The unequal distribution of COVID-19 and the uncertainty associated with this disease have harmed the health of older adults on both an individual and communal level (34). Oliveira et al. (35) have found that the degree of physical activity and lifestyle during the pandemic have had a significant impact on older adults. A considerable fall in physical activity levels throughout the lockdown has negatively influenced the level of physical fitness and increased sedentary lifestyles factors that have been directly associated with increasing weakness in this group.

Studies show that the mental health status of older adults has been negatively impacted during the pandemic. Some preventive measures that have been taken to increase the resilience of older adults seem to change their living conditions during lockdown and help them deal with self-isolation, social distancing, and stress disorders. However, in their study, Perlman and Peplau (36) showed an increase in aging symptoms in people due to a decrease in immunity and a rise in anxiety during this period. Loneliness or the lack of social relationships was among the issues that older adults experienced more than other people due to being in a high-risk group.

This group was also affected by the adherence to lockdown rules and the lack of communication with the outside world, the emotional loneliness brought on by the absence of an intimate relationship or an emotional dependency [Weiss, 1974, as cited in Gaaloul et al. (37)], and the social loneliness caused by the absence of communication with a larger group of contacts. Van Tilburg et al. (38) asserted that many older individuals adopted social media as a substitute for in-person communication during the epidemic because of the decline in social connections. According to Pouso et al. (26), there was no significant difference in the level of depression between people with partial restrictions and people without restrictions to access public open spaces and green spaces. This result showed the importance of contact with nature to maintain mental health and emphasized the quality of being in green space rather than its quantity. Despite the time limit imposed by authorities, the use of green spaces has a great impact on mental health (26) and the physical health of older adults (39).

The sense of isolation among older adults can also be attributed to individual factors. Research has shown that age greatly impacts access to services and amenities, as well as participation in cultural and leisure activities. Additionally, factors such as retirement and marital status may contribute to feelings of loneliness and isolation (40). Despite the effect of physical distancing policies on social isolation, such effects are only seen in married people or those who are not in touch with others through social networks (38).

In the various reviews, some policies need to be established to create friendly communities for older adults. In this context, places far from the community should be examined, people far from social activities should be studied, and policies at the neighborhood scale to increase social participation should be considered [(38); Table 1] shows the effects of Corona on the health of older adults.

Numerous studies have demonstrated that exposure to natural environments offers extensive physical and psychological benefits (18). These effects have been observed in various study designs, including experimental, ecological, cross-sectional, and longitudinal studies. It is important to note that the definition of “natural environment” varies among these studies and encompasses green spaces, parks, nature, outdoor environments, and more. Specifically, exposure to green spaces serves three key functions: reducing harm (e.g., minimizing air, noise, and heat pollution), restoring capabilities (e.g., physiological restoration and improvement), and fostering capabilities (e.g., promoting physical activity and facilitating social cohesion). Despite the diversity in study designs and definitions of exposure, we have compiled relevant evidence to establish the positive impact of outdoor environments (natural or built environment) on various health domains, as summarized in Table 2.

During lockdown, it is possible to enhance the mental and behavioral health of older adults by considering their personality traits, such as higher intelligence, emotional stability, and extroversion, while also promoting public communication [Killingsworth and Gilbert, 2010; Tost et al., 2019 as cited in Nigg et al. (18)]. Access to outdoor recreational facilities and nearby parks, as well as increased physical activities, can contribute to maintaining physical and mental wellbeing and establishing safe social relations during the pandemic, as environmental-spatial characteristics play a role in these aspects (1). Urban parks don't only benefit mental and physical health but also facilitate the development of social relations within neighborhoods [Hayward and Weitzer, 1984; Lloyd et al., 2008 as cited in Addas et al. (54)]. Considering the special physical needs of older individuals, it is crucial to ensure their presence and provide thoughtful design and planning of outdoor environments in residential areas during pandemics.

In a study by Bartalucci et al. (55), the comparison of the data before and during the lockdown period showed some improvements in people's perception of nature and the sounds of the environment. During the lockdown, people paid more attention to the sounds around them. Such improvement in the sound landscape was associated with the reduction of road, air, and rail traffic (55). The study also found that older people over the age of 60 were more sensitive to traffic noise during the lockdown period, which was likely associated with understanding sounds and their natural environment. Furthermore, with the reduction of traffic noise, the quality of the soundscape improved (56). The study claims that if a person lives alone, their judgment of various aspects of their surroundings will be more positive. However, the lockdown itself can hurt human perception. Changes in people's behavior due to an epidemic like COVID-19 can have positive effects on the environment, particularly regarding the soundscape (55).

The emphasis on green space in previous reviews has been consistent. However, other forms of nature, such as blue space [e.g., rivers or lakes; Britton et al., 2020 as cited in Nigg et al. (18)], green infrastructure, which pertains to a deliberate network of open spaces, and digital nature experiences (18) have unfortunately been overlooked.

In 40 selected articles, the focus was on factors such as the density of commercial facilities, the density of schools, access to public transportation, the density of roads, and access to green spaces, along with the environmental characteristics of built space, such as urban density and mixed language use, the health impacts of urban residents' land use, and long-term active travel behaviors.

Older adults, as a vulnerable group of people to epidemic diseases, rarely use green space due to the dread of infection (57). They are subject to the negative impacts of social isolation, dread of disease, despair (17), and depression (58). Providing green spaces in the vicinity of areas where a large number of older people live can satisfy their need for greenery, prevent social isolation, despair, and increase social interactions (20). As physical activity is closely linked to mental health, older adults' limited physical activity and lack of access to physical activities either online or at home during lockdown have damaged their health (41). Inactivity intensified by social isolation measures to combat COVID-19 can make the health conditions of older adults worse than others, resulting in sarcopenia, weakness, and cardiac abnormalities, which all can potentially lead to increased mortality issues. These problems can put them at risk of death. Efforts to develop measures related to public health and clinical interventions in physical activities are necessary during COVID-19 (49). In one research they concluded that older users of green spaces tended to spend more time in their yards than those who did not visit green spaces much [Lin et al., 2014, cited in Berdejo-Espinola et al. (20)]. This is against the assumption that those who have access to green spaces are not in the need of greenery.

This narrative review study shows that some socio- demographic factors (such as age, gender, and education) (54), and activity status of older adults, along with their racial characteristics, affect the use of urban space by older adults. A variety of factors, such as the socio-economic characteristics (59) of the place of residence, the sense of isolation and loneliness (53) and the attachment to the place, have also affected the quality of their presence in the urban space. Table 3 shows a summary of the conducted studies. Visitors' behavior in green spaces correlated with their status and occupation. Local residents who owned their own houses, had long years of housing, stable jobs, and higher education outperformed others in behavior and health perceptions when visiting green spaces (65).

During the COVID-19 pandemic, the requirements to observe social distancing highlight to what extent the quality of life (QOL) is related to social and physical activity in middle and old age. They also show the necessity for more mobility in the living space. During lockdown, the amount of activity and mobility of middle-aged people at home or in private outdoor spaces decreased (32). A study conducted among 60-year-old people in the early stages of social distancing in Sweden in 2020 showed that the level of satisfaction with the quality of life and feeling of loneliness did not change much, but the level of health and satisfaction with economic conditions changed, and as time went on, a greater impact on the physical and mental conditions of older adults was observed. This is because social distancing policies have either reduced or eliminated opportunities for outdoor activities such as events, artistic entertainment, social gatherings, sports classes, and political and religious meetings (32).

Urban green spaces are mainly used for various activities, such as running, walking, and outdoor sports, which depend on many interconnected variables and the type of city texture, including the construction and population density of the neighborhood, the amount of green space available, and the safety and security of traffic and crime (66). With regards to older people, men tend to exercise alone while women tend to exercise in groups. However, due to the spread of COVID-19, the absence of group activities and gyms may have led to a reduction in the time women spend walking (60). There is no doubt that the presence of large parks within residential areas has increased the amount of walking, especially for older adults, and the relationship between the distance to the park and the change in the amount of daily walking in older women is very evident (60). According to a survey, 40% of park-users are aged 60 years or older, and among this age group, 90% visit the park on a daily basis. In summary, the survey indicates that ~86% of older individuals visit a green space located within a 1-kilometer distance from their residence (30).

The study by Noszczyk et al. (67), in which 1,250 people participated, shows that people mentioned different reasons for visiting green spaces: walking outdoors (69.8%), improving general health (68.9%), access (65.7%), and the need to connect with nature (60.6%). It is interesting to note that playing sports at gyms and walking with pets were not the main reasons for residents to visit green spaces (67). More than 75% of the participants claimed that visiting green spaces had a very (42.2%) or great (34.5%) effect on reducing their stress, and only 4.3% believed that visiting green spaces was not effective in reducing their anxiety. More than 60% of the respondents expressed the need for physical activity, the possibility of spending time with family and friends, and reducing the feeling of depression as the reasons for visiting green spaces during the COVID-19 pandemic (67). In another study, the most important reason for people to visit green spaces was to improve their mental health (77.4%), followed by increasing their health and physical activity (62.8%) and the possibility of connecting with nature (52.4%). Being in green spaces to use clean air was the main reason for 32.0% of the people, while the need for gathering and social connection was only important for 6.4% of the participants (20). Visiting green spaces is primarily motivated by individual health concerns, as demonstrated by a survey conducted in another country. For example, in a survey conducted by the Department of Planning, Industry, and Environment in Australia, personal sports activities such as walking, running, fitness sports, and cycling were found to be the main reasons for using public spaces [NSW Department of Planning, Industry and Environment, 2020, as cited in Levinger et al. (1)]. Furthermore, older adults reported walking on the streets near their residences. From this, scholars emphasize the importance of “no traffic” streets for people to continue exercising with social distance (68).

Several studies have indicated that the physical and spatial characteristics of a neighborhood can influence the attendance of older adult individuals during the COVID-19 pandemic. Factors such as the physical attributes of housing, urban landscapes, land use, and activity levels have been found to impact the quality of attendance for this population (Figure 3). Notably, the building and population density of the neighborhood, as well as the quality of corridors providing views to green spaces inside and around the neighborhood, have shown the greatest impact (Table 4). The availability of transportation options, such as vehicles, public transportation, bicycles, and access to technology in the neighborhood, including routing and augmented reality (AR) technology, elevators, sound-sensitive doors, and smart homes, have also encouraged greater attendance among older individuals. Furthermore, increased visits to urban green spaces were closely related to the distribution of green spaces around parks and neighborhoods (65, 71).

The characteristics of the local environment in the neighborhood level play a vital role in promoting adaptive behaviors and enhancing the health and wellbeing of older adults. For instance, a study conducted in New York demonstrated that individuals living in disadvantaged neighborhoods, who faced challenges in leaving their homes due to physical disabilities, encountered similar difficulties (1). Those with functional limitations or a perception of an unsafe neighborhood had significantly lower mental health compared to those who considered their area of residence safe. This disparity in mental health could be attributed to reduced social cohesion in these neighborhoods, which exacerbates the negative effects of a lack of safety [Cramm et al., 2013; Carrapatoso et al., 2018; Choi and Matz-Costa, 2018; Bonaccorsi et al., 2020, as cited in Levinger et al. (1)].

However, the presence of greenspace alone does not guarantee access. Barriers such as inadequate transportation, connectivity infrastructure, provisions for disability, and socio-cultural issues, including harassment and violence against women, continue to persist (72). In summary, the benefits of green infrastructure depend on individuals' previous experiences with greenspace, perceived accessibility, and personal connections to the landscape [Wang et al., 2015; Roberts et al., 2019; Grilli et al., 2020; Groshong et al., 2020; Sonti et al., 2020, as cited in Maurer et al. (72)]. Additionally, socio-demographic attributes have a substantial impact on the use, attitudes, and perception of urban parks (54).

Neglecting the quality of design in green spaces, both in terms of their qualitative and quantitative aspects, can have detrimental effects on social interactions, civic participation, community involvement, and the health of older adults [Hassen and Kaufman, 2016, as cited in Levinger et al. (1)]. Due to concerns about disease transmission, people have been avoiding public transportation, leading many cities, such as New York, to allocate open spaces and streets primarily for pedestrians and cyclists (61).

While engaging in outdoor physical activities and being exposed directly to nature have been found to have a more positive impact on health, indirect contact with green spaces, such as viewing them from a window, has been evaluated positively for maintaining the mental health of individuals during strict lockdown conditions, as observed in Spain (26).

Although the restrictions imposed during the COVID-19 pandemic may not have altered the need for urban green spaces, they have increased people's desire to visit a variety of green spaces. For instance, some individuals have traveled outside the city, while others have stayed within urban areas. Tree-lined streets and urban green spaces have been particularly sought after. As a result, the desire for trips with environmental effects has grown when access to pocket parks is not available (45). The older adult population not only requires green spaces but also tends to travel longer distances within or outside the city to access urban green areas. The green spaces utilized by older adults should be located in densely populated environments and possess important features in terms of land use (45). The availability of green pathways within the street network is one of the factors influencing older adults when selecting a location for physical activity. Other factors, including the quality of the landscape, amenities, the surrounding environment, and space availability, also play a role in people's choices. In order to enhance access to appropriate infrastructure for walking, cycling, and engaging in key activities while maintaining social distancing, the need for a variety of transportation options increases, as it not only enables older adults to participate but also contributes to societal cohesion and flexibility through increased social interactions (73).

The difference in the use of green spaces by older adults is associated with their physical limitations, socio-economic characteristics, and living conditions. The green space used by older adults has been studied at different scales, ranging from home green spaces, neighborhood yards, and gardens, to large urban areas (21). In a study conducted in England and Scotland in 2020, it was found that older people spent less time in green spaces during lockdown (24). The fear of infection and death caused this age group to comply with the lockdown conditions, which led to many problems for the health of this group of people. Many studies have claimed that the amount and frequency of use of green spaces by older adults is related to their health [(1, 16, 20, 22); Guida and Carpentieri, 2021]. Appendix Table 1 briefly presents the types of green spaces used by older adults during the pandemic.

Pouso et al. (26) investigated the effect of interacting with nature on depression levels using indirect access (containing the presence of both an urban and natural scene or a combination of both) and direct access (including the presence of a garden and green space and access to a terrace balcony).

Posuso et al. identified three levels of lockdown: level 1, which permits people to go out only for essential jobs, buying food and medicine, emergencies, or walking the dog (as implemented in China, Italy, or Spain); level 2, which enforces strict lockdown but allows for outdoor exercise on certain days (as implemented in France or England); and level 3, which also enforces strict lockdown but permits outdoor exercise on certain days (as implemented in France or England) (26). Also, the restriction of movement is a recommendation rather than a binding rule. This is most likely due to the high feeling of comfort from the absence of infection and the possibility of the naturalness of the space compared to balconies, compared to being in public or shared green spaces (26).

According to Pouso et al. (26), contact with nature through houseplants and balcony gardens can reduce the probability of depression and anxiety symptoms only for people in severe lockdown. As other groups leave the house more often, access to nature becomes easier for them, and in this way, stress can be reduced. The existence of private gardens and gardening spaces in patios can contribute the most to improving mental health during the pandemic as it provides access to open space and increases physical activity (26).

The diversity and abundance of plants and greenery that can be seen from windows, terraces, balconies, or in the neighborhood, as well as the addition of having houseplants or a garden, and greenery, have also been related to mental health. The existence of common green spaces also has been reported to create communication between neighbors, increase support and participation between people, and reduce the feeling of isolation among older adults (16). In the United Kingdom, a study was conducted to investigate the relationship between the size of the garden and the health of older adults, and it showed that people with larger gardens that they tended to themselves had better general health [Brindley et al., 2018, as cited in Dzhambov et al. (16)] and improved dietary intake [Davis et al., 2011; Beavers et al., 2020, as cited in Nigg et al. (18)], it may be sustained effects on healthy eating behaviors (18). Studies found that more older adults visited regional parks with large areas after COVID-19. But for small-scale parks including community parks, neighborhood parks, and paly lots, older adult visitation was negatively affected by COVID-19 (74).

In an online survey conducted in Italy, Spano et al. investigated the relationship between the presence of green spaces inside and outside the home (i.e., the presence of pots, sunlight, green landscapes, and access to private green spaces and the natural environment outside) with the level of depression, anger, anxiety, and insomnia. They found that the presence of flower pots in the house and green spaces outside the house reduced mental health problems in people during lockdown (27). During the pandemic, the green walls of buildings (especially during lockdown) played a small role in creating a sense of connection with nature and somehow increased the sense of freedom of older adults (45). In another survey conducted among 2,969 individuals in Scotland to investigate the level of psychological problems during the COVID-19 pandemic, researchers concluded that residents of urban areas, people living in deprived areas, those who do not have access to green spaces in their residential areas, and individuals who do not use green spaces outside of their homes have had more problems compared to those who live in rural areas (24).

In another study in Scotland, the effect of the following three variables was investigated: gardening in the garden, relaxing in the garden, using the garden before and after the COVID pandemic. According to the findings, older people in Scotland spent more time in the garden during the COVID-19 lockdown, and compared to before the lockdown, they reported better physical health, emotional health, mental health, and sleep quality (10).

During the COVID pandemic, the existence of small-scale green spaces has been very effective for mental activity as well as strengthening physical health, especially for older adults (10). Based on these regulations and guidelines regarding the presence of a home garden, such a space will be important for maintaining physical activity for older adults at home. Among the issues examined in long-term planning for design and construction laws are changing in the design and use of common residential spaces for residents. There are some short-term plans, such as allowing private use of open and green spaces on certain days for each family, which also had a positive impact (24). The report has shown that in the absence of a balcony or a backyard, the use of green spaces in the yard and the green spaces, especially the private garden available in the vicinity of the residence, has increased. Therefore, it is necessary to provide sufficient green space in the neighborhoods and the vicinity of the residential space (75). During the pandemic, the design of public space to provide sufficient green physical space in compliance with policies against the spread of infectious diseases has become particularly important to the effectiveness of these programs and green spaces (61).

There is a positive relationship between physical activity and the proximity, accessibility, size, quantity, and quality of urban green spaces [Coombes et al., 2010; Zhang et al., 2017; Klompmaker et al., 2018, as cited in Zwierzchowska et al. (76)]. The World Health Organization (WHO) recommends that adults engage in at least 150 min of physical activities per week to maintain physical and mental health, and during epidemics when those activities for older people are limited, home and outdoor exercises need to be replaced (35). However, unfortunately, during the COVID-19 pandemic, lockdown led to a decrease in physical activity levels among the older adult population worldwide, with important factors including an increase in sitting time and sedentary behavior, a decrease in metabolism, and a reduction in the number of walks taken and even using the green spaces.

To highlight the benefits of green spaces in older adults' lives in this narrative review, worth noting is that, during the pandemic, living in greener neighborhoods with more public green spaces can increase older people's willingness to engage in physical activities such as walking and cycling (29) as well as relaxation (65). Furthermore, individuals residing in greener areas have reported experiencing milder pandemic fatigue (29) and a lesser decline in physical activity and leisure time (50). Interestingly, there has been a significant increase in the number of individuals spending more than 2 h in these spaces after the pandemic, suggesting a preference for outdoor activities among residents. Additionally, there has been an observed rise in visits with multiple companions (65). Although increasing urban agriculture in city centers is challenging, urban farms can improve mental wellbeing by enabling residents to grow food within 100–250 m of their homes, particularly during pandemics (77). Seasonal and age-related factors have influenced the reported behavioral changes in visiting parks among older people during COVID-19. However, promoting older adults' wellbeing needs to incorporate available green networks, such as pocket parks and roof gardens, into residential neighborhoods (50). Nature-based solutions, including green infrastructure (GI), nature restoration, and forest landscape restoration, focusing on urban greening (UG), are also crucial for maintaining cities' health and wellbeing during crises. These nature-based infrastructure areas are vital for conservation and enhancement (66).

Having more benefits of green space during the pandemic depends on reducing transmission by design based on three crucial factors: the density of development and construction, the level of connectivity and design of green infrastructure, and the availability of urban green-blue spaces (48). To minimize the risk of disease transmission, it is necessary to create distance between green spaces to discourage individuals from choosing these spaces as alternative options. The selection of green spaces determines the potential for movement within the urban space network, reflecting people's inclination to use green spaces as destinations or pathways. Planners can reduce the degree of selection by designing green spaces in pedestrian-friendly areas rather than focusing solely on primary nodes and traffic links (25). Therefore, flexible policies are required to ensure access to green spaces at various scales, and monitoring exercise, either through regular visits or phone calls, can be effective in enhancing the benefits of exercising at home [Chen et al., 2021, as cited in Oliveira et al. (35)].

Furthermore, Poh et al. (78) have found that the risk of infection is lower in urban areas with forests and green spaces, while it is higher in areas with denser urbanization patterns, often indicating higher population accumulation. According to Zhang et al. (62), population density is the most significant factor in determining the risk of contamination, followed by traffic density. On the other hand, the distance from markets and commercial spaces has a lesser impact on the spread of the disease. Finally, Ye and Qiu (48) discovered that factors such as forest patches, forest edge density, and the proportion of green edges are associated with infectious disease risk, as green infrastructure, including tall trees, is critical in preventing disease transmission.

Our goal was to investigate the impact of green spaces on older adults' wellbeing during the COVID19 pandemic. In the next studies, these benefits and effects can be examined in different socio-economic and cultural conditions. It is also possible to check how the policies of different countries have responded to the needs of older people during the pandemic.