Air Ions Research Articles

FORECASTING THE AEROIN COMPOSITION OF AIR IN THE PRESENCE OF NATURAL AND ARTIFICIAL SOURCES OF IONIZATION

It is shown that for the design of buildings and individual rooms with normative concentrations of light air ions of both polarities, a preliminary estimated assessment of the dynamics of this indicator in space and time is appropriate. In the general case, it is possible to use the continuity equation for weakly ionized plasma for one direction. This is due to the low concentration of air ions in the air. The ratio of molecular kinetic theory of gases is used to determine the necessary indicators - the average lifetime of air ions, free path length. To determine the average speed - Maxwell's distribution. It is shown that the propagation of air ions due to diffusion processes is insignificant, and the corresponding calculations have large errors. Calculations on the propagation of air ions by directed air movement from the source of artificial ionization are given. The distribution of air ion concentrations can be most accurately calculated taking into account their recombination, deposition on heavy air ions and neutral suspended parts (fine dust and aerosols). Relevant coefficients are mostly issued from reference sources. If there are electrostatic fields in the premises, generated due to the triboelectric effect and other factors, it is necessary to take into account the deposition of air ions on these surfaces. In order to correctly determine the concentrations of air ions, in addition to the values of the mobility of negative and positive air ions, data on electrostatic field strengths are required. The values of such fields are unpredictable, so they are measured by appropriate instruments in similar conditions. Verification of calculated data using electrostatic charge meters and air ion counter proved the reasonable convergence of expected and actual data. It is advisable to develop two- and three-dimensional models of the propagation of air ions of both polarities in rooms of different purposes, configurations of equipment placement, the presence of artificial ionization sources and directional air movement.

Effects of Altitude, Plant Communities, and Canopies on the Thermal Comfort, Negative Air Ions, and Airborne Particles of Mountain Forests in Summer

Forest bathing is considered an economical, feasible, and sustainable way to solve human sub-health problems caused by urban environmental degradation and to promote physical and mental health. Mountain forests are ideal for providing forest baths because of their large area and ecological environment. The regulatory mechanism of a mountain forest plant community in a microenvironment conducive to forest bathing is the theoretical basis for promoting physical and mental health through forest bathing in mountain forests. Based on field investigations and measurements, differences in the daily universal thermal climate index (UTCI), negative air ion (NAI), and airborne particulate matter (PM2.5 and PM10) levels in nine elevation gradients, six plant community types, and six plant community canopy parameter gradients were quantitatively analyzed. In addition, the correlations between these variables and various canopy parameters were further established. The results showed the following: (1) Altitude had a significant influence on the daily UTCI, NAI, PM2.5, and PM10 levels in the summer. The daily UTCI, NAI, PM2.5, and PM10 levels gradually decreased with the increase in altitude. For every 100 m increase in altitude, the daily UTCI decreased by 0.62 °C, the daily NAI concentration decreased by 108 ions/cm3, and the daily PM2.5 and PM10 concentrations decreased by 0.60 and 3.45 µg/m3, respectively. (2) There were significant differences in the daily UTCI, NAI, PM2.5, and PM10 levels among different plant communities in the summer. Among the six plant communities, the Quercus variabilis forest (QVF) had the lowest daily UTCI and the best thermal comfort evaluation. The QVF and Pinus tabuliformis forest (PTF) had a higher daily NAI concentration and lower daily PM2.5 and PM10 concentrations. (3) The characteristics of the plant community canopy, canopy density (CD), canopy porosity (CP), leaf area index (LAI), and sky view factor (SVF), had significant effects on the daily UTCI and NAI concentration, but had no significant effects on the daily PM2.5 and PM10 concentrations in the summer. The plant community with higher CD and LAI, but lower CP and SVF, showed a higher daily UTCI and a higher daily NAI concentration. In conclusion, the QVF and PTF plant communities with higher CD and LAI but lower CP and SVF at lower elevations are more suitable for forest bathing in the summer in mountainous forests at lower altitudes. The results of this study provide an economical, feasible, and sustainable guide for the location of forest bathing activities and urban greening planning to promote people’s physical and mental health.

Nickel Coated Polyester Sponge for Delaying the Specific Aggregation of Fine Particles Induced by Negative Air Ions.

Negative air ions (NAIs) produced by corona discharge is often used for indoor air purification; however, the specific aggregation of suspended particles caused by NAIs, especially fine particles (FPs), needs to be considered. Here, a nickel coated conductive sponge (NCCS) was used as the main adsorption interface for delaying the obstinate aggregation caused by NAIs on another surface. The specific aggregation of FPs is caused by the directional transfer of electric charge, and the oxidation characteristic of NAIs results in the surface reaction of FPs simultaneously. The conductivity and roughness of the adsorption interface determine the migration direction and enrichment number of FPs, respectively. Nickel coated conductive sponge with high conductivity and high specific surface area can effectively adsorb the FPs affected by NAIs and can effectively delay the specific aggregation on the surface of indoor objects.

Fundamental Understanding and Construction of Solid‐State Li−Air Batteries

Nonaqueous Li−air batteries with ultrahigh theoretical energy density have attracted much attention in the development of clean energy technology. However, a series of safety challenges including the flammable, volatile organic liquid electrolyte, together with the electrolyte decomposition have greatly hindered their practical development. Solid‐state electrolytes with superior mechanical strength, good chemical stability under open‐air system, wide electrochemical window, nonflammable properties provide a feasible strategy to overcome the safety issues and achieve a stable, applicable Li−air battery system. In this article, a comprehensive review of solid‐state Li−air batteries is provided. Based on the overall understanding of the necessity of developing a solid‐state Li−air battery and ion migration mechanism in solid electrolytes, the construction strategies of solid‐state Li−air battery including cathode fabrication, Li anode optimization, electrolyte design, and the interface regulation between electrodes and electrolyte are presented. The prospects of solid‐state Li−air batteries are also proposed at the end. It is expected that this review would provide a systematic understanding and theoretical guidance in designing and developing safe, stable, applicable solid‐state Li−air batteries.

Detection of ionized air using a photonic-crystal nanocavity excited by broadband light from a superluminescent diode.

It has been shown that silicon photonic crystal nanocavities excited by spectrally narrow light can be used to detect ionized air. Here, to increase the range of possible applications of nanocavity-based sensing, the use of broadband light is considered. We find that the use of a superluminescent diode (SLD) as an excitation source enables a more reproducible detection of ionized air. When our photonic-crystal nanocavity is exposed to ionized air, carriers are transferred to the cavity and the light emission from the cavity decreases due to free carrier absorption. Owing to the broadband light source, the resonance wavelength shifts caused by the carriers in this system (for example, due to temperature fluctuations) do not influence the emission intensity. SLD-excited cavities could be useful to determine the density of ions in air quantitatively.

Advances of the Research Department on Physicochemical and Electrical Measurements of FSUE "VNIIFTRI"

It is hard to imagine the development of the country's economy without constant development and improvement of its base of standards in order to ensure the uniformity of measurements both in a particular country and at the global level. For this purpose, there are four state metrological institutes with branches in Russia.The Research Department on Physicochemical and Electrical Measurements is a structural subdivision of The Federal State Unitary Enterprise «Russian Metrological Institute of Technical Physics and Radio Engineering». The activity of the Research Department is related to the measurement of pH, pX, inorganic components in liquids, with measurements of the parameters of particles in various matrices, gases dissolved in a liquid, such as oxygen, hydrogen, carbon dioxide, measurements of the parameters of air ions, etc. Scientists of the Research Department conducting research to develop the certified reference materials in order to establish the measurement traceability to the Russian Primary Standards, to the calibration and measurement capabilities of metrology institutes at the database of key comparisons of the International Bureau of Weights and Measures.The Research Department is constantly working to expand its capabilities for metrological support of industry and scientific research in the Russian Federation on the topics assigned to the institute, is actively working to improve its reference base, participates in technical committees and working groups of regional and international organizations related to metrology. Takes an active part in international and Russian conferences and seminars, round tables and discussions.This paper describes the achievements of the Research Department over the past two years.

Selection of a regression model for graduation of measuring instruments when it is necessary to estimate stability of the calibration curve

A method for choosing the best regression model for the cases when the measuring task is associated with the study of the stability of the metrological characteristics of the calibrated measuring instrument is described. A description of the experiment set up when using this method in the course of researching the metrological characteristics of measuring instruments for the numeric concentration of light air ions is given, and the research results obtained using this method are given.

Monitoring and management ion concentrations in the air of industrial and public premises

This paper reports a substantiated method and a designed device for controlling the concentrations of air ions in premises in accordance with the European standards SBM 2015. The use of an ultrasonic humidifier with a capacity of 25 W for two hours increases the concentration of negative ions around the device from 240 to 560 cm-3, positive ones ‒ from 260 to 410 cm-3. The intensity of the electrostatic field of a polymeric coating decreases from 5.1 to 0.2 kV/m. The disadvantage of the humidifier is a small radius of influence (1.0–1.5 m) and the inability to control the polarity of ions. It has been experimentally established that air cooling systems (split systems) deionize the air of the premises. Degrees of deionization and dominating polarity are unpredictable and different for devices of different manufacturers and brands. To control the ion composition of the air simultaneously with the maintenance of normative relative humidity and stresses of static fields, the structure was proposed and the effectiveness of a bipolar ultrasonic air ionizer with adjusted performance and dominating polarity has been tested. The maximum productivity of the ionizer is 4,000–5,000 cm-3. The radius of exposure is 5 m (reducing the concentration of ions with a distance to 500 cm-3). To pass the ionized air through an air capacitor, the number and predominant polarity of air ions are regulated by the polarity and voltage on the covers of the capacitor. It was established that in order to service a room with an area of 50 m2, an ultrasonic emitter with a capacity of 25 W would suffice. The adjustability of the device performance makes it possible to reduce or increase the service area. The ability to purify air from suspended particles is shown. During the two hours of operation of the ionizer, the dust content decreased from 4.3–4.4 mg/m3 to 1.4–1.6 mg/m3.

The impact of chronic exposure to MLX i3Dome on people under stress: effects on body detoxification, immune function, and mood state

ABSTRACT Using a parallel randomised control trial to demonstrate the effectiveness of 10 sessions of a Triple Combined Intervention (TCI, far-infrared, negative air ions and light therapy) in reducing stress-related symptoms in workers and detoxify the body. Twenty-one participants were randomly assigned to the experimental group (Gexp, N = 11) or the control group (Gcon, N = 10). The Gexp completed 10 × 20 min sessions using the MLX i3Dome over a 4-week period. Subjective questionnaires were assessed for sleep and psychological disturbances. Trace elements, toxic metals, cortisol, white blood count, muscular and joint soreness level (SL), body weight, resting blood pressure and well-being were also measured. Systolic blood pressure was lower after the 4-week period for Gexp participants only. Sleep improved for Gexp participants and insomnia index decrease significantly. The increase in zinc and copper concentrations were associated with a decrease in the level of lead, mercury and cortisol in the blood following the 10-session programme. An increase in lymphocyte count was reported in the Gexp only. Initial evidence suggests that a triple combined intervention (i.e. MLX i3Dome) reduces excessive stress, improves perceived sleep quality, increases general well-being, enhances body detoxification.

Study of the Vertical Structures, Thermal Comfort, Negative Air Ions, and Human Physiological Stress of Forest Walking Spaces in Summer

Forest walking is a popular, healthy, and light outdoor activity. The potential comprehensive relationships between the vertical structures, thermal comfort, negative air ions (NAI), and human physiological stress in forest walking spaces have not been determined. We performed an experiment in the Baishuihe National Nature Reserve, Sichuan Province, China. Thirty-two college students recruited as subjects completed a forest walk (approximately one kilometer) on the same trail divided into three vertical structure type subsections, namely: A (dense herb and shrub layers with a sparse tree layer), B (dense tree, herb and shrub layers), and C (dense tree and herb layers with a sparse shrub layer). When the subjects passed preset environmental measurement points, staff measured climatic indexes (air temperature, relative humidity, wind velocity, surface temperature and global radiation) and NAI levels, and these data were input into the Rayman model to form a comprehensive thermal comfort index, the physiologically equivalent temperature (PET). PET and NAI differences and dynamic data among the subsections were analyzed. The subjects’ brain waves, heart rates (HRs), and walking speed (S) were digitally recorded. We selected brain wave θ, γ and β-high/α rates, neuroemotional indexes (stress and relaxation) and HR as physiological indicators, and S as an auxiliary indicator. The correlations between PET and NAI with physiological and auxiliary indexes were analyzed. Forest type C showed the lowest PETs and highest NAIs along with the most stable dynamic changes. PET was negatively correlated with HR and positively correlated with γ (12 channels). NAI was positively correlated with S and relaxation and negatively correlated with γ (two channels) and the β-high/α ratio (five channels). These comprehensive relationships suggest that dense tree, sparse shrub, and high-coverage herb layers combined with optimal temporal conditions (before noon or after a light rain) form the best thermal comfort and NAI conditions conducive to reducing human physiological pressures during summer daytime forest walking. These results provide theoretical references for forest walking and spatial regulation.

Degradation of sulfadiazine in a cyclic V-SDBD plasma system: Parameters analysis and degradation pathway

A cyclic volume and surface dielectric barrier discharge (V-SDBD) plasma wastewater treatment system with stainless steel net as discharge electrode was established and applied to the sulfadiazine (SDZ) degradation. The discharge characteristics, active substance yield and relative emission spectra in different net electrode systems were compared. The SDZ degradation as well as the UV–vis spectra and COD removal of the SDZ solutions under different treatment conditions were investigated to achieve the appropriate mesh parameter of the net electrode and circulating velocity of the solution. The obtained results show that the SDZ had a better degradation in the cyclic V-SDBD system than that in the intermittent DBD system. 10-mesh stainless steel net and 333 mL min−1 circulating flow rate were the optimal reaction conditions for the SDZ degradation. Compared with the other three net electrodes (14, 20 and 40-mesh), the 10-mesh electrode system could produce more H2O2 and O3, and the relative emission spectrum had stronger intensity. The results of voltage and current waveform and Lissajous figures show that the air ionization in the V-SDBD system with 10-mesh electrode was higher, and more micro-discharge channels could be generated in the discharge space. UV–vis spectra and COD removal analysis of SDZ solutions also stated the SDZ degradation in the V-SDBD plasma system. According to the byproducts’ identification, SDZ degradation pathway was speculated and the change of solution toxicity was analyzed. The results verified that the total toxicity of the initial SDZ solution could be reduced after treating in the V-SDBD plasma system.

Impacts of Human Activities on the Generating Capacity of Negative Air Ions in Different Functional Areas of Hefei, China

Impacts of Human Activities on the Generating Capacity of Negative Air Ions in Different Functional Areas of Hefei, China

Variation characteristics of plant electrical signal and their relationship with negative air ion under different light intensities.

Negative air ion (NAI) is an essential indicator for measuring air cleanliness of a given area, with vital role in regulating psychological and physiological functions of human body. The photoelectric effect is an important source and influencing factor for the generation of NAI during photosynthesis, but the photoelectric effect is extremely weak and difficult to monitor. Plant electrical signal is an important indicator that indirectly reflects photoelectric effect. Previous studies mostly focused on the spatiotemporal variation of NAI in different forest communities and its relationship with meteorological factors. At present, there is little research on NAI and plant electrical signal. In this study, we explored the effect of different light intensities (0, 150, 300, 500, 700, 800, 1000 and 1200 μmol·m-2·s-1) on characteristics of the plant electrical signal and its relationship with negative air ion, with Pinus bungeana as the research object. The results showed that the intensity of plant electrical signal increased significantly with the increases of light intensity in the illumination range of 0-700 μmol·m-2·s-1. When light intensity reached 700 μmol·m-2·s-1, plant electrical signal activity reached the highest level, and plant was inhibited by light when light intensity increased further, with plant electrical signal activity decreased. The frequency-domain parameters (edge frequency, gravity frequency, power spectrum entropy and power spectrum peak) of plant electrical signals were significantly correlated with NAI. The correlation coefficient between edge frequency (E) and NAI was the highest, the relationship between them was NAI=30.981E+168.814 (R2=0.54), and the mean square error was 52.203. There was a significant correlation between plant electrical signals and NAI, which could characterize the change rule of NAI, and provide scientific evidence for further understanding the contribution potential and production mechanism of forest to NAI.

Global planetary ionization maps in Regener-Pfotzer cosmic ray maximum for GLE 66 during magnetic superstorm of 29–31 October 2003

High-energy particles of cosmic origin e.g. cosmic ray protons and heavier nuclei of galactic and/or solar origin induce complicated nuclear-electromagnetic-meson cascades in the Earth’s atmosphere, eventually leading to an ionization of the ambient air. The induced by cosmic rays atmospheric ionization is related to possible effect of precipitating particles on atmospheric physics and chemistry. These effects can be considerably enhanced during strong and moderately strong solar proton events. While the contribution of galactic cosmic ray particles to ion production in the atmosphere is slightly variable throughout a solar cycle, relativistic solar particles could produce a significant excess on ion pair production, particularly over polar caps. This effect is strong on a short time scales. On the other hand, depressions of the galactic cosmic ray flux, that is, Forbush decreases, can significantly impact the galactic cosmic ray induced ionization. The sequence of three ground level enhancements observed in October-November 2003, specifically the second: GLE 66 which occurred during a giant Forbush decrease, provides unique opportunity to study impact ionization on extended time scale, explicitly considering the reduced galactic cosmic ray flux. Using Monte Carlo simulations we computed the ion production rate and the corresponding ionization effect in the Earth atmosphere during GLE 66 occurred on 29 October 2003, explicitly considering the Forbush decrease and the complex geomagnetospheric conditions.

Spatiotemporal distribution of negative air ion and PM2.5 in urban residential areas

Urban environments are characterised by high pollution levels, which adversely affect the physiology, psychology and behaviour of the urban residents. In this study, on-site measurements and air quality evaluations were performed in urban residential areas. The negative air ion (NAI) concentration, fine particulate matter (PM2.5) concentration, temperature and relative humidity were measured in different seasons. Both PM2.5 and the NAI concentrations changed significantly with seasons. The PM2.5 concentration was the highest in winter, intermediate in autumn and the lowest in summer, while the NAI concentration showed an opposite trend. The overall changes in NAI and PM2.5 concentrations showed a trend of double peaks and double valleys, and there was a substantial difference between rainy days versus sunny days. The NAI concentration was positively correlated with temperature and relative humidity, and the influence of relative humidity on NAI was greater than that of temperature. There were notable spatial differences in the intensity of impact by different pollution sources. Based on these results, suggestions were made for optimising the layout of residential buildings and the rationalisation of traffic networks, with the aim of increasing NAI concentrations and reducing PM2.5 concentrations. This would help reduce the pollution levels in urban residential areas.

Seasonal and vegetational variations of culturable bacteria concentrations in air from urban forest parks: a case study in Hunan, China.

It is important to investigate the airborne bacterial air quality in urban forest parks as tree bacteriostasis practices are being increasingly advocated as measures to improve the air quality and public health in urban green spaces around the world. The aim of the study was to quantitatively investigate airborne culturable bacteria (ACB) concentration levels based on field measurements in every season in five selected forest communities and the uncovered space in an urban forest park, as well as the effects of several factors on the culturability of airborne bacteria. Results suggested that the airborne bacterial levels of all the forest communities reached the clean air quality standard with regard to the airborne bacteria content, with the highest concentration of ACB showing in the uncovered space (1658 ± 1298 CFU/m3) and the lowest showing in the mixed community (907 ± 567 CFU/m3). The temporal distribution analysis showed that the airborne bacteria were mostly concentrated in summer, as well as in the morning and afternoon. The bacteriostatic rates of the mixed community were significantly different with seasonal variation (p < 0.05). Spearman's correlations revealed that the concentration of ACB was significantly positively correlated with the season, wind speed (WS), temperature (T), ultraviolet light (UV), negative air ion (NAI), and total suspended particles (TSP) (p<0.05) but significantly negatively correlated with the forest community type (p < 0.05). Overall, the selection of tree species plays a key role in shaping the forest structure and improving air quality, and the urban forest highlights key priorities for future efforts toward a cleaner, healthier, and more diverse regional forest environment.

Atmospheric Pressure Mass Spectrometry of Single Viruses and Nanoparticles by Nanoelectromechanical Systems.

Mass spectrometry of intact nanoparticles and viruses can serve as a potent characterization tool for material science and biophysics. Inaccessible by widespread commercial techniques, the mass of single nanoparticles and viruses (>10MDa) can be readily measured by nanoelectromechanical systems (NEMS)-based mass spectrometry, where charged and isolated analyte particles are generated by electrospray ionization (ESI) in air and transported onto the NEMS resonator for capture and detection. However, the applicability of NEMS as a practical solution is hindered by their miniscule surface area, which results in poor limit-of-detection and low capture efficiency values. Another hindrance is the necessity to house the NEMS inside complex vacuum systems, which is required in part to focus analytes toward the miniscule detection surface of the NEMS. Here, we overcome both limitations by integrating an ion lens onto the NEMS chip. The ion lens is composed of a polymer layer, which charges up by receiving part of the ions incoming from the ESI tip and consequently starts to focus the analytes toward an open window aligned with the active area of the NEMS electrostatically. With this integrated system, we have detected the mass of gold and polystyrene nanoparticles under ambient conditions and with two orders-of-magnitude improvement in capture efficiency compared to the state-of-the-art. We then applied this technology to obtain the mass spectrum of SARS-CoV-2 and BoHV-1 virions. With the increase in analytical throughput, the simplicity of the overall setup, and the operation capability under ambient conditions, the technique demonstrates that NEMS mass spectrometry can be deployed for mass detection of engineered nanoparticles and biological samples efficiently.

Novel germanium-polyamide6 fibers with negative air ions release and far-infrared radiation as well as antibacterial property

There has been much concern about germanium because of its special atomic nuclear structure to generate negative electrons and far-infrared ray. In this study, novel germanium-polyamide6 fibers were prepared by using micro–nano structured germanium particles as a functional component via melt spinning. The effects of germanium concentration on the morphology, mechanical, negative air ion-releasing, and far-infrared radiation properties of the germanium-polyamide6 fibers were systematically investigated. Besides, the antibacterial activity and mechanism of the fibers against Staphylococcus aureus and Escherichia coli were also discussed. Even though the added germanium particles negatively affected the mechanical performance of the fiber, they were distributed well in the polyamide6 substrate when the concentration was increased from 2% to 6%. Increasing the temperature and pressure induced the germanium-polyamide6 fibers to produce more negative air ions and high far-infrared emissivity. The negative air ion-releasing property of the fiber led to antibacterial performance against S. aureus with more than 99% antibacterial rate. The results confirmed the great application potential of germanium in healthcare, medical, home, and apparel textiles.

Activation of sub-3 nm organic particles in the particle size magnifier using humid and dry conditions

The accurate measurement of aerosol particles and clusters smaller than 3 nm in diameter is crucial for the understanding of new particle formation processes. The particle counters used for measuring these particles are typically calibrated with metal or salt particles under dry conditions, which does not always represent the field conditions where these instruments are later used. In this study, we calibrated the A11 nano Condensation Nucleus Counter (nCNC), consisting of the PSM (Particle Size Magnifier) and a laminar flow butanol based CPC (Condensational Particle Counter), with well-defined biogenic oxidation products from β-caryophyllene oxidation and compared it to a calibration with tungsten oxide under the same conditions. The organic particles were detected less efficiently than the inorganic ones. This resulted in a higher cut-off size for β-caryophyllene oxidation products than for tungsten oxide. At the same PSM settings, the cut-off size for tungsten oxide was 1.2 nm and for β-caryophyllene oxidation products 1.9 nm. However, repeating the calibration of the biogenic particles at 13% relative humidity at 31°C, increased their detection efficiency in the PSM, increasing the cut-off diameter to 1.6 nm.Additionally, we present a comparison of the ion concentrations measured with the PSM and the NAIS (Neutral Cluster and Air Ion Spectrometer) during new particle formation experiments in the CLOUD (Cosmics Leaving Outdoors Droplets) chamber. In these experiments, we produced particles from different organic precursors, such as α-pinene, β-caryophyllene and isoprene, as well as iodine. This way, we could determine the shift in cut-off diameter of the PSM for several different atmospherically relevant chemical compounds and compare it to the laboratory calibrations. We saw a diameter shift for the organic precursors of +0.3 nm in the PSM compared to the NAIS. These two approaches agreed well with each other and show that it is important to know the chemical composition of the measured particles to determine the exact size distribution using a supersaturation scanning method.

ПОКАЗНИКИ РЕКРЕАЦІЙНОЇ ЦІННОСТІ ТА ПРИДАТНОСТІ МІСЬКИХ ЗЕЛЕНИХ ЗОН ДЛЯ ОЦІНКИ КУЛЬТУРНИХ ЕКОСИСТЕМНИХ ПОСЛУГ

The purpose of the work is to determine indicators of recreational importance and suitability, as well as to develop a system of indicators of the recreational potential of green areas for their further use in the assessment of CES: aesthetic, recreational, and social exchange services and relationships. The method of work involves the application of previous experience of domestic and foreign research in the areas of resource assessment of territories for the purposes of organization and development of recreation. Evaluation and categorization of green zones according to the recreational opportunities defined in the system of values is carried out according to 5-point scales with clearly defined criteria of recreational qualities. The overall recreational importance and suitability of green zones for the provision of cultural ecosystem services is objectively determined as the total score of their recreational evaluation based on a set of indicators. Recreational value and suitability, characterized by parameters of medical and biological favorability, aesthetics and landscaping, form the overall recreational potential of urban green areas. The first group of parameters reflects the recreational usefulness of the green zone, and includes values of: phytoncide, dust and gas resistance, air ionization. The second group of parameters includes the value of the diversity of the dendrological composition of the plantations, visibility and uniqueness of the landscape, which generally determine its aesthetics. The third group of parameters reflects the general improvement of urban green zones and includes the value of infrastructure development, the presence of water bodies, historical-cultural/architectural/natural monuments, points of landscape discovery, etc. Recreational potential directly affects the overall capacity of green areas to provide cultural ecosystem services (CES). Scientific novelty. The work analyzed approaches to the assessment of recreational resources, based on the results of the analysis of previous experience, 10 values of the recreational potential of urban green areas were determined, which are important in the formation of the CES proposal. The offer of CES in urban ecosystems is formed not only thanks to the subjective perception of city residents, but also depends to an equal extent on a set of objectively existing conditions and factors of the territory, which is capable of providing cultural ecosystem services. Practical meaning. The determined values of the recreational potential of urban green zones will allow more objective consideration during the evaluation of all the recreational properties of the green zone, which determine its potential in providing CES. It is advisable to use such indicators in CES evaluation to reduce subjectivity in determining their offer.