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Background: The role of environmental exposures in chronic obstructive pulmonary disease (COPD) remains inconclusive. We examined the association between environmental exposures (PM 2·5 , greenness, and urbanicity) and COPD prevalence using the UK Biobank cohort data to identify key built environment correlates of COPD., Methods: In this cross-sectional, observational study we used baseline data for UK Biobank participants. Included participants were aged 39 years and older, white, had available spirometry data, and had complete data for phenotypes and exposures. COPD was defined by spirometry with the 2017 Global Initiative for Chronic Obstructive Lung Disease criteria. Environmental exposures were PM 2·5 derived from monitoring data and interpolated using land-use regression at the participants' geocoded residential addresses. Built environment metrics of residential greenness were modelled in terms of normalised difference vegetation index from remotely sensed colour infrared data within a 500 m residential catchment, and an urbanicity index derived from spatial analyses and measured with a 1 km buffer around each participant's residential address. Logistic regression models examined the associations between environmental exposures and COPD prevalence adjusting for a range of confounders. Subgroup analyses by urbanicity and effect modification by white blood cell count as an inflammatory marker were also done., Findings: We assessed 96 779 participants recruited between April 4, 2006, and Oct 1, 2010, of which 5391 participants had COPD with a prevalence of 5·6%. Each 10 μg/m 3 increment in ambient PM 2·5 exposure at a participant's residential location was associated with higher odds of COPD (odds ratio 1·55, 95% CI 1·14-2·10). Among the built environment metrics, urbanicity was associated with higher odds of COPD (1·05, 1·01-1·08 per interquartile increment), whereas residential greenness was protective, being associated with lower odds of COPD (0·89, 0·84-0·93 for each interquartile increment in greenness). The results remained consistent in models of COPD defined as per lower limit of normal criteria. The highest quartile of white blood cell count was associated with lower lung function and higher COPD risk with a significant interaction between PM 2·5 and white blood cell count only in the model of lung function (p=0·0003)., Interpretation: In this study of the built environment and COPD, to our knowledge the largest done in the UK, we found that exposure to ambient PM 2·5 and urbanicity were associated with a higher risk of COPD. Residing in greener areas, as measured by normalised difference vegetation index, was associated with lower odds of COPD, suggesting the potential value of urban planning and design in minimising or offsetting environmental risks for the prevention and management of COPD., Funding: University of Hong Kong, UK Biobank, and UK Economic & Social Research Council., (Copyright © 2019 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license. Published by Elsevier Ltd.. All rights reserved.)

Built environment factors, especially street-scale design and traffic casualties, are intrinsically interlinked. Starting from Alker Tripp's seminal ideas about city design, street morphology, and accident risk, this article summarizes results from an increasingly sophisticated line of enquiry at the boundaries between transport geography, network modeling, urban geography, and planning. It goes on to specify what we believe to be the most comprehensive study yet, based on five years' worth of road casualty data from London; GIS data on street morphology and physical features captured at a street-link unit of analysis; socio-economics and other determinants of accidents; and individual data about casualty victims. We test hypotheses about links between urban morphology and casualty severity using multi-level models with individual victim attributes at level-one, street-link morphology attributes (various measure of network connectivity) at level-two, and neighborhood descriptors at level-three. Results indicate that street-level morphology and design (expressed in terms of betweenness, divergence ratio, and hull radius), together with traffic volume and physical features of streets are all significantly associated with odds of “Killed and Seriously Injured” (KSI) causality incidents. We find the strongest evidence yet recorded that London's 20-MPH speed-restricted residential zones reduce the incidence of KSI; while neighborhood-level factors such as population density, deprivation of living environment, and access to services are also significant predictors of KSI indicating that selective urban territorial enclosure can save lives. [ABSTRACT FROM AUTHOR]

[Display omitted] • Examined associations of walkability and greenness with arterial stiffness. • Target sample comprised N = 169,704 UK Biobank cohort participants. • Both walkability and greenness were associated with lower arterial stiffness. • Greater inverse association with green in women, older adults, high walkable areas. Arterial stiffness is a key non-invasive marker of early vascular ageing, however, little is known of its associations with urban built environment. We examined the associations of objectively-measured residential walkability and greenness with arterial stiffness in a large UK-wide population cohort. We employed data from the baseline UK Biobank cohort comprising adult participants recruited over the period of 2006 to 2010. Residential walkability index, defined as a function of density (residential, retail and public transit), street-level design, and destination accessibility was measured using a 1-Km dwelling catchment, while greenness was modelled as the mean Normalized Difference Vegetation Index (NDVI) of 0.5-metre resolution assessed within a 0.5-Km catchment. Arterial stiffness index (ASI) was measured non-invasively from the pulse waveform. Linear regression models were developed to examine associations of walkability and greenness with arterial stiffness. Restricted cubic spline (RCS) models were developed to examine dose–response relationships. We also examined effect modifications by sex and age, as well as the interaction effect of greenness and walkability. This cross-sectional study used a target sample of 169,704 UK Biobank participants aged ≥ 39 years. After full adjustments, in reference to the lowest walkability exposure quartile, those in the highest were associated with lower ASI (β = −0.083 m/s, 95% CI: −0.14 to −0.03, p = 0.005). Participants in the third and fourth NDVI greenness exposure quartiles were also associated with lower ASI (β = −0.074 m/s, −0.14 to −0.01, p < 0.020 for the third and β = −0.293 m/s, −0.36 to −0.23, p < 0.001 for the fourth quartiles in reference to the first). The inverse association between NDVI greenness and ASI was more pronounced among women (p < 0.001), older adults (p = 0.011) and among participants in the highest walkability quartile (p < 0.001). Designing more walkable and greener residential environments can be a preventive intervention aimed at lowering the population distribution of vascular ageing and associated cardiovascular risks. [ABSTRACT FROM AUTHOR]

With increasing urbanisation, the role of urban density on mental wellbeing has gained importance. However, the evidence linking housing density, a fundamental attribute of urban built environment, with loneliness and social isolation has been scarce. We examined associations of neighbourhood housing density with loneliness and social isolation in a UK-wide cohort by using the high-resolution UK Biobank Urban Morphometric Platform (known as UKBUMP) database created by our team. We leveraged data from UK Biobank, a cohort of adult participants aged 37–73 years recruited between 2006 and 2010. Neighbourhood housing unit density was objectively measured within a walkable scale of 1km and 2km street catchments of participant's geocoded dwelling (equivalent to approximately a 10-min and 20-min walk). Other built environment factors, including density of public transport, traffic intensity of the nearest street, terrain variability, street-level physical walkability, and greenspace, were also modelled. A series of logistic regression models examined the associations of housing density with loneliness and social isolation after rigorous adjustments for built environment and sociodemographic covariates. Restricted cubic spline models were used to examine non-linear associations. We stratified analyses by sex and age. Ethical approval was received by the UK Biobank from the National Health Service National Research Ethics Service and data access for the study was approved by the UK Biobank Scientific Committee. Our study comprised 478 265 participants (260 641 [54·5%] of whom were women) with complete data on either outcome and housing density. 281 418 and 291 190 participants remained after full adjustment in models of loneliness and social isolation, respectively. Each 1000 units per km2 increment in housing density within a 1 km residential street catchment was independently associated with an increase of 3·7% (OR 1·037 [95% CI 1·02–1·05], p<0·0001) and 17·4% (1·174 [1·16–1·19], p<0·0001) in odds of loneliness and social isolation after full adjustment. The results remained consistent for a catchment of 2km. A non-linear dose-response was observed. The association between housing density and loneliness was more pronounced among participants aged 50–59 years (participants aged <50 years: OR 1·108 [95% CI 0·97–1.26], p=0·1171; 50–59 years: 1·188 [1·06–1·33], p=0·0023; ≥60 years: 1·114 [0·99–1·25], p=0·0646 for the highest housing density quartile vs the lowest; p interaction =0.0171) and among men (men: 1·235 [1·12–1·36], p<0·0001; women: 1·051 [0·96–1·16], p=0·3054 for the highest exposure quartile vs the lowest; p interaction <0·0001). Limitations included the cross-sectional study design, non-representativeness of the UK Biobank base population, and potential residual confounding. In a UK-wide study, we found that increased neighbourhood housing density was associated with increased odds of loneliness and social isolation. High density environments might exacerbate unwanted social contacts, resulting in higher social stress and reduced social connections. With more than 65% of the global population projected to reside in urban areas by 2050, strategic city planning achieved by optimising residential density might constitute a population-wide preventive approach for reducing burdens of loneliness and social isolation. Post-graduate research fellowship of the University of Hong Kong. [ABSTRACT FROM AUTHOR]

Urban life has long been pilloried in history for its negative effects on the human condition and mind. From Thomas Jefferson to Emile Durkheim, high density urban living as an aberration to be rectified has been part of the modern discourse on cities. While empirical studies into the psychiatric effects of unwanted social contact began in earnest after WW2 and we now know much about environmental causes of stress, the evidence of the impacts of increasing urban densification upon loneliness and social isolation in humans still remains inconclusive. We employed high-resolution geospatial built environment exposure data to examine associations between residential density and loneliness and social isolation among 405,925 UK Biobank cohort participants. Residential unit density was measured within a 1- and 2-Km residential street network catchment of participant's geocoded dwelling. Other health-specific built environment (i.e., street-level physical walkability, density of public transport, traffic intensity of the nearest road, mean street distance to destinations), and physical environment exposures (terrain variability and greenspace exposure modelled from remotely-sensed data) were also measured at individual-level, within pre-specified catchments of each participant's geocoded dwelling. We found for the UK, that every 1,000 units/km2 increment in residential density within a 1-Km network catchment was independently associated with a 2.8% (odds ratio: 1.028, p = 0.0058) and 11.4% (OR: 1.114, p < 0.0001) higher odds of loneliness and social isolation respectively. This can be interpreted as the density elasticity of loneliness (social isolation), which we coin as the Anomie Density Ratio (ADR). In addition, with reference to the lowest density quartile, the fourth-quartile was associated with 14.4% and 30.4% higher odds of loneliness and social isolation respectively. The associations were slightly more pronounced at spatial scale of 2-Km, indicating the possibility of a scale effect in this emblematic urban-ill. Higher density of detached housing was negatively associated with both loneliness and social isolation, while density of flats was positively associated with both outcomes. More pronounced effects of residential density on loneliness were identified among males and those retired, while for social isolation, similar effect was observed among the retired. As far as we know, this is the first study to measure the density-loneliness effect using individual (non-ecological) data on a large national sample, controlling for personal confounders and mitigating environmental factors such as green space. Density was associated with loneliness and social isolation independently of other factors, which means that urban design and density planning strategies matter; especially in an age of accelerating suburban densification. [ABSTRACT FROM AUTHOR]