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- Exposure to airborne ultrafine particles from cooking in Portuguese homesPublication . Bordalo, J. C.; Gomes, João; Albuquerque, PaulaCooking was found to be a main source of submicrometer and ultrafine aerosols from gas combustion in stoves. Therefore, this study consisted of the determination of the alveolar deposited surface área due to aerosols resulting from commom domestic cooking activities (boiling fish; vegetables, or pasta, and frying hamburgers and eggs). The concentration of ultrafine particles during the cooking events significantly increased from a baseline of 42.7 um2 / cm3 (increased to 72.9 um2 / cm3 due to gas burning) to a maximun of 890.3 um2 / cm3 measured during fish boiling in water, and a maximun of 4500 um2 / cm3 during meat frying. This clearly show that a domestic activity such as cooking can lead expures as hight as those of occupational exposure activities.
- Evaluation of the amount of nanoparticles emitted in LASER additive manufacture/weldingPublication . Gomes, J. F.; Miranda, R.; Oliveira, J. P.; Esteves, H. M.; Albuquerque, PaulaObjectives: The objective of this study was the evaluation of the professional exposure to nanoparticles during tasks performed in workstations for production of metallic parts by laser welding additive manufacturing. Materials and methods: The study was developed in an installed additive manufacturing machine, having controlled temperature and humidity in an industrial unit where metal parts were being produced using stainless steel powders of granulometry of 10 to 35 μm. Results and discussion: Monitoring of airborne nanoparticles emission was made using adequate equipment, which showed considerable number of nanoparticles over the baseline, having the same composition as the steel powder used. Conclusion: It is concluded that the values of professional exposure to nanoparticles are high in these workstations and that the nanoparticles to which the workers are exposed are small in size (around 15 nm), thus having a strong capacity for alveolar penetration and, consequently, with a strong possibility of passing to the bloodstream, accumulating in the body.
- Characterization of airborne particles generated from metal active gas welding processPublication . Guerreiro, C.; Gomes, João; Carvalho, P.; Santos, T. J. G.; Miranda, R. M.; Albuquerque, PaulaThis study is focused on the characterization of particles emitted in the metal active gas welding of carbon steel using mixture of Ar + CO2, and intends to analyze which are the main process parameters that influence the emission itself. It was found that the amount of emitted particles (measured by particle number and alveolar deposited surface area) are clearly dependent on the distance to the welding front and also on the main welding parameters, namely the current intensity and heat input in the welding process. The emission of airborne fine particles seems to increase with the current intensity as fume-formation rate does. When comparing the tested gas mixtures, higher emissions are observed for more oxidant mixtures, that is, mixtures with higher CO2 content, which result in higher arc stability. These mixtures originate higher concentrations of fine particles (as measured by number of particles by cm 3 of air) and higher values of alveolar deposited surface area of particles, thus resulting in a more severe worker's exposure.
- Determination of airborne nanoparticles from welding operationsPublication . Gomes, João; Albuquerque, Paula; Miranda, Rosa Maria Mendes; Vieira, Maria Teresa FreireThe aim of this study is to assess the levels of airborne ultrafine particles emitted in welding processes (tungsten inert gas [TIG], metal active gas [MAG] of carbon steel, and friction stir welding [FSW] of aluminum) in terms of deposited area in pulmonary alveolar tract using a nanoparticle surface area monitor (NSAM) analyzer. The obtained results showed the dependence of process parameters on emitted ultrafine particles and demonstrated the presence of ultrafine particles compared to background levels. Data indicated that the process that resulted in the lowest levels of alveolar deposited surface area (ADSA) was FSW, followed by TIG and MAG. However, all tested processes resulted in significant concentrations of ultrafine particles being deposited in humans lungs of exposed workers.
- Risk assessment of welding operations and processes in terms of ultrafine particles emissionsPublication . Gomes, João; Miranda, Rosa M.; Esteves, Helder M.; Albuquerque, PaulaWelding is extensively used in metallic construction worldwide, in spite of being able to produce dangerous fumes that may be hazardous to the welder’s health. It is estimated that, presently, 1-2% of workers from different professional backgrounds (which accounts for more than 3 million persons) are subject to welding fume and gas action. Recently, studies have proved the existence of ultrafine particle emissions, from welding processes, thus increasing the health risks to exposed welders. In particular, it was found that the amount of emitted particles (measured by particle number and alveolar deposited surface area) is clearly dependent on the distance to the welding front, and also on the main welding parameters, namely the applied current intensity, heat input, nature of base metal, nature of addition metal, and nature of welding gases used. The emission of airborne ultrafine particles increases with the increase of current intensity as the fume-formation rate does. In regards to welding gas mixtures, higher emissions are observed for more oxidant mixtures, that is, mixtures with a higher CO2 content, which result in higher electric arc stability. These mixtures originate higher concentrations of ultrafine particles (as measured by the number of particles per cm3 of air) and higher values of the alveolar deposited surface area of particles, thus resulting in more severe worker exposure. Combining the obtained data, it is possible to compare different welding processes and operating conditions, in order to assess different levels of welder’s exposure. Also, the graphical representation of measured concentrations of airborne ultrafine particles, with time and distance, allows us to define “safe” and “critical” regions within a welding workshop in terms of welder exposure. This information may be combined with the results of risk analysis derived by control banding and helps to categorize the sites where regulatory measures such as operation containment or dedicated exhaust ventilation need to be implemented.
- Characterization of airborne emission of nanoparticles in the ceramic industry in PortugalPublication . Esteves, Hélder; Bordado, J.; Gomes, João; Miranda, R.; Albuquerque, PaulaThe objective of this study was to evaluate occupational exposure to nanoparticles during some tasks performed in different production processes of different ceramic industries in Portugal, to select the places of greatest occupational exposure through the analysis of the sampled data, to verify what is the pulmonary accumulation in these places, to identify the composition of the released nanoparticles, apply a Control Banding Tool and try to understand which companies require more risk control measures. The study was carried out in three different national ceramics production industries, one for sanitary ceramics production, another for porcelain crockery production and finally another for the production of ornamental crockery (red paste). It is concluded that occupational exposure values to nanoparticles are high in all cases and that nanoparticles are very small in size (11.5 to 15.4 nm). Existing risk control measures are insufficient and verified risk levels are high (Risk Level 3 and 4). The chemical composition of the analyzed nanoparticles is similar regardless of the typology of the ceramic production plant and their chemical composition as a percentage of certain materials has a direct influence on crystallinity.
- Exposição profissional a nanopartículas na fabricação de peças por soldadura a laserPublication . Esteves, H.; Gomes, João; Miranda, R.; Albuquerque, PaulaA soldadura é o principal processo industrial utilizado para unir metais. Contudo, pode produzir fumos nocivos para a saúde dos trabalhadores e estima-se que, presentemente, 1-2% de trabalhadores (cerca de mais de 3 milhões), estejam sujeitos à ação de fumos e gases de soldadura. Os riscos inerentes aos processos de soldadura podem ser classificados como riscos decorrentes de agentes físicos e riscos relacionados com os componentes químicos. Por outro lado, as propriedades físicas e químicas dos fumos e os fatores individuais dos trabalhadores são fatores preponderantes na deposição de partículas inaladas. No entanto, ainda existem incertezas sobre o papel das partículas finas e ultrafinas (nanopartículas) em relação a outros poluentes atmosféricos que causam efeitos adversos para a saúde. A nível dos processos de soldadura, diversos autores demonstraram um aumento da incidência de doenças respiratórias de quatro vezes na incidência de asma entre soldadores dos Estados Unidos da América (EUA) em relação à população geral, e um aumento de duas vezes na capacidade de resposta das vias aéreas em soldadores versus não-soldadores no mesmo ambiente de trabalho. A exposição a fumos de soldadura no corpo humano pode despoletar o aparecimento de efeitos diferentes dependendo da composição desses fumos. Algumas dessas composições têm efeitos a curto prazo, tais como a designada “febre do soldador”. Contudo, os fumos de soldadura podem provocam efeitos a longo prazo nomeadamente: irritação da pele, irritação do trato respiratório, lesões nos rins e fígado, efeitos dermatológicos, doenças pulmonares do tipo asmáticas; efeitos crónicos que incluem cancro (nariz, laringe, pulmão). Estas situações de exposição profissional são de elevada complexidade e envolvem a componente inerente ao indivíduo, às condições de trabalho e à atividade desenvolvida sendo necessário aplicar uma abordagem integrada no processo de diagnóstico, avaliação e gestão do risco, adaptada a cada situação específica.
- On the assessment of exposure to airborne ultrafine particles in urban environmentsPublication . Gomes, João; Bordado, João; Albuquerque, PaulaThe aim of this study was to contribute to the assessment of exposure levels of ultrafine particles in the urban environment of Lisbon, Portugal, due to automobile traffic, by monitoring lung deposited alveolar surface area (resulting from exposure to ultrafine particles) in a major avenue leading to the town center during late spring, as well as in indoor buildings facing it. Data revealed differentiated patterns for week days and weekends, consistent with PM2.5 and PM10 patterns currently monitored by air quality stations in Lisbon. The observed ultrafine particulate levels may be directly correlated with fluxes in automobile traffic. During a typical week, amounts of ultrafine particles per alveolar deposited surface area varied between 35 and 89.2 mu m2/cm3, which are comparable with levels reported for other towns in Germany and the United States. The measured values allowed for determination of the number of ultrafine particles per cubic centimeter, which are comparable to levels reported for Madrid and Brisbane. In what concerns outdoor/indoor levels, we observed higher levels (32 to 63%) outdoors, which is somewhat lower than levels observed in houses in Ontario.
- Evaluation of the amount of nanoparticles emitted in LASER additive manufacture/weldingPublication . Gomes, João; Miranda, R.; P. Oliveira, J.; Esteves, Helder; Albuquerque, PaulaObjectives: The objective of this study was the evaluation of the professional exposure to nanoparticles during tasks performed in workstations for production of metallic parts by laser welding additive manufacturing.Materials and methods: The study was developed in an installed additive manufacturing machine, having controlled temperature and humidity in an industrial unit where metal parts were being produced using stainless steel powders of granulometry of 10 to 35m.Results and discussion: Monitoring of airborne nanoparticles emission was made using adequate equipment, which showed considerable number of nanoparticles over the baseline, having the same composition as the steel powder used.Conclusion: It is concluded that the values of professional exposure to nanoparticles are high in these workstations and that the nanoparticles to which the workers are exposed are small in size (around 15nm), thus having a strong capacity for alveolar penetration and, consequently, with a strong possibility of passing to the bloodstream, accumulating in the body.
- Determination of airborne nanoparticles in elderly care centresPublication . Almeida-Silva, Marina; Almeida, Susana Marta; Gomes, João; Albuquerque, Paula; Wolterbeek, H. T.According to numerous studies, airborne nanoparticles have a potential to produce serious adverse human health effects when deposited into the respiratory tract. The most important parts of the lung are the alveolar regions with their enormous surface areas and potential to transfer nanoparticles into the blood stream. These effects may be potentiated in case of the elderly, since this population is more susceptible to air pollutants in general and more to nanoparticles than larger particles. The main goal of this investigation was to determine the exposure of institutionalized elders to nanoparticles using Nanoparticle Surface Area Monitor (NSAM) equipment to calculate the deposited surface area (DSA) of nanoparticles into elderly lungs. In total, 193 institutionalized individuals over 65 yr of age were examined in four elderly care centers (ECC). The occupancy daily pattern was achieved by applying a questionnaire, and it was concluded that these subjects spent most of their time indoors, including the bedroom and living room, the indoor microenvironments with higher prevalence of elderly occupancy. The deposited surface area ranged from 10 to 46 mu m(2)/cm(3). The living rooms presented significantly higher levels compared with bedrooms. Comparing PM10 concentrations with nanoparticles deposited surface area in elderly lungs, it is conceivable that living rooms presented the highest concentration of PM10 and were similar to the highest average DSA. The temporal distribution of DSA was also assessed. While data showed a quantitative fluctuation in values in bedrooms, high peaks were detected in living rooms.