Measurement report : The influence of traffic and new particle formation on the size distribution of 1–800 nm particles in Helsinki – a street canyon and an urban background station comparison

Peer reviewe

Lung-depositing surface area (LDSA) of particles in office spaces around Europe : Size distributions, I/O-ratios and infiltration

Air pollution, and specifically particulate matter pollution, is one of the greatest dangers to human health. Outdoor air pollution ranks third in causes for premature death. Improving indoor air quality is of immense importance, as the time spent indoors is often much greater than the time spent outdoors. In this experimental study, we evaluate the levels of particle pollution in indoor air in four offices across Europe, compare the indoor particles to outdoor particles and assess where the particles originate from. The measurements were conducted with an Electrical Low-Pressure Impactor (ELPI+) for particles between 6 nm and 1 μm. The chosen metric, lung-deposited particle surface area (LDSA), targets the health impacts of particle pollution. Based on the measurements, we determined that most of the indoor air particles infiltrated from outdoor air, although two of the offices had very limited indoor activity during the measurement campaigns and may not represent typical use. The highest median indoor LDSA concentration during daytime hours was 27.2 μm2/cm3, whereas the lowest was 2.8 μm2/cm3. Indoor air in general had lower LDSA concentrations than outdoor air, the corresponding outdoor LDSA concentrations being 35.8 μm2/cm3 and 9.8 μm2/cm3. The particle size ranges which contributed to the highest concentrations were 50–100 nm and 300–500 nm. These size ranges correspond to soot mode and accumulation mode particles, which represent local and regional sources, respectively. Based on this study, limiting particle infiltration is the key factor in keeping indoor air in offices free of lung-depositing particles.Peer reviewe

Keskeisten päivystyspotilaiden triagen ja hoidon aloittamisen osaaminen : hoitosuositusten kehittäminen

Tarve opinnäytetyölle tuli esille Ruoveden terveyskeskuksen päivystyspoliklinikalla työskenteleviltä hoitajilta, sillä kaikilla työntekijöillä ei välttämättä ole riittävää osaamista ensihoito- tai päivystyshoitotyöstä. Opinnäytetyön tarkoituksena on kuvata sairaanhoitajien päivystyshoitotyön osaamista keskeisten potilasryhmien triagessa ja hoidon aloittamisessa ja kehittää sen perusteella hoitosuositukset. Tavoitteena on kehittää Ruoveden terveyskeskuksen päivystyspoliklinikan työntekijöiden hoitotyön laatua luomalla yhtenäiset toimintakäytänteet, jotka edistävät potilaan jatkohoitoa ja selviytymismahdollisuuksia. Hoitosuositukset perustuvat alan kirjallisuuteen, valtakunnallisiin hoitosuosituksiin ja eri tietokannoista etsittyihin suomalaisiin ja kansainvälisiin aiheeseen liittyviin tutkimuksiin. Keskeiset potilasryhmät ovat rintakipupotilas, hengitysvaikeuspotilas, halvausoireinen potilas, vaikean allergisen reaktion saanut potilas ja akuutti vatsakipupotilas. Potilasryhmien lisäksi käsitellään hätätilapotilaan tunnistamista. Tutkimusten mukaan päivystysluonteinen hoitotyön osaaminen vaatii kehittämistä Suomessa. Kehitettäviä osa-alueita ovat potilaan tutkiminen ja seuranta, peruselintoimintojen ongelmien havaitseminen ja niihin reagoiminen sekä teoriatieto ja sen hyödyntäminen triagessa. Kirjalliset hoitosuositukset koetaan helpottavan triagea ja hoidon aloittamista.The need for our study was expressed by the nurses of the Casualty and Emergency Department of the Ruovesi Health Care Centre, Finland. Not all of the nurses had enough special competency to be able to work for the Casualty and Emergency Department. The purpose of our study was to describe the triage competency in the most common emergency care patient cases and the start of care, and based on that, we developed care practice recommendations. The aim of this study was to improve the quality of the nursing and health care at the Casualty and Emergency Department of the Ruovesi Health Centre, Central Finland. Uniform nursing procedures were created to promote the longterm follow up and possibility of survival of patients. Data for our study were collected from nursing science literature, the Finnish national recommendations and various nursing and emergency care science databases. Based on the data, we developed recommendations for the most common emergency care patient groups, for the Casualty and Emergency Department of the Ruovesi Health Care Centre. The most common patient groups suffered from the following problems: chest pain, shortness of breath, stroke, severe allergic reactions and acute stomach ache. We also dealt with how to recognize the emergency care patient. The results showed that the emergency care competence of nurses required improvement in Finland. The areas which must be improved were the examining and monitoring of the patient, observing and reacting to the problem of body function, the augmentation of theory and the usage of that in triage. Written recommendation eased triage and the start of emergency care

Number concentration of non-volatile aerosol particles in a busy street canyon

Euroopan unionin lainsäädännössä ajoneuvojen hiukkaslukumääräpäästön rajoitukset ottavat huomioon vain yli 23 nm:n kokoiset haihtumattomat hiukkaset. Vaikka alle 23 nm:n päästöhiukkasten tiedetään monissa tapauksissa olevan haihtuvia, on tässä kokoluokassa havaittu myös haihtumattomia hiukkasia. Tässä diplomityössä tutkittiin haihtumattomien aerosolihiukkasten lukumääräpitoisuutta vilkasliikenteisessä katukuilussa Mäkelänkadulla, Helsingissä. Kondensaatiohiukkaslaskuripatterilla (CPC-patteri) mitattiin samanaikaisesti 1,4 nm:ä, 3 nm:ä, 10 nm:ä ja 23 nm:ä suurempien hiukkasten lukumääräpitoisuutta sekunnin aikaresoluutiolla kuukauden ajan toukokuussa 2018. Haihtuvien yhdisteiden poisto toteutettiin näytelinjassa kuuman ja kylmän ejektorilaimentimen yhdistelmällä. Hiukkaset luokiteltiin haihtumattomiksi, jos ne olivat olemassa 300 °C:n lämpökäsittelyn jälkeen. Näytelinjan häviöt mitattiin ja karakterisoitiin työssä huolellisesti. CPC-patteri osoittautui toimivaksi työkaluksi tienvarsimittauksiin, joissa hiukkasten koko ja lukumääräpitoisuus saattavat vaihdella suuresti lyhyellä aikavälillä. Mäkelänkadun mittausten alkupuolella lämpökäsittely tuotti virheellistä pitoisuutta 1,4–3 nm:n kokoluokassa. Suuremmissa kokoluokissa vastaavaa ilmiötä ei havaittu. Alle 23 nm:n haihtumattomien hiukkasten lukumääräpitoisuus kohosi Mäkelänkadulla aamuruuhkan aikaan. Tämä viittaa siihen, että ajoneuvopäästöt sisälsivät pieniä haihtumattomia hiukkasia. Kokoluokan 3–23 nm haihtumattomien hiukkasten päästökertoimeksi määritettiin likimäärin 4×10^14 #/(kg polttoainetta), joka oli noin kolme kertaa suurempi kuin yli 23 nm:n kokoisille haihtumattomille hiukkasille määritetty päästökerroin. Tutkimusten merkittävin havainto oli se, että yli 23 nm:n haihtumattomien hiukkasten pitoisuuden osuus haihtumattomien hiukkasten kokonaislukumääräpitoisuudesta oli alle 10 %. On siis mahdollista, ettei suurinta osaa ajoneuvojen lukumääräpäästöstä säädellä lainsäädännössä. Aihepiiri vaatii lisätutkimuksia, sillä tämän tutkimuksen perusteella nykyiseen lainsäädäntöön voisi olla syytä tehdä muutoksia.The European Union legislation limiting the number of particles emitted by vehicles takes into account only non-volatile particles above 23 nm in size. Even though sub-23 nm emission particles are in many cases known to be volatile, also non-volatile particles have been observed in this size range. In this work, the number concentration of non-volatile aerosol particles was studied in a busy street canyon at Mäkelänkatu, Helsinki. A Condensation Particle Counter Battery (CPC Battery) was used to measure simultaneously the number concentration of particles larger than 1.4 nm, 3 nm, 10 nm, and 23 nm with a time resolution of one second for one month in May 2018. Volatile compounds were removed in the sampling line using a combination of a hot and a cold ejector diluter. Particles were classified non-volatile, if they existed in the downstream of the thermal treatment of 300 °C. Losses in the sampling line were measured and characterized carefully in this study. The CPC Battery was found to be an advantageous measurement tool for roadside measurements as the concentration and particle size may be highly variable. In the beginning of Mäkelänkatu measurements, the thermal treatment produced an artefact in the size range of 1.4–3 nm. However, no such phenomenon occurred in other size ranges. The number concentration of non-volatile sub-23 particles increased during the morning rush hour in Mäkelänkatu. This suggests that the vehicle emissions contained small non-volatile particles. The emission factor of approximately 4×10^14 #/(kg fuel) was calculated for the number concentration of non-volatile 3–23 nm particles. This was about three times greater than the emission factor calculated for non-volatile particles above 23 nm in size. The most significant observation of this study was that the number concentration of non-volatile particles above 23 nm in size accounted for less than 10 % of the total non-volatile particle number concentration. Thus, it is possible that the majority of emission particles are not regulated by legislation. The topic calls for further research as, according to this study, amendments may be needed to the current legislation

Number concentration of non-volatile aerosol particles in a busy street canyon

Euroopan unionin lainsäädännössä ajoneuvojen hiukkaslukumääräpäästön rajoitukset ottavat huomioon vain yli 23 nm:n kokoiset haihtumattomat hiukkaset. Vaikka alle 23 nm:n päästöhiukkasten tiedetään monissa tapauksissa olevan haihtuvia, on tässä kokoluokassa havaittu myös haihtumattomia hiukkasia. Tässä diplomityössä tutkittiin haihtumattomien aerosolihiukkasten lukumääräpitoisuutta vilkasliikenteisessä katukuilussa Mäkelänkadulla, Helsingissä. Kondensaatiohiukkaslaskuripatterilla (CPC-patteri) mitattiin samanaikaisesti 1,4 nm:ä, 3 nm:ä, 10 nm:ä ja 23 nm:ä suurempien hiukkasten lukumääräpitoisuutta sekunnin aikaresoluutiolla kuukauden ajan toukokuussa 2018. Haihtuvien yhdisteiden poisto toteutettiin näytelinjassa kuuman ja kylmän ejektorilaimentimen yhdistelmällä. Hiukkaset luokiteltiin haihtumattomiksi, jos ne olivat olemassa 300 °C:n lämpökäsittelyn jälkeen. Näytelinjan häviöt mitattiin ja karakterisoitiin työssä huolellisesti. CPC-patteri osoittautui toimivaksi työkaluksi tienvarsimittauksiin, joissa hiukkasten koko ja lukumääräpitoisuus saattavat vaihdella suuresti lyhyellä aikavälillä. Mäkelänkadun mittausten alkupuolella lämpökäsittely tuotti virheellistä pitoisuutta 1,4–3 nm:n kokoluokassa. Suuremmissa kokoluokissa vastaavaa ilmiötä ei havaittu. Alle 23 nm:n haihtumattomien hiukkasten lukumääräpitoisuus kohosi Mäkelänkadulla aamuruuhkan aikaan. Tämä viittaa siihen, että ajoneuvopäästöt sisälsivät pieniä haihtumattomia hiukkasia. Kokoluokan 3–23 nm haihtumattomien hiukkasten päästökertoimeksi määritettiin likimäärin 4×10^14 #/(kg polttoainetta), joka oli noin kolme kertaa suurempi kuin yli 23 nm:n kokoisille haihtumattomille hiukkasille määritetty päästökerroin. Tutkimusten merkittävin havainto oli se, että yli 23 nm:n haihtumattomien hiukkasten pitoisuuden osuus haihtumattomien hiukkasten kokonaislukumääräpitoisuudesta oli alle 10 %. On siis mahdollista, ettei suurinta osaa ajoneuvojen lukumääräpäästöstä säädellä lainsäädännössä. Aihepiiri vaatii lisätutkimuksia, sillä tämän tutkimuksen perusteella nykyiseen lainsäädäntöön voisi olla syytä tehdä muutoksia.The European Union legislation limiting the number of particles emitted by vehicles takes into account only non-volatile particles above 23 nm in size. Even though sub-23 nm emission particles are in many cases known to be volatile, also non-volatile particles have been observed in this size range. In this work, the number concentration of non-volatile aerosol particles was studied in a busy street canyon at Mäkelänkatu, Helsinki. A Condensation Particle Counter Battery (CPC Battery) was used to measure simultaneously the number concentration of particles larger than 1.4 nm, 3 nm, 10 nm, and 23 nm with a time resolution of one second for one month in May 2018. Volatile compounds were removed in the sampling line using a combination of a hot and a cold ejector diluter. Particles were classified non-volatile, if they existed in the downstream of the thermal treatment of 300 °C. Losses in the sampling line were measured and characterized carefully in this study. The CPC Battery was found to be an advantageous measurement tool for roadside measurements as the concentration and particle size may be highly variable. In the beginning of Mäkelänkatu measurements, the thermal treatment produced an artefact in the size range of 1.4–3 nm. However, no such phenomenon occurred in other size ranges. The number concentration of non-volatile sub-23 particles increased during the morning rush hour in Mäkelänkatu. This suggests that the vehicle emissions contained small non-volatile particles. The emission factor of approximately 4×10^14 #/(kg fuel) was calculated for the number concentration of non-volatile 3–23 nm particles. This was about three times greater than the emission factor calculated for non-volatile particles above 23 nm in size. The most significant observation of this study was that the number concentration of non-volatile particles above 23 nm in size accounted for less than 10 % of the total non-volatile particle number concentration. Thus, it is possible that the majority of emission particles are not regulated by legislation. The topic calls for further research as, according to this study, amendments may be needed to the current legislation

Sub-23 nm Particles Dominate Non-Volatile Particle Number Emissions of Road Traffic

Ultrafine particles (<100 nm) in urban air are a serious health hazard not yet fully understood. Therefore, particle number concentration monitoring was recently included in the WHO air quality guidelines. At present, e.g., the EU regulates particle number only regarding the emissions of solid particles larger than 23 nm emitted by vehicles. The aim of this study was to examine the non-volatile fraction of sub-23 nm particles in a trafficinfluenced urban environment. We measured the number concentration of particles larger than 1.4, 3, 10, and 23 nm in May 2018. Volatile compounds were thermally removed in the sampling line and the line losses were carefully determined. According to our results, the sub-23 nm particles dominated the non-volatile number concentrations. Additionally, based on the determined particle number emission factors, the traffic emissions of non-volatile sub-10 nm particles can be even 3 times higher than those of particles larger than 10 nm. Yet, only a fraction of urban sub-10 nm particles consisted of non-volatiles. Thus, while the results highlight the role of ultrafine particles in the traffic-influenced urban air, a careful consideration is needed in terms of future particle number standards to cover the varying factors affecting measured concentrations

Connection between lung deposited surface area (LDSA) and black carbon (BC) concentrations in road traffic and harbour environments

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Experimental and numerical analysis of fine particle and soot formation in a modern 100 MW pulverized biomass heating plant

The formation of soot, organic, and inorganic aerosols has a profound effect on the environmental and technological feasibility of biomass combustion. In this work, the soot and aerosol processes are examined for a modern pulverized wood-burning 100 MWth district heating plant. Experimental data was collected from two locations inside the furnace (30% and 100% thermal loads), including measurements for fine particle (PM1) number size distribution, number concentration, and chemical composition. The experiments were complemented with Computational Fluid Dynamics (CFD) simulations and Plug-Flow Reactor (PFR) modeling. The measurements and modeling are combined in a comprehensive analysis, providing fundamental understanding on the aerosol processes inside the furnace. The wood-powder combustion is efficient under both thermal loads, indicated by the low unburned carbon content in fly-ash, and the low CO, NO and soot emissions (<0.3 mg/Nm3). The fine particles consist mainly of K2SO4, and of lesser amounts of alkali salts (NaCl, KCl), and Ca and Mg compounds (oxides or sulfates). A large concentration of KOH/K2CO3 vapor may exist in the flue gas and play a significant role in the heat exchanger fouling. The applied modeling tools are shown to provide accurate estimations for the composition and formation regions of fine particles inside the industrial biomass furnaces.publishedVersionPeer reviewe

Exhaust emissions from a prototype non-road natural gas engine

Since gas engines are considered a future solution to improve air quality and to mitigate climate impacts, there is an urgent need to understand their emissions. The aim for this study was to understand the phenomena affecting the formation of particulate emissions of a non-road natural gas engine. To achieve this, the engine's exhaust emissions were characterized under different operating conditions. The regulated pollutants (gaseous CO, HC, and NOx; particulate matter (PM) and particle number (PN)) were determined experimentally and a detailed characterization of particulate pollutants over a wide particle size range (particles down to 1.2 nm) was conducted with state-of-the-art instrumentation considering both physical and chemical properties of the exhaust aerosol. The test engine was a prototype non-road spark-ignited natural gas engine, which was studied over the non-road steady test cycle (NRSC). The role of the three-way catalyst (TWC) was studied by sampling and characterizing the exhaust aerosol both with and without the TWC. The TWC was observed to efficiently remove the vast majority of the regulated gaseous (96% CO, 98% HC, 98% NOx) and particulate mass emissions (98%). In general, the measured particle number emission factors were highly dependent on the cut-off sizes of the condensation particle counters. Using CPCs with smaller cut-off sizes resulted in higher particle number emission factors. For black carbon (BC), the intermediate engine speed conditions (modes 5–7) led to lower BC emissions than the high speed conditions (modes 1–3). In contrast, highest BC emissions on a work basis were observed during idling. TWC did not influence BC levels. Without the TWC, PM was comprised mostly of organic compounds (70–100%). Downstream of the TWC, the majority of PM was, depending on the load, composed of organic compounds, sulfate, or black carbon. A statistical source apportionment based on mass spectra revealed that the PM1 was mostly related to unburned and burned lubricating oil, indicating a minor role of fuel in PM formation.publishedVersionPeer reviewe

Snapshots of wintertime urban aerosol characteristics : local sources emphasized in ultrafine particle number and lung deposited surface area

Urban air fine particles are a major health-relating problem. However, it is not well understood how the healthrelevant features of fine particles should be monitored. Limitations of PM2.5 (mass concentration of sub 2.5 μm particles), which is commonly used in the health effect estimations, have been recognized and, e.g., World Health Organization (WHO) has released good practice statements for particle number (PN) and black carbon (BC) concentrations (2021). In this study, a characterization of urban wintertime aerosol was done in three environments: a detached housing area with residential wood combustion, traffic-influenced streets in a city centre and near an airport. The particle characteristics varied significantly between the locations, resulting different average particle sizes causing lung deposited surface area (LDSA). Near the airport, departing planes had a major contribution on PN, and most particles were smaller than 10 nm, similarly as in the city centre. The high hourly mean PN (>20 000 1/cm3) stated in the WHO’s good practices was clearly exceeded near the airport and in the city centre, even though traffic rates were reduced due to a SARS-CoV-2-related partial lockdown. In the residential area, wood combustion increased both BC and PM2.5, but also PN of sub 10 and 23 nm particles. The high concentrations of sub 10 nm particles in all the locations show the importance of the chosen lower size limit of PN measurement, e.g., WHO states that the lower limit should be 10 nm or smaller. Furthermore, due to ultrafine particle emissions, LDSA per unit PM2.5 was 1.4 and 2.4 times higher near the airport than in the city centre and the residential area, respectively, indicating that health effects of PM2.5 depend on urban environment as well as conditions, and emphasizing the importance of PN monitoring in terms of health effects related to local pollution sources