The overall goals of this doctoral dissertation are to provide knowledge of workers' exposure to nanomaterials and to assist in the development of standard methods to measure personal exposure to nanomaterials in workplace environments. To achieve the first goal, a field study investigated airborne particles generated from the weighing of bulk carbon nanotubes (CNTs) and the manual sanding of epoxy test samples reinforced with CNTs. This study also evaluated the effectiveness of three local exhaust ventilation (LEV) conditions (no LEV, custom fume hood and biosafety cabinet) for control of exposure to particles generated during sanding of CNT-epoxy nanocomposites. Particle number and respirable mass concentrations were measured with direct-read instruments, and particle morphology was determined by electron microscopy. Sanding of CNT-epoxy nanocomposites released respirable size airborne particles with protruding CNTs very different in morphology from bulk CNTs that tended to remain in clusters (>1µm). Respirable mass concentrations in the operator's breathing zone were significantly greater when sanding took place in the custom hood (p <0.0001) compared to the other LEV conditions. This study found that workers' exposure was to particles containing protruding CNTs rather than to bulk CNT particles. Particular attention should be placed in the design and selection of hoods to minimize exposure. Two laboratory studies were conducted to realize the second goal. Collection efficiency of submicrometer particles was evaluated for nylon mesh screens with three pore sizes (60, 100 and 180 µm) at three flow rates (2.5, 4, and 6 Lpm). Single-fiber efficiency of nylon mesh screens was then calculated and compared to a theoretical estimation expression. The effects of particle morphology on collection efficiency were also experimentally measured. The collection efficiency of the screens was found to vary by less than 4% regardless of particle morphology. Single-fiber efficiency of the screens calculated from experimental data was in good agreement with that estimated from theory for particles between 40 and 150 nm but deviated from theory for particles outside of this range. New coefficients for the single-fiber efficiency model were identified that minimized the sum of square error (SSE) between the experimental values and those estimated with the model. Compared to the original theory, the SSE calculated using the modified theory was at least threefold lower for all screens and flow rates. Since nylon fibers produce no significant spectral interference when ashed for spectrometric examination, the ability to accurately estimate collection efficiency of submicrometer particles makes nylon mesh screens an attractive collection substrate for nanoparticles. In the third study, laboratory experiments were conducted to develop a novel nanoparticle respiratory deposition (NRD) sampler that selectively collects nanoparticles in a worker's breathing zone apart from larger particles. The NRD sampler consists of a respirable cyclone fitted with an impactor and a diffusion stage containing eight nylon- mesh screens. A sampling criterion for nano-particulate matter (NPM) was developed and set as the target for the collection efficiency of the NRD sampler. The sampler operates at 2.5 Lpm and fits on a worker's lapel. The cut-off diameter of the impactor was experimentally measured to be 300 nm with a sharpness of 1.53. Loading at typical workplace levels was found to have no significant effect (2-way ANOVA, p=0.257) on the performance of the impactor. The effective deposition of particles onto the diffusion stage was found to match the NPM criterion, showing that a sample collected with the NRD sampler represents the concentration of nanoparticles deposited in the human respiratory system.

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The elderly population is sensitive to damages caused by air pollution on health. They spend relatively more time indoors, however there is limited information on the air quality they breathe inside their residences. The objectives of this work are to characterise mass of sizesegregated particulate matter (PM) in elderly residences in Metropolitan Area of Sao Paulo (MASP) in Brazil; assess the meteorological parameters influence; evaluate the indoor and outdoor relationship of PM; quantify the ions, trace elements and black carbon (rBC) in quasi-ultrafine particles (qUFP) and identify their sources, and estimate the respiratory deposition doses (RDD). To achieve these objectives, we measured during 24 hours the mass concentrations of PM in differents sizes (102.5, 2.51.0, 1.00.5, 0.50.25 and <0.25 µm (PM0.25, qUFP) in 59 elderly residences in MASP using a Personal Cascade Impactor Sampler. The PM10 is the sum of all size and PM2.5 is PM10 less PM102.5. The PM2.5 and PM0.25 contributed 78% and 38% of total PM10, respectively. About 77% and 40% of the residences had higher PM2.5 and PM10 than those in outdoor environments. About 13 and 43% of the measurements exceeded the World Health Organization (WHO) guidelines for PM10 and PM2.5, respectively. The PM0.25 exceeded the WHO guideline for PM2.5 in 8.3% of residences. Residences with higher PM concentration in all size bins are predominantly near the heavy traffic areas during the nonprecipitation days. About 68% of residences have the highest mass concentration in PM0.25. We analysed ions by chromatography, trace elements by x-ray fluorescence and rBC by reflectance. The major of ions concentrations in qUFP were found to be SO42- and NH4+, and the major trace elements were Si and Fe. Around 26% of the qUFP is rBC. Some residences have a high concentration of the toxic heavy metals Cu, Ni, Pb and Cr. We identified 6 dominant sources of the indoor qUFP by positive matrix factorization: vehicular emission (57%), secondary inorganic aerosol (21%), soil and construction (7%), wall painting (7%), cooking (5%) and industry (3%). The RDD for coarse and fine particles were found to be 20% and 24.6% higher for male than female elderly during seated position, respectively. The maximum RDD of qUFP and rBC are in the tracheobronchial part. It is important the control of PM sources in the elderly residences to limit adverse health effects of PM, especially fine particles. We suggest consider the rBC as one regulated air pollutant in terms of public control actions for air quality improvement in MASP. / A população idosa é sensível aos riscos da poluição do ar à saúde. Os idosos passam mais tempo dentro de suas casas, mas há pouca informação sobre a qualidade do ar dentro de suas residências. Os objetivos deste trabalho são caracterizar a massa do material particulado (PM) de diferentes tamanhos em residências de idosos na Região Metropolitana de São Paulo (RMSP) no Brasil; avaliar a influência dos parâmetros meteorológicos e a relação entre PM de ambiente interno e externo; quantificar os íons, elementos traços e black carbon (rBC) em partículas quasi-ultrafinas (qUFP) e identificar suas fontes, e estimar as doses de deposição de PM no trato respiratório (RDD). Para alcançar esses objetivos, medimos durante 24 horas as concentrações em massa de PM nos tamanhos 10-2,5; 2,5-1,0; 1,0-0,5; 0,5-0,25 e <0,25 m (PM0.25, qUFP) em 59 residências de idosos na RMSP usando o Personal Cascade Impactor Sampler. O PM10 é a soma da massa em todos os tamanhos e PM2.5 é o PM10 menos o PM10-2.5. O PM2.5 e PM0.25 contribuíram com 78% e 38% do total de PM10, respectivamente. Cerca de 77% e 40% das residências apresentaram maior concentração de PM2.5 e PM10 do que aqueles em ambientes externos. Cerca de 13 e 43% das medidas excederam as diretrizes da Organização Mundial de Saúde (OMS) para PM10 e PM2.5, respectivamente. O PM0.25 excedeu o limiar da OMS para PM2.5 em 8.3% das residências. As residências com maior concentração de PM em todos os tamanhos estão próximas das áreas de intenso tráfego veicular e não houve precipitação durante a medição. Cerca de 68% das residências têm a maior concentração de massa em PM0.25. Analisamos os íons por cromatografia, elementos traços por fluorescência de raios-x e rBC por reflectância. A maior concentração de íons em qUFP foi SO42- e NH4+, e os principais elementos traços foram Si e Fe. Cerca de 26% do qUFP é rBC. Algumas residências têm uma alta concentração dos metais pesados tóxicos Cu, Ni, Pb e Cr. Identificou-se 6 fontes de qUFP por fatoração de matriz positiva: emissão de veículos (57%), aerossol inorgânico secundário (21%), solo e construção (7%), pintura de parede (7%), cozimento (5%) e indústria (3%). O RDD para PM10-2.5 e PM2.5 foi 20% e 24,6% maior para homens do que mulheres enquanto sentados, respectivamente. O RDD máximo de qUFP e rBC foi na parte traqueobrônquica. É importante o controle de fontes de PM nas residências de idosos para limitar os efeitos adversos à saúde, especialmente partículas finas. Sugerimos considerar o rBC como um poluente atmosférico regulado em termos de ações de controle público para a melhoria da qualidade do ar na RMSP.

The elderly population is sensitive to damages caused by air pollution on health. They spend relatively more time indoors, however there is limited information on the air quality they breathe inside their residences. The objectives of this work are to characterise mass of sizesegregated particulate matter (PM) in elderly residences in Metropolitan Area of Sao Paulo (MASP) in Brazil; assess the meteorological parameters influence; evaluate the indoor and outdoor relationship of PM; quantify the ions, trace elements and black carbon (rBC) in quasi-ultrafine particles (qUFP) and identify their sources, and estimate the respiratory deposition doses (RDD). To achieve these objectives, we measured during 24 hours the mass concentrations of PM in differents sizes (102.5, 2.51.0, 1.00.5, 0.50.25 and <0.25 µm (PM0.25, qUFP) in 59 elderly residences in MASP using a Personal Cascade Impactor Sampler. The PM10 is the sum of all size and PM2.5 is PM10 less PM102.5. The PM2.5 and PM0.25 contributed 78% and 38% of total PM10, respectively. About 77% and 40% of the residences had higher PM2.5 and PM10 than those in outdoor environments. About 13 and 43% of the measurements exceeded the World Health Organization (WHO) guidelines for PM10 and PM2.5, respectively. The PM0.25 exceeded the WHO guideline for PM2.5 in 8.3% of residences. Residences with higher PM concentration in all size bins are predominantly near the heavy traffic areas during the nonprecipitation days. About 68% of residences have the highest mass concentration in PM0.25. We analysed ions by chromatography, trace elements by x-ray fluorescence and rBC by reflectance. The major of ions concentrations in qUFP were found to be SO42- and NH4+, and the major trace elements were Si and Fe. Around 26% of the qUFP is rBC. Some residences have a high concentration of the toxic heavy metals Cu, Ni, Pb and Cr. We identified 6 dominant sources of the indoor qUFP by positive matrix factorization: vehicular emission (57%), secondary inorganic aerosol (21%), soil and construction (7%), wall painting (7%), cooking (5%) and industry (3%). The RDD for coarse and fine particles were found to be 20% and 24.6% higher for male than female elderly during seated position, respectively. The maximum RDD of qUFP and rBC are in the tracheobronchial part. It is important the control of PM sources in the elderly residences to limit adverse health effects of PM, especially fine particles. We suggest consider the rBC as one regulated air pollutant in terms of public control actions for air quality improvement in MASP. / A população idosa é sensível aos riscos da poluição do ar à saúde. Os idosos passam mais tempo dentro de suas casas, mas há pouca informação sobre a qualidade do ar dentro de suas residências. Os objetivos deste trabalho são caracterizar a massa do material particulado (PM) de diferentes tamanhos em residências de idosos na Região Metropolitana de São Paulo (RMSP) no Brasil; avaliar a influência dos parâmetros meteorológicos e a relação entre PM de ambiente interno e externo; quantificar os íons, elementos traços e black carbon (rBC) em partículas quasi-ultrafinas (qUFP) e identificar suas fontes, e estimar as doses de deposição de PM no trato respiratório (RDD). Para alcançar esses objetivos, medimos durante 24 horas as concentrações em massa de PM nos tamanhos 10-2,5; 2,5-1,0; 1,0-0,5; 0,5-0,25 e <0,25 m (PM0.25, qUFP) em 59 residências de idosos na RMSP usando o Personal Cascade Impactor Sampler. O PM10 é a soma da massa em todos os tamanhos e PM2.5 é o PM10 menos o PM10-2.5. O PM2.5 e PM0.25 contribuíram com 78% e 38% do total de PM10, respectivamente. Cerca de 77% e 40% das residências apresentaram maior concentração de PM2.5 e PM10 do que aqueles em ambientes externos. Cerca de 13 e 43% das medidas excederam as diretrizes da Organização Mundial de Saúde (OMS) para PM10 e PM2.5, respectivamente. O PM0.25 excedeu o limiar da OMS para PM2.5 em 8.3% das residências. As residências com maior concentração de PM em todos os tamanhos estão próximas das áreas de intenso tráfego veicular e não houve precipitação durante a medição. Cerca de 68% das residências têm a maior concentração de massa em PM0.25. Analisamos os íons por cromatografia, elementos traços por fluorescência de raios-x e rBC por reflectância. A maior concentração de íons em qUFP foi SO42- e NH4+, e os principais elementos traços foram Si e Fe. Cerca de 26% do qUFP é rBC. Algumas residências têm uma alta concentração dos metais pesados tóxicos Cu, Ni, Pb e Cr. Identificou-se 6 fontes de qUFP por fatoração de matriz positiva: emissão de veículos (57%), aerossol inorgânico secundário (21%), solo e construção (7%), pintura de parede (7%), cozimento (5%) e indústria (3%). O RDD para PM10-2.5 e PM2.5 foi 20% e 24,6% maior para homens do que mulheres enquanto sentados, respectivamente. O RDD máximo de qUFP e rBC foi na parte traqueobrônquica. É importante o controle de fontes de PM nas residências de idosos para limitar os efeitos adversos à saúde, especialmente partículas finas. Sugerimos considerar o rBC como um poluente atmosférico regulado em termos de ações de controle público para a melhoria da qualidade do ar na RMSP.