Abstract
With China’s remarkable progress in smart city and Information and Communication Technologies (ICTs), novel technologies have gradually permeated through research on micro-scale environmental exposure research. Consequently, the research has undergone a series of transitions and seen new progress. This article reviews and summarizes three transitions of micro-scale environmental monitoring, exposure, and individual response in Chinese literature:(1) the micro-scale transition in individual-level environment monitoring, including technologies such as mobile particulate monitors, portable physiological monitors, and virtual reality for micro-scale environmental monitoring; (2) the real-time transition towards individual environmental exposure measurement; (3) the individual response to environmental exposure. In this context, environmental exposure research intersects with many disciplines and contributes practical value in the fields of micro-spatial governance, healthy spatiotemporal behavior, and targeted pollution prevention.
Introduction
In recent decades, China has made significant strides in addressing environmental pollution, leading to improved urban environments, reduced urban noise pollution, and progress in tackling other environmental issues. Efforts have also been made to investigate the link between environmental exposure and public health (Xie et al., 2010). Numerous studies have identified that environmental exposure has an impact on the physical and mental health of individuals on a macro spatial scale with statistical methods (Wu, 2012; Xu et al., 2013). However, existing studies often lack control over individual health indicators and social attributes, leading to inconclusive and controversial conclusions. Alternative methods, such as exposure experiments in controlled laboratory settings, offer some advantages but still fail to fully replicate real-life scenarios. As a result, these approaches do not adequately address the evolving challenges both in research and practice.
In response to these emerging challenges and the increasingly diverse environmental and lifestyle requirements of urban residents, some individual-based research approaches have been proposed. They aim to address these needs with reduced biases and inaccuracies. Traditional methods for assessing residents’ environmental exposure often rely on stationary or mobile observation stations. However, these methods may not adequately capture differences in air pollution exposure between indoor and outdoor environments, as well as travel-related micro-environments. This limitation can lead to significant bias or inaccuracy in individual environmental exposure, hindering effective problem-solving in the contemporary urban space. In response, scholars in recent years have shifted their focus towards studying micro-environmental exposure based on the real-life experiences of individuals.
The significance of micro-environment exposure research in China is evident in two main aspects. Firstly, from an urban environmental perspective, China has made substantial advancements in urban environment restoration and urban spatial quality, achieving notable progress in macro-scale environmental research and implementation. To further explore urban spaces more precisely, the focus of research has shifted to micro-level domains. Secondly, from a human perspective, with the improvement of income and living standards among the Chinese population, there is a shift towards pursuing higher-level needs such as safety, social interactions, and health perceptions, as described in Maslow’s Hierarchy of Needs theory. Understanding how the quality of micro-environments in various contexts (home, work, recreation) influences people’s perceptions is crucial, highlighting the importance of relevant perceptual research.
When comparing English publications with studies on micro-environment exposure in Chinese publications, there are some unique characteristics in the latter, even though the research content tends to be consistent overall. We employed bibliometric methods to conduct a comparative analysis of articles in the field of environmental exposure between English and Chinese journals. In total, 754 and 810 valid articles from the Web of Science Core Collection (https://www.webofscience.com/wos) and CNKI (https://www.cnki.net/) database were selected as data sources (from 2004 to 2023). Utilizing CiteSpace software, a keyword co-appearance network graph, demonstrating the time of first appearance, frequency of occurrence, and co-appearance relationships of key words in publications over 20 years were generated. Figure 1 shows the keyword co-appearance network, where the Chinese keywords were translated into English. Based on the co-appearance network of keywords, we summarized the differences between Chinese and English articles. Firstly, in the keyword co-appearance network, the frequencies of appearance of the keywords “air pollution” and “noise” in Chinese journal articles are significantly higher than those of other keywords, reflecting the continuous attention of Chinese researchers to these two issues and also indicating the expectations of Chinese society for improving urban environmental quality. Secondly, Chinese journals tended to publish more application-oriented research articles, such as the studies related to the urban design and traffic safety practice, while English journals were more inclined towards theory-oriented research, such as the studies on the psychological effects of environmental exposure.
Key words co-appearance network diagram of environmental exposure research.
The rapid development and widespread adoption of emerging technologies have facilitated the exploration of individual-based environmental exposure, expanding the concept of environment from the natural surroundings to encompass the built and social environments. Specifically, the study of environmental exposure in the Chinese publication reveals three progressive transitions. The first is the micro transition: portable and intelligent devices enable researchers to conduct mobile monitoring, acquire high-resolution spatiotemporal data, and drive a microscopic transition in environment monitoring research. The second is real-time exposure measurement: high-resolution mobile environmental exposure data facilitate the identification and analysis of specific environments in which individuals are situated. This enables the study of real-time individual environmental exposure from the perspective of spatiotemporal behavior, leading to meaningful research conclusions. The third is individual response transition: there is a shift from assessing environmental exposure to the assessing individual responses to environmental exposure and their interaction. This transition is supported by advances in portable physiological monitors and Virtual Reality (VR) technology. Portable physiological monitors gather parameters related to physical activities and cognitive processes, while VR explores how human spatial behavior is influenced in diverse built environments. This exploration reveals the relationship between spatial cognition and spatial decision-making. As a result, these three types of research transitions offer practical value and implications for the fields of precise pollution prevention, space governance, and healthy travel. The framework of our review is summarized in Figure 2.
Framework of technological advance and its influence in the field of environmental exposure research.
By summarizing the above transitions, we find that current environmental exposure research in Chinese literatures focus on discussing individual environmental exposure from a microscopic perspective and the empirically analyzing spatiotemporal behavior patterns. This approach offers an innovative understanding of the impact of geographical environment on individual health and provides a scientific basis for the sustainable development of Chinese cities. While these research efforts are still in their early stages, they are progressing rapidly and merit broader exploration. However, due to the language barrier, Chinese publications have limited global dissemination, and there is insufficient dialogue between Chinese and English academic circles.
Hence, this article provides a review of publications in the field of environmental exposure in the Chinese world in the past 20 years, and anticipates its future development trend. It delves into how technological advancements have driven the transformation in environmental exposure research, examines the theoretical and practical significance of this transformation, and illustrates how technology contributes to multi-domain environmental exposure research, thereby enhancing our understanding of the relationship between individual environmental exposure and health outcomes.
Microscopic transition in individual-level environment monitoring
Conventional methods for monitoring and simulating particulate matter have limitations when it comes to meeting the requirements of individual-scale micro-environmental exposure research. However, recent advancements in environmental monitoring technology have enhanced the capability to identify and analyze micro-environmental characteristics. This progress has allowed for the monitoring and analysis of environmental elements at a high spatiotemporal resolution, and has played a crucial role in studying the spatiotemporal distribution and detailed mapping of environmental pollution. These advancements have facilitated a transition towards a more microscopic approach in environmental exposure research.
Technical transition of the traditional monitoring methods
Traditional environmental monitoring primarily relies on macro-scale monitoring methods, such as fixed-site monitoring, fixed stations combined with mathematical model simulation (Tao et al., 2014; Wu et al., 2012), and ground monitoring combined with remote sensing inversion (He et al., 2010; Wu et al., 2012). These methods enable large-scale, long-term monitoring of the spatiotemporal distribution of environmental exposure at a low cost. Previous studies have emphasized the distribution patterns and evolutionary trends of large-scale environmental factors. Among these methods, fixed-site monitoring stands out for its low cost, ease of operation, and suitability for large-scale continuous monitoring. The model simulation method typically utilizes existing data to construct a model that simulates more detailed environmental conditions, requiring less manpower and incurring lower costs. Additionally, remote sensing inversion technology, when combined with ground monitoring data, enables large-scale and fine-grid monitoring of the spatiotemporal distribution of environmental elements (Du et al., 2015).
In recent years, researches in the fields of traditional monitoring have undergone a technical transition, marked by improvements in monitoring accuracy and advancements in simulation methods. Key technological evolutions include:(1) the addition of monitoring stations and enhancement of site density; (2) the integration of traditional remote sensing and geographic information system technology with machine learning methods such as the random forest model, resulting in a more detailed monitoring of the spatial and temporal distribution of environmental exposure (Li et al., 2020a, 2020b); and (3) a thematic transition towards more nuanced content, such as high-temperature exposure and green environmental exposure (Li et al., 2020b). However, the above methods still face challenges such as the inability to precisely monitoring micro-environments and the difficulty of incorporating all influencing factors.
Targeted measurement of environmental exposure through mobile monitoring
The development of mobile monitoring technology has addressed the challenge of inadequate precision in environmental data resulting from the high cost and low density of fixed monitoring stations. One predominant focus of environmental exposure research within the Chinese world has been on the mobile monitoring methods especially the measurement of PM2.5 exposure. In contrast to water and soil pollution, air pollution exhibits conspicuous spatial and temporal heterogeneity and exerts a more direct impact on individuals. Approximately 30% of air pollution in China comes from civil and mobile sources (Ministry of Ecology and Environment of China, 2022) which are often challenging to scrutinize. Among numerous air pollutants, PM2.5 stands as the primary pollutant in most Chinese cities (Wang and Wang, 2014). The escalation of PM2.5 concentration in the air significantly influences air quality. PM2.5 absorbs various harmful and toxic substances, thereby exerting enduring effects on the human respiratory system, cardiovascular system, immune system, fertility, and nervous system. Traditional monitoring methods face challenges in comprehensively covering particulate matter exposure monitoring. This chapter will review the micro-scale transition in environment monitoring, focusing on mobile monitoring of particulate matter.
Utilizing mobile monitoring technology, the researchers investigated the spatiotemporal distribution of particulate matter, achieving a high level of resolution in their analyses. These studies revealed that the distribution of particulate matter in cities was influenced by various factors, including seasons, weekends and holidays, time of day, urban spatial structure, urban roads, and land use.
Previous studies have investigated how particulate matter concentration changes over time on various scales. A study in Shanghai City found that individual PM2.5 exposure levels followed the pattern of autumn > spring > summer > winter (Chen et al., 2021). Additionally, it was observed that the exposure level during the heating period was significantly higher than that during the non-heating period in Taiyuan City (Shi et al., 2008). Another study conducted in the urban area of Xiangyang, utilizing over 180 air quality monitoring micro-stations, revealed the presence of a “weekend effect” and a “Spring Festival effect” on particulate matter exposure. The study further highlighted that the “weekend effect” was more pronounced during winter (Liu et al., 2023). On the basis of the above study, the researchers studied the spatiotemporal changes of air pollution during the Spring Festival in downtown Xiangyang based on multi-year time series data, and evaluated the effectiveness of the implementation of measures to ban fireworks and firecrackers during the Spring Festival in previous years (Liu et al., 2022). This article revealed that the spatial pattern of PM2.5 can be described through a high-density station monitoring network combined with high-temporal-resolution spatial analysis, which could be used for accurate identification and process derivation of local-scale air pollution spatiotemporal changes.
Studies have also examined the distribution of particulate matter concentration in urban areas. Mobile particulate monitor was utilized to monitor PM2.5 pollution in the central urban area of Guangzhou Ring Expressway (Song et al., 2020). A high-resolution PM2.5 pollution simulation, with a spatiotemporal resolution of 10 m × 10 m, was conducted for the research area. The results revealed significant spatiotemporal differentiation characteristics of PM2.5 pollution in the central area of Guangzhou. Fixed high-mass concentration areas and low-mass concentration areas were observed during both dry and wet seasons. The targeted spatiotemporal distribution pattern of road PM2.5 was simulated using machine learning techniques and data collected by the mobile PM2.5 monitor (Lin and Zhou, 2023). The proposed fine-grained mapping method for PM2.5 concentration in this study achieved a spatial accuracy of up to 1 m, enabling a more accurate description of spatial heterogeneity. A study installed mobile monitor on express vehicles to collect PM2.5 concentrations in various settings within the southern part of Fuzhou’s main urban area. The study then employed a combination of geographic weighted regression and gradient boosting decision tree methods to propose a PM2.5 concentration simulation and scene analysis model based on Geographic Weighted Regression combined with Gradient Boosting Decision Tree (GWR-GBDT) (Xie et al., 2022). This model enhances the precise monitoring capabilities of urban PM2.5 pollution.
Different groups lead to heterogeneity of environmental exposure due to differences in activity patterns. Therefore, scholars have carried out researches on the particulate matter exposure of key public places in cities, such as urban parks, schools, and residential area. Green space is a key part of the urban ecological environment and a key place for residents’ outdoor activities, which plays an important role in urban ecology, landscape, society, and public health (Mao et al., 2012). Therefore, the environmental exposure in green spaces is worth studying. In a pioneering research, mobile air quality monitors were used to measure the air quality of 33 community parks in the central urban area of Guangzhou, and the result proved that the risk of particulate matter exposure and its spatial pattern distribution in community parks in the central urban area of Guangzhou were quite various. In a study based on questionnaires, more than one-third of residents’ subjectively perceived PM2.5 levels were better than objective observations in green space, indicating that a considerable number of residents overestimated the air quality of community parks (Yang et al., 2021). School is a primary space for the daily activities of children and teenagers, so the air quality of school has an important impact on children’s health. Mobile particulate matter monitor was used to monitor the PM2.5 exposure of a primary school in Guangzhou, and the daily potential exposure levels were estimated. Results showed that traffic pollution source was one of the sources of indoor and outdoor PM2.5 in the primary school (Ke et al., 2011). Some scholars have also carried out real-time particulate matter monitoring in residential areas to study activity satisfaction of air quality, and explored its impact on residents’ quality of life. Through mobile monitoring and daily activity log, one research in Beijing found that subjective exposure assessment could significantly reduce activity satisfaction, while objective exposure had no significant impact (Rao et al., 2022), proving objective environmental exposure had a significant indirect effect on activity satisfaction mainly by influencing subjective pollution evaluation in residential areas.
Mobile measuring of build environment with wearable camera
Besides the mobile monitoring of environmental pollution, in recent years, researchers have started to utilize wearable cameras to monitor individuals’ exposure to the built environment. This research method considers the individual life trajectory and can effectively meet people’s needs for convenience in daily travel, surpassing the traditional built environment assessment method. Studies have demonstrated that the built environment is linked to the occurrence of chronic diseases such as allergies, asthma, obesity, coronary heart disease, hypertension, hyperlipidemia, and type 2 diabetes (Huang et al., 2021; Lu and Tan, 2015). Additionally, it can induce or alleviate individual anxiety, depression, and mental stress (Chen et al., 2016; Wang et al., 2022). Measuring the characteristics of the built environment perceived by people is a key step for evaluating the extent of an individual’s exposure to the built environment.
The emergence of wearable cameras has provided new possibilities for monitoring individual behavior in space and creating individual ‘life logs’. By wearing a camera and capturing photos of the built environment, researchers can evaluate these photos and obtain participants’ exposure measurements through statistical evaluations. In terms of theoretical research, two new methods can be employed to measure exposure to the built environment. One method involves overlaying the spatiotemporal movement trajectories of individuals and evaluating the characteristics of the built environment reflected in Street View images to obtain measurement results. The other method entails individuals wearing a wearable camera, and the images captured by these cameras can reflect the features of the built environment to which individuals are exposed (Li and Long, 2021). In practical studies, wearable cameras are worn by individuals to collect photos along their daily trajectories, allowing for the exploration of the spatiotemporal distribution of individual behavioral characteristics and environmental exposure scenes (Zhang and Long, 2019). The large number of images collected by wearable cameras contain abundant information on individual behavior and spatiotemporal dynamics. These images effectively describe the characteristics of individual behavior in space, and hold great potential for studying the relationship between individual behavior and the built environment.
Research transition towards individual environmental exposure measurement
By correlating data from mobile monitoring devices with individual spatiotemporal activity patterns, researchers can accurately assess individual environmental exposure in real time. This is helpful in understanding the impact of dynamic environment on individual health, and directly advances the theoretical discussion of the Uncertain Geographic Context Problem (UGCOP). From the perspective of environmental justice, researchers have also explored the group differences in environmental exposure and its health effects. The risk of environmental exposure varies according to sociodemographic attributes and activity types, among which the most concerned research direction is travel mode (Kim and Kwan, 2021). Therefore, this article reviews the relevant studies according to the different populations and different travel modes.
Exposure measurements for different populations
Significant differences exist in particulate matter exposure among sociodemographic attribute groups. Gender, age, education, and other factors are correlated with the difference in residents’ environmental exposure level. Scholars have been paying attention to comparative studies of environmental exposure of different groups and research on environmental fairness in the care of vulnerable groups. There are significant differences in air pollution exposure among different socioeconomic attribute groups (Guo et al., 2015). Car ownership, real estate ownership, and middle income are potential causes for environmental exposure differences. Social groups experience distinct environmental exposures due to their diverse work-life rhythms. Responsively, scholars have been paying attention to residents’ socioeconomic attributes, specifically focusing on the adverse environmental impact experienced by different social groups (Ma et al., 2017).
Some literature focused on vulnerable groups such as the elderly and children, highlighting the importance of environmental justice and health inequality. Due to the decline in physical function and metabolism, the elderly population are more susceptible to air pollutant particles. With the acceleration of China’s aging population, the number of elderly living in cities continues to rise. As of 2020, China’s population aged 65 and above accounted for 13.52%, indicating the country’s transition into a moderately aging society. Therefore, some research focused on the assessment of air pollution exposure in the elderly population and its influencing factors. An environmental exposure research in Shanghai conducted four times of follow-up visits to the same elderly group in four seasons, and conducted activity and household questionnaire surveys. It was found that season, climate, and behavior pattern could affect the deviation between official Air Quality Index (AQI) and elderly’s individual exposure (Chen et al., 2021). Childhood is a critical period of growth and development, and children’ resistance to particulate matter is poor. Studies have shown that particulate matter not only increase the prevalence of children’s respiratory system, but also reduce children’s lung function and immune function (Wang et al., 2007). Mobile monitors were utilized to evaluate the PM2.5 concentration of children’s main activity places and calculated the exposure level of individuals based on children’s activity log (Deng et al., 2009). The results showed a strong correlation between the PM2.5 index and the exposure level of individual children. One interesting finding was that the distance from children’s living rooms to traffic arteries was negatively correlated with exposure levels.
Due to the contact of particulate matter in working environment, special occupational groups are often exposed to highly polluted environment in the long term, and the relative health damage is serious. Scholars have begun to pay attention to the level of pollution exposure of special groups such as traffic police and painting workers. Using staff who work indoors as the control group, a research found that the PM2.5 exposure of traffic police in Taiyuan was significantly higher than which of the control group, and the decline in lung function of male traffic police may relate to long-term motor vehicle exhaust exposure (Xu et al., 2013). Through comparative analysis, researcher found that volatile organic compound pollution in newly renovated residences was in high concentration, and the exposure of painting workers was much higher than that of non-occupational groups (Gao et al., 2006).
In addition to particulate matter exposure, noise exposure studies in general population and certain groups are also research focus,. Researchers conducted a series of studies to examine the relationship between noise exposure level and health outcomes. These studies identified that cumulative noise exposure raised the incidence of hearing loss (Xie et al., 2015), kidney damage (Chen et al., 2022), and the risk of hypertension (Su et al., 2020). For certain occupational groups, such as workers in urban transportation departments (Zhu et al., 2007), oil enterprises (Li et al., 2004), and hydropower stations (Li and Li, 2016), noise is the primary occupational hazard factor, exposing them to a greater risk of noise pollution compared to the general population. Scholars have employed mobile noise meters to investigate the noise exposure of these specific occupational groups. The findings revealed that a significant number of staff members in subway station halls, computer rooms, traffic patrols, and drilling enterprises were subjected to noise intensities exceeding 80 dB(A), indicating a relatively high level of noise exposure. Noise exposure not only has a detrimental impact on mental health but also contributes to hearing loss and increases the risk of cardiovascular diseases.
Currently, the latest research trend has shifted the focus of environmental exposure measurement from specific group to all the citizen, yielding more valuable research results. A recent study found that residents’ exposure to noise and particulate matter could reduce their momentary happiness (Su et al., 2024).
Residents’ travel modes and environmental exposure measurement
Mobile particulate matter monitor enables the collection of exposure data during traveling process. Exposure to particulate matter during travel is significant, with individuals experiencing 2 to 5 times higher exposure levels in public transport micro-environments compared to residential and other activity spaces (Moreno et al., 2015) The choice of travel mode is a key factor influencing differences in exposure levels. Examining variations in exposure levels across different travel modes can provide guidance for the public to make informed choices and avoid high exposure risks.
Researchers used mobile monitors to explore particulate exposure in different travel modes in the same city (Li et al., 2015). This study revealed that walking could cause the highest individual exposure amount, whereas taxis caused the lowest. An assessment system was established to evaluate travelers’ intake quantity of particulate matter when traveling with different travel mode (Zhu et al., 2022). Analysis results based on experimental data from Xi’an showed that compared to data from environment monitoring stations, there was a significant difference for the PM concentration detected in taxi, bus carriage and subway carriage, while the difference was not significant for the PM concentration detected in sidewalk, non-motor taxi stop, bus stop, subway station hall, and subway platform.
Bus micro-environmental pollution and its adverse impacts on passengers’ health has become an increasing concern. In Guangzhou, a study successfully evaluated the air quality of six typical bus lines in real-time. Through the implementation of the random forest algorithm, researchers examined the relationship between the bus micro-environment and passenger comfort (Zhang et al., 2021). The study revealed that PM2.5 concentrations in buses had the greatest impact on passenger comfort, compared to temperature, relative humidity, and noise.
In regards of metro, online monitor was used to measure individual black carbon exposure on both underground and ground metro lines in Shanghai (Lei et al., 2016). The study found that black carbon exposure in the underground lines was significantly higher than that in the surface lines. Additionally, meteorological conditions such as rainfall and wind speed had a certain impact on the black carbon exposure level of the subway station, with a greater impact on the surface lines compared to the underground lines.
The aforementioned investigations focused on the natural environmental exposures encountered by individuals. Within contemporary urban landscapes in China, the diverse built environment plays a significant role in influencing individual behavior, and exerts direct or indirect impacts on the physical and mental health of residents. The mechanisms and effects associated with such impacts are often multifaceted. Notably, certain scholars have started the explorations of built environment exposure and its influences on individuals, employing novel technologies like VR and mobile physiological monitors. Subsequent chapter will provide a comprehensive review of relevant research in this domain.
Research transition towards individual response to environmental exposure
While the development of mobile monitoring technology has advanced the micro-scale transition of environmental monitoring and research towards individual environmental exposure measurement, there is still a lack of subjective dimension research in related studies. This is mainly manifested in two ways: First, when using the “environment-cognition-behavior” framework to study, the individual cognition and decision-making process remain in a black box state, making it difficult to summarize and verify a clear causal mechanism. Second, subjective dimension measurement mostly relies on self-report methods, which lacks timeliness. However, the development of VR technology and physiological monitoring technology provide an opportunity to solve the above problems. These technologies collects physiological information on physical function activities and emotional cognitive processes during individual activities, and integrates methods such as behavior tracking and in-depth interview to help a deeper understanding of the interaction between environment and people, driving a transition towards individual response to environmental exposures. Significant progress has been achieved in Chinese research within this domain.
Constructing virtual spaces and evaluating built environments through virtual reality technology
The virtual world created by VR technology can integrate various real-world experiences and enable researchers to conduct environmental exposure experiments in a laboratory setting. In comparison to videos and photos, VR technology offers interactivity and immersion, making itself an essential tool for studying human response to environment. More recently, the planning and urban design community has started utilizing VR technology to explore individuals’ perceptions of the environment and the effects of the environment on individuals. Subsequently, they provide recommendations for planning and design practices.
The researchers conducted studies assessing the built environment on various spatial scales, ranging from the urban road network to individual buildings. The street network space constructed using VR technology can be utilized to conduct cognitive experiments and study people’s response to environmental exposure in urban areas. VR enables the establishment of a correlation between the spatial form of the street network and subjective cognition (Yuan and Zhang, 2012). By summarizing relevant VR experiments, this study provided insights into the methods and workflow of applying virtual reality technology in urban design and architectural research. Good walkability can encourage residents to choose non-motorized modes of travel. By employing the Mars VR evaluation engine and visual stated-preference method, the utility level of various street spatial features in terms of walkability could be calculated by comparing the old and new urban areas in Guangzhou (Chen et al., 2022). Additionally, the assessment of the built environment was complemented by the use of physiological monitoring devices, providing supplementary conclusions to the aforementioned VR experiment. In another major city in China, Shanghai, a case study was conducted focusing on the streets of Jing’an District. Through the modeling of virtual reality scenes and the visualized stated-preference method, the researcher compared the influence of various design interventions on pedestrians’ walking suitability. Furthermore, a decision tree-based machine learning algorithm was employed to measure the influence of street spatial interface feature elements on walking suitability evaluation (Shi et al., 2020). The urban underground space has become an integral part of the urban built environment, and individuals’ activities in underground spaces have become a part of their daily routines. A virtual environment pathfinding experiment conducted in a subway station scene demonstrated the feasibility of a pedestrian simulation and traffic behavior data acquisition platform based on VR systems. The experimental results aligned with the behavioral characteristics of pedestrians in the actual environment and could accurately assess the detailed traffic behaviors of pedestrians (Wang et al., 2021). By focusing on the scale of individual buildings, VR technology can be utilized to conduct quantitative research on the social utility of lower public spaces in tall buildings (Ye et al., 2019). In a case study conducted in Shanghai, over 200 volunteers made their preferences based on their experiences within a VR model. The experimental results obtained can be used to design lower public spaces in tall buildings and provide targeted guidance for the specific areas in question.
Exploring individual responses to environmental exposure through physiological monitoring studies
Physiological monitoring encompasses various observation targets, such as eyeballs (eye movement), skin (electrodermal activity), and the brain (electroencephalography, magnetic resonance, etc.), which can record physical functional activities and emotional cognitive processes during environmental exposure. Devices such as Electroencephalogram (EEG) monitors, electrodermal activity monitors, and eye movement trackers can provide more detailed physiological response data of the human body under specific environmental exposure conditions such as: road, tunnel and indoor environment. They facilitate studies that were challenging to conduct using previous research methods.
The physiological and psychological factors of drivers fluctuate with changes in road environmental factors, which can impact driving safety. The combination of EEG monitors and simulated cockpits can be used to investigate the relationship between road environment monotony and driver fatigue. One study discovered a significant decline in the driver’s heart rate in a monotonous driving environment, revealing a notable pattern of heart rate changes (Zhao et al., 2011). During night-time driving, the mental load on drivers increases to a certain extent, making it more challenging for them to process environmental information and affecting driving safety. Researchers conducted driving experiments using driving simulators and wearable physiological instruments. The results showed that compared to daytime driving, drivers experienced significantly increased subjective pressure during night driving experiments, with the subjective pressure being directly proportional to the driving difficulty. Additionally, physiological indices such as power spectrum density of heart rate variability and EEG load level exhibited significant differences, and respiratory frequency also showed changes. However, respiratory amplitude and Electrocardiogram (ECG) indices did not exhibit significant changes. These research findings can be used for quantitative safety evaluations of night-time road traffic (Wang et al., 2017). Given that China is a mountainous country with numerous roads featuring twists and slopes in mountainous areas, road safety is a significant concern. The results of a study involving the use of wearable physiological and psychological instruments to collect drivers’ physiological data indicated that additional safety facilities and warning signs had positive effects on driving safety (Qin et al., 2022).
The improvement of the tunnel environment can help improve road safety, and wearable devices can assist in monitoring drivers’ health indicators in tunnel environments. In practice, paintings on tunnel sidewall are often used to influence driver behavior (Liu, 2019). The effect of side wall patterns was tested through simulation experiments, collecting behavioral and physiological data (ECG, EEG, electromyography, and other electrophysiological signals). Undersea tunnel environments are characterized by enclosed spaces, poor visibility, and monotonous road landscapes, which can impact drivers’ physiological and psychological factors, leading to traffic accidents. Researchers utilized wearable eye trackers, video recorders, and other devices to collect real-time data on drivers’ eye movement characteristics, driving speed, and position. Based on this data, the characteristics of drivers’ eye movement and variations in vehicle speed were analyzed, and corresponding mathematical models were established (Pan et al., 2022). Indoor environmental exposure is a new focus of Chinese research in recent years. Wearable physiological devices can assist researchers in conducting exposure studies in indoor environments. An experiment involving pathfinding was conducted in an airport departure hall, where physiological data and eye movement data of participants were collected to analyze visual efficacy and comfort. The study aimed to explore the influence of the light environment on airport passengers (Liu et al., 2021). Wearable eye trackers can also contribute to interior design research. The Tobii Pro Glass eye tracker was utilized in large shopping malls to record participants’ eye movement data in the real visual field during the pathfinding process (Sun and Yang, 2019). The study investigated the visual salience of different markers and the influence of these markers on users’ psychology. The findings of this study can help analyze the weak points in visual observation during the pathfinding process and provide theoretical support and additional data for the design and optimization of complex building interiors.
When Chinese cities enter the stage of stock development, urban renewal has become the main work in the current urban planning, and urban renewal needs a light but effective intervention means. Physiological monitoring is also applied to the exploration of urban renewal in response to China’s urban design transformation. Compared with the traditional methods, this method has the characteristics of universality and embodiment, and comprehensively improves the objectivity and accuracy of the study of street spatial quality (Chen, 2023; Kang et al., 2023). An urban renewal project in Shanghai adopted this method and derived guidelines for the design of walking and activity spaces. To address the problem of excessive building setbacks in specific locations, it is proposed to profile these sections, optimize the layout of landscape greenery and various facilities, strengthen path guidance, improve the visibility of shop signs, and create streets that offer a good walking experience. To enhance the vitality of open spaces in specific locations, it is suggested to design them as pocket parks or civic leisure squares, and to arrange urban furniture to improve the quality of these spaces.
Based on the understanding individuals’ response mechanisms to the environment, planners can solidly apply health concepts in urban planning and management practices. A possible approach is to integrate residents’ spatiotemporal behavior data, environmental data, and health response data to understand the interactions between daily activities, urban spaces, environmental exposure, and health. This approach can guide residents in reducing exposure risks during daily activities and movements. It is also crucial to focus on the provision and construction of relevant community facilities tailored to the exposure characteristics of different groups.
The integration of mobile physiology monitoring and virtual reality holds considerable ability to advance research into individual behavioral processes and public health. The research results have started to play a crucial role in areas such as environmental health, urban planning, and traffic safety. Prospectively, the integration of real-time physiological data and long-term data promises to enhance the effectiveness of environmental health research, enabling thorough explorations of relevant issues in the field.
Summary
In the context of emerging technologies, including mobile particulate monitors, wearable devices, and virtual reality, this article reviews the micro-scale transition of environment monitoring, the transition towards individual environmental exposure measurement, and the transition towards individual response to environmental exposure in the Chinese world. These transitions are clearly technologically oriented. By sorting out the advantages and disadvantages of these monitoring techniques and their application scenarios (Table 1), it will help researchers to choose the appropriate technical methods to carry out research. In summary, compared to traditional fixed monitoring stations, mobile monitoring devices are suitable for targeted, individualized, and mobile environmental exposure research. Wearable cameras are suitable for the study of the association between spatiotemporal behavior and health effects, as well as the exposure study of urban built environment through refined behavior and environmental recording. Physiological monitoring devices can record the physiological response of individuals in real time, which is suitable for exploring the mechanism of health effects of the environment. Due to its unique scene simulation function, VR technology is suitable for urban planning scheme simulation, public policy research, and extreme environmental health effect research.
Comparison of micro-environment monitoring techniques.
Environmental exposure research is interdisciplinary in nature, and is linked to many disciplines such as public health, traffic safety, urban design, and others. Emerging technologies help to study health issues in the context of mobility and provide us with a better understanding of the individuals-environment interaction at the micro scale. Firstly, traditional health research focuses on the impact of air, noise, and green space on residents’ health on a city or neighborhood scale. In this era, researchers combine individual trajectories and behaviors with environmental factors to explore the environmental impact on individual scale. This research has shifted the focus of urban planning in China from economic efficiency to human perception, reflecting the pursuit of wellbeing in Chinese cities. Secondly, in traffic safety studies, researchers use wearable physiological devices to collect physiological data, and use this data to analyze how the environment affects the physiological and psychological state of vehicle drivers. Thirdly, many researchers in the field of urban design have entered into the field of environmental exposure, utilizing physical health outcomes to assess individual’s perception of the environment. Their research can help us better understand the relationship between the built environment and public health.
The research transitions also provide practical value to the fields of precise pollution prevention, space governance, healthy travel. Environmental monitoring is carried out with mobile devices and wearable cameras to achieve the measurement of environment information and targeted pollution prevention. Physiological monitor and virtual reality are integrated into the governance process of urban problems, providing support for public policy through the understanding of cognitive process and emotional state, and helping the planning practice of urban landscape and street renewal. Particulate matter information and built environment information help contribute to better understanding of the health effects of individual travel, and help to formulate policies about residents’ travel behaviors.
Although some achievements have been made in the research on environmental exposure, the following problems in terms of theory and technical methods still need to be solved: Firstly, in terms of research scale, the relevant researches using mobile monitoring and physiological monitoring technology are mostly carried out in micro-space, and how to apply them to macro scale still needs to be further discussed. Secondly, the physiological and social significance and related relationships of objective physiological indicators obtained based on neuroscience and technology need to be clarified, which provide a theoretical basis for understanding the complex relationship between mind, brain, body, and environment. Thirdly, with the development of integration with neurophysiology, data fusion between multiple devices has become an important task. At the same time, the effective combination of interviews and questionnaires and other data to achieve subjective and objective fusion research will become an important research topic.
Footnotes
Declaration of conflicting interests
The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
Funding
This work was supported by National Natural Science Foundation of China (No. 42271234).
