Browsing by Author "Esteves, Helder"
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- 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.
- Influence of an extreme saharan dust event on the air quality of the west region of PortugalPublication . Gomes, João; Esteves, Helder; Rente, LuísThis paper describes how an extreme Saharan dust event that took place in March 2022 affected the Iberian Peninsula and was noticed not only by the outdoor air quality monitoring stations measuring PM2.5 and PM10 but also by indoor air monitoring systems in Fatima, central Portugal. The observed particulate matter concentrations clearly show the influence that such an event has on the indoor air quality inside buildings and that the magnitude of that influence is also dependent on the specific characteristics of the buildings, mainly the ventilation conditions, as should be expected. Therefore, this study alerts us to the necessity of integrating indoor and outdoor air quality monitoring systems to achieve automated air conditioning systems capable of efficiently controlling both temperature and air cleanliness.
- Occupational exposure to nanoparticles in the ceramic industryPublication . Esteves, Helder; Gomes, João; Miranda, Rosa; Albuquerque, PaulaSome studies on occupational exposure to particulates have pointed out to dangerous effects for workers about inhalable and respirable particles. These scenarios of occupational exposure are extremely complex since they involve components inherent to individuals, working conditions and the activity itself. Regarding the ceramic industry, workers may be exposed to nanomaterials throughout the production process because of their unintentional release. Taking into account these considerations we have been conducting a study evaluating the professional exposure to nanoparticles in several jobs in different plants of the Portuguese ceramic industry, within European Project CERASAFE (SIINN/0002/2014). This study aims to characterize and evaluate the occupational exposure of workers to nanoparticles in different types of ceramic industries, namely identify exposure scenarios in the workplace and characterize the exposure for the manufacture of ceramic nanomaterials; identify relevant nanomaterials and assess their toxicity and contribute to increase knowledge about the health effects of exposure of workers to nanoparticles in the ceramics industry.
- Professional exposure to nanoparticles in the manufacture of parts by laser weldingPublication . Esteves, Helder; Gomes, João; Miranda, Rosa; Albuquerque, PaulaSome studies on occupational exposure to particulates have pointed out to dangerous effects for workers as regards inhalable and respirable particles. These scenarios of occupational exposure are extremely complex since they involve components inherent to individuals, working conditions and the activity itself. The influence of welding fumes on the human body has different effects depending on the composition of these fumes. Some of these compositions have short-term effects, such as the so-called welding fever. However, welding fumes may cause long-term effects, in particular: skin irritation, respiratory tract irritation, kidney and liver damage, dermatological effects, asthmatic-type lung diseases; chronic effects including cancer (nose, larynx, lung). Taking these considerations into account, we have conducted a study evaluating the professional exposure to nanoparticles in the production of parts by laser addition. This study aims to characterize and evaluate the occupational exposure of workers to nanoparticles in this industry, namely: identify scenarios of exposure in the workplace and characterize the exposure in the manufacturing of the parts; identify relevant nanomaterials and assess their toxicity; contribute to increase knowledge about the health effects of workers' exposure to nanoparticles in this industry typology.