Papers by Jaakko Kukkonen
This study presents an evaluation and modeling of the size fractionated aerosol number concentrat... more This study presents an evaluation and modeling of the size fractionated aerosol number concentrations that were measured near a major road of Itäväylä in Helsinki, during 23 August-19 September 2003 and 14 January-11 February 2004. The measurement system contained also electronic traffic counts, on-site meteorological measurements, and urban background concentration measurements. We have evaluated the temporal variations and the dependencies on local meteorological conditions of the measured aerosol number concentrations and size distributions. The ultrafine particle (UFP) number concentrations at the roadside site were approximately an order of magnitude higher than those at the urban background site during daytime, due to vehicular emissions from the road. We also determined the statistical correlations of the sequential time series of the particle number size distributions at the roadside site, and the traffic densities. The computed Pearson correlation coefficients for the downwind cases were substantially high for UFP's (>0.6), and low for accumulation mode particles; the latter is due to the substantial contribution of long-range transported particles in that size range. We also utilized this dataset for evaluating the performance of a modeling system that consists of a roadside dispersion model CAR-FMI (Contaminants in the Air from a Road-Finnish Meteorological Institute), a meteorological pre-processing model MPP-FMI and an aerosol process model UHMA (University of Helsinki Model for Aerosol processes). Model simulations underpredicted the particle number concentrations at the measurement site, which was caused by uncertainties in the emission modeling, especially in the UFP size range. many other aerosol properties including particle number concentration and chemical 4002
The intake fraction (iF) has been defined as the integrated incremental intake of a pollutant rel... more The intake fraction (iF) has been defined as the integrated incremental intake of a pollutant released from a source category or region summed over all exposed individuals. In this study we evaluated the iFs in the population of Europe for emissions of anthropogenic primary fine particulate matter (PM 2.5) from sources in Europe, with a more detailed analysis of the iF from Finnish sources. Parameters for calculating the iFs include the emission strengths, the predicted atmospheric concentrations, European population data, and the average breathing rate per person. Emissions for the whole of Europe and Finland were based on the inventories of the European Monitoring and Evaluation Programme (EMEP) and the Finnish Regional Emission Scenario (FRES) model, respectively. The atmospheric dispersion of primary PM 2.5 was computed using the regional-scale dispersion model SILAM. The iFs from Finnish sources were also computed separately for six emission source categories. The iFs corresponding to the primary PM 2.5 emissions from the European countries for the whole population of Europe were generally highest for the densely populated Western European countries, second highest for the Eastern and Southern European countries, and lowest for the Northern European and Baltic countries. For the entire European population, the iF values varied from the lowest value of 0.31 per million for emissions from Cyprus, to the highest value of 4.42 per million for emissions from Belgium. These results depend on the regional distribution of the population and the prevailing long-term meteorological conditions. Regarding Finnish primary PM 2.5 emissions, the iF was highest for traffic emissions (0.68 per million) and lowest for major power plant emissions (0.50 per million). The results provide new information that can be used to find the most cost-efficient emission abatement strategies and policies.
Environmental Research, Sep 1, 2019
Background: There is some evidence that prenatal exposure to low-level air pollution increases th... more Background: There is some evidence that prenatal exposure to low-level air pollution increases the risk of preterm birth (PTB), but little is known about synergistic effects of different pollutants. Objectives: We assessed the independent and joint effects of prenatal exposure to air pollution during the entire duration of pregnancy. Methods: The study population consisted of the 2568 members of the Espoo Cohort Study, born between 1984 and 1990, and living in the City of Espoo, Finland. We assessed individual-level prenatal exposure to ambient air pollutants of interest at all the residential addresses from conception to birth. The pollutant concentrations were estimated both by using regional-to-city-scale dispersion modelling and land-use regression-based method. We applied Poisson regression analysis to estimate the adjusted risk ratios (RRs) with their 95% confidence intervals (CI) by comparing the risk of PTB among babies with the highest quartile (Q 4 ) of exposure during the entire duration of pregnancy with those with the lower exposure quartiles (Q 1 -Q 3 ). We adjusted for season of birth, maternal age, sex of the baby, family's socioeconomic status, maternal smoking during pregnancy, maternal exposure to environmental tobacco smoke during pregnancy, single parenthood, and exposure to other air pollutants (only in multi-pollutant models) in the analysis. Results: In a multi-pollutant model estimating the effects of exposure during entire pregnancy, the adjusted RR was 1.37 (95% CI: 0.85, 2.23) for PM 2.5 and 1.64 (95% CI: 1.15, 2.35) for O 3 . The joint effect of PM 2.5 and O 3 was substantially higher, an adjusted RR of 3.63 (95% CI: 2.16, 6.10), than what would have been expected from their independent effects (0.99 for PM 2.5 and 1.34 for O 3 ). The relative risk due to interaction (RERI) was 2.30 (95% CI: 0.95, 4.57). Discussion: Our results strengthen the evidence that exposure to fairly low-level air pollution during pregnancy increases the risk of PTB. We provide novel observations indicating that individual air pollutants such as PM 2.5 and O 3 may act synergistically potentiating each other's adverse effects.
International Journal of Environmental Research and Public Health, Aug 14, 2019
Exposure to fine particles in ambient air has been estimated to be one of the leading environment... more Exposure to fine particles in ambient air has been estimated to be one of the leading environmental health risks in Finland. Residential wood combustion is the largest domestic source of fine particles, and there is increasing political interest in finding feasible measures to reduce those emissions. In this paper, we present the PM 2.5 emissions from residential wood combustion in Finland, as well as the resulting concentrations. We used population-weighed concentrations in a 250 × 250 m grid as population exposure estimates, with which we calculated the disease burden of the emissions. Compared to a projected baseline scenario, we studied the effect of chosen reduction measures in several abatement scenarios. In 2015, the resulting annual average concentrations were between 0.5 and 2 µg/m 3 in the proximity of most cities, and disease burden attributable to residential wood combustion was estimated to be 3400 disability-adjusted life years (DALY) and 200 deaths. Disease burden decreased by 8% in the 2030 baseline scenario and by an additional 63% in the maximum feasible reduction scenario. Informational campaigns and improvement of the sauna stove stock were assessed to be the most feasible abatement measures to be implemented in national air quality policies.
. This article has investigated the contribution of residential wood combustion (RWC) to the fine... more . This article has investigated the contribution of residential wood combustion (RWC) to the fine particulate matter (PM2.5) concentrations in the Helsinki Metropolitan Area (HMA) for six years, from 2009 to 2014. We have used the PM2.5 concentrations measured at eight air quality measurement stations. The dispersion of emissions on an urban scale was evaluated with multiple source Gaussian dispersion models UDM-FMI and CAR-FMI, and on a regional scale using the chemical transport model SILAM. The overall agreement of the predicted concentrations with measurements of PM2.5 was good or fairly good for all stations and years, e.g., at the permanent residential station the daily average values of the index of agreement ranged from 0.69 to 0.81, and the fractional bias values ranged from −0.08 to 0.11, for the considered six years. Both the measured and predicted daily averaged concentrations showed increasing trends towards the lower temperature values. The highest predicted annual averaged concentrations in the region occurred in the vicinity of major roads and streets, and the suburban residential areas, to the northwest, north and northeast of the city centre. The average concentrations attributed to RWC in winter were up to 10- or 15-fold, compared to the corresponding concentrations in summer. During the considered six-yearly period, the spatially highest predicted fractions of RWC of the annual PM2.5 concentrations ranged from 12 to 14 %. In winter, the corresponding contributions ranged from 16 to 21 %. The RWC contribution was higher than the corresponding urban vehicular traffic contribution at all the residential stations during all years. The study has highlighted new research needs for the future, in particular (i) the modelling of the RWC emissions that would be explicitly based on the actual ambient temperatures, and (ii) the modelling of the impacts of the most important holiday periods on the emissions from RWC.
BMC Public Health, Jul 4, 2022
Background: Residential wood combustion (RWC) is one of the largest sources of fine particles (PM... more Background: Residential wood combustion (RWC) is one of the largest sources of fine particles (PM 2.5) in the Nordic cities. The current study aims to calculate the related health effects in four studied city areas in Sweden, Finland, Norway, and Denmark. Methods: Health impact assessment (HIA) was employed as the methodology to quantify the health burden. Firstly, the RWC induced annual average PM 2.5 concentrations from local sources were estimated with air pollution dispersion modelling. Secondly, the baseline mortality rates were retrieved from the national health registers. Thirdly, the concentration-response function from a previous epidemiological study was applied. For the health impact calculations, the WHO-developed tool AirQ + was used. Results: Amongst the studied city areas, the local RWC induced PM 2.5 concentration was lowest in the Helsinki Metropolitan Area (population-weighted annual average concentration 0.46 µg m − 3) and highest in Oslo (2.77 µg m − 3). Each year, particulate matter attributed to RWC caused around 19 premature deaths in Umeå (95% CI: 8-29), 85 in the Helsinki Metropolitan Area (95% CI: 35-129), 78 in Copenhagen (95% CI: 33-118), and 232 premature deaths in Oslo (95% CI: 97-346). The average loss of life years per premature death case was approximately ten years; however, in the whole population, this reflects on average a decrease in life expectancy by 0.25 (0.10-0.36) years. In terms of the relative contributions in cities, life expectancy will be decreased by 0.10 (95%
Atmospheric Environment, Feb 1, 2017
Atmospheric Measurement Techniques
Sea spray aerosols (SSAs) emitted from ocean surfaces significantly affect climate, but their spe... more Sea spray aerosols (SSAs) emitted from ocean surfaces significantly affect climate, but their specific role in, e.g., cloud formation remains uncertain (Brooks and Thornton, 2018; Wilson et al., 2015). SSAs both scatter the incoming solar radiation and indirectly act as cloud condensation nuclei (CCN) or ice nuclei (IN), modifying cloud properties and precipitation patterns. The parameters influencing the production of SSAs include water temperature, salinity, sea
Springer proceedings in complexity, 2022
Frontiers in Environmental Science
Feedbacks between air pollutants and meteorology play a crucial role in the direction of the resp... more Feedbacks between air pollutants and meteorology play a crucial role in the direction of the response of future climate and air pollution. These feedbacks are important to understand and quantify the potential impact of adaptation and mitigation policies setup for protecting the population against air pollution and heat stress. We review the interactions between climate and air pollution, with special focus on the projections of air pollution under different future climate scenarios and time horizons, based on a literature review of research articles and reports from the last decade. The assessment focuses on 1) the specific impacts of climate change on air pollution and natural particle and precursor emissions in Europe in the near future (2030), by mid-century (2050) and by end of the century (2100), 2) impacts on air pollution due to changes in emissions vs. changes in climate, 3) feedbacks from air pollution on climate, 4) impacts of climate change on wildland fires and air poll...
A new bubble-generating glass chamber design with an extensive set of aerosol production experime... more A new bubble-generating glass chamber design with an extensive set of aerosol production experiments is presented. Compared to the experiments described in the literature, current setup is among the medium-sized installations allowing precise control over the air discharge, water temperature and salinity. The size and material of the chamber offer variety of applications due to its portability, measurement setup adjustability and sterilization option. The experiments have been conducted in a cylindrical bubbling tank of 10 L volume filled by ~30-40 % with water of controlled salt content and temperature and covered with a hermetic lid. The chamber was used to study the characteristics of the aerosols produced by bursting bubbles under different conditions. In line with previous findings, the sea spray aerosol production was shown to depend linearly on the surface area covered by the bubbles, which in turn is a near-linear function of the air discharge through the water. Observed dependencies of the aerosol size spectra and particle fluxes on water salinity and temperature, being qualitatively comparable with the previous experiments, substantially refined the existing parameterizations. In particular, the
This review provides a community's perspective on air quality research focusing mainly on develop... more This review provides a community's perspective on air quality research focusing mainly on developments over the past decade. The article provides perspectives on current and future challenges as well as research needs for selected key topics. While this paper is not an exhaustive review of all research areas in the field of air quality, we have selected key topics that we feel are important from air quality research and policy Published by Copernicus Publications on behalf of the European Geosciences Union. R. S. Sokhi et al.: Advances in air quality research perspectives. After providing a short historical overview, this review focuses on improvements in characterizing sources and emissions of air pollution, new air quality observations and instrumentation, advances in air quality prediction and forecasting, understanding interactions of air quality with meteorology and climate, exposure and health assessment, and air quality management and policy. In conducting the review, specific objectives were (i) to address current developments that push the boundaries of air quality research forward, (ii) to highlight the emerging prominent gaps of knowledge in air quality research, and (iii) to make recommendations to guide the direction for future research within the wider community. This review also identifies areas of particular importance for air quality policy. The original concept of this review was borne at the International Conference on Air Quality 2020 (held online due to the COVID 19 restrictions during 18-26 May 2020), but the article incorporates a wider landscape of research literature within the field of air quality science. On air pollution emissions the review highlights, in particular, the need to reduce uncertainties in emissions from diffuse sources, particulate matter chemical components, shipping emissions, and the importance of considering both indoor and outdoor sources. There is a growing need to have integrated air pollution and related observations from both ground-based and remote sensing instruments, including in particular those on satellites. The research should also capitalize on the growing area of low-cost sensors, while ensuring a quality of the measurements which are regulated by guidelines. Connecting various physical scales in air quality modelling is still a continual issue, with cities being affected by air pollution gradients at local scales and by long-range transport. At the same time, one should allow for the impacts from climate change on a longer timescale. Earth system modelling offers considerable potential by providing a consistent framework for treating scales and processes, especially where there are significant feedbacks, such as those related to aerosols, chemistry, and meteorology. Assessment of exposure to air pollution should consider the impacts of both indoor and outdoor emissions, as well as application of more sophisticated, dynamic modelling approaches to predict concentrations of air pollutants in both environments. With particulate matter being one of the most important pollutants for health, research is indicating the urgent need to understand, in particular, the role of particle number and chemical components in terms of health impact, which in turn requires improved emission inventories and models for predicting high-resolution distributions of these metrics over cities. The review also examines how air pollution management needs to adapt to the abovementioned new challenges and briefly considers the implications from the COVID-19 pandemic for air quality. Finally, we provide recommendations for air quality research and support for policy. Dedication. We wish to dedicate this article to the following eminent scientists who made immense contributions to the science of air quality and its impacts:
Environmental Research, 2020
Background: Previous studies have provided evidence that prenatal exposure to low-level air pollu... more Background: Previous studies have provided evidence that prenatal exposure to low-level air pollution increases the risk of preterm birth (PTB), but the findings of the effects of short-term exposure have been inconclusive. Moreover, there is little knowledge on potential synergistic effects of different combinations of air pollutants. Objectives: To assess independent and joint effects of prenatal exposure to air pollutants during the week prior to the delivery on the risk of PTB. Methods: The study population included 2568 members of the Espoo Cohort Study, living in the City of Espoo, Finland, born between 1984 and 1990. We assessed individual-level prenatal exposure to ambient air pollutants of interest based on maternal residential addresses, while taking into account their residential mobility. We used both regional-to-city-scale dispersion modelling and land-use regression-based method to estimates the pollutant concentrations. We contrasted the risk of PTB in the highest quartile (Q 4 ) of exposure to the lower exposure quartiles (Q 1 -Q 3 ) during the specific periods of pregnancy. We applied Poisson regression analysis to estimate the adjusted risk ratios (RRs) with their 95% confidence intervals (CI), adjusting for season of birth, maternal age, sex of the baby, family's socioeconomic status, maternal smoking, and exposure to environmental tobacco smoke during pregnancy, single parenthood, and exposure to other air pollutants (this in multi-pollutant models). Results: The risk of PTB was related to exposures to PM 2.5 , PM 10 and NO 2 during the week prior to the delivery with adjusted RRs of 1.67 (95%CI: 1.14, 2.46), 1.60 (95% CI: 1.09, 2.34) and 1.65 (95% CI: 1.14, 2.37), from three-pollutant models respectively. There were no significant joint effects for these different air pollutants (during the week prior to the delivery). Conclusion: Our results provide evidence that exposure to fairly low-level air pollution may trigger PTB, but synergistic effects of different pollutants are not likely.
The summer of 2006 was exceptionally dry in the areas surrounding the Gulf of Finland; this resul... more The summer of 2006 was exceptionally dry in the areas surrounding the Gulf of Finland; this resulted in frequently occurring wild land fires, especially in Russia and Estonia. The regionally transported smokes emitted by biomass burning had a strong impact on the PM 2.5 mass concentrations in Helsinki from 18 July to 28 August, 2006; the PM 2.5 concentrations were especially high from 7 to 28 August. The concentrations of PM 2.5 were substantially also elevated at regional background stations in Southern Finland. The air quality modelling system SILAM was used for the forecast of the PM 2.5 concentrations generated by wildland fires. The emission fluxes of PM 2.5 from wildland fires were evaluated based on the MODIS temperature anomalies. The SILAM model forecasted well the overall temporal and spatial distribution of the concentration plumes; however, the absolute values of the fine particular matter concentrations were underpredicted, most likely due to inaccuracies in the emission modelling.
Springer Proceedings in Complexity
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Papers by Jaakko Kukkonen