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Air negative ion concentration in different modes of courtyard forests in southern mountainous areas of Jinan, Shandong Province of East China
Abstract
Taking five typical courtyard forests and a non-forest courtyard in southern mountains areas of Jinan as test objects, a synchronous observation was conducted on the air negative ion concentration and related meteorological factors in March-December, 2010. The air negative ion concentration in the test courtyards showed an obvious seasonal variation, being in the order of summer > autumn > spring > winter. The diurnal variation of the air negative ion concentration presented a double peak curve, with the maximum in 10:00 - 11:00 and 16:00 - 17:00 and the minimum around 12:00. The daily air quality was the best at 10:00 and 16:00, and better in afternoon than in the morning. Summer time and garden sketch mode had the best air quality in a year. The mean annual air negative ion and the coefficient of air ion (CI) of the test courtyards were in the order of garden sketch > economic fruit forest > natural afforested forest > flowers and bonsai > farm tourist > non-forest, with the air negative ion concentration being 813, 745, 695, 688, 649, and 570 ions.cm-3, and the CI being 1.22, 1.11, 0.85, 0.84, 0.83, and 0.69, respectively. It could be concluded that garden sketch was the ideal courtyard forest mode. The air negative ion concentration was significantly positively correlated with air temperature and relative humidity, but irrelevant to light intensity.
... The aeroionisation, as a process, can be outlined as having an annual and diurnal regime. The concentration of n-is generally higher in summer and autumn rather than in winter and spring, with no consistent pattern across regions (Xiaolei et al, 2013). It has been proved that, in general, the concentration n-, n+ or total n-/n+ is high from midnight to early morning, then gradually decreases at midday and, after that, gradually increases in the evening, showing an U-shaped distribution (Yunhe et al., 2015, Hui et al., 2020, Mihăilă et al., 2023. ...
This study is the first of its kind, conducted for a city and its surroundings, in Romania. The air ionisation monitoring for Suceava Metropolitan Area (SvMA) was carried out with the PC Connectable Highly Accurate Air Ion Counter Tester COM-3200PRO II, in 34 points from SvMA (Suceava Metropolitan Area), in four time sequences of the year (January, March, July and November), in different parts of the day (morning, afternoon and evening), on active surfaces differentiated in properties (from anthropogenic to natural). The annual average value of the positive (n+) ion levels at the SvMA monitoring points was 576.6 ions/cm-3. The annual average of negative (n-) ions at the monitoring points in SvMA in 2022 was 379.5 ions/cm-3. The study shows an annual regime of n- levels which has specifically a maximum in July (598.6 ions/cm-3) and an annual regime of n+, which has a minimum in the same month (415.3 ions/cm-3). The unipolarity coefficient (k) had a value of 1.52 for the whole of SvMA for the year 2022, ranging from 5.8 in January to 0.73 in July. The lowest k values were calculated for the observation points located in the rural localities from the vicinity of the urban perimeter of Suceava and for the natural ones from the municipality.
... Forests in urban and natural territories are the main zones for tourism and recreation due to the high concentration of negative air ions [71,72]. The negative air ions concentration in suburban forest green areas has been found to be between 1000 and 2000 ions cm −3 , and that in most urban parks has been found to be between 300 and 1500 ions cm −3 , whereas this concentration in attached green spaces has been found to be generally below 1000 ions cm −3 [73]. Forests in the Smolyan Municipality are used by visitors for the recreation and restoration of their health condition for decades. ...
The study considers forest therapy as a tool for diversification of forest management. An up-to-date integrated approach for assessing and mapping potential of forest areas which could provide conditions for forest therapy services is developed and tested. It is based on combining data from the traditional forest inventory in Bulgaria and other open databases with methods for integrated assessment and mapping of ecosystem services: 7 criteria groups and 22 indicators are proposed, rated on a 5-point scale. Overlay analysis is applied to generate a composite assessment for each forest unit. Using spatial statistics tools, territorial hot spots with potential for forest therapy are identified. The methodology was successfully tested in a pilot case-study region, Smolyan Municipality, but it is applicable at broader scale, regardless of the type and ownership of forests. This approach could be transferred to other countries as well after adapting to their geographical, geoecological and socio-cultural specifics and database available. It is a cost-effective and informative tool to support forest owners and managers to diversify forest welfare services focusing on insufficiently used forest recreation potential.
... "Negative air ions" are positively correlated with relative humidity and their concentration is higher in natural environments compared in urban environment [11][12][13][14]. Waterfalls not only produce high levels of negative air ions, they also create a specific microbiological atmosphere by spreading of microbes in the impact zone of a waterfall, which may influence immunological and physiological parameters. ...
Background
The specific microclimate of alpine waterfalls with high levels of ionized water aerosols has been suggested to trigger beneficial immunological and psychological effects. In the present three-armed randomized controlled clinical study, we focused on effects on (i) immunological reagibility, on (ii) physiological stress responses, and on (iii) stress-related psychological parameters.
Methods
People with moderate to high stress levels (n = 65) spent an active sojourn with daily hiking tours in the National Park Hohe Tauern (Großkirchheim, Austria). Half of the group was exposed to water aerosol of an alpine waterfall for 1 h/day (first arm, n = 33), whereas the other half spent the same time at a distant site (second arm, n = 32). A third arm (control, n = 26) had no intervention (except vaccination) and stayed at home, maintaining their usual lifestyle. The effect of the interventions on the immune system was tested by oral vaccination with an approved cholera vaccine and measuring specific salivary IgA antibody titers. Lung function was determined by peak expiratory flow measurement. Electric skin conductance, heart rate, and adaption of respiration rate were assessed as physiological stress parameters. Psychological stress-related parameters were analyzed by questionnaires and scales.
Results
Compared to the control group, both intervention groups showed improvement of the lung function and of most physiological stress test parameters. Analysis of the mucosal immune response revealed a waterfall-specific beneficial effect with elevated IgA titers in the waterfall group. In line with these results, exposure to waterfall revealed an additional benefit concerning psychological parameters such as subjective stress perception (measured via visual analog scale), the Global Severity Index (GSI), and the Positive Symptom Total (PST).
Conclusions
Our study provides new data, which strongly support an “added value” of exposure to waterfall microclimate when combined with a therapeutic sojourn at high altitude including regular physical activity.
... Microbes also interact with two other "unseen" constituents of the near-surface atmosphere in natural environments-phytoncides and air ions. Numerous studies have found a relatively higher concentration of negatively charged ions within natural environments, especially within forests and areas close to bodies of water [25,46,47]. Waves, whitecaps, and waterfalls can produce a relative increase in negative ions [48] and also promote the ejection of microbes into the atmosphere [49]. ...
Recent advances in research concerning the public health value of natural environments have been remarkable. The growing interest in this topic (often housed under terms such as green and/or blue space) has been occurring in parallel with the microbiome revolution and an increased use of remote sensing technology in public health. In the context of biodiversity loss, rapid urbanization, and alarming rates of global non-communicable diseases (many associated with chronic, low-grade inflammation), discussions of natural vis-a-vis built environments are not merely fodder for intellectual curiosity. Here, we argue for increased interdisciplinary collaboration with the aim of better understanding the mechanisms—including aerobiological and epigenetic—that might help explain some of the noted positive health outcomes. It is our contention that some of these mechanisms are related to ecodiversity (i.e., the sum of biodiversity and geodiversity, including biotic and abiotic constituents). We also encourage researchers to more closely examine individual nature relatedness and how it might influence many outcomes that are at the interface of lifestyle habits and contact with ecodiversity.
... The preponderance of available evidence shows that air with a relative increase in negatively charged ions may help facilitate positive mental outlook [230][231][232]. The relative concentration of negatively charged air ions is higher in natural environments [233][234][235] and lower in urban (as well as indoor) environments that are subject to airborne pollutants [236,237]. Forests and areas rich in vegetation can help offset the loss of negatively charged air ions within urban environments [238]. ...
Famed microbiologist René J. Dubos (1901–1982) was an early pioneer in the developmental origins of health and disease (DOHaD) construct. In the 1960s, he conducted groundbreaking research concerning the ways in which early-life experience with nutrition, microbiota, stress, and other environmental variables could influence later-life health outcomes. He recognized the co-evolutionary relationship between microbiota and the human host. Almost 2 decades before the hygiene hypothesis, he suggested that children in developed nations were becoming too sanitized (vs. our ancestral past) and that scientists should determine whether the childhood environment should be “dirtied up in a controlled manner.” He also argued that oft-celebrated growth chart increases via changes in the global food supply and dietary patterns should not be equated to quality of life and mental health. Here in the second part of our review, we reflect the words of Dubos off contemporary research findings in the areas of diet, the gut-brain-axis (microbiota and anxiety and depression) and microbial ecology. Finally, we argue, as Dubos did 40 years ago, that researchers should more closely examine the relevancy of silo-sequestered, reductionist findings in the larger picture of human quality of life. In the context of global climate change and the epidemiological transition, an allergy epidemic and psychosocial stress, our review suggests that discussions of natural environments, urbanization, biodiversity, microbiota, nutrition, and mental health, are often one in the same.
... Research suggests that phytochemicals (phytoncides) secreted by trees and plants might have a beneficial influence on the immune and central nervous systems [186][187][188]. Natural environments, especially coastal, forest, and vegetation-rich locations, also have higher levels of negative ions within the outdoor air sampled in built urban settings [140,189,190]. Although there are mixed results on the influence of negative ion generators in clinical studies related to asthma and lung function [191], some research suggests value in the treatment of depression [192,193]. ...
This paper summarizes the discussions from the Natural Environments Initiative meeting hosted by the Harvard School of Public Health’s Center for Global Health and the Environment and the Harvard Radcliffe Institute for
Advanced Studies in October 2013. It presents ongoing worldwide research on health benefits stemming from exposure to natural environments and design cues with particular attention applications in urban environments.
This meeting generated a Workshop statement forged by the participants that affirms the health benefits of nature and presents the need for additional collaborative, transdisciplinary to refine salutogenic planning and design practices.
Workshop participants represented disciplinary and professional perspectives from medicine, landscape architecture, public heath, and forestry science rooted in the cultural, ecological and political realities of a dozen countries and five continents. When framing the benefits of nature, they considered health outcomes including mental health disorders, obesity, Type 2 diabetes, metabolic disorders, allergies, cardiovascular disease, and more. Many environmental factors (including those related to physical activity, residential planning, environmental contamination and severe weather attributed to climate change) mediate these health outcomes at local, regional and global levels. This paper provides an illustrative review that captures many relevant studies discussed during the workshop. Although not exhaustive, our review indicates that the available evidence is applicable to various populations and ecological settings, and broadly supports the association of improved health outcomes with exposure to natural environments.
Full report available at: http://www.chgeharvard.org/sites/default/files/resources/Paper-NaturalEnvironmentsInitiative_0.pdf
... Research suggests that phytochemicals (phytoncides) secreted by trees and plants might have a beneficial influence on the immune and central nervous systems [186][187][188]. Natural environments, especially coastal, forest, and vegetation-rich locations, also have higher levels of negative ions within the outdoor air sampled in built urban settings [140,189,190]. Although there are mixed results on the influence of negative ion generators in clinical studies related to asthma and lung function [191], some research suggests value in the treatment of depression [192,193]. ...
This paper summarizes the discussions from the Natural Environments Initiative meeting hosted by the Center for Health and the Global Environment at the Harvard School of Public Health and the Harvard Radcliffe Institute for Advanced Studies in October 2013. It presents ongoing worldwide research on health benefits stemming from exposure to natural environments and design cues with particular attention applications in urban environments.
This meeting generated a Workshop statement forged by the participants that affirms the health benefits of nature and presents the need for additional collaborative, transdisciplinary to refine salutogenic planning and design practices. Workshop participants represented disciplinary and professional perspectives from medicine, psychology, landscape architecture, public heath, and forestry science rooted in the cultural, ecological and political realities of a dozen countries and five continents. When framing the benefits of nature, they considered health outcomes including mental health disorders, obesity, Type 2 diabetes, metabolic disorders, allergies, cardiovascular disease, and more. Many environmental factors (including those related to physical activity, residential planning, environmental contamination and severe weather attributed to climate change) mediate these health outcomes at local, regional and global levels. This paper provides an illustrative review that captures many relevant studies discussed during the workshop. Although not exhaustive, our review indicates that the available evidence is applicable to various populations and ecological settings, and broadly supports the association of improved health outcomes with exposure to natural environments.
http://www.chgeharvard.org/sites/default/files/resources/NaturalEnvironmentsInitiative.pdf http://www.chgeharvard.org/resource/natural-environments-initiative-illustrative-review-and-workshop-statement http://www.chgeharvard.org/NEI_Paper
Many studies have shown that negative air ions (NAIs) are beneficial for human health. Therefore, the spatial and temporal variations of NAIs and their influencing factors have attracted much attention. The Wudalianchi Scenic Area was selected as the research area in which to determine the differences of environmental factors that influence NAIs at different time and space scales. The sampling frequency of the field observation data was 1 h. NAI, meteorological factors, gas pollutants, and particulate matter were monitored simultaneously. Pearson correlation analysis, linear regression analysis, principal component analysis, and the Random Forest algorithm were used to quantify the relationship between NAIs and the influencing factors. The results revealed the following: (1) The NAI concentration from least to greatest appeared in the following order: open space (blank) (843 ions cm−3) ≈ lake (892 ions cm−3) PM10 > temperature > radiation; outside the forest, humidity > ozone > NO. In general, the relationships between the NAI concentration and the influencing factors were greatly affected by the observed spatio-temporal scale. The research results are of great significance to the construction of forest healthcare.
This paper investigated the capacity of plants (Schlumbergera truncata, Aloe vera var. chinensis, Chlorophytum comosum, Schlumbergera bridgesii, Gymnocalycium mihanovichii var. friedrichii, Aspidistra elatior, Cymbidium kanran, Echinocactus grusonii, Agave americana var. marginata, Asparagus setaceus) to generate negative air ions (NAI) under pulsed electric field stimulation. The results showed that single plant generated low amounts of NAI in natural condition. The capacity of C. comosum and G. mihanovichii var. friedrichii generated most NAI among the above ten species, with a daily average of 43 ion · cm(-3). The least one was A. americana var. marginata with the value of 19 ion · cm(-3). When proper pulsed electric field stimulation was applied to soil, the NAI of ten plant species were greatly improved. The effect of pulsed electric field u3 (average voltage over the pulse period was 2.0 x 10(4) V, pulse frequency was 1 Hz, and pulse duration was 50 ms) was the greatest. The mean NAI concentration of C. kanran was the highest 1454967 ion · cm(-3), which was 48498.9 times as much as that in natural condition. The lowest one was S. truncata with the value of 34567 ion · cm(-3), which was 843.1 times as much as that in natural condition. The capacity of the same plants to generate negative air ion varied extremely under different intensity pulsed electric fields.
A new kind of hybrid self-assembled film was obtained by means of alternating deposition of the polyoxometalate (POM), K 13 [Eu(SiW 11 -O 39) 2 ], and polyacrylamide (PAA) on the 3-aminopropylsilanized precursor film. The experimental results showed that the polyanions were successfully incorporated into the self-assembled multilayers of the polyacrylamide. The scanning electron microscopy (SEM) was taken to study the surface morphology of the film. The X-ray photoelectron spectra (XPS) verified that the polyoxometalates were incorporated into the multilayer films with a certain adsorption interaction. The effects of the polyacrylamide on the luminescence of the polyoxometalate were discussed in detail. The luminescence spectra showed that the energy was transferred from the ligands to the Eu 3+ ions in the self-assembled films.
This randomized controlled trial investigates the efficacy of two non-pharmacologic treatments, bright light and high-density negative air ions for non-seasonal chronic depression. Both methods have shown clinical success for seasonal affective disorder (SAD).
Patients were 24 (75%) women and 8 (25%) men, ages 22-65 years (mean age +/- S.D., 43.7 +/- 12.4 years), with Major Depressive Disorder, Single Episode (DSM-IV code, 296.2), Chronic (episode duration > or = 2 years). Patients were entered throughout the year and randomly assigned to exposure to bright light (10 000 lux, n = 10), or high-density (4.5 x 10(14) ions/s flow rate, n = 12) or low-density (1.7 x 10(11) ions/s, n = 10, placebo control) negative air ions. Home treatment sessions occurred for 1 h upon awakening for 5 weeks. Blinded raters assessed symptom severity weekly with the Structured Interview Guide for the Hamilton Depression Rating Scale--Seasonal Affective Disorder (SIGH-SAD) version. Evening saliva samples were obtained before and after treatment for ascertainment of circadian melatonin rhythm phase.
SIGH-SAD score improvement was 53.7% for bright light and 51.1% for high-density ions v. 17.0% for low-density ions. Remission rates were 50%, 50% and 0% respectively. The presence or severity of atypical symptoms did not predict response to either treatment modality, nor were phase advances to light associated with positive response.
Both bright light and negative air ions are effective for treatment of chronic depression. Remission rates are similar to those for SAD, but without a seasonal dependency or apparent mediation by circadian rhythm phase shifts. Combination treatment with antidepressant drugs may further enhance clinical response.
The concentration of negative air ions in different seasons was monitored in typical garden areas of Beijing, i. e. the Fragrant Hill, the Summer Palace and the Botanical Garden. Comparative analyses were conducted combined with the results from open spaces and urban areas. The results show that the presence of landscape plants can significantly enhance the negative air ion concentration, which was significantly higher in vegetation areas than that in non-vegetation areas. The negative air ion concentration showed a single peak curve with increasing elevation and was closely correlated with the condition of the vegetation at specific elevations. The diurnal fluctuation of negative air ion concentration in garden areas showed a bimodal curve. The negative air ion concentration in different habitats changed clearly with the seasons, with higher concentrations in the summer and autumn. The concentration of negative air ions was also positively correlated with temperature and relative humidity.
In this study, sampling plots and control were chosen in the Beijing Olympic Forest Park(BOFP) and negative air ion(NAI) concentrations were measured continually in clear days of August 18-20, 2009. The results indicated that the effect of plant community structure on NAI was significantly different. NAI concentration of the tree-shrub-grass communities was higher than that in the simple plant communities, especially higher than that in the single-layer ones. The correlation between multiple plant communities and NAI concentration was significant. Moreover, NAI concentration of the deciduous broad-leaved forest regions was higher than those of the coniferous forest and mixed conifer and broad-leaved one. The results showed that there was positive correlations between NAI concentration and air relative humidity and air temperature.
Mensurational and spatio-temporal changes of negative air ion concentrations in Beijing were studied between 1999 and 2002. The results showed that negative air ion concentrations increased gradually and ion polarity ratio decreased gradually from city center to suburb. The negative air ion concentrations in forested areas, were obviously higher than those in non-forested areas; their annual average values in coniferous forests were higher than those in broad-leaved forests but the opposite was true in spring and summer. The negative air ion concentrations obviously increased in the areas where moving water, such as waterfall and rivulet, exist. Indoor negative air ion concentrations were lower than outdoor ones but potted green plants could improve it. Over the span of a whole day it was higher during day time than during night time. Over a year its maximum appeared in summer and the minimum in winter.
From March 2006 to February 2007, a synchronous observation was conducted on the air negative ion concentration and related meteorological factors in the greenbelts of Jiamusi, with their relationships studied. There was an obvious diurnal and monthly Variation in the air negative ion concentration, being higher in early morning and midnight and lower in mid-day and late afternoon, with the minimum of 217 ions per cubic centimeter, and being the highest in summer and the lowest in winter, with the maximum (782 ions per cubic centimeter) in July and the minimum (283 ions per cubic centimeter) in December. The air negative ion concentration was significantly negatively correlated with air temperature, and positively correlated with air pressure and relative humidity.
The purpose of this research was to determine changes in negative air ion (NAI) concentrations produced by plants grown under different light intensities. NAI concentrations were observed and analyzed in an outdoor green space with five plant species (Aloe arborescens, Clivia miniata, Chlorophytum comosum, Opuntia brunnescens, Crassula portulacea) and A. arborescens was then grown under controlled-light conditions in an enclosed space for the subsequent light intensity experiment. (1) Two peaks in NAI concentration were observed over the course of 24 h in the outdoor green space: one occurred between 9:00 and 10:00 AM; the other was at approximately 8:00 PM. (2) Among the five plant species, A. arborescens produced the highest levels of NAI and responded most effectively to light with an increase in NAI generation. Accordingly, it was chosen as the model plant for studies on the changes in NAI concentration under different light intensities. (3) In enclosed-space experiments, isolated from sunlight and under controlled-light conditions, the concentrations of NAI varied with changes in light intensities. (4) Using regression analysis, a logistic model was developed showing that changes in NAI concentrations as a function of illumination intensity followed an exponential relationship.
The effect of negatively charged ions on respiratory organs and blood of rats has been studied. It was shown that the inhaling of negative air ions (NAI) for 60 min with a concentration of NAI at the place of location of animals 320-350 000 ions/cm2 activated the secretion of goblet cells without damaging the mucosa of the trachea and changed the spectrum of proteins of bronchopulmonary lavage. It was also found that the spontaneous production of reactive oxygen species (ROS) by cells of nonfractionated blood after the exposure to NAI increased in both males and females; the intensity of ROS generation induced by opsonized zymosan increased only in females. Different sensitivity of the antioxidant enzymes superoxide dismutase and glutathione reductase of blood to NAI in females and males was revealed. These results enable one to consider the effect of NAI as priming and a weak activation of the respiratory organs through the direct action on the mucosa of the primary target organs of the respiratory tract and then on the blood.
The effects of negative air ions on computer operation were examined using a biochemical index of the activity of the sympathetic/adrenomedullary system (i.e. salivary chromogranin A-like immunoreactivity (CgA-like IR)) and a self-report questionnaire (State-Trait Anxiety Inventory, Anxiety State--STAI-S). Twelve female students carried out a word processing task for 40 min. The salivary CgA-like IR increased more than three times on the task, but the salivary cortisol did not change. The increase in the CgA-like IR level was attenuated by the exposure to negative air ions during the task. The exposure to the ions during the recovery period following the task was effective for rapidly decreasing the CgA-like IR level that had increased after the task. These effects by negative air ions were also observed using STAI-S. Task performance was slightly but significantly improved by the presence of negative air ions. These results suggest that negative air ions are effective for the reduction of and the prompt recovery from stress caused by computer operation.
Air negative charge ion concentration (ANCIC) has a close relationship with air quality. The observations on the ANCIC, sunlight intensity, air temperature, and air relative humidity in different ecological functional zones of Hefei City from 2003 to 2004 showed that the diurnal change pattern of ANCIC was of single peak in sightseeing and habitation zones, dual peak in industrial zone, and complicated in commercial zone. Different ecological functional zones had different appearance time of their daily ANCIC extremum. The diurnal fluctuation of ANCIC was in the order of commercial zone > industrial zone > habitation zone and sightseeing zone. The annual change pattern of ANCIC in these zones was similar, being the highest in summer and lowest in winter, and the mean annual ANCIC was 819, 340, 149 and 126 ions x cm(-3), respectively. The most important meteorological factor affecting the ANCIC in Hefei City was air relative humidity, followed by sunlight intensity and air temperature. There was an exponential relationship between ANCIC and air relative humidity.
The neural mechanism by which negative air ions (NAI) mediate the regulation of autonomic nervous system activity is still unknown. We examined the effects of NAI on physiological responses, such as blood pressure (BP), heart rate (HR), and heart rate variability (HRV) as well as neuronal activity, in the paraventricular nucleus of the hypothalamus (PVN), locus coeruleus (LC), nucleus ambiguus (NA), and nucleus of the solitary tract (NTS) with c-Fos immunohistochemistry in anesthetized, spontaneously breathing rats. In addition, we performed cervical vagotomy to reveal the afferent pathway involved in mediating the effects of NAI on autonomic regulation. NAI significantly decreased BP and HR, and increased HF power of the HRV spectrum. Significant decreases in c-Fos positive nuclei in the PVN and LC, and enhancement of c-Fos expression in the NA and NTS were induced by NAI. After vagotomy, these physiological and neuronal responses to NAI were not observed. These findings suggest that NAI can modulate autonomic regulation through inhibition of neuronal activity in PVN and LC as well as activation of NA neurons, and that these effects of NAI might be mediated via the vagus nerves.