Air Ion Concentration Research Articles

Changes of atmospheric properties over Belgrade, observed using remote sensing and in situ methods during the partial solar eclipse of 20 March 2015

Measurements of atmospheric parameters were carried out during the partial solar eclipse (51% coverage of solar disc) observed in Belgrade on 20 March 2015. The measured parameters included height of the planetary boundary layer (PBL), meteorological parameters, solar radiation, surface ozone and air ions, as well as Very Low Frequency (VLF, 3–30 kHz) and Low Frequency (LF, 30–300 kHz) signals to detect low-ionospheric plasma perturbations. The observed decrease of global solar and UV-B radiation was 48%, similar to the solar disc coverage. Meteorological parameters showed similar behavior at two measurement sites, with different elevations and different measurement heights. Air temperature change due to solar eclipse was more pronounced at the lower measurement height, showing a decrease of 2.6 °C, with 15-min time delay relative to the eclipse maximum. However, at the other site temperature did not decrease; its morning increase ceased with the start of the eclipse, and continued after the eclipse maximum. Relative humidity at both sites remained almost constant until the eclipse maximum and then decreased as the temperature increased. The wind speed decreased and reached minimum 35 min after the last contact. The eclipse-induced decrease of PBL height was about 200 m, with minimum reached 20 min after the eclipse maximum. Although dependent on UV radiation, surface ozone concentration did not show the expected decrease, possibly due to less significant influence of photochemical reactions at the measurement site and decline of PBL height. Air-ion concentration decreased during the solar eclipse, with minimum almost coinciding with the eclipse maximum. Additionally, the referential Line-of-Sight (LOS) radio link was set in the area of Belgrade, using the carrier frequency of 3 GHz. Perturbation of the receiving signal level (RSL) was observed on March 20, probably induced by the solar eclipse. Eclipse-related perturbations in ionospheric D-region were detected based on the VLF/LF signal variations, as a consequence of Lyα radiation decrease.

Effect of Atmospheric Pollution on Air Ion Concentration

In the article, the possible impact of atmospheric pollution on air ions of various classes were analysed by the method of statistical analysis. The raw data summarized and analysed in the article were obtained within one year period in a monitoring station, by measuring CO, NO, NO2, SO2, O3, PM10, temperature, relative humidity, wind speed and direction, as well as spectrum of air ion concentrations, where ion size varied between 0.75 to 36.6nm. With a help of stepwise regression, the significant parameters were selected and mathematic equations were obtained in order to explain concentrations of positive and negative small, intermediate and heavy air ions with the selected parameters.

EFFECTS OF URBAN GREEN BELTS ON THE AIR TEMPERATURE, HUMIDITY AND AIR QUALITY

As urbanization increases, designing green space that offers ecological benefits is an increasingly important goal of urban planning. As a linear green space in an urban environment, green belts lower air temperature, increase relative humidity, and improve air quality. To quantify the ecological effects of urban green belts and to identify a critical width for effective urban green belts, we analysed the width of urban green belts in terms of their effects on air temperature (T), relative humidity (RH), concentration of negative air ions (NAI) and bacteria rate (BR). The air T, RH and NAI from 8:00 to 18:00 and BR at 9:00 over seven days were investigated on six widths of green belts (0–10 m, 10–20 m, 20–30 m, 30–40 m, 40–50 m and over 50 m) along the west Fourth Ring Road of Beijing in April, July, October and December 2009. We found that (1) the T-RH benefits increased with the width of the green belts, and the 6 m belt had the smallest effect on T-RH, followed by the 16 m and 27 m belts, whereas the effect was obvious with the 34 m belt and conspicuous and stable with the 42 m belt (approximately 80% green coverage) (P < 0.05); (2) the critical width reference value of urban green belts for an obvious effect on the increase in NAI concentration was approximately 42 m (approximately 80% green coverage) (P < 0.05) and the NAI concentration increased with the width of green belts even in July; and (3) the positive effect on the decrease in the BR was greater than the negative effect, the BR decreased with the green belt width and the changes in the brs were stable with the 34 m belt. The results of this study may help urban planners and designers achieve urban green space designs that optimize ecological effects and cultural benefits.

Application of corona discharge-generated air ions for filtration of aerosolized virus and inactivation of filtered virus

The effect of corona discharge-generated air ions on the filtration of aerosolized bacteriophage MS2 was studied. A carbon-fiber ionizer was installed upstream of a medium-efficiency air filter to generate air ions, which were used to charge the virus aerosols and increase their filtration efficiency. After the virus aerosols were captured by the filter for a certain time interval, they were exposed to a newly incoming air ion flow. Captured virus particles were detached from the filter by sonication, and their antiviral efficiency due to air ions was calculated by counting the plaque-forming units. The antiviral efficiency increased with ion exposure time and ion concentration. When the concentration of positive air ions was 107ions/cm3, the antiviral efficiencies were 46.1, 78.8, and 83.7% with exposure times of 15, 30, and 45min, respectively. When the ionizer was operated in a bipolar mode, the number concentrations of positive and negative ions were 6.6×106 and 3.4×106ions/cm3, respectively, and the antiviral efficiencies were 64.3, 89.1, and 97.4% with exposure times of 15, 30, and 45min, respectively. As a quantitative parameter for the performance evaluation of air ions, the susceptibility constant of bacteriophage MS2 to positive, negative, bipolar air ions was calculated as 5.5×10−3, 5.4×10−3 and 9.5×10−3, respectively. These susceptibility constants showed bipolar ion treatment was more effective about 1.7 times than unipolar ion treatment.

Measuring Light Air Ions in a Speleotherapeutic Cave

Abstract The paper deals with a methodology proposed for measuring the concentration of air ions in the environment of speleotherapeutic caves, and with the implementation of the AK-UTEE-v2 ionmeter. Speleotherapy, in the context of its general definition, is the medical therapy that utilizes the climate of selected caves to treat patients with health problems such as asthma. These spaces are characterized by the presence of high air humidity and they make extreme demands on the execution of the measuring device, the Gerdien tube (GT in the following) in particular, and on the amplifier electronics. The result is an automated measuring system using a GT with low-volume air flow, enabling long-term measuring of air ion concentration and determination of spectral ion characteristics. Interesting from the instrumentation viewpoint are the GT design, active shielding, and execution of the electrometric amplifier. A specific method for the calculation of spectral ion characteristics and the mode of automatic calibration were proposed and a procedure of automatic measurement in the absence of attendants was set up. The measuring system is designed for studying and long-term monitoring of the concentration of light negative ions in dependence on climatic conditions and on the mobility of ions occurring in the cave.

Thoron, radon and air ions spatial distribution in indoor air

Spatial distribution of radioactive gasses thoron (Tn) and radon (Rn) in indoor air of 9 houses mostly during winter period of 2013 has been studied. According to properties of alpha decay of both elements, air ionization was also measured. Simultaneous continual measurements using three Rn/Tn and three air-ion active instruments deployed on to three different distances from the wall surface have shown various outcomes. It has turned out that Tn and air ions concentrations decrease with the distance increase, while Rn remained uniformly distributed. Exponential fittings function for Tn variation with distance was used for the diffusion length and constant as well as the exhalation rate determination. The obtained values were similar with experimental data reported in the literature. Concentrations of air ions were found to be in relation with Rn and obvious, but to a lesser extent, with Tn.

How do air ions reflect variations in ionising radiation in the lower atmosphere in a boreal forest?

Abstract. Most of the ion production in the atmosphere is attributed to ionising radiation. In the lower atmosphere, ionising radiation consists mainly of the decay emissions of radon and its progeny, gamma radiation of the terrestrial origin as well as photons and elementary particles of cosmic radiation. These types of radiation produce ion pairs via the ionisation of nitrogen and oxygen as well as trace species in the atmosphere, the rate of which is defined as the ionising capacity. Larger air ions are produced out of the initial charge carriers by processes such as clustering or attachment to pre-existing aerosol particles. This study aimed (1) to identify the key factors responsible for the variability in ionising radiation and in the observed air ion concentrations, (2) to reveal the linkage between them and (3) to provide an in-depth analysis into the effects of ionising radiation on air ion formation, based on measurement data collected during 2003–2006 from a boreal forest site in southern Finland. In general, gamma radiation dominated the ion production in the lower atmosphere. Variations in the ionising capacity came from mixing layer dynamics, soil type and moisture content, meteorological conditions, long-distance transportation, snow cover attenuation and precipitation. Slightly similar diurnal patterns to variations in the ionising capacity were observed in air ion concentrations of the cluster size (0.8–1.7 nm in mobility diameters). However, features observed in the 0.8–1 nm ion concentration were in good connection to variations of the ionising capacity. Further, by carefully constraining perturbing variables, a strong dependency of the cluster ion concentration on the ionising capacity was identified, proving the functionality of ionising radiation in air ion production in the lower atmosphere. This relationship, however, was only clearly observed on new particle formation (NPF) days, possibly indicating that charges after being born underwent different processes on NPF days and non-event days and also that the transformation of newly formed charges to cluster ions occurred in a shorter timescale on NPF days than on non-event days.

COMPLEX OF NUMERICAL MODELS FOR COMPUTATION OF AIR ION CONCENTRATION IN PREMISES

Purpose. The article highlights the question about creation the complex numerical models in order to calculate the ions concentration fields in premises of various purpose and in work areas. Developed complex should take into account the main physical factors influencing the formation of the concentration field of ions, that is, aerodynamics of air jets in the room, presence of furniture, equipment, placement of ventilation holes, ventilation mode, location of ionization sources, transfer of ions under the electric field effect, other factors, determining the intensity and shape of the field of concentration of ions. In addition, complex of numerical models has to ensure conducting of the express calculation of the ions concentration in the premises, allowing quick sorting of possible variants and enabling «enlarged» evaluation of air ions concentration in the premises. Methodology. The complex numerical models to calculate air ion regime in the premises is developed. CFD numerical model is based on the use of aerodynamics, electrostatics and mass transfer equations, and takes into account the effect of air flows caused by the ventilation operation, diffusion, electric field effects, as well as the interaction of different polarities ions with each other and with the dust particles. The proposed balance model for computation of air ion regime indoors allows operative calculating the ions concentration field considering pulsed operation of the ionizer. Findings. The calculated data are received, on the basis of which one can estimate the ions concentration anywhere in the premises with artificial air ionization. An example of calculating the negative ions concentration on the basis of the CFD numerical model in the premises with reengineering transformations is given. On the basis of the developed balance model the air ions concentration in the room volume was calculated. Originality. Results of the air ion regime computation in premise, which is based on numerical 2D CFD model and balance model, are presented. Practical value. A numerical CFD model and balance model for the computation of air ion regime allow calculating the ions concentration in the premises in the conditions of artificial air ionization taking into account the main physical factors determining the formation of ions concentration fields.

Interpretation of Atmospheric Aerosol Measurements by Means of a Numerical Simulator of New Particle Formation Events

ABSTRACTWe performed a more comprehensive test of a new NPF parameter estimator published recently. The estimator considers measurements as test data and automatically adjusts the values of its physical control parameters according to the criterion of best fit. The parameters estimated within this procedure include nucleation rate, particle growth rate, birth size of nanoparticles etc. We analyzed all new particle formation events recorded during a measurement campaign at Hyytiala, Finland. The results show a good performance in reproducing the time series of the concentrations of small air ions and aerosol nanoparticles in the diameter interval of 2.8–8.6 nm. The numerically estimated values of the parameters are in accordance with the results known from certain other studies carried out at Hyytiala. We conclude the new method may appear useful in the analysis of several air ion and atmospheric aerosol measurements during new particle formation events.

Использование сильвинита Верхнекамского месторождения калийно-магниевых солей для повышения качества воздушной среды и уровня ее ионизации

Urbanization of territories and growth of man-made air pollution require creating and widely implementing means, methods and materials to increase air quality of indoor premises through ionization. Increase of air quality of indoor premises is on the front burner which is caused by following reasons of natural air deionization: aerosol and gas pollution and air cleaning from its pollution. Wherein, use of conventional methods of electrostatic generation of air ions is restricted by its side effects. This paper reviews new prospecting methods to create qualitative and treatment air environment inside premises through its air ionization by interaction of air and natural sylvinite, containing silvite (potassium chloride). The paper presents generalized experimental data including air ionization of premises for treatment and health-recovering purposes that represent sylvinite speleoclimatic chambers with surfaces of different design made of either sawn sylvinite blocks of natural sylvinite or pressed salt tile with high concentration of potassium chloride etc. Air ionization occurs primarily due to beta radiation of natural radioactive isotope potassium-40. Concentration of air ions of positive and negative polarity and different mobility (light, moderate and heavy air ions) are studied. Spectrum distribution of air ions of light mobility group of negative polarity are analyzed in details. In the range of mobility more than 2 cm 2 В –1 sec –1 unipolarity coefficient is always less than 1. In the range of 1–2 cm 2 В –1 sec –1 unipolarity coefficient is larger than 1. Obtained results prove high efficiency of application of sylvinite construction materials to create high-quality, treatment or health-recovering air environment, allow to select special construction and decoration materials based on sylvinite depending on required parameters of air ion composition it order to create high-quality air in the premises.

Variability of air ion concentrations in urban Paris

Abstract. Air ion concentrations influence new particle formation and consequently the global aerosol as potential cloud condensation nuclei. We aimed to evaluate air ion concentrations and characteristics of new particle formation events (NPF) in the megacity of Paris, France, within the MEGAPOLI (Megacities: Emissions, urban, regional and Global Atmospheric Pollution and climate effects, and Integrated tools for assessment and mitigation) project. We measured air ion number size distributions (0.8–42 nm) with an air ion spectrometer and fine particle number concentrations (> 6 nm) with a twin differential mobility particle sizer in an urban site of Paris between 26 June 2009 and 4 October 2010. Air ions were size classified as small (0.8–2 nm), intermediate (2–7 nm), and large (7–20 nm). The median concentrations of small and large ions were 670 and 680 cm−3, respectively, (sum of positive and negative polarities), whereas the median concentration of intermediate ions was only 20 cm−3, as these ions were mostly present during new particle formation bursts, i.e. when gas-to-particle conversion produced fresh aerosol particles from gas phase precursors. During peaks in traffic-related particle number, the concentrations of small and intermediate ions decreased, whereas the concentrations of large ions increased. Seasonal variations affected the ion population differently, with respect to their size and polarity. NPF was observed in 13 % of the days, being most frequent in spring and late summer (April, May, July, and August). The results also suggest that NPF was favoured on the weekends in comparison to workdays, likely due to the lower levels of condensation sinks in the mornings of weekends (CS weekdays 09:00: 18 × 10−3 s−1; CS weekend 09:00: 8 × 10−3 s−1). The median growth rates (GR) of ions during the NPF events varied between 3 and 7 nm h−1, increasing with the ion size and being higher on workdays than on weekends for intermediate and large ions. The median GR of small ions on the other hand were rather similar on workdays and weekends. In general, NPF bursts changed the diurnal cycle of particle number as well as intermediate and large ions by causing an extra peak between 09:00 and 14:00. On average, during the NPF bursts the concentrations of intermediate ions were 8.5–10 times higher than on NPF non-event days, depending on the polarity, and the concentrations of large ions and particles were 1.5–1.8 and 1.2 times higher, respectively. Because the median concentrations of intermediate ions were considerably higher on NPF event days in comparison to NPF non-event days, the results indicate that intermediate ion concentrations could be used as an indication for NPF in Paris. The results suggest that NPF was a source of ions and aerosol particles in Paris and therefore contributed to both air quality degradation and climatic effects, especially in the spring and summer.

Exposure to Air Ions in Indoor Environments: Experimental Study with Healthy Adults.

Since the beginning of the 20th century there has been a scientific debate about the potential effects of air ions on biological tissues, wellbeing and health. Effects on the cardiovascular and respiratory system as well as on mental health have been described. In recent years, there has been a renewed interest in this topic. In an experimental indoor setting we conducted a double-blind cross-over trial to determine if higher levels of air ions, generated by a special wall paint, affect cognitive performance, wellbeing, lung function, and cardiovascular function. Twenty healthy non-smoking volunteers (10 female, 10 male) participated in the study. Levels of air ions, volatile organic compounds and indoor climate factors were determined by standardized measurement procedures. Air ions affected the autonomous nervous system (in terms of an increase of sympathetic activity accompanied by a small decrease of vagal efferent activity): In the test room with higher levels of air ions (2194/cm3 vs. 1038/cm3) a significantly higher low to high frequency ratio of the electrocardiography (ECG) beat-to-beat interval spectrogram was found. Furthermore, six of nine subtests of a cognitive performance test were solved better, three of them statistically significant (verbal factor, reasoning, and perceptual speed), in the room with higher ion concentration. There was no influence of air ions on lung function and on wellbeing. Our results indicate slightly activating and cognitive performance enhancing effects of a short-term exposure to higher indoor air ion concentrations.

Impact of Microclimate and Indoor Plants on Air Ion Concentration

Saturation of air ions is essentially important for all living beings, especially for human health. Existing sanitary norms provide that concentration of small ions has to be in range of 400-50000 ions cm-3 and unipolarity coefficient 0.4 ≤ K ≤ 1.0. Many species of indoor plants emit organic volatile compounds and air ions, therefore they could be used for improving the quality of indoor air. The results show that ionization level of indoor air is significantly insufficient and selected species of indoor plants are not able to improve it. They serve rather as supplementary surfaces for ion absorption. Possible interaction between microclimate, ion concentration and indoor plants in different times of the day is analyzed.

Complex Evaluation Of Air Quality In Rezekne

Paper presents results of air ionization level measurements made in past 3 years in Rezekne city. The concentrations of positive and negative air ions with mobility factor k ≥ 0,4 cm2/V·s were obtained by portative air-ion counter “Sapfir-3M” (Russia) in 8 parts of the city thrice per day. The approximate interconnections among ionization and chemical and mechanical pollution of air were analyzed. The complex evaluation of long – term air pollution impact on different parts of city is carried out using methods of lichenoindication and air ion research.

Effect of Environmental Factors on Air Ion Concentration

<p class="R-AbstractKeywords"><span lang="EN-US">The paper discusses and analyzes the effect of environmental factors on ion concentrations in urban air. Statistically mathematical method was used to analyze the measurements of air ion concentration collected in a period of several months, with ion size ranging from 0.75 to 36.6 nm. As environmental factors related to air ions, the following chemical and physical parameters of the atmospheric air were analyzed: CO, NO, NO<sub>2</sub>, NO<sub>x</sub>, SO<sub>2</sub>, O<sub>3</sub>, PM10, PM2.5, temperature, relative humidity, wind speed and direction. When analyzing data in this combination, there is often a problem of multicollinearity between air chemical and physical parameters. This paper addresses this problem by using the component regression. Regression equations were elaborated to understand the dependence of concentrations of various classes of positive and negative air ions on chemical and physical parameters of the air.</span></p>

Air ions as indicators of short-term indoor radon variations

Diurnal variations in the air ion concentration are subject to changes in the radon concentration. In this experiment, the air ion and radon concentrations were simultaneously measured using two air ion detectors and two continuous radon detectors. The results of the indoor measurements revealed a strong correlation between the concentrations of positive air ions and radon (with a correlation coefficient greater than 0.9). The radon-to-ion concentration ratio changes with an increase in the radon concentration from a linear to a square-root relation. This correlation provides a means of using air ion measurements as a high-confidence indicator of changes in the radon concentration, especially for short-term measurements on the order of seconds or minutes, which is too short a measurement interval for conventional radon monitors. The use of air ions as an indicator of changes in radon concentration allows for investigation of the behavior of indoor radon and also allows radon to be used as a tracer gas for air mass exchange.

Characteristics of Atmospheric Small Ions and Their Application to Assessment of Air Quality in a Typical Semi-Arid City of Northwest China

Observations of atmospheric air ions at most geographic areas have been undertaken, but there are still very few observations at middle-latitude semi-arid areas throughout the world. To quantify characteristics of small air ions in semi-arid areas of China, measurements of small air ions and particulate matter (PM10) were conducted at 16 different sites in Xi'an (34°26′N, 108°94'E), China, from August 2009 to July 2010 along with meteorological parameters. The influences of meteorological parameters and PM10 concentration on small air ions as well as their influence mechanisms were discussed in detail. The results showed that both spatial and temporal distributions of small ions were uneven in Xi’an city. Spatially, the concentration of small ions increased gradually from city center to the suburbs. The mean annual concentration of small negative ions was in the range of 200–400 cm–3 with the mean value of 261 ± 39 cm–3 at urban areas, while more than 500 cm–3 at suburban areas. Significant seasonal variations of small ions were observed with highest level in summer, followed by spring and autumn, and lowest in winter at various types of sites. The positive correlations were found between small ions concentration and temperature as well as relative humidity, while negative correlation between the small ions concentration and PM10 concentration. Air ions concentration was also applied to the assessment of air quality in Xi’an. The assessment results indicated that the air quality was better at suburban areas than at urban areas, suggesting that the unipolarity model is reasonable to indicate air cleanness.

ДОСЛІДЖЕННЯ РОЗПОДІЛУ АЕРОІОНІВ У ПОВІТРЯНОМУ СЕРЕДОВИЩІ ПРИМІЩЕННЯ

In the paper the experimental results of the different charge air ions distribution for working ionizer of effluence type in the office space are given. The study has been carried out using the ions generator IWS-12D1-AE (Israel) – corona type with the productivity of 5·109 ion/sec. The small air ions counter MAC-01 (Russia) was used for determination of ions concentration. The results are presented as scheme demonstrating the air ions distribution at various height and distance from the ionizer. The high local area concentration of negative air ions under the ionizer is detected. It is established that trajectory of air ions distribution from corona type ionizer IWS-12D1-AE is characterized by a parabolical shape. The concrete recommendations for the arrangement of this device are determined.

The spatial-temporal pattern and influencing factors of negative air ions in urban forests, Shanghai, China

Negative air ions are natural components of the air we breathe. Forests are the main continuous natural source of negative air ions (NAI). The spatio-temporal patterns of negative air ions were explored in Shanghai, based on monthly monitoring in 15 parks from March 2009 to February 2010. In each park, sampling sites were selected in forests and open spaces. The annual variation in negative air ion concentrations (NAIC) showed peak values from June to October and minimum values from December to January. NAIC were highest in summer and autumn, intermediate in spring, and lowest in winter. During spring and summer, NAIC in open spaces were significantly higher in rural areas than those in suburban areas. However, there were no significant differences in NAIC at forest sites among seasons. For open spaces, total suspended particles (TSP) were the dominant determining factor of NAIC in summer, and air temperature and air humidity were the dominant determining factors of NAIC in spring, which were tightly correlated with Shanghai’s ongoing urbanization and its impacts on the environment. It is suggested that urbanization could induce variation in NAIC along the urban-rural gradient, but that may not change the temporal variation pattern. Furthermore, the effects of urbanization on NAIC were limited in non-vegetated or less-vegetated sites, such as open spaces, but not in well-vegetated areas, such as urban forests. Therefore, we suggest that urban greening, especially urban forest, has significant resistance to the effect of urbanization on NAIC.

ПОШИРЕННЯ АЕРОІОНІВ У ПОВІТРЯНОМУ СЕРЕДОВИЩІ ПРИМІЩЕННЯ ВІД ІОНІЗАТОРІВ РІЗНОГО ТИПУ

In the paper the experimental results of air ions distribution from corona charge ionizers of different designs and capacities in the office space are given. The study has been carried out using such ionizers as:- effluence bipolar ionizer IWS-12D1-AE (Israel) with the productivity of 5·109 ion/sec working in «dark corona»;- effluence unipolar ionizer «Super Plus-Eco» (Russia) with the productivity of 5·1010 ion/sec working in «glowing corona»;- ionizer «Breeze» equipped with fan and designed using the device IWS-12D1-AE working in «dark corona».The small air ions counter MAC-01 (Russia) was used for determination of ions concentration. The results are presented as schemes demonstrating the air ions distribution at various height and distance from the ionizer to the breathing space of the person. The high local area concentration of negative air ions under the ionizer is detected. It is established that trajectories of air ions distribution from tested ionizers is characterized by a parabolical shape. The concrete recommendations for the arrangement of these devices are determined.