Source Specific Risk Assessment of Indoor Aerosol Particles

In the urban environment, atmospheric aerosols consist mainly of pollutants from anthropogenic sources. The majority of these originate from traffic and other combustion processes. A fraction of these pollutants will penetrate indoors via ventilation. However, indoor air concentrations are usually predominated by indoor sources due to the small amount of dilution air. In modern societies, people spend most of their time indoors. Thus, their exposure is controlled mainly by indoor concentrations from indoor sources. During the last decades, engineering of nanosized structures has created a new field of material science. Some of these materials have been shown to be potentially toxic to human health. The greatest potential for exposure to engineered nanomaterials (ENMs) occurs in the workplace during production and handling of ENMs. In an exposure assessment, both gaseous and particulate matter pollutants need to be considered. The toxicities of the particles usually depend on the source and age. With time, particle morphology and composition changes due to their tendency to undergo coagulation, condensation and evaporation. The PM exposure risk is related to source specific emissions, and thus, in risk assessment one needs to define source specific exposures. This thesis describes methods for source specific risk assessment of airborne particulate matter. It consists of studies related to workers ENM exposures during the synthesis of nanoparticles, packing of agglomerated TiO2 nanoparticles, and handling of nanodiamonds. Background particles were distinguished from the ENM concentrations by using different measurement techniques and indoor aerosol modelings. Risk characterization was performed by using a source specific exposure and calculated dose levels in units of particle number and mass. The exposure risk was estimated by using non-health based occupational exposure limits for ENMs. For the nanosized TiO2, the risk was also assessed from dose-biological responses which had been extrapolated from inhalation studies conducted in mice. The ENM exposure levels were compared with background particle concentrations in order to determine the relevant ENM exposure metrics and exposure scenarios.Sisäilman epäpuhtaudet koostuvat ilmanvaihdon mukana tulevista ulkoilman epäpuhtauksista ja sisätilan lähteistä. Koska sisätilassa on vähän laimennosilmaa, niin sisätilan lähteet yleensä määräävät sisätilan pitoisuustasot. Koska modernissa yhteiskunnassa ihmiset viettävät valtaosan ajasta sisätiloissa, niin heidän altistuminen määräytyy suurelta osin sisätilan lähteiden aiheuttamista päästöistä. Viime vuosikymmenien aikana materiaalitekniikka on alkanut hyödyntämään synteettisiä nanohiukkasia (SNH). Jotkut näistä SNH:ta on mahdollisesti myrkyllisiä ihmisille jo pienissä pitoisuuksissa. Altisuminen näille SNH tapahtuu pääosin työpaikoilla tuotannon ja käsittelyn yhteydessä. Koska hiukkasien haitallisuudet vaihtelevat voimakkaasti niiden syntyperän mukaan niin altistuksen ja riskin arviointi tulisi tehdä lähdekohtaisten päästöjen mukaisesti. Tässä väitöskirjassa esitetään eri menetelmiä ilmassa olevien hiukkasten lähdekohtaiseen riskinarviointiin. Menetelmiä sovellettiin työntekijöiden SNH altistuksen arvioinnissa SNH:n tuotannossa, pakkauksessa ja käsittelyssä. Työntekijöiden altistuksesta aiheutunutta riskiä arvioitiin lähdekohtaisesti käyttämällä laskennallisia annoksia sekä annosvastetta, jota oltiin arvioitu altistuskokeilla. Altistuksen arvioinnissa käytettävää mittausmetriikan sopivuutta arvioitiin eri altistustapahtumille ja altistumistasoja verrattiin epävirallisiin altistusraja-arvoihin. Tutkimus tuotti tietoa SNH:n riskinarviointiin, riskimallinnuksiin, raja-arvojen sekä säädöksien määrittämiseen

Data Shepherding in Nanotechnology : The Exposure Field Campaign Template

In this paper, we demonstrate the realization process of a pragmatic approach on developing a template for capturing field monitoring data in nanomanufacturing processes. The template serves the fundamental principles which make data scientifically Findable, Accessible, Interoperable and Reusable (FAIR principles), as well as encouraging individuals to reuse it. In our case, the data shepherds’ (the guider of data) template creation workflow consists of the following steps: (1) Identify relevant stakeholders, (2) Distribute questionnaires to capture a general description of the data to be generated, (3) Understand the needs and requirements of each stakeholder, (4) Interactive simple communication with the stakeholders for variables/descriptors selection, and (5) Design of the template and annotation of descriptors. We provide an annotated template for capturing exposure field campaign monitoring data, and increase their interoperability, while comparing it with existing templates. This paper enables the data creators of exposure field campaign data to store data in a FAIR way and helps the scientific community, such as data shepherds, by avoiding extensive steps for template creation and by utilizing the pragmatic structure and/or the template proposed herein, in the case of a nanotechnology project (Anticipating Safety Issues at the Design of Nano Product Development, ASINA).In this paper, we demonstrate the realization process of a pragmatic approach on developing a template for capturing field monitoring data in nanomanufacturing processes. The template serves the fundamental principles which make data scientifically Findable, Accessible, Interoperable and Reusable (FAIR principles), as well as encouraging individuals to reuse it. In our case, the data shepherds' (the guider of data) template creation workflow consists of the following steps: (1) Identify relevant stakeholders, (2) Distribute questionnaires to capture a general description of the data to be generated, (3) Understand the needs and requirements of each stakeholder, (4) Interactive simple communication with the stakeholders for variables/descriptors selection, and (5) Design of the template and annotation of descriptors. We provide an annotated template for capturing exposure field campaign monitoring data, and increase their interoperability, while comparing it with existing templates. This paper enables the data creators of exposure field campaign data to store data in a FAIR way and helps the scientific community, such as data shepherds, by avoiding extensive steps for template creation and by utilizing the pragmatic structure and/or the template proposed herein, in the case of a nanotechnology project (Anticipating Safety Issues at the Design of Nano Product Development, ASINA).Peer reviewe

Digital Twins applied to the implementation of Safe-by-Design strategies in nano-processes for the reduction of airborne emission and occupational exposure to nano-forms

Digital Twins (DTs) are one of the most promising enabling technologies for the deployment of the factory of the future and the Industry 4.0 framework. DTs could be labelled as an inherently Safe-by-Design (SbD) strategy and can be applied at different stages in the life cycle of a process. The EU-funded project ASINA has the ambition to promote coherent, applicable and scientifically sound SbD nano-practices. In particular, in the field of nanomanufacturing, ASINA intends to deliver innovative SbD solutions applied to process (P-SbD). In this context, ASINA will investigate the use of DTs as a disruptive digital technology for the prevention, prediction and control of nano-forms airborne emission and worker exposure. This paper introduces the concept of DT in the field of nano-processes SbD and outlines the preliminary architecture of ASINA-DT, that will be developed and implemented by ASINA in one industrial scenario.The project ASINA received funding from the European Union’s Horizon 2020 research and innovation programme, under grant agreement Nº 862444. This paper reflects only the authors’ views, and the Commission is not responsible for any use that may be made of the information contained therein

First order risk assessment for nanoparticle inhalation exposure during injection molding of polypropylene composites and production of tungsten-carbide-cobalt fine powder based upon pulmonary inflammation and surface area dose

AbstractInhalation exposure to low toxicity and biodurable particles has shown to induce polymorphonuclear neutrophilia (PMN) in the lungs, which is a strong indicator for lung inflammation. Recently, Schmid and Stoeger (2016; http://dx.doi.org/10.1016/j.jaerosci.2015.12.006) reviewed mice and rat intratracheal instillation studies and assessed the relation between particles dry powder BET surface area dose and PMN influx for granular biodurable particles (GBPs) and transition metal oxides. In this study, we measured workers alveolar lung deposited surface area (LDSA) concentrations (μm2 cm−3) during injection molding of polypropylene (PP) car bumpers and production of tungsten-carbide-cobalt (WCCo) fine grade powder using diffusion chargers. First order risk assessment was performed by comparing the doses calculated from measured LDSA concentrations during an 8-h work day with the NOEL1/100, the one hundredth of no observed effect level, assigned for GBPs (0.11cm2g−1) and transition metal oxide particles (9×10−3cm2g−1). During the injection molding of PP car bumpers, LDSA concentrations varied from 23 to 39.8μm2cm−3. During 8-h exposure PP, particle doses were at a maximum of 1.4×10−3cm2g−1, which was a factor 100 lower compared to the NOEL1/100 assigned for GBPs. In the WCCo fine powder production plant, the LDSA concentrations were below 18.7μm2cm−3, which corresponds to the 8-h dose of 2.7×10−3cm2g−1. This is 3 times lower than the NOEL1/100 assigned for transition metal oxide particles. The LDSA concentrations were generally low compared to urban background levels of 44.2μm2cm−3 in European cities

First order risk assessment for nanoparticle inhalation exposure during injection molding of polypropylene composites and production of tungsten-carbide-cobalt fine powder based upon pulmonary inflammation and surface area dose

AbstractInhalation exposure to low toxicity and biodurable particles has shown to induce polymorphonuclear neutrophilia (PMN) in the lungs, which is a strong indicator for lung inflammation. Recently, Schmid and Stoeger (2016; http://dx.doi.org/10.1016/j.jaerosci.2015.12.006) reviewed mice and rat intratracheal instillation studies and assessed the relation between particles dry powder BET surface area dose and PMN influx for granular biodurable particles (GBPs) and transition metal oxides. In this study, we measured workers alveolar lung deposited surface area (LDSA) concentrations (μm2 cm−3) during injection molding of polypropylene (PP) car bumpers and production of tungsten-carbide-cobalt (WCCo) fine grade powder using diffusion chargers. First order risk assessment was performed by comparing the doses calculated from measured LDSA concentrations during an 8-h work day with the NOEL1/100, the one hundredth of no observed effect level, assigned for GBPs (0.11cm2g−1) and transition metal oxide particles (9×10−3cm2g−1). During the injection molding of PP car bumpers, LDSA concentrations varied from 23 to 39.8μm2cm−3. During 8-h exposure PP, particle doses were at a maximum of 1.4×10−3cm2g−1, which was a factor 100 lower compared to the NOEL1/100 assigned for GBPs. In the WCCo fine powder production plant, the LDSA concentrations were below 18.7μm2cm−3, which corresponds to the 8-h dose of 2.7×10−3cm2g−1. This is 3 times lower than the NOEL1/100 assigned for transition metal oxide particles. The LDSA concentrations were generally low compared to urban background levels of 44.2μm2cm−3 in European cities

Testing the performance of one and two box models as tools for risk assessment of particle exposure during packing of inorganic fertilizer

Modelling of particle exposure is a useful tool for preliminary exposure assessment in workplaces. However, actual exposure measurements are needed to assess models reliability. Worker exposure was monitored during packing of a complex inorganic granulate fertilizer at industrial scale using small and big bags. Particle concentrations were modelled with one and two box models, where the emission source was estimated with the fertilizer’s dustiness index. The exposure levels were used to calculate inhaled dose rates and test accuracy of the exposure modellings. The particle number concentrations were measured from worker area by using a mobility and optical particle sizer which were used to calculate surface area and mass30 concentrations. The concentrations in the worker area during pre-activity ranged from 63797 - 81073 cm-3, 4.6x106 to 7.5x106 um2 cm-3, and 354 to 634 μg m-3 31 (respirable mass fraction) and during packing from 50300 to 85949 cm-3, 4.3x106 to 7.6x106 um2 32 cm-3, and 279 to 668 μg m-3 33 (respirable mass fraction). Thus, the packing process did not significantly increase the exposure levels. High particle number concentration was partly due to the use of diesel-powered forklifts. The particle surface area deposition rate in respiratory tract was up to 7.6x106 μm2 min-1 during packing, with 52% - 61% of deposition occurring in the alveolar region. Ratios of the modelled and measured concentrations were 0.98 ± 0.19 and 0.84 ± 0.12 for small and big bags, respectively, when using the one box model, and 0.88 ± 0.25 and 0.82 ± 0.12, for small and big bags, respectively, when using the one box model, and 0.88 ± 0.25 and 0.82 ± 0.12, respectively, when using the two box model. The modelling precision improved for both models when outdoor particle concentrations were included. This study shows that exposure concentrations during packing of fertilizers can be predicted with a reasonable accuracy by using a concept of dustiness and mass balance models

Indoor Particle Concentrations, Size Distributions, and Exposures in Middle Eastern Microenvironments

There is limited research on indoor air quality in the Middle East. In this study, concentrations and size distributions of indoor particles were measured in eight Jordanian dwellings during the winter and summer. Supplemental measurements of selected gaseous pollutants were also conducted. Indoor cooking, heating via the combustion of natural gas and kerosene, and tobacco/shisha smoking were associated with significant increases in the concentrations of ultrafine, fine, and coarse particles. Particle number (PN) and particle mass (PM) size distributions varied with the different indoor emission sources and among the eight dwellings. Natural gas cooking and natural gas or kerosene heaters were associated with PN concentrations on the order of 100,000 to 400,000 cm−3 and PM2.5 concentrations often in the range of 10 to 150 µg/m3. Tobacco and shisha (waterpipe or hookah) smoking, the latter of which is common in Jordan, were found to be strong emitters of indoor ultrafine and fine particles in the dwellings. Non-combustion cooking activities emitted comparably less PN and PM2.5. Indoor cooking and combustion processes were also found to increase concentrations of carbon monoxide, nitrogen dioxide, and volatile organic compounds. In general, concentrations of indoor particles were lower during the summer compared to the winter. In the absence of indoor activities, indoor PN and PM2.5 concentrations were generally below 10,000 cm−3 and 30 µg/m3, respectively. Collectively, the results suggest that Jordanian indoor environments can be heavily polluted when compared to the surrounding outdoor atmosphere primarily due to the ubiquity of indoor combustion associated with cooking, heating, and smoking

Erratum: Hussein et al. Indoor Particle Concentrations, Size Distributions, and Exposures in Middle Eastern Microenvironments. Atmosphere 2020, 11, 41

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