Associations of co-exposures to air pollution and noise with psychological stress in space and time: A case study in Beijing, China.

Air pollution and noise are both ubiquitous environmental stressors that pose great threats to public health. Emerging evidence has noticed the combined health risks caused by the coexistence of traffic-related air pollutants and noise in the residential context. However, less is known about how mobile individuals are simultaneously exposed to multiple sources of air pollution and noise, and thus respond with more acute psychological responses beyond the residence. This study examines the co-exposures to fine particles (PM2.5) and noise across spatiotemporal contexts where the concurrent exposures are jointly associated with momentary psychological stress. An innovative research protocol, including GPS-equipped activity-travel diaries, air pollutant and noise sensors, and ecological momentary assessment, was adopted to collect real-time data from a sample of residents in Beijing, China. The results showed a minor correlation between PM2.5 and noise exposures after accounting for individual mobility and the spatiotemporal dynamics of these two environmental pollutants. Further, exposure to PM2.5 was more associated with momentary psychological stress given the insignificant independent effect and the weak moderating effect of noise exposure. Three specific spatiotemporal contexts involving the health risks of co-exposures were delineated, including morning rush hours and traveling by public transits with intensified stress risks caused by combined exposures to air pollution and noise, workplaces with counteracting stress effect of both exposures, and evening time at home with stress-induced air pollution and stress-relieving social noise. In conclusion, the mobility-based and context-aware analysis provides a more nuanced understanding of the associations of co-exposures to environmental pollution and synchronous psychological stress in space and time.

An Integrated Individual Environmental Exposure Assessment System for Real-Time Mobile Sensing in Environmental Health Studies.

The effects of environmental exposure on human health have been widely explored by scholars in health geography for decades. However, recent advances in geospatial technologies, especially the development of mobile approaches to collecting real-time and high-resolution individual data, have enabled sophisticated methods for assessing people's environmental exposure. This study proposes an individual environmental exposure assessment system (IEEAS) that integrates objective real-time monitoring devices and subjective sensing tools to provide a composite way for individual-based environmental exposure data collection. With field test data collected in Chicago and Beijing, we illustrate and discuss the advantages of the proposed IEEAS and the composite analysis that could be applied. Data collected with the proposed IEEAS yield relatively accurate measurements of individual exposure in a composite way, and offer new opportunities for developing more sophisticated ways to measure individual environmental exposure. With the capability to consider both the variations in environmental risks and human mobility in high spatial and temporal resolutions, the IEEAS also helps mitigate some uncertainties in environmental exposure assessment and thus enables a better understanding of the relationship between individual environmental exposure and health outcomes.

Understanding the relationships among individual-based momentary measured noise, perceived noise, and psychological stress: A geographic ecological momentary assessment (GEMA) approach.

This study aims to understand how the relationship between individual-based noise exposure and psychological stress is influenced by perceived noise and context. Using geographic ecological momentary assessment, along with activity-travel diaries, GPS tracking, and portable noise sensors, this study collected real-time data of individuals' daily movement, noise exposure, and self-reported noise perception and psychological stress. Structural equation modeling was used to examine the direct and indirect pathways among context, momentary measured noise, perceived noise, and psychological stress. The study finds that momentary measured noise influences psychological stress through the mediating effect of perceived noise. Further, different activity and travel, social, and temporal contexts significantly influence people's momentary measured noise, perceived noise, and psychological stress. These findings advance our understanding of specific contexts, individual-based objectively measured and subjectively perceived environmental exposures, and their effects on psychological health at a high spatiotemporal resolution.

Assessing personal noise exposure and its relationship with mental health in Beijing based on individuals' space-time behavior.

BACKGROUND: Most prior studies adopted a static residence-based approach in the assessment of noise exposure, which may lead to biased exposure estimates and misleading findings in noise-health relationships. Relatively little is known about personal noise exposure based on individuals' space-time behavior and its effect on mental health. OBJECTIVES: This study aims to analyze and geo-visualize personal exposure to noise in various microenvironments based on individuals' space-time trajectories at a very fine resolution and to further investigate the relationships between mental health and personal noise exposure at both the activity/travel episode level and the entire day level. METHODS: Individual-level real-time data were collected with portable noise sensors and GPS trackers from a sample of 117 residents aged 18-60 years old from December 2017 to February 2018 in Beijing, China. Descriptive statistics and geo-visualization methods were used to examine how personal noise exposure varied across different activity types, travel modes, and among residents living in the same residential neighborhood on workdays and weekends based on individuals' space-time behaviors. Logistic regression models were applied to examine the relationships between personal noise exposure and self-reported mental health. RESULTS: We observed substantial differences in personal noise exposure across different activity types. The equivalent sound levels (Leq, dB(A)) for sleeping were the lowest, while the average Leq for work-related activities was the highest in indoor environments. The noise exposure levels for activities in outdoor environments were higher than indoor noise levels but differed between workdays and weekends. Variations in noise exposure associated with different travel modes were also evident, with the average Leq for public transport being much higher than that of other travel modes. A-weighted equivalent sound pressure level measured over 24 h for each individual (Leq,24h, dB(A)) varied significantly for residents living in the same residential neighborhood, ranging from 36 to 97 dB(A), with the majority of respondents being exposed to noise levels above 55 dB(A) on both workdays and weekends. Regarding the noise-health relationships, the modeling results showed that individual-level objective noise exposure based on space-time behaviors measured over a 24-h period (Leq,24h) was strongly associated with residents' self-reported mental health. Higher exposure to noise was significantly associated with worse mental health. However, personal noise exposure at the activity/travel episode level (Leq) was not significantly associated with mental health on weekdays, but this link turned out to be significant in the weekend model. CONCLUSIONS: There were large variations in personal noise exposure associated with different activity types and travel modes, and the individual-level noise exposure varied significantly across time of day and between residents living in the same residential neighborhood. Variations in personal exposure strongly depend on different space-time behaviors and individual-specific microenvironments experienced in daily life, and they were significantly correlated with mental health.

Seasonal mobility and well-being of older people: The case of 'Snowbirds' to Sanya, China.

Seasonal retired migrants have increased rapidly in developing countries in recent years. This article adopts a relational perspective to understand the relationships between older people's seasonal mobility and well-being. It shows that the complex spatiotemporal dynamics of seasonal mobility and the non-western sociocultural context influence older people's relations with their places of origin and destination, which in turn shape their well-being experiences during seasonal mobility. Narrative analysis of interview data from five pairs of 'snowbirds' to Sanya, China, reveals that seasonal mobility and well-being of older people are evolving processes, interwoven with risks and opportunities. Older people construct routinized daily activities, stable social relations, and peer-supporting and active-aging environments in their place of destination to maintain short-term well-being. However, they encounter difficulties in integrating the corporeal and social dimensions of their bodily experiences and constructing long-term well-being due to their separations from their lifelong relations in their places of origin. But overall, seasonal mobility creates alternative options for aging across multiple places and promotes leisure-oriented aging life.

Understanding seasonal mobilities, health and wellbeing to Sanya, China.

Both the ageing of the Chinese population and elderly mobility impact on the Chinese social infrastructure, triggering challenges to maintain elderly wellbeing. This paper reflects on the notion that seasonal mobility promotes wellbeing, and explores how two crucial factors, namely, forced migration and health conditions, influence the relations between seasonal retirement mobility and wellbeing. This study analyses amenity-led seasonal retired mobilities to Sanya as a case study, and adopts and develops a conceptual framework for relations between mobility and wellbeing in terms of daily activity, sociality, and context through seasonal mobility. Qualitative methods including participant observation, non-participant observation, in-depth interviews, and mobile ethnography were used to collect data. This revealed the heterogeneity of health conditions, and the constrained mobilities of seasonal retirees. Health and willingness for mobility are shown as significant factors in influencing the relations between mobility and wellbeing, which are in turn complicated and dynamic. Seasonal mobilities bring about difficulties for retirees particularly in terms of their efforts to reconstruct their previous life and self-continuities. However, it is argued that these retirees can merely maintain temporary and superficial wellbeing due to constant health concerns and uncertainties over potential temporary or permanent return to their places of origin. Those with serious health problems have more limitations, sacrificing other aspects of wellbeing for physical health. Practical implications from state, destination, and individual levels to better facilitate seasonal mobility and promote wellbeing are provided.