Air quality and mental health: evidence, challenges and future directions.

BACKGROUND: Poor air quality is associated with poor health. Little attention is given to the complex array of environmental exposures and air pollutants that affect mental health during the life course. AIMS: We gather interdisciplinary expertise and knowledge across the air pollution and mental health fields. We seek to propose future research priorities and how to address them. METHOD: Through a rapid narrative review, we summarise the key scientific findings, knowledge gaps and methodological challenges. RESULTS: There is emerging evidence of associations between poor air quality, both indoors and outdoors, and poor mental health more generally, as well as specific mental disorders. Furthermore, pre-existing long-term conditions appear to deteriorate, requiring more healthcare. Evidence of critical periods for exposure among children and adolescents highlights the need for more longitudinal data as the basis of early preventive actions and policies. Particulate matter, including bioaerosols, are implicated, but form part of a complex exposome influenced by geography, deprivation, socioeconomic conditions and biological and individual vulnerabilities. Critical knowledge gaps need to be addressed to design interventions for mitigation and prevention, reflecting ever-changing sources of air pollution. The evidence base can inform and motivate multi-sector and interdisciplinary efforts of researchers, practitioners, policy makers, industry, community groups and campaigners to take informed action. CONCLUSIONS: There are knowledge gaps and a need for more research, for example, around bioaerosols exposure, indoor and outdoor pollution, urban design and impact on mental health over the life course.

How Does Living in Temporary Accommodation and the COVID-19 Pandemic Impact under 5s' Healthcare Access and Health Outcomes? A Qualitative Study of Key Professionals in a Socially and Ethnically Diverse and Deprived Area of London.

Background: Children < 5 years living in temporary accommodation (U5TA) are vulnerable to poor health outcomes. Few qualitative studies have examined service provider perspectives in family homelessness; none have focused on U5TA with a cross-sector approach. This study explored professionals' perspectives of the barriers and facilitators, including pandemic-related challenges, experienced by U5TA in accessing healthcare and optimising health outcomes, and their experiences in delivering services. Methods: Sixteen semi-structured online interviews were conducted. Professionals working in Newham (London) with U5TA families were recruited from non-profit organisations, the health sector, and Local Authority. A thematic analysis was conducted. Findings: Professionals described barriers including poor parental mental health; unsuitable housing; no social support; mistrust of services; immigration administration; and financial insecurity. Digital poverty, language discordance, and the inability to register and track U5TA made them even less visible to services. Professionals tried to mitigate barriers with improved communication, and through community facilitators. Adverse pandemic effects on U5TA health included delay and regression in developmental milestones and behaviours. In-person services were reduced, exacerbating pre-existing barriers. Interpretation: COVID-19 further reduced the ability of professionals to deliver care to U5TA and significantly impacted the lives of U5TA with potential life-long risks. Innovative and tailored cross-sector strategies are needed, including co-production of public health services and policies focusing on early development, mental health support, employment training, and opportunities for parents/carers.

Exploring the Interactions between Housing and Neighbourhood Environments for Enhanced Child Wellbeing: The Lived Experience of Parents Living in Areas of High Child Poverty in England, UK.

Children's health can be affected by the interrelated characteristics of the physical and social environment where they live, including housing quality, neighbourhood characteristics and the local community. Following a systems-based approach, this exploratory project sought to understand how the needs and aspirations associated with the home environment can work in synergy with, or be exacerbated by, other aspects of the local area. The study recruited parents of children aged 2-12 years old from two local authorities in England with high levels of child poverty: Tower Hamlets in East London, and Bradford District in West Yorkshire. Thematic analysis of participant interviews highlighted ten themes and opportunities for improvements. The evidence presented in this research emphasises how environmental quality issues within and outside the home, compounded further by delays in repairs and reduction in service standards, as well as affordability issues, are likely to deeply affect the wellbeing of an entire generation of disadvantaged children whose parents can feel disempowered, neglected and often isolated when attempting to tackle various dimensions of inequalities. Interventions which can improve the quality of housing, and access to space and services, are urgently needed, including initiatives to support and empower families and local communities, especially those prioritising opportunities for action.

A Citizen Science Approach to Identifying Indoor Environmental Barriers to Optimal Health for under 5s Experiencing Homelessness in Temporary Accommodation.

The first five years of life are critical for optimal growth, health, and cognitive development. Adverse childhood experiences, including experiencing homelessness, can be a risk factor for multiple health issues and developmental challenges. There is a dearth of data collected with and by families with children under age five living in temporary accommodation due to experiencing homelessness (U5TA) describing indoor environmental barriers that prevent U5TA from achieving and maintaining optimal health. The aim of this study was to address this current gap using a citizen science approach. Fifteen participants, who were mothers of U5TA living in a deprived area of London, and the lead researcher collected data in late 2019/early 2020 using: (I) a housing survey conducted via a mobile app; (II) house visits; and (III) collaborative meetings. Data were analyzed using thematic analysis. Key themes included: overcrowding/shared facilities, dampness/mold growth, poor/inadequate kitchen/toilet facilities, infestations/vermin, structural problems/disrepair, unsafe electrics, excessively cold temperatures, and unsafe surfaces that risk causing trips/falls, with all participants experiencing multiple concurrent indoor environmental barriers. The citizen science approach was successfully used to collect meaningful data demonstrating the need for child-centered housing policies meeting the needs of current and future generations of families living in TA.

Effects of thermal sensation and acclimatization on cognitive performance of adult female students in Saudi Arabia using multivariable-multilevel statistical modeling.

In the hot climate of Saudi Arabia, people living year-round in air-conditioned spaces are likely to develop high expectations for homogeneity and cool temperatures, becoming potentially more sensitive if thermal conditions deviate from the comfort zone they expect. This paper presents the results from a field intervention investigating the association between participants' thermal sensations with cognitive performance in a female university in Saudi Arabia. The climatic context plays a key role in choosing Saudi Arabia, whereas the total reliance on air-conditioners (AC) for cooling is believed to have significant effects on occupants' perceptions of the comfort temperature. Results reveal discrepancies in the actual thermal sensations between the Saudi and non-Saudi participants which affected their performances. "Cool" and "Slightly Cool" sensations versus neutral were associated with significant lower percentage of errors and significant higher speed for all participants independently of any association with ethnicity and acclimatization. The estimates remained significant even after adjusting for ethnicity and the number of years spent in the country and the set temperature of AC at home. Implications of the study suggest a preference for staying cool when working independently of acclimatization status.

Combined effects of ventilation rates and indoor temperatures on cognitive performance of female higher education students in a hot climate.

Impairment in mental functions attributed to the effects of indoor air quality and thermal conditions has received considerable attention in the past decade, particularly for educational buildings where students' cognitive performance is essential to foster learning. This study explores the combined effects of indoor temperatures and CO2  levels as markers for ventilation rates on cognitive performance among female students (16-23 years old) in Saudi Arabia. The longitudinal experiments involved nine conditions combining three CO2 concentration levels (achieved via changes in ventilation) and three temperature levels involving 499 participants, all exposed to the nine conditions. The study implemented a computer-based cognitive performance battery with "9Button" keyboards. Univariable and multivariable multilevel regression models explored the association of indoor temperature and CO2  levels (as markers for ventilation rates) with cognitive performance after adjusting for potential confounders. Potential benefits were found on speed and accuracy of tasks of cognitive performance when indoor temperature was set between 20 and 23ºC and at CO2  levels of 600 ppm compared to higher temperatures and poorer ventilation rates and that both ventilation and thermal environmental control are important and need to be improved for achieving optimum learning conditions. Nevertheless, the results are relevant for short-term exposures lasting no more than 2 h.

How did living in temporary accommodation during the COVID-19 pandemic affect children younger than 5 years' access to health care and health outcomes? A qualitative study of key professionals in a socially and ethnically diverse and deprived area of London.

BACKGROUND: Children younger than 5 years living in temporary accommodation due to homelessness (U5TA) are extremely vulnerable to the effects of the COVID-19 pandemic. Few qualitative studies have examined provider perspectives in family homelessness, but none focused on U5TA specifically. We aimed to qualitatively explore professionals' perspectives of pandemic-related challenges and barriers experienced by U5TA in accessing health care and optimising health outcomes, and their experiences of delivering U5TA services. METHODS: 16 semi-structured interviews were done online. Professionals working in the London Borough of Newham with U5TA families were purposively sampled and recruited from non-profit organisations, the health sector, and local authority. A thematic codebook approach was used to analyse the data combining inductive and deductive codes using an adapted socioecological model as a guiding theoretical framework. FINDINGS: Two non-profit organisation professionals, seven health visitors, one GP, therapist, dietician, nurse, public health consultant, and two social workers from the local authority's No Recourse to Public Funds team described adverse pandemic effects on U5TA health: delay and regression in developmental milestones and behaviours-eg, toileting, feeding skills, emotional regulation, and social-communication skills. Pre-existing systemic barriers were exacerbated during the pandemic when the reduction of in-person services with professionals necessitated remote delivery of health and social care services. Differential effects of digital poverty, language discordance, and inability to register and track U5TA rendered this population invisible to services. Professionals highly agreed that barriers to optimal health outcomes and service access included poor mental health, unsuitable housing, no social support, mistrust of mainstream services, immigration administration, financial insecurity, and loss of informal jobs among U5TA families. Professionals sometimes mitigated these barriers with good communication skills, developing trusting relations, and through community facilitators. INTERPRETATION: COVID-19 widened health inequalities and inequities, substantially affecting the lives of U5TA and ability of professionals to deliver quality care to U5TA. Innovative and tailored cross-sector strategies, including co-production of public health services, are required. Policies and services urgently need to focus on early development, mental health support, employment training, and opportunities for parents and carers, plus unambiguous definitions of what is deemed suitable accommodation and actionable planned steps to ensure enforcement. FUNDING: None.

Can Exhaled Carbon Monoxide Be Used as a Marker of Exposure? A Cross-Sectional Study in Young Adults.

Carbon monoxide (CO) poisoning is a major public health issue worldwide. People are exposed to CO in their daily lives, with one of the common sources of CO being cigarette smoking. Inhalation of CO leads to elevated carboxyhaemoglobin (COHb) levels in the blood and also in exhaled CO concentration. Several factors have been shown to affect COHb concentration and COHb half-life. However, factors affecting exhaled CO concentration and exhaled CO half-life are not well understood. The present study aimed to investigate the potential factors related to baseline exhaled CO concentration and exhaled CO half-life among smokers. A cross-sectional study was conducted between 26 January and 30 June 2019, and young adults were recruited into the study. A total of 74 participants (mean age: 27.1 years, 71.6% males and 28.4% females) attended the study. They were invited to complete a questionnaire, including demographic, physiological, and behavioural factors. Then, exhaled CO measurements were taken. These measurements were taken before and after smoking a single cigarette for smokers and only once for non-smokers. The average baseline exhaled CO concentration was 6.9 ± 4.9 ppm for smokers and 1.9 ± 0.5 ppm for non-smokers. The mean of exhaled CO half-life was around 273.3 min (4.6 h) for smokers. No difference was seen in exhaled CO half-life between light smokers and heavy smokers in the smoking group. Gender and cigarettes smoked weekly affected baseline exhaled CO in smokers. Even though height seemed to positively associate with exhaled CO half-life, the relationship disappeared when adjusting by gender and weight. Therefore, exhaled CO could be used as a marker of CO exposure, but we cannot ignore the factors mentioned in the study. For future study, considering factors related to smoking habits and smoking style are recommended as these may affect total inhaled CO.

Measuring the Built Environment in Studies of Child Health-A Meta-Narrative Review of Associations.

Although the built environment (BE) is important for children's health, there is little consensus about which features are most important due to differences in measurement and outcomes across disciplines. This meta-narrative review was undertaken by a multi-disciplinary team of researchers to summarise ways in which the BE is measured, and how this links to children's health. A structured search of four databases across the relevant disciplines retrieved 108 relevant references. The most commonly addressed health-related outcomes were active travel, physical activity and play, and obesity. Many studies used objective (GIS and street audits) or standardised subjective (perceived) measurements of the BE. However, there was a wide variety, and sometimes inconsistency, in their definition and use. There were clear associations between the BE and children's health. Objective physical activity and self-reported active travel, or obesity, were positively associated with higher street connectivity or walkability measures, while self-reported physical activity and play had the strongest association with reduced street connectivity, indicated by quieter, one-way streets. Despite the high heterogeneity found in BE measures and health outcomes, the meta-narrative approach enabled us to identify ten BE categories that are likely to support children's health and be protective against some non-communicable disease risk factors. Future research should implement consistent BE measures to ensure key features are explored. A systems approach will be particularly relevant for addressing place-based health inequalities, given potential unintended health consequences of making changes to the BE.

School Flexible Learning Spaces, Student Movement Behavior and Educational Outcomes among Adolescents: A Mixed-Methods Systematic Review.

BACKGROUND: To achieve sustainability, we must consider scalable improvements in student movement behavior in the classroom setting, educational priorities. Flexible learning spaces that employ student-centered pedagogy and contain a range of furniture and layout options, implemented to improve educational outcomes, may enable unintended health benefits. In this review, we summarize the evidence on the effects of flexible learning spaces on adolescent student movement behaviors and educational outcomes. METHODS: We searched 5 databases, retrieving 5 quantitative and one qualitative article meeting the review criteria. RESULTS: Students in flexible learning spaces spent less time sitting, and more time standing and moving. Students were also more engaged, on-task, and collaborated and interacted more. Academic results for English, Mathematics and Humanities for those in flexible learning spaces were higher than peers in traditional classrooms. CONCLUSION: Evidence from the reviewed studies suggests that there may be beneficial outcomes across some movement behaviors as well as learning outcomes in classrooms that employ student-centered pedagogy and use a built environment that facilitates autonomy and choice around where and how to learn. These learning environments present an opportunity for an interdisciplinary approach to address sedentary behavior in classrooms.

ActEarly: a City Collaboratory approach to early promotion of good health and wellbeing.

Economic, physical, built, cultural, learning, social and service environments have a profound effect on lifelong health. However, policy thinking about health research is dominated by the 'biomedical model' which promotes medicalisation and an emphasis on diagnosis and treatment at the expense of prevention. Prevention research has tended to focus on 'downstream' interventions that rely on individual behaviour change, frequently increasing inequalities. Preventive strategies often focus on isolated leverage points and are scattered across different settings. This paper describes a major new prevention research programme that aims to create City Collaboratory testbeds to support the identification, implementation and evaluation of upstream interventions within a whole system city setting. Prevention of physical and mental ill-health will come from the cumulative effect of multiple system-wide interventions. Rather than scatter these interventions across many settings and evaluate single outcomes, we will test their collective impact across multiple outcomes with the goal of achieving a tipping point for better health. Our focus is on early life (ActEarly) in recognition of childhood and adolescence being such critical periods for influencing lifelong health and wellbeing.

Occupational Physical Activity Habits of UK Office Workers: Cross-Sectional Data from the Active Buildings Study.

Habitual behaviours are learned responses that are triggered automatically by associated environmental cues. The unvarying nature of most workplace settings makes workplace physical activity a prime candidate for a habitual behaviour, yet the role of habit strength in occupational physical activity has not been investigated. Aims of the present study were to: (i) document occupational physical activity habit strength; and (ii) investigate associations between occupational activity habit strength and occupational physical activity levels. A sample of UK office-based workers (n = 116; 53% female, median age 40 years, SD 10.52) was fitted with activPAL accelerometers worn for 24 h on five consecutive days, providing an objective measure of occupational step counts, stepping time, sitting time, standing time and sit-to-stand transitions. A self-report index measured the automaticity of two occupational physical activities (“being active” (e.g., walking to printers and coffee machines) and “stair climbing”). Adjusted linear regression models investigated the association between occupational activity habit strength and objectively-measured occupational step counts, stepping time, sitting time, standing time and sit-to-stand transitions. Eighty-one per cent of the sample reported habits for “being active”, and 62% reported habits for “stair climbing”. In adjusted models, reported habit strength for “being active” were positively associated with average occupational sit-to-stand transitions per hour (B = 0.340, 95% CI: 0.053 to 0.627, p = 0.021). “Stair climbing” habit strength was unexpectedly negatively associated with average hourly stepping time (B = −0.01, 95% CI: −0.01 to −0.00, p = 0.006) and average hourly occupational step count (B = −38.34, 95% CI: −72.81 to −3.88, p = 0.030), which may reflect that people with stronger stair-climbing habits compensate by walking fewer steps overall. Results suggest that stair-climbing and office-based occupational activity can be habitual. Interventions might fruitfully promote habitual workplace activity, although, in light of potential compensation effects, such interventions should perhaps focus on promoting moderate-intensity activity.

Associations between the Objectively Measured Office Environment and Workplace Step Count and Sitting Time: Cross-Sectional Analyses from the Active Buildings Study.

Office-based workers spend a large proportion of the day sitting and tend to have low overall activity levels. Despite some evidence that features of the external physical environment are associated with physical activity, little is known about the influence of the spatial layout of the internal environment on movement, and the majority of data use self-report. This study investigated associations between objectively-measured sitting time and activity levels and the spatial layout of office floors in a sample of UK office-based workers. Participants wore activPAL accelerometers for at least three consecutive workdays. Primary outcomes were steps and proportion of sitting time per working hour. Primary exposures were office spatial layout, which was objectively-measured by deriving key spatial variables: 'distance from each workstation to key office destinations', 'distance from participant's workstation to all other workstations', 'visibility of co-workers', and workstation 'closeness'. 131 participants from 10 organisations were included. Fifty-four per cent were female, 81% were white, and the majority had a managerial or professional role (72%) in their organisation. The average proportion of the working hour spent sitting was 0.7 (SD 0.15); participants took on average 444 (SD 210) steps per working hour. Models adjusted for confounders revealed significant negative associations between step count and distance from each workstation to all other office destinations (e.g., B = -4.66, 95% CI: -8.12, -1.12, p < 0.01) and nearest office destinations (e.g., B = -6.45, 95% CI: -11.88, -0.41, p < 0.05) and visibility of workstations when standing (B = -2.35, 95% CI: -3.53, -1.18, p < 0.001). The magnitude of these associations was small. There were no associations between spatial variables and sitting time per work hour. Contrary to our hypothesis, the further participants were from office destinations the less they walked, suggesting that changing the relative distance between workstations and other destinations on the same floor may not be the most fruitful target for promoting walking and reducing sitting in the workplace. However, reported effect sizes were very small and based on cross-sectional analyses. The approaches developed in this study could be applied to other office buildings to establish whether a specific office typology may yield more promising results.

Supportive environments for physical activity in deprived communities in the United Kingdom: A qualitative study using photo elicitation.

The health benefits of regular physical activity are substantial and well-established. However, population activity levels are insufficient to obtain health benefits in the United Kingdom (UK), and strategies to increase activity, particularly in income-deprived communities, are sought. Socioecological models of physical activity posit that activity levels are influenced by social, physical and wider environmental factors. In line with a growing evidence base, there is a need to understand the factors that contribute to an activity-supportive neighbourhood within deprived settings within the UK. This study used photo-elicitation qualitative interviews to explore environmental facilitators and barriers to neighbourhood-based, outdoor physical activity in 23 adults living in two income-deprived neighbourhoods in Glasgow, UK. Data were collected between June and October 2015, and were explored using thematic analysis. Five themes were identified: 'diversity of destinations in the neighbourhood', 'provision of services to support healthy environments', 'ownership of public space and facilities to encourage physical activity', 'collective control of public space to prevent disorder' and 'perceived value of the neighbourhood'. Findings highlighted the close interaction between these themes and more broadly between social and physical facets of neighbourhood environments that were unsupportive of physical activity. Discourse about economic aspects was pervasive and emerged as deeply affecting characteristics of the social and physical environment and upstream influences on physical activity. This study supports evidence that multi-faceted interventions addressing aspects of the social, physical and economic environment may be needed to support outdoor physical activity in deprived communities.

Cross-sectional interactions between quality of the physical and social environment and self-reported physical activity in adults living in income-deprived communities.

BACKGROUND: Understanding the environmental determinants of physical activity in populations at high risk of inactivity could contribute to the development of effective interventions. Socioecological models of activity propose that environmental factors have independent and interactive effects of physical activity but there is a lack of research into interactive effects. OBJECTIVES: This study aimed to explore independent and interactive effects of social and physical environmental factors on self-reported physical activity in income-deprived communities. METHODS: Participants were 5,923 adults in Glasgow, United Kingdom. Features of the social environment were self-reported. Quality of the physical environment was objectively-measured. Neighbourhood walking and participation in moderate physical activity [MPA] on ≥5 days/week was self-reported. Multilevel multivariate logistic regression models tested independent and interactive effects of environmental factors on activity. RESULTS: 'Social support' (walking: OR:1.22,95%CI = 1.06-1.41,p<0.01; MPA: OR:0.79,95%CI = 0.67-0.94,p<0.01), 'social interaction' (walking: OR:1.25,95%CI = 1.10-1.42,p<0.01; MPA: OR:6.16,95%CI = 5.14-7.37,p<0.001) and 'cohesion and safety' (walking: OR:1.78,95%CI = 1.56-2.03,p<0.001; MPA: OR:1.93,95%CI = 1.65-2.27,p<0.001), but not 'trust and empowerment', had independent effects on physical activity. 'Aesthetics of built form' (OR:1.47,95%CI = 1.22-1.77,p<0.001) and 'aesthetics and maintenance of open space' (OR:1.32, 95%CI = 1.13-1.54,p<0.01) were related to walking. 'Physical disorder' (OR:1.63,95%CI = 1.31-2.03,p<0.001) had an independent effect on MPA. Interactive effects of social and physical factors on walking and MPA were revealed. CONCLUSIONS: Findings suggest that intervening to create activity-supportive environments in deprived communities may be most effective when simultaneously targeting the social and physical neighbourhood environment.

Simultaneous evaluation of physical and social environmental correlates of physical activity in adults: A systematic review.

BACKGROUND: Ecological models of physical activity posit that social and physical environmental features exert independent and interactive influences on physical activity, but previous research has focussed on independent influences. This systematic review aimed to synthesise the literature investigating how features of neighbourhood physical and social environments are associated with physical activity when both levels of influence are simultaneously considered, and to assess progress in the exploration of interactive effects of social and physical environmental correlates on physical activity. METHODS: A systematic literature search was conducted in February 2016. Articles were included if they used an adult (≥15 years) sample, simultaneously considered at least one physical and one social environmental characteristic in a single statistical model, used self-reported or objectively-measured physical activity as a primary outcome, reported findings from quantitative, observational analyses and were published in a peer-reviewed journal. Combined measures including social and physical environment items were excluded as they didn't permit investigation of independent and interactive social and physical effects. Forty-six studies were identified. RESULTS: An inconsistent evidence base for independent environmental correlates of physical activity was revealed, with some support for specific physical and social environment correlates. Most studies found significant associations between physical activity and both physical and social environmental variables. There was preliminary evidence that physical and social environmental variables had interactive effects on activity, although only 4 studies examined interactive effects. CONCLUSIONS: Inconsistent evidence of independent associations between environmental variables and physical activity could be partly due to unmeasured effect modification (e.g. interactive effects) creating unaccounted variance in relationships between the environment and activity. Results supported multiple levels of environmental influence on physical activity. It is recommended that further research uses simultaneous or interaction analyses to gain insight into complex relationships between neighbourhood social and physical environments and physical activity, as there is currently limited research in this area.

Indoor Tracking to Understand Physical Activity and Sedentary Behaviour: Exploratory Study in UK Office Buildings.

Little is known of the patterns of physical activity, standing and sitting by office workers. However, insight into these behaviours is of growing interest, notably in regard to public health priorities to reduce non-communicable disease risk factors associated with high levels of sitting time and low levels of physical activity. With the advent and increasing availability of indoor tracking systems it is now becoming possible to build detailed pictures of the usage of indoor spaces. This paper reports initial results of indoor tracking used in conjunction with the ActivPAL activity monitoring device. In this paper we give an overview of the usage of the tracking system and its installation and illustrate some of the resultant data. We also provide preliminary results that investigate the relationship between location, light physical activity and sitting in a small sample of office workers (n=33) from two separate office environments in order to demonstrate the relevance and explanatory power of the technique.

Weekday and weekend patterns of objectively measured sitting, standing, and stepping in a sample of office-based workers: the active buildings study.

BACKGROUND: There is a growing body of research into the total amount and patterns of sitting, standing and stepping in office-based workers and few studies using objectively measured sitting and standing. Understanding these patterns may identify daily times opportune for interventions to displace sitting with activity. METHODS: A sample of office-based workers (n = 164) residing in England were fitted with thigh-worn ActivPal accelerometers and devices were worn 24 hours a day for five consecutive days, always including Saturday and Sunday and during bathing and sleeping. Daily amounts and patterns of time spent sitting, standing, stepping and step counts and frequency of sit/stand transitions, recorded by the ActivPal accelerometer, were reported. RESULTS: Total sitting/standing time was similar on weekdays (10.6/4.1 hrs) and weekends (10.6/4.3 hrs). Total step count was also similar over weekdays (9682 ± 3872) and weekends (9518 ± 4615). The highest physical activity levels during weekdays were accrued at 0700 to 0900, 1200 to 1400, and 1700 to 1900; and during the weekend at 1000 to 1700. During the weekday the greatest amount of sitting was accrued at 0900 to 1200, 1400 to 1700, and 2000 to 2300, and on the weekend between 1800 and 2300. During the weekday the greatest amount of standing was accrued between 0700 and 1000 and 1700 and 2100, and on the weekend between 1000 and 1800. On the weekday the highest number of sit/stand transitions occurred between 0800 to 0900 and remained consistently high until 1800. On the weekend, the highest number occurred between 1000 to 1400 and 1900 to 2000. CONCLUSION: Office based-workers demonstrate high levels of sitting during both the working week and weekend. Interventions that target the working day and the evenings (weekday and weekend) to displace sitting with activity may offer most promise for reducing population levels of sedentary behaviour and increasing physical activity levels, in office-based workers residing in England.

Active buildings: modelling physical activity and movement in office buildings. An observational study protocol.

INTRODUCTION: Health benefits of regular participation in physical activity are well documented but population levels are low. Office layout, and in particular the number and location of office building destinations (eg, print and meeting rooms), may influence both walking time and characteristics of sitting time. No research to date has focused on the role that the layout of the indoor office environment plays in facilitating or inhibiting step counts and characteristics of sitting time. The primary aim of this study was to investigate associations between office layout and physical activity, as well as sitting time using objective measures. METHODS AND ANALYSIS: Active buildings is a unique collaboration between public health, built environment and computer science researchers. The study involves objective monitoring complemented by a larger questionnaire arm. UK office buildings will be selected based on a variety of features, including office floor area and number of occupants. Questionnaires will include items on standard demographics, well-being, physical activity behaviour and putative socioecological correlates of workplace physical activity. Based on survey responses, approximately 30 participants will be recruited from each building into the objective monitoring arm. Participants will wear accelerometers (to monitor physical activity and sitting inside and outside the office) and a novel tracking device will be placed in the office (to record participant location) for five consecutive days. Data will be analysed using regression analyses, as well as novel agent-based modelling techniques. ETHICS AND DISSEMINATION: The results of this study will be disseminated through peer-reviewed publications and scientific presentations. Ethical approval was obtained through the University College London Research Ethics Committee (Reference number 4400/001).