmental research today. The knowledge on the dynamics and complexity of air pollutants behavior has made artificial intelligence models as a useful tool for a more accurate pollutant concentration prediction. This paper focuses on an innovative method of daily air pollution prediction using combination of Support Vector Machine (SVM) as predictor and Partial Least Square (PLS) as a data selection tool based on the measured values of CO concentrations. The CO concentrations of Rey monitoring station in the south of Tehran, from Jan. 2007 to Feb. 2011, have been used to test the effectiveness of this method. The hourly CO concentrations have been predicted using the SVM and the hybrid PLS���SVM models. Similarly, daily CO concentrations have been predicted based on the aforementioned four years measured data. Results demonstrated that both models have good prediction ability; however the hybrid PLS���SVM has better accuracy. In the analysis presented in this paper, statistic estimators including relative mean errors, root mean squared errors and the mean absolute relative error have been employed to compare performances of the models. It has been concluded that the errors decrease after size reduction and coefficients of determination increase from 56 to 81% for SVM model to 65���85% for hybrid PLS���SVM model respectively. Also it was found that the hybrid PLS���SVM model required lower computational time than SVM model as expected, hence supporting the more accurate and faster prediction ability of hybrid PLS���SVM model.

Determinants of eco-efficiency in the Chinese industrial sector

This study measures productive inefficiency within the context of multi-environmental pollution (eco-efficiency) in the Chinese industrial sector. The weighted Russell directional distance model is applied to measure eco-efficiency using production technology. The objective is to clarify how external factors affect eco-efficiency. The major findings are that both foreign direct investment and investment for pollution abatement improve eco-efficiency as measured by air pollutant substances. A levy system for wastewater discharge improves eco-efficiency as measured by wastewater pollutant substances. However, an air pollutant levy does not significantly affect eco-efficiency as measured by air pollutants.

Ozone-induced signaling in Arabidopsis thaliana

Tropospheric ozone (O3) is one of the most common air pollutants in industrialized countries, and an increasing problem in rapidly industrialising and developing countries in Asia, Africa and South America. Elevated concentrations of tropospheric O3 can lead to decrease in photosynthesis rate and therefore affect the normal metabolism, growth and seed production. Acute and high O3 episodes can lead to extensive damage leading to dead tissue in plants. Thus, O3 derived growth defects can lead to reduction in crop yield thereby leading to economical losses. Despite the extensive research on this area, many questions remain open on how these processes are controlled. In this study, the stress-induced signaling routes and the components involved were elucidated in more detail starting from visual damage to changes in gene expression, signaling routes and plant hormone interactions that are involved in O3-induced cell death. In order to elucidate O3-induced responses in Arabidopsis, mitogen-activated protein kinase (MAPK) signaling was studied using different hormonal signaling mutants. MAPKs were activated at the beginning of the O3 exposure. The activity of MAPKs, which were identified as AtMPK3 and AtMPK6, reached the maximum at 1 and 2 hours after the start of the exposure, respectively. The activity decreased back to clean air levels at 8 hours after the start of the exposure. Both AtMPK3 and AtMPK6 were translocated to nucleus at the beginning of the O3 exposure where they most likely affect gene expression. Differences were seen between different hormonal signaling mutants. Functional SA signaling was shown to be needed for the full protein levels and activation of AtMPK3. In addition, AtMPK3 and AtMPK6 activation was not dependent on ethylene signaling. Finally, jasmonic acid was also shown to have an impact on AtMPK3 protein levels and AtMPK3 activity. To further study O3-induced cell death, an earlier isolated O3 sensitive Arabidopsis mutant rcd1 was mapped, cloned and further characterized. RCD1 was shown to encode a gene with WWE and ADP-ribosylation domains known to be involved in protein-protein interactions and cell signaling. rcd1 was shown to be involved in many processes including hormonal signaling and regulation of stress-responsive genes. rcd1 is sensitive against O3 and apoplastic superoxide, but tolerant against paraquat that produces superoxide in chloroplast. rcd1 is also partially insensitive to glucose and has alterations in hormone responses. These alterations are seen as ABA insensitivity, reduced jasmonic acid sensitivity and reduced ethylene sensitivity. All these features suggest that RCD1 acts as an integrative node in hormonal signaling and it is involved in the hormonal regulation of several specific stress-responsive genes. Further studies with the rcd1 mutant showed that it exhibits the classical features of programmed cell death, PCD, in response to O3. These include nuclear shrinkage, chromatin condensation, nuclear DNA degradation, cytosol vesiculation and accumulation of phenolic compounds and eventually patches of HR-like lesions. rcd1 was found to produce extensive amount of salicylic acid and jasmonic acid in response to O3. Double mutant studies showed that SA independent and dependent processes were involved in the O3-induced PCD in rcd1 and that increased sensitivity against JA led to increased sensitivity against O3. Furthermore, rcd1 had alterations in MAPK signature that resembled changes that were previously seen in mutants defective in SA and JA signaling. Nitric oxide accumulation and its impact on O3-induced cell death were also studied. Transient accumulation of NO was seen at the beginning of the O3 exposure, and during late time points, NO accumulation coincided with the HR-like lesions. NO was shown to modify defense gene expression, such as, SA and ethylene biosynthetic genes. Furthermore, rcd1 was shown to produce more NO in control conditions. In conclusion, NO was shown to be involved in O3-induced signaling leading to attenuation of SA biosynthesis and other defense related genes.

Environmental remediation by photocatalysis

Photocatalysis refers to the oxidation and reduction reactions on semiconductor surfaces, mediated by the valence band holes and conduction band electrons, which are generated by the absorption of ultraviolet or visible light radiation. Photocatalysis is widely being practiced for the degradation and mineralization of hazardous organic compounds to CO2 and H2O, reduction of toxic metal ions to their non-toxic states, deactivation and destruction of water borne microorganisms, decomposition of air pollutants like volatile organic compounds, NOx, CO and NH3, degradation of waste plastics and green synthesis of industrially important chemicals. This review attempts to showcase the well established mechanism of photocatalysis, the use of photocatalysts for water and air pollution control,visible light responsive modified-TiO2 and non-TiO2 based materials for environmental and energy applications, and the importance of developing reaction kinetics for a comprehensive understanding and design of the processes.

Avalia����o das propriedades f��sico-qu��micas do biodiesel de soja, algod��o e mamona e da mistura de biodiesel de soja e algod��o

Uma das maiores atividades humanas que gera impacto ao meio ambiente �� o setor de transportes automotores, especialmente ve��culos que utilizam ��leo diesel mineral como forma de combust��vel. Independente do conforto ou objetivos que levem a utiliza����o deste tipo de transporte, estes produzem emiss��es que cont��m diversos tipos de poluentes atmosf��ricos. A substitui����o de ��leo diesel mineral pelo biodiesel vegetal, vem se apresentando como uma alternativa para este setor, especialmente para o Brasil, que com base em sua imensa biodiversidade com plantas oleaginosas dever�� se constituir em um dos maoires produtores mundiais de biodiesel vegetal. Este trabalho apresenta um estudo comparativo entre tr��s tipos de oleaginosas (soja, algod��o e mamona) e uma msitura bin��ria v/v soja e algod��o. Os resultados obtidos neste estudo foram comparados as especifica����es definidas pelas normas: Brasileira (RANP 07/2008), Europ��ia (EN/14214) e Americana (ASTM D-6751). Entre todas as amostras estudadas, o ��leo de mamona n��o atende algumas propiedades f��sico-qu��micas das normas em quest��o. As amostras de biodiesel de soja e algod��o, individualmente e combinadas, com caracteristicas, aplica����es, zoneamento agroclim��tico e sazonalidade de produ����o regionalmente diferente apresentam propiedades f��sico-qu��micas semelhantes, podendo ser considerada uma fonte renovav��l de energia.

Qualidade do ar e atendimentos m��dicos de emerg��ncia por sintomas respirat��rios em crian��as residentes em Jacarepagu��, Rio de Janeiro

Apesar da cidade do Rio de Janeiro ser uma das mais importantes metr��poles brasileiras s��o muito pouco conhecidos os efeitos da exposi����o aos poluentes atmosf��ricos na sa��de da popula����o carioca. Este trabalho foi idealizado para suprir uma parte desta car��ncia. Os poluentes investigados foram PM10, SO2, NO2, CO e O3 e os desfechos envolveram os atendimentos pedi��tricos de emerg��ncia por sintomas respirat��rios em tr��s unidades p��blicas de sa��de de Jacarepagu��, entre abril de 2002 e mar��o de 2003. As vari��veis de confus��o foram a tend��ncia temporal, sazonalidade, temperatura, umidade relativa do ar, precipita����o de chuva e infec����es respirat��rias. Tamb��m foram ajustados os efeitos do calend��rio, isto ��, determinados dias do ano que apresentaram comportamentos anormais como feriados e finais de semana. Houve in��meras falhas no monitoramento de todos os poluentes e devido ao reduzido volume de dados, optou-se por n��o incluir o SO2 nas an��lises. Uma vez que os determinantes e as conseq����ncias cl��nicas das exposi����es aos poluentes atmosf��ricos s��o bastante distintos nas vias a��rias superiores e nas vias a��reas inferiores, um dos estudos verificou a associa����o dos poluentes do ar com transtornos nestes dois segmentos. Embora de pequena magnitude, somente o O3 apresentou resultado positivo e estatisticamente significativo, tanto com todos os atendimentos de emerg��ncia por queixas respirat��rias como com os atendimentos motivados por sintomas nas vias a��reas inferiores. O efeito foi no mesmo dia da exposi����o (lag 0). No outro estudo, investigou-se a associa����o dos poluentes do ar com os atendimentos de emerg��ncia por sintomas de obstru����o br��nquica. Neste caso, as crian��as foram categorizadads em tr��s faixas et��rias. Somente as crian��as com idades menores que 2 anos tiveram um resultado positivo e estatisticamente significativo, de expressiva magnitude com PM10. Semelhante efeito foi visto com o O3, embora com significado estat��stico lim��trofe (p<0,06). Tamb��m neste estudo o efeito ocorreu no mesmo dia da exposi����o. Apesar das falhas no monitoramento, nos dois estudos, os par��metros da polui����o ambiental estiveram associados ao aumento do n��mero de atendimentos pedi��tricos de emerg��ncia por motivos respirat��rios em Jacarepagu��. Durante o per��odo de estudos, os n��veis de todos os poluentes monitorados permaneceram abaixo dos limites recomendados.