Engenharia Mecânica
ON THE TOXICOLOGICAL EFFECTS OF NANOPARTICLES
Gomes, J.F.P.a,b; Santos, R.e; Albuquerque, P.C.c; Miranda, R.M.d; Vieira, M.T.e
aIBB – Instituto de Biotecnologia e Bioengenharia / Instituto Superior Técnico – Universidade
Técnica de Lisboa, 1049-001 Lisboa, Portugal
bISEL, Instituto Superior de Engenharia de Lisboa, Área Departamental de Engenharia
Química, 1959-007 Lisboa, Portugal
cESTESL – Escola Superior de Tecnologias de Saúde de Lisboa – Instituto Politécnico de
Lisboa, 1990-096 Lisboa, Portugal
dUNIDEMI, Departamento de Engenharia Mecânica e Industrial, Faculdade de Ciências e
Tecnologia, FCT, Universidade Nova de Lisboa, 2829-516 Caparica, Portugal
eCEMUC, Departamento de Engenharia Mecânica, Faculdade de Ciências e Tecnologia da
Fonte: Proceedings of the EuroNanoForum 2011, 2011
Conferência: EuroNanoForum 2011, Budapest, Hungria, 2011 Tipo de Documento: Proceeding Paper
Resumo: Nanotechnology is frequently hailed as the next general purpose technology that will greatly impact society. Applications of nanoscience and nanotechnology will have a significant impact on sustainable development, influencing virtually all industrial sectors. Nanoengineering can contribute to resource saving, reduced consumption of materials, the possibility of replacing current materials and it also holds promise for improving the environment. However, the increasing demand for appropriate risk assessment of nanotechnologies affects every organisation involved in the research, development and commercialisation of products that contain nanoenabled components. Thus, organisations dealing with nanotechnologies, must adopt responsible risk assessment, as well as risk management strategies, in order to protect both their staff and end-users from the potentially hazardous effects thus arising. Nanotoxicological research is still in its infancy and the issuing and implementation of standards for appropriate safety control systems can still take several years. Yet, the advanced understanding of toxicological phenomena on the nanometre scale is largely dependent on technological innovations and scientific results stemming from enhanced R&D. Meanwhile, the nanotechnology industry has to adopt proactive risk management strategies in order to provide a safe working environment for their staff, clients and customers, and obtain products without posing health threats at any point of their lifecycle. Nano particle materials can enter the body via three main routes: a) inhalation, b) ingestion, and c) dermal penetration. The detrimental health effects of inhaling fine aerosols were recognised long ago and various attempts have been made to minimise exposure, as the issuing of specific regulations on emissions and objectives for air quality. While toxicological test of nanoparticles entering through the skin or the gastrointestinal tract are still in their infancy, inhalation technology has been concerned with both naturally occurring and engineered nanometre sized materials for some time. Most studies, however, resulted in contradictory and controversial conclusions, and little or no standardisation of experimental parameters was derived thereafter. In particular, standard toxicology tests have been found to be unsuitable to explain the high toxicity of nanometre-sized particles; leading nanotoxicology laboratories to recommend the adoption of another type of metrics that take into account the materials active surface area and structure. Therefore, recent nanotoxicology studies are trying to reach reproducible results by determining the surface effects and other physical parameters of materials. This question is considerably important, namely for the European chemical industry due to REACH regulations and it has been recommended that nanoparticulated materials are to be treated as new substances under the REACH regulation, which will supersede the existing notification of new substances. Studies have shown the dominant role of indoor air in personal exposure to many air pollutants. These findings are explained by the high proportion of time that people spend indoors and by the high concentrations of many air pollutants found there. The main issue in designing exposure assessment studies is which of the microenvironments where people send their time should be studied to provide data allowing for most accurate assessments, while limiting the costs and efforts relating to the studies. When considering human exposures to airborne pollutants, of particular importance is the exposure to airborne particles, and specifically to its finer fractions: nano particles, ultra-fine particles, sub micrometer particles, PM2.5 and PM10
fraction. Obviously, the smaller the particles the higher the probability of penetration into deeper parts of the respiratory tract and also contain higher levels of trace elements, toxins and mutagens. It should be noted that, in air, smaller and larger particles behave differently, and the penetration of particles of different sizes through the building envelope is different.
Theoretically, the indoor particle concentration is a function of a number of factors, such as the generation rate of particles indoor, the outdoor particle concentration, air exchange rate, particle penetration efficiency from the outdoor to the indoor environment, and the particle deposition rate on indoor surfaces. However, in practice, it is usually very difficult to assess the exposure due to the lack of data and information on the correlation between indoor and outdoor particles, which are house and environment specific. Understanding the relationship of indoor and outdoor aerosol particles, especially in the nano range, under different environmental conditions is of major importance for improving exposure estimates and for developing efficient control strategies to reduce human exposure and thus health risk. Current exposure assessment models are often based on the outdoor pollutant concentration used as input parameter for predicting total exposure. But, the indoor concentrations may be different than the outdoor ones even in the absence of any significant indoor pollution sources, and this is particularly true when the nano range of particulate is considered. Understanding the relationship of airborne nano sized particulate and human health, under different environmental conditions is of great importance for improving exposure estimates and for developing efficient control strategies to reduce human exposure and health risk and for establishing, evaluating and improving regulations and legislation both on air quality, airborne emissions and the incorporation of nano sized materials in other products and commodities.
OPTIMAL CONFIGURATION OF THERMALLY COUPLED DISTILLATION