Negative Air Research Articles

Synergistic Disinfection by 222 nm Far-UVC and Negative Air Ions of Airborne Bacteria and the Induced Oxidative Stress Responses: A Bioaerosol Chamber Study

Synergistic Disinfection by 222 nm Far-UVC and Negative Air Ions of Airborne Bacteria and the Induced Oxidative Stress Responses: A Bioaerosol Chamber Study

Empirical analysis of the influence mechanism of vegetation and environment on negative air ion in warm temperate forest ecosystems

Air pollution presents a significant threat to public health in megacities globally. Negative air ions (NAI), often referred to as “air vitamins,” are recognized for their effectiveness in alleviating the harmful effects of air pollution. Forest ecosystems serve as natural generators of NAI, with both vegetation and environmental conditions playing critical roles in the formation and persistence of NAI. Gaining a comprehensive understanding of how forest ecosystems regulate NAI production is essential for leveraging their potential to enhance air quality. However, the intricate dynamics of forest ecosystems, along with seasonal fluctuations in vegetation and environmental factors, introduce uncertainties in NAI generation. This study utilized long-term observational data to explore the relationships between environmental variables, vegetation photosynthetic capacity (using solar-induced chlorophyll fluorescence, SIF), and NAI concentrations. By employing machine learning algorithms, we analyzed the spatiotemporal distribution of NAI, identifying the key contributing factors and their relative influence within forest ecosystems. The results revealed distinct seasonal variations in NAI levels, with higher values in summer and lower in winter. SIF and PM2.5 primarily influenced NAI through direct effects across seasons, whereas ambient temperature (TA), relative humidity, photosynthetically active radiation (PAR), and soil moisture predominantly impacted SIF on NAI through indirect effects in summer. TA was the primary influencing factor in spring and winter, contributing 28% and 25%, respectively, while PAR played a more significant role in summer and autumn, accounting for 37% and 27%. Vegetation had a greater impact on NAI levels during spring and summer, contributing 66% and 62%, whereas environmental factors dominated in autumn and winter, with contributions of 83% and 89%. This study offers both a theoretical foundation and technical guidance for enhancing the role of forest ecosystems in improving air quality and human living environments.

A novel sustainable wood-based negative air anion generator utilizing in-situ polymerization of polylactic acid to reinforce the cellulose framework

The generation of negative air ions (NAI) by furniture contributes to indoor air purification and enhances the living environment. However, commercially available furniture typically relies on surface coatings to release NAI. Over time, the degradation of these coatings leads to a significant decline in NAI release performance, presenting a persistent challenge for sustained effectiveness. Here, a novel sustainable wood-based negative air anion generator (SWNG) had been developed, utilizing a cellulose framework as the substrate. The in-situ synthesis of polylactic acid (PLA) within the wood incorporated titanium dioxide (TiO2), tourmaline (TL), and cellulose acetate, firmly anchoring these materials within the wood structure. Compared to the cellulose framework alone, the NAI production of the SWNG had increased by 406.67 %. The impregnation with PLA enhanced the enduring photocatalytic activity of TiO2 and TL in this innovative wooden NAI generator. After undergoing 200 cycles of testing between −40 °C and 50 °C, it continued to sustain NAI production, demonstrating exceptional antibacterial performance. Overall, this study introduced a novel sustainable wood-based negative air ion generator as a highly stable material with sustainable properties, offering significant potential for applications in improving indoor air quality and in the domain of home construction.

ОБҐРУНТУВАННЯ РОЗШИРЕНОГО СКЛАДУ СПОСТЕРЕЖЕНЬ НА ВОДНО-БАЛАНСОВИХ СТАНЦІЯХ ТА ДОСЛІДНИЦЬКИХ ГІДРОГЕОФІЗИЧНИХ ПОЛІГОНАХ

The current level of understanding of the subordination and multifactorial dependence of the determining processes in the atmosphere, lithosphere and hydrosphere of the Earth requires a corresponding reorganization of the basic system of environmental monitoring, improvement and expansion of research on water these stations, which can become the supporting 'nodes' of the balance of this system. The appearance of fundamentally new theoretical developments, modern devices and equipment, a large number of software tools, etc., prompts a significant reorganization and strengthening of the environmental monitoring system. The article substantiates an additional set of studies, which should be included in the regulation of observations at already existing water balance stations, with their mandatory modernization. Spheres are subject to control - the atmosphere, surface and underground (subsurface) hydrospheres, which change over time at different rates and pedosphere. A certain inertia of hydrogeological processes implies the possibility of using meteorological indicators, which can be used to predict changes in the moisture regime in the aeration zone and shallow groundwater in the near future; based on the reliably predictable changes of the latter - to forecast changes in interlayer groundwater resources, etc. It is proposed to include in the monitoring regulations the following indicators of the state of the environment, which will allow to identify and analyze the causes of changes in the water situation, balance and resources, to determine the mechanisms of moisture transfer and accumulation, as well as to build models and perform predictive assessments. The results of comprehensive research at the «Lutiz» landfill demonstrate significant variability of hydrogeophysical indicators and changes in the intensity of natural signals depending on the landscape timing, the latest tectonics, the geological basis and the composition of the overlying sediments. Original devices are presented, which are used to determine indicators of electric and thermal fields, the ratio of positive and negative air ions, etc.

Ensuring the normalization of the aero-ionic regime in production areas by means of ultrasonic air ionization

The results of studies on the normalization of the aeroionic regime in rooms under ultrasonic ionization of humidified air are presented. The increase in the concentration of negative aeroions under these conditions by the combined effect of the balloelectric effect and ultrasonic cavitation is substantiated. It has been established that when distilled water is used as a source of air ions under the action of a 10 W ultrasonic generator at a distance of 0.5 m, the concentration of negative air ions increases almost sixfold. At the same time, due to the joint effect of ultrasonic cavitation in the surface layer of water and the balloelectric effect, no generation of ozone and nitrogen oxides is caused. It is proved that with a decrease in the degree of water mineralization, the concentrations of negative and positive aeroions increase due to changes in the physicochemical properties of water and the resulting mechanochemical phenomena. The mechanism of formation of air ions in the air of industrial premises under the combined action of the balloelectric effect and ultrasound is proposed. It is substantiated that the quality of the air ionic composition of industrial premises air improves at a temperature of demineralized water of 20-25 °C and a directed air flow of 6 m/s towards the working area with the combined effect of ultrasound and balloelectric effect, which contributes to the improvement of sanitary and hygienic working conditions. The structure of an automated system for controlling the aeroionic regime of the working area of industrial premises with artificial ionization of humidified air using an aeroion generator and a ventilation system is proposed. This will allow monitoring and processing of information on technological, electrical and microclimatic parameters, adjusting, coordinating and jointly controlling the ventilation system devices and the ultrasonic generator of air ions.

Impact of Pulse Electric Field Stimulation on Negative Air Ion Release Capacity of Snake Plants

To investigate the effects of pulse electric field stimulation on the photosynthetic electron transport chain and negative air ion (NAI) release capacity of snake plants, the chlorophyll content, fluorescence induction kinetics curve (OJIP curve), chlorophyll fluorescence parameters, and NAI release concentration of snake plants kept under identical greenhouse conditions under different pulse electric field stimulations were compared and analyzed. The experimental results show that (1) after pulse electric field stimulation, the chlorophyll content in treatment group T1 (5 kv) and T2 (7 kv) of snake plants increased by 6.30% and 6.70%, respectively, with significant differences observed between the two treatment groups and the control group (CK). (2) In both treatment groups, the OJIP curve exhibited higher values for the inflection point (I) and peak (P) compared to the origin (O) and inflection point (J) values, with the rising trend in the I–P segment being more gentle than that of the O–J segment. Additionally, the J band was above 0, with the peak value in the T2 group being higher than that in the T1 group. (3) The chlorophyll fluorescence parameters showed fluctuating variations. Specifically, Fm, TRo/CSo, ETo/CSo, and DIo/CSo showed ascending trends in the treatment groups. Fv/Fo, Sm, and ABS/RC exhibited descending trends; Fv/Fm, Vj, ETo/RC, and φEo showed relatively minor changes. The PIabs displayed a decreasing trend. The PItotal in the CK was greater than that in the T1 and T2 groups. (4) After 4 h of pulse electric field stimulation, the NAI concentration increased by 87.60% in the T1 group and by 62.09% in the T2 group, compared to the same measurement taken at 3 h. Pulse electric field impacts the photosynthetic electron transport chain of snake plants, thereby influencing their NAI release capacity. This study aims to elucidate the physiological responses of the chloroplasts in snake plants to pulsed electric field stimulation and to lay the foundation for enhancing the plant’s release of negative air ion concentrations through physical and technological means.

The Combined Effects of the Thermal Environment and Air Quality at Recreation Places on the Physiology and Psychology of People in Urban Parks

Urban forests, crucial to urban ecosystems, are increasingly threatened by the challenges of urbanization, such as deteriorating thermal environments and declining air quality. Despite their recognized benefits to city dwellers’ quality of life, a systematic understanding of the impact of these environmental factors on public psychophysiological well-being in recreational sites is a notable gap in the literature. The objective of this research was to bridge this gap by examining the effects of the thermal environment and air quality in urban forests on the public’s perception, offering scientific evidence to inform environmental optimization and health management strategies for urban parks, essential for sustainable urban development and public health. Three urban parks in Fuzhou, Fujian Province, namely Fuzhou National Forest Park, Xihu Park, and Jinniushan Sports Park, were selected as research sites. Environmental monitoring and questionnaire surveys were conducted at 24 recreation places from October to December 2020, collecting temperature, humidity, and wind speed; the atmospheric composition includes PM2.5, PM10, negative oxygen ion, and psychophysiological data from the public. Multivariate statistical methods were employed to assess the environmental characteristics of different recreation places types and their impact on public health. The findings reveal that environmental factors explained 1.9% to 11.8% of the variation in physiological and psychological responses, mainly influenced by temperature, wind speed, and negative oxygen ions. Forests and waterfront recreation places significantly outperform canopy and open recreation places in promoting mental invigoration, stress relief, emotional tranquility, and attention restoration. Environmental monitoring results indicate that favorable meteorological conditions and good air quality are crucial for enhancing the service functions of recreation places. Notably, the positive correlation between a negative air ion concentration and psychological well-being provides a novel perspective on understanding the health benefits of urban forests. The thermal environment and air quality of urban recreation places exert a significant influence on the psychophysiological status of the public. Increasing green coverage, improving water body environments, and rationally planning recreation places layout are of great theoretical and practical significance for enhancing the environmental quality and service functions of urban forests.

PM1.0 removal enhancement in cooperated electric-ionic field by negative air ions carbon fiber electrode

The study focuses on improving the removal efficiency of submicron particles using negative air ions (NAIs), which are challenging to remove. To enhance this efficiency, cascaded carbon fiber tubular (CFT) chargers were designed to boost particle charging. Through experiments and numerical simulations, the chargers’ enhancement mechanisms, cooperation effects, and overall performance were evaluated. The optimal configuration for the CFT charger was identified as a gap distance (d = 2.0 r0) and grounded electrode length (L0 = 4πr03) that ensures high collection efficiency (96.7 % for 0.5 μm particles at 4 m/s) and ultra-low ozone generation (7.25 ppb). The study found that while the average electric field strength (E¯) and ion density significantly influence charging, an unusual improvement in collection efficiency was observed the charger with d = 2.0 r0 at u = 3 m/s, likely due to the potential predominance of the maximum electric field strength (Emax) at relative higher velocity. Besides, the CFT charger demonstrated balanced performance compared to other reported works, although higher relative humidity (80 ± 5 % RH) inhibits removal efficiency, which can be mitigated by reducing gas velocity.

Impact of Negative Air Ions on Hematological and Hormonal Parameters in Cerebral Palsy

Impact of Negative Air Ions on Hematological and Hormonal Parameters in Cerebral Palsy

Empirical analysis of the influence of vegetation photosynthetic productivity on negative air ions in forest ecosystems driven by solar radiation

Air pollution stands as the single largest environmental risk to human health globally, and negative air ions (NAIs) serve as essential indicators for measuring regional air quality. They play a crucial role in alleviating the pressure and risks posed by air pollution. NAIs are notably abundant in forests, where the photosynthesis of vegetation serves as a significant factor influencing their presence. However, a dearth of quantitative research exists regarding the relationship between vegetation photosynthesis and NAIs. Current literature only offers qualitative insights, suggesting that vegetation photosynthesis may foster NAIs production. The mechanisms through which the photosynthetic process influences NAIs and the potential contribution of forest vegetation to NAIs remain unclear, lacking quantitative investigation. In this study, Quercus variabilis, a typical tree species in the warm temperate zone, was chosen as the research subject. We examined the dynamic changes in NAIs and net ecosystem productivity (NEP) from 2019 to 2021. The results demonstrated a strong correlation between NAIs and NEP at the ecosystem scale during the primary vegetation growing season. NEP effectively tracked daily changes in NAIs and exhibited a good fit. Notably, the scatter plots of NAIs and NEP exhibited clear stratification under varying photosynthetically active radiation (PAR) intensities. The correlation between NAIs and NEP was significantly higher under high PAR conditions compared to low PAR conditions, with R2 values of 0.458 and 0.367, respectively. Consequently, NEP emerges as a superior indicator for tracking NAIs variation characteristics at the ecosystem scale compared to PAR. This finding offers a rapid and accurate evaluation method for discerning the spatial and temporal distribution patterns of NAIs within forest ecosystems. Such insights provide a theoretical foundation for further assessing the potential contribution of forest vegetation to NAIs.

Application of DBD air plasma for indoor particulate matter removal

The use of non thermal plasma (NTP) to improve indoor air quality (IAQ) has grown considerably in recent years. This paper demonstrates the advantage of NTP for IAQ improvement in terms of particulate matter (PM) removal. The PM removal mechanism using active air ions and radicals has been investigated. From the developed dielectric barreir discharge (DBD) air plasma reactor, the total PM removal efficiency of 61.72% has been achieved at an optimised concentration of negative and positive air ions in 2 hours of continuous operation. Due to the utilised sensor's limit of quantification (LOQ), PM 2.5 and PM 10 have been reduced to a certain value. The findings revealed that DBD air plasma can be effectively used for PM removal in an enclosed environment.

Negative Air Ions (NAIs) as Cognitive Rehabilitation Therapy for Cerebral Palsy Patients

Negative Air Ions (NAIs) as Cognitive Rehabilitation Therapy for Cerebral Palsy Patients

NIoBReTH: A novel integrative paradigm of protection against SARS-CoV-2 and other airborne pathogens with fewer socioeconomic constraints

There is an imperative need of an effective prophylactic strategy to contain or even end the SARS-CoV-2 pandemic, and to protect the human race from further such pandemics. We propose that NIoBReTH, a composite paradigm of Negative air Ions, virus Blockage, Respiratory Treatment with disinfectants, and Hand hygiene, may provide enough protection against infection by SARS-CoV-2 and perhaps other airborne pathogens, with acceptable safety and less restriction on social/economic activities. Compared to traditional paradigms like N95 respirators and strict social distancing or even large-scale lockdown, the new paradigm may be more easily practiced by individuals, and government adoption may be more robust to individual non-compliance.

Progress and Prospects of Research on the Impact of Forest Therapy on Mental Health: A Bibliometric Analysis

This study aims to assess the global progress in research on the impact of forest therapy on mental health by using bibliometric analysis. We analyzed the relevant literature from the Web of Science Core Collection (WoSCC) database by utilizing software tools such as Bibliometrix (Version 4.1), VOSviewer (Version 1.6.19), and CiteSpace (Version 6.3.R1). There appears to be a growing trend in annual publication volumes from 2006 to 2023. Miyazaki was identified as the most prolific author in this field. Japan and South Korea lead in research contributions, while China has the highest number of publications. The International Journal of Environmental Research and Public Health is the journal with the most publications and citations in this area. Recent keyword clustering reveals an increasing frequency of studies on anxiety and urban green spaces. Research findings suggest that exposure to negative air ions and compounds released by plants can stimulate the five human senses, reduce cortisol levels, and improve mental health. Although studies have demonstrated significant effects of forest therapy in alleviating stress, anxiety, and depression, more large-scale and long-term studies are needed for further evidence. Additionally, it is crucial to explore the impact of different forest types, terrains, altitudes, climates, and air conditions on the effectiveness of forest therapy on mental health.

Design and preparation of durable intelligent haze removal and self-cleaning protective coatings

Conventional superhydrophobic coatings lose effectiveness over due to degradation from ultraviolet (UV) radiation, contaminants, and abrasion. Moreover, external cleaning methods are often needed to maintain self-cleaning performance in the presence of oils and organic contaminants. This study develops an organic-inorganic hybrid coating comprising polymethylhydrosiloxane (PMHS)-modified diatomaceous earth (DE) loaded with titanium dioxide (TiO2) on a room-temperature vulcanized rubber (RTV) substrate. The PMHS-DE-TiO2 coating achieves a synergistic effect, combining superhydrophobicity and photocatalysis. Notably, it exhibits a water contact angle (WCA) of 162.2°, a sliding angle (SA) of 5°, and achieves complete degradation of methylene blue (MB). It maintains hydrophobicity, integrity and functionality under UV radiation, prolonged abrasion, and acidic/alkaline salt solution immersion. The coating also degrades NO at 73.09 % maximum rate. Integration with a negative air ion generator further harnesses the timely superhydrophobic self-cleaning and photocatalysis to significantly enhance dust and fog removal efficiency beyond conventional commercial ion generators. Aligning with green low-carbon principles, this multifunctional coating provides an innovative solution for environmentally-friendly construction materials suitable for long-lasting exterior and interior usage. It resists pollution while mitigating airborne hazards, meeting growing demands for healthy buildings.

Efficient removal of oil mist via triboelectric negative air ions

Oil mist poses a long-term threat to both the environment and human health, and the high stability of fine oil mist particles makes them difficult to remove efficiently using traditional methods. This study reports on a strategy for the efficient removal of oil mist based on triboelectric negative air ions (TENAIs), delving into the charging and migration characteristics of the air/oil mist system during the oil mist removal process by TENAI. It was found that TENAIs could charge oil mist particles, causing the oil droplets to accelerate or change direction. During this process, submicron oil droplets coalesce into larger droplets, which are then efficiently removed under the coupled action of gravity and electric field forces. Experimental results indicate that the addition of the triboelectric negative air ion system increased the velocity of the oil mist flow field by 15–20 times, and the removal efficiency was enhanced by 280%. This study reveals the microscopic mechanism by which negative air ions promote rapid aggregation and settling of particles, providing a scientific basis for the efficient and sustainable management of oil mist.

Study of air deionization factors

The object of research is the dynamics in the concentration of air ions and suspended particles in atmospheric air and in supply-exhaust ventilation systems. An urgent task is to determine the factors and obtain quantitative data on the deionization of the atmospheric air that enters the environment where people live. Quantitative data on changes in the concentration of air ions depending on the time of day, temperature, and relative air humidity have been established. It was shown that even in the absence of significant man-made influence on the concentration of suspended particles, this indicator is at least 7000 cm-3. In the presence of wind, this indicator reaches 30000 cm-3 and higher. Measurement of the spectrum of suspended particles in the range of 0,3–6,0 μm showed that the predominant fraction is particles with sizes of about 3 μm. Studies have been conducted on changes in the concentrations of air ions in supply-exhaust ventilation systems. It was established that in the air duct made of galvanized iron, which has a length of 16 m, the concentration of negative air ions is reduced by 67 %, and positive by 78 %. Laboratory studies of air deionization in air ducts made of different materials were carried out. There is significant air deionization in metal and cardboard ducts while it is absent in wooden ducts. This indicates the electrical nature of deionization. A calculation method for forecasting the aero-ionic mode of premises, taking into account the factors of air deionization, is proposed. For rooms with supply-exhaust ventilation, a calculation apparatus is proposed taking into account the air exchange rate (the number of complete air changes per unit of time). The results make it possible to choose the required performance of artificial air ionization devices for normalizing the aero-ionic regimes in the premises

Exploring the Potential Effect of Negative Air Ions for Rehabilitation in Cerebral Palsy and Polycystic Ovary Syndrome

Exploring the Potential Effect of Negative Air Ions for Rehabilitation in Cerebral Palsy and Polycystic Ovary Syndrome

Negative Air ions induced amelioration of biochemical parameters in Cerebral Palsy patients

Cerebral palsy (CP) is an umbrella term for a group of neurological abnormalities that impair a person's ability to stand, balance, walk, and maintain posture. It is caused by injury or anomalies in the developing brain, which tend to happen before or soon after birth or in early childhood. The study aimed to explore the influence of negative air ions (NAIs) on biochemical parameters in CP-inflicted patients and was conducted from February 1st to March 30th, 2021. Ethical permission from the Institutional Bioethics Committee (Ref: IBC-2017) and the Al-Umeed Rehabilitation Association (AURA) was obtained before the study. Thirty-one structured sessions of exposure to NAIs were conducted at AURA for six weeks after randomly allocating CP-inflicted participants into control (n=12; Median age: 14±5 years) and intervention groups (n=16; M age: Median age=14.5±7.1 years). Biochemical parameters included blood urea nitrogen, calcium, creatinine, electrolytes (bicarbonate, chloride, potassium, and sodium), liver function tests (alkaline phosphatase, alanine aminotransferase, aspartate transaminase, bilirubin total, direct bilirubin, and ?-glutamyl transpeptidase), protein tests (albumin, globulin, A/G ratio, and total proteins), and random blood sugar. For all tests, a trained phlebotomist collected blood samples from the premises of the rehabilitation center at baseline and sixth week. Paired t-tests were performed for within-group comparisons using SPSS v28. The biochemical parameters were normal in both groups at baseline and sustained normality in assessment at the sixth week. The NAI intervention showed no negative effects, indicating that it can be a progressive, non-pharmacological, cost-effective, and effective method to improve the quality of life of CP-inflicted patients.

Microbicidal effect of negative air ion against Penicillium citrinum and quality control of Chinese bayberry

Chinese bayberry is susceptible to decay caused by Penicillium citrinum infection, which will cause food safety problems. Negative air ion (NAI) is a novel type of non-thermal microbicidal technology. This study presented NAI treatment's inhibitory effect and antimicrobial mechanism on P. citrinum isolated from Chinese bayberry fruit. The results indicated that NAI treatment had the optimal inhibitory effect on P. citrinum. P. citrinum cell membrane appeared to have visible wrinkles and damage after NAI treatment, which was observed by scanning electron microscopy (SEM) and transmission electron microscope (TEM). The contents of malondialdehyde (MDA), relative conductivity, soluble protein, soluble carbohydrate, nucleic acid leakage, and lactate dehydrogenase (LDH) in the culture medium increased obviously, which indicated that the membrane permeability of P. citrinum increased. With the laser confocal assay, NAI increased reactive oxygen species (ROS) accumulation and caused oxidative damage to membrane lipids. The membrane lipidomics of P. citrinum hyphae was determined by LC-MS. The results revealed that NAI treatment can hydrolyze the glycerophospholipid into phosphatidic acid (PA) and lysophosphatidylinositol (LPI). Besides, the results of energy metabolism illustrated that NAI treatment reduced the mitochondrial membrane potential (MMP) and energy charge of P. citrinum hyphae. Overall, the microbicidal effect of NAI consisted of two pathways: 1) NAI induced the accumulation of ROS and damaged the membrane structures; 2) NAI reduced mitochondrial membrane potential and caused energy metabolism disorders. In addition, the storage experiment proved that NAI could maintain the quality of Chinese bayberry by inhibiting microbial growth and delaying fruit decay. Hence, NAI hold promises as a potential low-temperature sterilization method for fruit and vegetable storage.