Olli Sippula

• PhD
• Professor at University of Eastern Finland

The chemical composition of particulate matter (PM) emissions from a medium-speed four-stroke marine engine, operated on both heavy fuel oil (HFO) and distillate fuel (DF), was studied under various operating conditions. PM emission factors for organic matter, elemental carbon (soot), inorganic species and a variety of organic compounds were determ...

Ship engine emissions are important with regard to lung and cardiovascular diseases especially in coastal regions worldwide. Known cellular responses to combustion particles include oxidative stress and inflammatory signalling. To provide a molecular link between the chemical and physical characteristics of ship emission particles and the cellular...

Residential wood combustion (RWC) emits large amounts of gaseous and particulate organic aerosol (OA). In the atmosphere, the emission is transformed via oxidative reactions, which are under daylight conditions driven mainly by hydroxyl radicals (OH). This continuing oxidative ageing produces secondary OA and may change the health- and climate-rela...

Development of thermal processes for selective recovery of Zn and other valuable elements from municipal solid waste incineration (MSWI) fly ash requires comprehensive knowledge of the impact of gas atmosphere on the volatile behaviour of the element constituents of the ash at different reaction temperatures. This study assesses the partitioning of...

Air pollution emitted by residential biomass combustion (RBC) is known cause of adverse health and climate effects. Currently, manufacturers of stoves and fireplaces are facing challenges due to tightening emission regulations, such as the Ecodesign Directive in the European Union. Consequently, there is a demand for new emission control solutions...

Exposure to airborne particulate matter (PM) has been attributed to millions of deaths annually. However, the PM components responsible for observed health effects remain unclear. Oxidative potential (OP) has gained increasing attention as a key property that may explain PM toxicity. Using online measurement methods that impinge particles for OP qu...

Fuel-operated auxiliary heaters (AH) are potentially significant additional sources of particle and gas phase pollution from vehicles, but information on their emissions is scarce. Especially understanding of AH exhaust−originated secondary aerosol formation is lacking. In this study, we measured the gas and particle emissions, including secondary...

Ship traffic is known as an important contributor to air pollution. Regulations aimed at reducing sulfur oxide pollution by limiting the fuel sulfur content (FSC) may also decrease primary particulate matter (PM) emitted from ships. However, there is a knowledge gap regarding how the FSC affects secondary aerosol formation. The emissions from a res...

Aviation is an important source of urban air pollution, but the impacts of photochemical processing on the exhaust emissions remain insufficiently characterized. Here, the physical-chemical properties of fresh and photochemically aged emissions from a laboratory-scale jet engine burner operated with JP-8 kerosene were studied in detail with a range...

Thermal processes are emerging as promising solutions to recovering phosphorus and other nutrient elements from anaerobic digestates. The feasibility of nutrient element recovery depends largely on the fates of nutrient elements and heavy metals during thermal processing. This study assesses the partitioning of macronutrients (N, P, K, Na, Ca and M...

Substituting alternative materials and energy sources with forest biomass can cause significant environmental consequences, such as alteration in the released emissions which can be described by displacement factors (DFs). Until now, DFs of wood‐based materials have included greenhouse gas (GHG) emissions and have been associated with lower fossil...

Air pollution is one of the largest environmental health risks and one of the leading causes of adverse health outcomes and mortality worldwide. The possible importance of the oxidative potential (OP) as a metric to quantify particle toxicity in air pollution is increasingly being recognized. In this work, the OP and reactive oxygen species (ROS) a...

Ship traffic is known as one important contributor to air pollution. Recent regulations aimed at reducing sulfur oxide (SOx) pollution by limiting the fuel sulfur content (FSC) may also decrease fresh particulate matter (PM) emitted from ships. However, there is a knowledge gap regarding how the FSC affects secondary aerosol formation. Aerosol part...

Residential wood combustion (RWC) is a significant source of gaseous and particulate emissions causing adverse health and environmental effects. Several factors affect emissions, but the effects of the fuel wood species on emissions are currently not well understood. In this study, the Nordic wood species (named BirchA, BirchB, Spruce, SpruceDry, P...

Peatland fires emit organic carbon rich particulate matter into the atmosphere. Boreal and Arctic peatlands are becoming more vulnerable to wildfires, resulting in a need for better understanding of the emissions of these special fires. Extractable, non-, and low-polar organic aerosol species emitted from laboratory-based boreal and Arctic peat bur...

Oxidation flow reactors (OFRs) have been increasingly used to conduct research on secondary aerosol formation potential and composition in laboratory and field studies by exposing aerosols to high levels of oxidants in short time periods. In order to assess the atmospheric relevance of the triggered chemical reactions, kinetic models have been deve...

Emissions from road traffic and residential heating contribute to urban air pollution. Advances in emission reduction technologies may alter the composition of emissions and affect their fate during atmospheric processing. Here, emissions of a gasoline car and a wood stove, both equipped with modern emission mitigation technology, were photochemica...

The most recent European regulation, the Euro 6d emission standard, requires all gasoline direct injection (GDI) vehicles to use both a three-way catalyst (TWC) and a gasoline particle filter (GPF) as exhaust aftertreatment. These aftertreatment methods are aimed at reducing NOx and primary particle emissions. However, the formation of secondary or...

Residential combustion of brown coal can be an important source of ambient air pollution in areas with abundant brown coal deposits, such as Eastern Europe or China. The exhaust emission contents may vary regionally depending on the fuel composition, calling for detailed characterization of emissions from different coal types. In this work, the org...

Peatlands in the northern hemisphere are a major carbon storage but face an increased risk of wildfires due to climate change leading to large-scale smoldering fires in boreal and Arctic peatlands. Smoldering fires release organic carbon rich particulate matter, which influences the earth’s radiative balance and can cause adverse health effects for...

Residential biomass combustion significantly contributes to light-absorbing carbonaceous aerosols in the atmosphere, impacting the earth's radiative balance at regional and global levels. This study investigates the contribution of brown carbon (BrC) to the total particulate light absorption in the wavelength range of 370–950 nm (BrC370–950) and th...

Agricultural fires are a major source of biomass-burning organic aerosols (BBOAs) with impacts on health, the environment, and climate. In this study, globally relevant BBOA emissions from the combustion of sugar cane in both field and laboratory experiments were analyzed using comprehensive two-dimensional gas chromatography time-of-flight mass sp...

Thermal processes are emerging as promising solutions to recovering phosphorus and other nutrient elements from anaerobic digestates. The feasibility of nutrient element recovery depends largely on the fates of nutrient elements and heavy metals during thermal processing. This study assesses the partitioning of macronutrients (N, P, K, Na, Ca and M...

Natural graphite is currently considered as a critical raw material in EU. The demand for graphite is still increasing as it is commonly used in the anodes of the Li-ion batteries (LIBs). The total graphite content for energy storage applications such as LIBs should be more than 99.95%. Several purification processes for natural graphite exist but...

Residential biomass combustion significantly contributes to light-absorbing carbonaceous aerosols in the atmosphere, impacting the Earth's radiative balance at regional and global levels. This study investigates the contribution of brown carbon to the total particulate light absorption in the wavelength range of 370 to 950 nm (BrC370-950) and the p...

Black carbon (BC) particles produced by incomplete combustion of biomass and fossil fuels warm the atmosphere and decrease the reflectivity of snow and ice, hastening their melt. Although the significance of BC in Arctic climate change is widely acknowledged, observations on its deposition and sources are few. We present BC source types in a 300‐ye...

Traffic emissions contribute to ambient air pollution, posing a threat to human health. The installation of stricter exhaust emission standards and particle filters led to a significant decrease of particulate matter emissions by cars. However, little is known about how atmospheric transformation changes the toxicity of exhaust emissions from moder...

Residential heating with solid fuels is one of the major drivers for poor air quality in Central and Eastern Europe, and coal is still one of the major fuels in countries, such as Poland, the Czech Republic, and Hungary. In this work, emissions from a single-room heater fueled with brown coal briquettes (BCBs) and spruce logs (SLs) were analyzed fo...

Effective density (ρeff) is an important property describing particle transportation in the atmosphere and in the human respiratory tract. In this study, the particle size dependency of ρeff was determined for fresh and photochemically aged particles from residential combustion of wood logs and brown coal, as well as from an aerosol standard (CAST)...

Soot particles (SP) are ubiquitous components of atmospheric particulate matter and have been shown to cause various adverse health effects. In the atmosphere, freshly emitted SP can be coated by condensed low-volatility secondary organic and inorganic species. In addition, gas-phase oxidants may react with the surface of SP. Due to the chemical an...

The combustion of wood in small-scale appliances emits significant amounts of particulate and gaseous pollutants into the atmosphere, leading to impaired air quality and adverse health and climate effects. Simple and easily implemented reduction techniques are needed to address this issue. In this study, different air staging strategies in a sauna...

Small-scale wood combustion is a significant source of particulate emissions. Atmospheric transformation of wood combustion emissions is a complex process involving multiple compounds interacting simultaneously. Thus, an advanced methodology is needed to study the process in order to gain a deeper understanding of the emissions. In this study, we a...

Membrane transporters are important for maintaining brain homeostasis by regulating the passage of solutes into, out of, and within the brain. Growing evidence suggests neurotoxic effects of air pollution exposure and its contribution to neurodegenerative disorders, including Alzheimer’s disease (AD), yet limited knowledge is available on the exact...

Several studies indicate that short-sea shipping is an important source of air pollution for coastal areas and port cities. This paper reports results of a non-reactive particles dispersion model and a new set of experiments implemented for the Channel of Procida (Italy), an area with a high signal-to-noise ratio, due to intense marine traffic and...

The health effects of exposure to secondary organic aerosols (SOAs) are still limited. Here, we investigated and compared the toxicities of soot particles (SP) coated with β-pinene SOA (SOA βPin-SP) and SP coated with naphthalene SOA (SOA Nap-SP) in a human bronchial epithelial cell line (BEAS-2B) residing at the air-liquid interface. SOA βPin-SP m...

Background: Secondary organic aerosols (SOAs) formed from anthropogenic or biogenic gaseous precursors in the atmosphere substantially contribute to the ambient fine particulate matter [PM ≤2.5μm in aerodynamic diameter (PM2.5)] burden, which has been associated with adverse human health effects. However, there is only limited evidence on their di...

Epidemiological studies reveal that air pollution exposure may exacerbate neurodegeneration. Ultrafine particles (UFPs) are pollutants that remain unregulated in ambient air by environmental agencies. Due to their small size (<100 nm), UFPs have the most potential to cross the bodily barriers and thus impact the brain. However, little information e...

Soil and water contaminations are caused by rare earth elements (REEs) due to mining and industrial activities, that threaten the ecosystem and human health. Therefore, phytoremediation methods need to be developed to overcome this problem. To date, little research has been conducted concerning the phytoremediation potential of Salix for REEs. In t...

Epidemiological studies reveal that air pollution exposure may exacerbate neurodegeneration. Ultrafine particles (UFPs) are pollutants that remain unregulated in ambient air by environmental agencies. Due to their small size (<100nm), UFPs have the most potential to cross the bodily barriers and thus impact the brain. However, little information ex...

Solid fuel usage in residential heating and cooking is one of the largest sources of ambient and indoor air particulate matter, which causes adverse effects on the health of millions of peoples worldwide. Emissions from solid fuel combustion, such as biomass or coal, are detrimental to health, but toxicological responses are largely unknown. In the...

Although biomass fuel has always been regarded as a source of sustainable energy, it potentially emits polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). This study investigated PCDD/F emissions from industrial boilers fired with three types of biomass fuel (i.e., bagasse, coffee residue, and biomass pellets) via stack sampling and labo...

The absorption Ångström exponent (AAE) describes the spectral dependence of light absorption by aerosols. AAE is typically used to differentiate between different aerosol types for example., black carbon, brown carbon, and dust particles. In this study, the variation of AAE was investigated mainly in fresh aerosol emissions from different fuel and...

Utilization of natural gas fuels in heavy duty vehicles offers an effective solution to reduce global warming and improve urban air quality. However, there are problems related to catalyst durability and release of unburned methane (methane slip). Catalyst durability can be achieved through clever designs of both catalyst material and its regenerat...

During the bioethanol production process, vast amounts of residues are generated as process waste. To extract more value from lignocellulosic biomass and improve process economics, these residues should be used as feedstock in additional processes for the production of energy or fuels. In this paper, barley straw was used for bioethanol production...

Background Advancement in the instrumentation techniques made it possible to identify the compositions and concentrations of various chemicals, such as organic compounds or metals in combustion aerosols. However, the prediction of combustion aerosol-induced toxicity end points in lung epithelium cells is difficult due to the large number of non-lin...

New particulate matter (PM) filtering technologies are needed to meet the emission regulations for small combustion appliances. In this work, we investigate the performance of a novel electrical particle filtration system, the single needle shielded corona charger (SCC), which offers an advantageous solution for PM control in boilers by enhancing p...

Anthropogenic air pollution has a severe impact on climate and human health. The immense molecular complexity and diversity of particulate matter (PM) is a result of primary organic aerosol (POA) as well as secondary organic aerosols (SOAs). In this study, a direct inlet probe (DIP), i.e., atmospheric solids analysis probe (ASAP), with ion mobility...

Background Wood combustion emissions have been studied previously either by in vitro or in vivo models using collected particles, yet most studies have neglected gaseous compounds. Furthermore, a more accurate and holistic view of the toxicity of aerosols can be gained with parallel in vitro and in vivo studies using direct exposure methods. Moreov...

This study assesses the potential of thermal processing for detoxification of wood-combustion ashes that contain high levels of Cr and Cd. Thermal treatment (1000 °C) of bottom ash and fly ash in an oxidising gas (air) atmosphere resulted in: low volatilisation of Cd and most other heavy metals, oxidation of Cr in the ashes to Cr (VI), and, in the...

Generally, large-scale production of graphene is currently not commercially viable due to expensive raw materials, complexity and the high-energy consumption of the processes currently used in the production. The use of biomass precursors and energy efficient procedures for carbonization have been proposed to reduce the cost of the graphene materia...

Municipal solid waste incineration fly ashes can contain high concentrations of Zn and other valuable elements including Cu, Pb, Sn, and Sb. These elements can potentially be separated from fly ashes by selectively volatilising and condensing them in thermal processes. This study presents a thermal process for production of zinc concentrates from f...

The industrial combustion of biomass, which has always been considered a source of clean and sustainable energy, might be phased out in China because it is believed to cause extremely high emissions of volatile organic compounds (VOCs), which are the key precursors in the formation of ozone and haze, although the emission factors have rarely been m...

Ambient particulate matter (PM) is a leading global environmental health risk. Current air quality regulations are based on airborne mass concentration. However, PM from different sources have distinct chemical compositions and varied toxicity. Connections between emission control measures, air quality, PM composition, and toxicity remain insuffici...

Abstract. Primary emissions of wood combustion are complex mixtures of hundreds or even over a thousand compounds, which pass through a series of chemical reactions and physical transformation processes in the atmosphere ( aging ). This aging process depends on atmospheric conditions, such as concentration of atmospheric oxidizing agents (OH radica...

Sauna Stoves (SS) are simple wood combustion appliances used mainly in Nordic countries. They generate emissions that have an impact on air quality and climate. In this study, a new measurement concept for comparing the operation, thermal efficiency, and real-life fine particle and gaseous emissions of SS was utilized. In addition, a novel, simple,...

This study assesses the volatility of 15 elements (As, Bi, C, Cd, Cl, Cu, K, Mn, Na, P, Pb, S, Sb, Sn, and Zn) during thermal processing of fly ashes obtained from four waste-to-energy plants and one wood-combustion plant. Differences in volatility in oxidising and reducing atmospheres (air and 10% H 2 /90% N 2) were assessed at two temperatures, 7...

Airborne particles may effect on indoor air quality in schools. One significant particle source is outdoor dust and soil transported indoors on people's shoes, which may be resuspended, and further inhaled by pupils and teachers. In many Finnish schools, shoes are taken off by coat racks near the classrooms (shoe schools). The new course of action...

Abstract. Residential wood combustion (RWC) emits large amounts of gaseous and particulate organic aerosol (OA). In the atmosphere, the emission is transformed via oxidative reactions, which are under daylight conditions driven mainly by hydroxyl radicals. This continuing oxidative aging produces secondary OA and may change the health- and climate-...

Small-scale biomass combustion is an important source of fine particles in ambient air, causing adverse health and environmental effects. Thus, there is a clear need to develop efficient and feasible flue gas cleaning technologies for small-scale combustion appliances. In this study a novel electrical charging condensing heat exchanger (eCHX) for c...

The combustion of spruce logwood in a modern residential stove was found to emit polycyclic aromatic hydrocarbons (PAH) and oxygenated polycyclic aromatic hydrocarbons (OPAH) with emission factors of 404 μg MJ⁻¹ of 35 analysed PAH, 317 μg MJ⁻¹ of 11 analysed Oxy-PAH and 12.5 μg MJ⁻¹ of 5 analysed OH-PAH, most of which are known as potential mutagen...

In this study, the aerosol release from the silver-indium-cadmium control rods during the air-ingress phase of the QUENCH-18 bundle test was investigated both experimentally and by using simulation tools. During the QUENCH-18 test, the aerosol mass size distribution was measured using two Berner low pressure impactors, aerosol samples were collecte...

There is currently great interest in replacing fossil-oil with renewable fuels in energy production. Fast pyrolysis bio-oil (FPBO) made of lignocellulosic biomass is one such alternative to replace fossil oil, such as heavy fuel oil (HFO), in energy boilers. However, it is not known how this fuel change will alter the quantity and quality of emissi...

Aerosols emitted from various anthropogenic and natural sources undergo constant physico-chemical transformations in the atmosphere, altering their impacts on health and climate. This paper presents the design and characteristics of a novel Photochemical Emission Aging Flow Tube Reactor (PEAR). The PEAR was designed to provide sufficient aerosol ma...

In vitro, direct aerosol nanoparticle exposure of cells cultured at the air-liquid interface (ALI) has shown great potential over the conventional submerged cell exposure methods due to exposure relevancy and more accurate dose determination. Here, we present a design of an ALI cell exposure device, the thermocollector, which applies thermophoresis...

Small-scale batch combustion of wood is a major source of fine particles, black carbon emission and polycyclic aromatic hydrocarbons in Finland. The mass and chemical compositions of batch combustion emissions are known to be highly time-dependent. In this study, the gaseous and particulate batch combustion emissions of three European wood species...

Industrial processes, coal combustion, biomass burning (BB), and vehicular transport are important sources of atmospheric fine particles (PM2.5) and contribute to ambient air concentrations of health-hazardous species, such as heavy metals, polycyclic aromatic hydrocarbons (PAH), and oxygenated-PAHs (OPAH). In China, emission controls have been imp...

Elemental carbon (EC) concentrations in the exhaust of a medium-speed marine engine was evaluated using thermal-optical analysis (TOA). Particulate matter (PM) samples were collected at 75% and 25% engine loads using residual and distillate fuels with sulphur contents of 2.5%, 0.5% and 0.1%, and a biofuel (30% of bio-component). The EC analysis of...

Ambient inhalable particulate matter (PM) is a serious health concern worldwide, but especially so in China where high PM concentrations affect huge populations. Atmospheric processes and emission sources cause spatial and temporal variations in PM concentration and chemical composition, but their influence on the toxicological characteristics of P...

Soot particles from combustion sources are known to have significant environmental effects. One of the major sources of soot particles is small-scale wood combustion, and there is an urgent need to develop methods to abate soot emissions from these appliances. The oxidation of soot particles in the combustion chamber is essential for the control of...

Residential wood combustion (RWC) emits high amounts of volatile organic compounds (VOCs) into ambient air, leading to formation of secondary organic aerosol (SOA) and various health and climate effects. In this study, the emission factors of VOCs from a logwood-fired modern masonry heater were measured using a Proton-Transfer-Reactor Time-of-Fligh...

The consumption of wood fuel is markedly increasing in developing and industrialized countries. Known side effects of wood smoke inhalation manifest in proinflammatory signaling, oxidative stress, DNA damage and hence increased cancer risk. In this study, the composition and acute biological impact of emissions of state-of-the-art wood combustion c...

Intensive forest harvesting techniques are being used in Finland to enhance the share of bioenergy. However, there are no clear indications as to how environmentally safe are these practices. We address this issue in the INDO-NORDEN project through field studies addressing the climate impacts on the ecosystem carbon balance. Also, we will address s...

Combustion technologies of small-scale wood combustion appliances are continuously developed decrease emissions of various pollutants and increase energy conversion. One strategy to reduce emissions is the implementation of air staging technology in secondary air supply, which became an established technique for modern wood combustion appliances. O...