Introduction

As medical science advances, the World Health Organization (WHO) statistics indicate that most of the world’s advanced countries already have aging societies (Fathollahi-Fard et al. 2020b). People all over the world live longer. Many people can expect to live in their 60s and beyond today, for the first time in history. The global population is estimated to be 2 billion by 2050 at 60 years of age and older, up from 900 million in 2015. At present, there are 125 million people 80 years of age or older. By 2050, approximately these (120 million) people will live in China alone, and in this age group around the world, there will be 434 million people. Eighty per cent of all older people will be living in countries with low and middle incomes by 2050. However, an extended lifespan does not mean that all older adults can maintain their health as they age. Physiological degeneration and chronic diseases develop with age and require medical treatment and care (Aseervatham et al. 2013). Psychologically, physiological and cognitive degeneration caused by aging and reduced social networking can cause chronic mental illnesses, such as depression (Chen and Feeley 2014; Wu et al. 2020a). Furthermore, the reduction in labour and productivity associated with an aging society can indirectly reduce domestic economic growth and international competitiveness. Thus, maintaining and promoting physical and mental health in older adults and reducing burdens on families and societies are crucial topics when faced with an aging population. Environmental factors play a crucial role in aging. Studies have demonstrated that the social functioning and health of older adults can be affected by environmental stimulation (Jennings and Bamkole 2019). Much environmental psychology and behaviour research has been conducted on the relationship between the natural environment and psychological benefits (Yang et al. 2020), how natural scenery can promote psychological health (Liu et al. 2020) and how exercising in a natural environment has more health benefits than exercising indoors does (Pretty et al. 2005). Thus, explorations of how to promote healthy aging in elderly Chinese people must consider the relationship between environmental factors and physical and mental health in this population.

Aging-in-place policies promoted widely to refer to elderly people continuing to live in their home communities rather than in care centres (Van Hees et al. 2017). In the lives of older persons, the home atmosphere is fundamental, intimately intertwined with one’s sense of self and belonging. Aging in place (AIP), continuing to live for as long as possible in the same or familiar place or culture, not only fulfils a neoliberal and economic imperative but also aligns with the preferences of most elderly people who choose to age in place. The possible bearing of the narratives embodied in AIP or age-friendly policies remains unexamined, considering the contributions of policies to various aging experiences. The concept of aging in place includes an attachment to the “home”, which refers to a place where one can continue to find meaning rather than simply a specific residence. The meaning of “home” can include one’s neighbourhood and community (Van Hees et al. 2017). The emotion of place attachment towards a neighbourhood or community can provide older adults with a sense of security and meaning and promote their well-being (Chang et al. 2020; Cristoforetti et al. 2011). Furthermore, local environmental factors play a crucial role in explorations of aging-in-place topics. For example, adequate urban green zone environments can increase elderly residents’ place attachment to them, thereby affecting their leisure behaviour and health (Afshar et al. 2017; Pitas et al. 2018). Thus, older adults who live near urban green zones often consider the natural environments closest to their residence to be their main outdoor leisure site, and they alleviate stress through outdoor leisure activities at the site. However, elderly residents of cities must also bear environmental stressors associated with the city, such as noise and air pollution.

Few urban greening studies have focused on middle-aged and elderly residents or explored the relationship between place attachment, outdoor leisure activities, well-being and environmental stressors. Therefore, this study explored the relationship between environmental stressors associated with urban greening in Fujian Province felt by middle-aged and elderly residents and their well-being as well as the mediating effect of place attachment and outdoor leisure activities on this relationship. The research results can clarify the potential interaction between urban greening and the psychological health of middle-aged and elderly residents. The study results can serve as a reference for related health promotion policies for middle-aged and older adults and urban green zone and environmental planning.

The rest of this paper can be organized as follows: Section 2 is the literature review and hypothesis development based on the research fields of environmental stressors, outdoor leisure behaviour and mediating effects. Section 3 is the proposed methodology to discuss about the case study, measurements and the data analysis of the case study. Section 4 is the results and our discussion to highlight the practical insights of this study. Section 5 is the conclusion and future research recommendations.

Literature review and hypothesis development

Environmental stressors and well-being

Lachowycz and Jones (2012) explored the relationship between green zones and health, and they considered various potential mediating factors, such as environmental awareness and green zone activities. In addition, they discussed age differences in the relationship between green zones and health. For example, young people and older adults had more acute perceptions of green zones than middle-aged people did. This was because young people and older adults spend more time in their home environments and are more reliant on the resources provided by the home environment. Other factors, such as physical activity preferences, health, mobility and environmental awareness, are closely related to green zone use. Other social and environmental factors, such as cultural attitude and community activities, also indirectly affect the relationship between green zones and health. Studies have indicated that the social meaning of attachment to a green zone can promote individual health more effectively than the quality of a green zone can (Lager et al. 2012; Patwardhan et al. 2020; Williams et al. 1992). Urban greening can improve the urban microclimate, compensate for lack of green zones in urban development and alleviate the conflict between people and vehicles, as well as provide city dwellers with places to relieve stress, engage in leisure activities and increase their emotional connection with the local area. However, because of population density, green zone size, facility quality and environmental pollution, green zones in urban neighbourhoods may not be able to provide local residents with sufficient health resources or activity opportunities. In exploring the benefits of urban green zones, Jennings and Bamkole (2019) used a geographic information system to develop a research model that included urban planning, traffic, regional air quality, microclimate and noise to evaluate how urbanization affects the benefits of the city and green zones. Thus, when exploring the characteristics and benefits of urban green belts, the role of urban environmental stressors must be considered.

Although urban greening can help urban dwellers connect with nature and engage in outdoor leisure activities, environmental stressors produced by the city can prevent residents from receiving the benefits of urban green belts. Environmental stressors are stimuli in the environment (e.g. noise, air pollution and crowded spaces) that threaten an individual’s mental and physical balance (Schulte 2014; Shabbir and Wisdom 2020). As the world becomes more urbanized, environmental stressors have become crucial factors that urban development and planning managers must consider. Thus, although a majority of studies have emphasized that urban open green belts provide natural resources and benefits to surrounding neighbourhoods, studies must consider how environmental stressors affect the mental and physical health of city dwellers. Studies have proven that environmental stressors negatively affect human health. For example, air pollution increases the risk of cardiovascular diseases (Shabbir and Wisdom 2020). The WHO conducted a survey of how harmful environments affect human health and developed the concept of the environmental burden of disease with relevant agencies. They surveyed different types of negative environmental impact factors (e.g. noise, indoor air quality, outdoor air pollution, second-hand smoke, climate change and water pollution) to identify the environmental stressors that cause diseases (Prüss-Ustün et al. 2017). Generally, long-term contact with stressors can have harmful health effects, such as emotional disturbances, social withdrawal, insomnia and high blood pressure (Fliege et al. 2005; Honold et al. 2012).

The PERMA psychological well-being model stands for the five well-being elements, namely positive emotion, engagement, relationship, meaning and accomplishment (Goodman et al. 2018; Seligman 2011). Positive emotion involves emotions such as joy, interest, satisfaction, pride and gratitude (Fathollahi-Fard et al. 2020b). According to broaden-and-build theory, positive emotion can help individuals expand their thinking and behaviour as well as build psychological flexibility and resources and adjust stressors to increase their well-being (Goodman et al. 2018; Wu et al. 2020a, b). The concept of engagement emphasizes a state of concentration in which individuals forget themselves when participating in activities. This status is similar to flow experience, and active engagement in a leisure activity can help middle-aged and older adults increase their sense of self-control, thereby promoting well-being (Wu et al. 2020a, b). Relationships are interdependent social relations in a group that an individual belongs to (e.g. families, friends or colleagues). A relationship can make one feel a sense of closeness (Wu et al. 2020c) or reduce stress (Umberson and Montez 2010). Studies have demonstrated that relationships can provide social support (e.g. love, recommendation and care) and can increase an individual’s self-esteem and well-being (Tang et al. 2020; Fathollahi-Fard et al. 2019). A study by Tavernier and Willoughby (2012) demonstrated that among adults who have lost loved ones, those who have a sense of the meaning of life exhibited more satisfactory psychological adjustment ability than those without a sense of the meaning of life. Accomplishment refers to an individual undertaking a task on the basis of intrinsic motivation to achieve a goal. Studies have indicated that people who can maintain goals have a high sense of well-being (McAdams and Guo 2015).

Relevant studies have verified that environmental stressors negatively affect human health. The WHO surveyed different types of environmental impact factors (e.g. noise, air pollution, water pollution, crowded spaces and the high traffic flow) to identify the environmental stressors that increase the risk of diseases (Prüss-Ustün et al. 2017; Fathollahi-Fard et al. 2020a). Generally speaking, long-term contact with stressors can cause health risks such as emotional disturbances, social withdrawal, insomnia and high blood pressure (Tang et al. 2020; Tavernier and Willoughby 2012). Thus, this study hypothesized that environmental stressors and the well-being of residents are negatively correlated (H1).

Outdoor leisure behaviour and place attachment

Outdoor leisure refers to an individual engaging in outdoor leisure activities (e.g. bicycling, camping and playing Frisbee) in their free time. Generally, engaging in outdoor leisure activities can have positive psychological feedback (e.g. enjoyment, relaxation and joy; Orsega-Smith et al. 2004). Most relevant studies have indicated that engaging in outdoor leisure activities has positive physiological, psychological and social health benefits for middle-aged and older adults (Orsega-Smith et al. 2004; Sugiyama and Thompson 2007; Sugiyama et al. 2009). The study by Sugiyama and Thompson (2007) further divided the sources of these positive benefits into leisure activity factors and outdoor environmental factors.

Leisure activity factors include participation frequency and activity type. Different participation frequencies and activity types have different benefits for the health of older adults. Kerr et al. (2012) used an accelerometer and GPS to understand the relationship between the outdoor activity participation time and health in elderly participants, revealing that engaging in outdoor activities for more than 30 min per day resulted in fewer symptoms of depression and higher self-perceived body function in older adults. Furthermore, Jacobs et al. (2008) used secondary data to analyze the outdoor activities and long-term health of people older than 70 years. This result indicated that older adults who engage in outdoor activities daily have higher independence and self-perceived health. Regarding activity type, most outdoor activities (e.g. gardening and walking in parks) are beneficial to the health and quality of life of middle-aged and older adults (Sugiyama and Thompson 2007). Outdoor environmental factors include those of outdoor environments that can improve health and quality of life (Curl et al. 2020). Studies have indicated that establishing adequate natural outdoor environments (e.g. sufficient green zones, parks and gardens) can effectively promote social interaction among residents (Kerr et al. 2012; Sugiyama et al. 2009). Furthermore, people older than 45 years who live within 1 km of a green zone have higher physical activity levels and a lower risk of mental illness (Dzhambov et al. 2020).

Generally, when researchers have explored local attachment from the perspectives of environmental psychology, tourism and local branding, they mainly focus on individuals’ social identities and reliance on a local area (Wu et al. 2020c; Yi et al. 2018). Studies have indicated that place attachment is a consumer’s relationship with an area and the internalization of their experiences (Scannell and Gifford 2017). Interaction among people, an area and local products enables consumers to form a symbolic meaning of the area. Furthermore, from the perspective of the relationship between a travel destination and residents, the relationship between residents and an area can prompt their intended or actual behaviour, thereby influencing destination promotion (Yi et al. 2018). Place attachment is a tool for measuring the relationship between an individual and an area. A place is a space that has been transformed into a meaningful location through people’s experience and thought (Scannell and Gifford 2017), and place attachment is an assessment of the relationship between people and a place, the positive emotional link between an individual and a specific location and the preference for continuing to be close to the area. Place attachment generally can be measured using place dependence and place identity (Patwardhan et al. 2020). Furthermore, some scholars have argued that because it is an emotional bond between people and a place, affect dependence can replace place dependence (Yi et al. 2018). In addition, researchers have demonstrated that place attachment is a highly influential factor in destination loyalty and that higher place attachment triggers positive behavioural willingness and behaviour (e.g. word-of-mouth communication, recommendation and revisits; Hanks et al. 2020).

The concept of place attachment has long been explored by environmental psychologists and geographers (Yu et al. 2019). However, research on outdoor recreation areas expands the concept of place attachment to topics of park and recreation management, such as cooperative sponsorship of park facilities (Pitas et al. 2018), travel behaviour (Hanks et al. 2020) and outdoor leisure participation (Curl et al. 2020). Place attachment to outdoor recreation areas can be divided into two concepts, namely, place identity and place dependence (Williams et al. 1992). Emotionally, place identity is an individual’s psychological identification with a place, particularly their emotional link with a recreational area (Patwardhan et al. 2020). Place dependence is the needs and objectives produced by an individual’s reliance on the functions of a place; place dependence emphasizes the satisfaction of needs by a specific recreational area (Williams et al. 1992). A study by Lager et al. (2012) demonstrated that even if a neighbourhood’s environment has been damaged or has poor quality, elderly residents generally still have high place attachment to their neighbourhood environment. Both place identity and place dependence are significantly and positively correlated with the social well-being of middle-aged and older adults (Afshar et al. 2017). In addition, middle-aged and older adults with higher place attachment have stronger feelings of self-control and social identity, and they can better interact with community residents, thereby reducing feelings of loneliness (Lager et al. 2012).

Individuals who engage in outdoor leisure activities in their free time can achieve positive psychological feedback; high-frequency activities can induce stronger positive psychological responses. Furthermore, studies have indicated that older adults who participate in outdoor activities can not only improve their psychological health but also expand their social networks (Lager et al. 2012; Pitas et al. 2018; Williams et al. 1992). When these outdoor activities occur in the surroundings of middle-aged and older adults, these adults’ willingness to participate increases. Thus, this study proposed H2 as follows: the more frequently middle-aged and older adults participate in leisure activities, the higher their level of place attachment will be.

Mediating effect

Most studies have discussed the effects of single stressors on health. However, Honold et al. (2012) asserted that when exploring the stressors in urban neighbourhoods, we should consider multiple stressors at the same time. This is because some stressors can be produced at the same time or from the same source. For example, traffic flow in a city can simultaneously cause noise and produce undesirable odours and air pollution. Their study indicated that residents who live in areas with more environmental stressors engage in more behaviours that pose health risks, such as smoking and drinking alcohol at a higher frequency and participate less in physical activities. Residents in neighbourhoods with higher environmental stress generally have lower socioeconomic status, lower satisfaction with their neighbourhoods and poorer mental and physical health (Van Hees et al. 2017). Older adults’ perceptions of the physical environment play a crucial role in the relationship between a neighbourhood and their health, as confirmed in studies demonstrating that air pollution, noise, residential status and open space are physical environmental factors related to the health of elderly residents (Balfour and Kaplan 2002; Zhang et al. 2019). Furthermore, elderly residents are sensitive to neighbourhood environmental stressors (O’Campo et al. 2015; Zhang et al. 2019). Therefore, this study proposes the following hypotheses: Environmental stressors and residents’ outdoor leisure behaviour are negatively correlated (H3), and environmental stressors and residents’ place attachment are negatively correlated (H4).

The more frequently middle-aged and older adults participate in outdoor activities, the more beneficial they are for their health. In conclusion, outdoor leisure activities and the mental and physical health of middle-aged and older adults may be positively correlated. Studies have often used place attachment or leisure activities as independent variables. These studies have also proven that older adults who have higher place attachment and participate in more leisure activities have improved well-being (Curl et al. 2020; Tang et al. 2020). In exploring the sense of place, leisure activities and well-being, Williams et al. (1992) asserted that place attachment is a crucial factor in whether an individual will visit a natural destination and engage in outdoor activities, thereby improving their well-being. Thus, this study proposes the following hypotheses: the outdoor leisure behaviour of residents mediates the relationship between environmental stressors and residents’ well-being (H5); the place attachment of residents mediates the relationship between environmental stressors and residents’ well-being (H6).

Proposed methodology

Participants for our case study

Fuzhou, Quanzhou and Xiamen in Fujian Province were selected as the research settings because they are the most urbanized and economically developed cities in Fujian Province. In addition, their high urbanization levels mean that green zones in these cities were neglected early in their construction. In recent years, economic development has resulted in city residents increasingly valuing living quality, and city construction has gradually valued urban greening. We performed convenience sampling to select residents of Fuzhou, Quanzhou and Xiamen who were aged 55 years or older to complete a questionnaire. The middle-aged and elderly participants did not have communication obstacles, could move freely and lived near green zones.

Questionnaires were distributed in Fuzhou, Quanzhou and Xiamen from October to December 2019. In total, 907 questionnaires were recovered. After 36 invalid questionnaires were removed, 871 valid questionnaires remained, yielding a recovery rate of 96%. The sample comprised 468 (54%) men and 403 (46%) women. The respondents’ average age was 58.38 years, their average monthly income was 6000 RMB and their average length of living at their present location was 23.5 years.

Measurement

Environmental stressors were measured by referencing the scale of Honold et al. (2012) and using four questions, including those related to air pollution and behaviour-related noise. Cronbach’s α for this portion was 0.88.

Outdoor leisure behaviour was measured with four questions by referencing the scale of Lachowycz and Jones (2012), including those related to leisure activities and social interaction behaviour in green zones. Cronbach’s α for this portion was 0.83.

Place attachment was measured by referencing the scale of Ryan (2005) and using a total of 12 questions, including “I have a special connection with people who come here” and “I feel very satisfied with this green zone.” Cronbach’s α for this part was 0.81.

Well-being was measured by referencing the PERMA well-being model scale of Seligman (2011) with 15 questions in total, including “In general, I feel joyful” and “In general, I lead a purposeful and meaningful life.” Cronbach’s α for this portion was 0.86.

All items were scored on 7-point Likert scales. The scores for each item were added and averaged to calculate scale indicators. Higher scores indicated feeling more environmental stressors, higher place attachment and well-being, and more participation in outdoor leisure activities.

Data analysis

All questionnaire data were input into a computer and analyzed with SPSS 21 and AMOS 20 to determine the relationships among environmental stressors, outdoor leisure behaviour, place attachment and well-being (Fig. 1). During verification with structural equation modelling (SEM), maximum likelihood estimation was performed to estimate the parameters. Furthermore, direct and indirect effect analysis was performed to examine the mediating effect of place attachment and outdoor leisure behaviour on the relationship between environmental stressors and well-being. The individual effects of independent variables on dependent variables are called direct effects. The effects of independent variables on dependent variables through mediating factors are indirect effects. Together, the two types of effects form the total effect. If mediating factors are present in a model and make the direct effect nonsignificant, then the mediating factors have a complete mediating effect. In this case, the independent variable and dependent variable produce a correlation only through the mediating factors. However, if the mediating factors make the direct effect less significant, then they have a partial mediating effect.

Fig. 1
figure 1

Research model

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Results

In the confirmatory factor analysis (CFA), two commonly used indicators, namely composite reliability (CR) and average variance extracted (AVE), were selected for the second-stage CFA. CR is used to measure the construct indicators’ internal consistency, and AVE is used to calculate the explanatory power of the potential variables on various measured variables. The CFA in the model reached the standard (see Table 1). Furthermore, model fitness analysis was conducted in AMOS and yielded the following results: χ2(775) = 1614.52, p < .001; root mean square error of approximation = 0.07, standardized root mean residual = 0.05, Tucker–Lewis index = 0.89, comparative fit index = 0.92.

Table 1 Result of confirmatory factor analysis (CFA)
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After passing the model fitness test, this study used SEM to further identify relationships among model variables. The results of the hypotheses after SEM verification are presented in Fig. 2. First, environmental stressors and well-being were significantly negatively correlated (β = − 0.31, p < 0.01), indicating that the more affected residents were by environmental stressors, the lower well-being they felt. Therefore, H1 was supported. Outdoor leisure behaviour and place attachment were significantly and positively correlated (β = 0.23, p < 0.05), meaning that the more outdoor leisure activities the residents engage in, the higher their place attachment will be. Therefore, H2 was supported. Environmental stressors and outdoor leisure behaviour were significantly and negatively correlated (β = − 0.26, p < 0.01). In other words, the more environmental stressors residents feel, the lower their engagement in outdoor leisure activities will be. Therefore, H3 was supported. Environmental stressors and place attachment were significantly and negatively correlated (β = − 0.28, p < 0.01), indicating that the more environmental stressors residents feel, the lower their place attachment will be. Therefore, H4 was supported.

Fig. 2
figure 2

Path analysis

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When environmental stressors were the independent variables and outdoor leisure was the mediating factor in the subsequent analysis of the mediating effect on well-being, the confidence interval for the total effect of environmental stressors on well-being did not include 0. This means that a significant total effect was present and that this model was meaningful (shown in Table 2). The confidence interval for the indirect effect did not include 0, meaning that this model had a mediating effect. The confidence interval of the direct effect did not include 0, meaning that the mediation was partial. Outdoor leisure behaviour had partially mediated the relationship between environmental stressors and well-being. When environmental stressors were the independent variables and place attachment was a mediating factor influencing well-being, the confidence interval of the total effect of environmental stressors on well-being did not include 0. This means that the total effect was significant, and this model was meaningful. The confidence interval for the indirect effect did not include 0, indicating that this model had a mediating effect. The confidence interval of the direct effect did not include 0, meaning that the mediation was partial. Therefore, place attachment partially mediated the relationship between environmental stressors and well-being.

Table 2 Mediation path analysis
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Discussions

Fuzhou, Quanzhou and Xiamen in Fujian Province were the research settings for this exploration of whether perceived environmental stressors by middle-aged and older adults living near urban green zones affected their well-being and whether place attachment and outdoor leisure behaviour play mediating roles in this relationship. The results indicate that environmental stressors reduce the well-being of residents and that outdoor leisure activities and place attachment mediate the relationship between environmental stressors and well-being. In addition, this study proved that outdoor leisure activities among residents increase their place attachment.

The research results demonstrate that when middle-aged and elderly residents feel more environmental stressors (e.g. noise, air pollution or crowded spaces), their mental and physical balance can be threatened, thereby reducing their well-being. This result is consistent with previously published results demonstrating that when an individual’s physical and mental health is threatened by the external environment, their living quality decreases (Schulte 2014), which in turn reduces their participation in outdoor leisure activities and affects their place attachment and well-being. Environmental stressors such as noise, air pollution and trash in urban green zones can make middle-aged and elderly residents reduce or stop their participation in outdoor leisure activities to avoid exposure to negative environmental stressors. Consequently, their well-being decreases. This study’s results reflect those of past research demonstrating that outdoor leisure activities can promote well-being in middle-aged and older adults. Conversely, reduced participation in outdoor activities is positively correlated with lower well-being (Orsega-Smith et al. 2004; Pretty et al. 2005; Sugiyama et al. 2009). This result shows that environmental stressors not only affect outdoor leisure behaviour among middle-aged and elderly residents but also further affects their psychological health.

Past studies have demonstrated that even if a neighbourhood environment is damaged or poor quality, elderly residents generally have a high place attachment to their neighbourhood (Lager et al. 2012). However, this study revealed a different result, namely that environmental stressors and place attachment have a negative correlation. Place attachment generally can be divided into place identity and place dependence. To middle-aged and elderly residents, the green zones near their homes are optimal leisure activity sites. However, if the environmental stressors near the green zone are excessively high, the willingness of middle-aged and elderly residents to use those zones will decrease, in turn reducing their reliance on green zones. Thus, the results of this study indicate that environmental stressors can reduce the level of attachment to green zones among middle-aged and elderly residents. Previous studies have also verified that middle-aged and older adults with higher place attachment have a higher sense of self-control and social identity (Lager et al. 2012), and they can build a social network to relieve their feelings of loneliness.

Theoretical implications

Most past studies have used green park zones as their research bases. However, this study recruited middle-aged and elderly residents who live near green zones in Fuzhou, Quanzhou and Xiamen as the study participants. Fujian Province has long promoted urban greening, but because Fujian Province is in China’s coastal area and has a large population, urban green zones are typically located next to high-rise buildings. Urban green zones have always been the main sites for local people to engage in outdoor activities. Thus, this study explored the relationship between environmental stressors and the outdoor leisure behaviour, place attachment and well-being of residents living near urban green zones. Urban green zones often coexist with high-rise buildings and are easily affected by external environmental stressors. Studies in gerontology, environmental psychology, behavioural science and public health have argued that outdoor leisure activities have positive benefits for older adults. However, as people begin to pay attention to environmental pollution and climate change, activities in urban green zones might have different effects from those demonstrated in previous studies. This study used a positive psychology perspective (Seligman 2011) to explore the effect of environmental stressors on the well-being of residents living near urban green zones. The results of this study were consistent with those of past studies; environmental stressors reduce the well-being of residents living near urban green zones (Fliege et al. 2005; Honold et al. 2012). However, the present results indicate that the outdoor leisure activity behaviour and place attachment of residents near green zones mediate the relationship between environmental stressors and resident well-being. This means that individuals with a higher willingness to engage in outdoor leisure activities in their neighbouring urban green zones or higher place attachment to these green zones can obtain more positive benefits. This result reflects the value of the aging-in-place policy that is currently promoted. Such a policy allows older adults to live in a familiar and meaningful environment, and this feeling can provide a sense of security and meaning as well as promote well-being (Chang et al. 2020; Cristoforetti et al. 2011). Therefore, place attachment is crucial in aging in place and healthy aging.

Implications for practice

This study demonstrated that the higher the environmental stressors, the lower the individual’s place attachment is. The environmental stressors that middle-aged and older adults dislike or make them feel uncomfortable can reduce their sense of attachment to nearby urban green zones. External pollution and environmental changes can make middle-aged and older adults feel physically or physiologically uncomfortable, thereby reducing both their willingness to engage in outdoor leisure activities and their reliance on green zones. Therefore, this study concluded that an emotional factor affects place memory among middle-aged and older adults, especially if they have lived in the same location for more than 20 years. These long-term residents have knowledge and memories of the surrounding environment, and stimuli from environmental stressors may make them think of the comfortable environment in a location in the past and environmental changes in nearby green zones over the years. Consequently, this nostalgia can increase their place attachment and place dependence on the green zone that they were familiar with in the past. These feelings of place attachment can increase the self-control and social identity of middle-aged and older adults. They can use the same place memory to interact with neighbours or community residents, thereby reducing feelings of loneliness that often accompany aging as well as promoting well-being (Afshar et al. 2017; Lager et al. 2012). The results of this study can serve as a reference for agencies that plan urban green zones and organizations promoting geriatric health. In the face of rapidly aging societies and increasing environmental pollution, physical urban green zones should be improved to reduce environmental stressors and their impacts on users. Thus, green zones can facilitate optimal health benefits for elderly users and promote their participation in outdoor activities to maintain their health. They can improve older adults’ emotions toward a place and reduce the use of government and social resources.

Conclusion and further research

This study surveyed middle-aged and older adults who are active in green zones in Fuzhou, Quanzhou and Xiamen. Environmental stressors were used as independent variables, and the role of environmental stressors in the outdoor leisure activities–place attachment–well-being relationship was used to determine the impact of major current environmental stressors on the results of past research. The results of this study can provide a reference for future research. When the relationship between physical activities and mental or physical benefits is explored, activity location and environmental pollution should be considered. Future studies can include objective measurement data, such as air quality indicators, to test the model developed here from the perspectives of objective and subjective air quality. Questionnaire items related to green zone buildings can be added to identify the facilities that middle-aged and elderly residents require and expect to increase their use of green zones, living quality and overall well-being.

This study can be expanded with many suggestions and recommendations. First, the use of approximation methods like red deer algorithm (Fathollahi-Fard et al. 2020c) or the social engineering optimizer (Fathollahi-Fard et al. 2018) is one continuation of this study to do further data analytics. Our methodology can be applied to study the healthcare systems (Fathollahi-Fard et al. 2020d) or the water distribution network (Fathollahi-Fard et al. 2020e) in urban planning of our case study. Finally, the implementation and application of the proposed method for other real-case studies can be ordered for future research studies.