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.

长期以来，城市生活因其对人类状况和思想的负面影响而饱受诟病。从托马斯·杰斐逊 (Thomas Jefferson) 到埃米尔·涂尔干 (Emile Durkheim)，高密度城市生活作为一种需要纠正的失常现象，已成为现代城市讨论的一部分。虽然在二战后开始认真研究不想要的社会接触的精神影响的实证研究，而且我们现在对压力的环境原因有了很多了解，但城市密度增加对人类孤独和社会孤立的影响的证据仍然没有定论。我们采用高分辨率地理空间建​​筑环境暴露数据来检查 405,925 名英国生物银行队列参与者的居住密度与孤独和社会隔离之间的关联。在参与者的地理编码住宅的 1 公里和 2 公里住宅街道网络集水区内测量住宅单元密度。其他特定于健康的建筑环境（即街道层面的物理步行性、公共交通密度、最近道路的交通强度、到目的地的平均街道距离）和物理环境暴露（根据遥感数据建模的地形变化和绿地暴露) 也在个人层面进行了测量，在每个参与者的地理编码住宅的预先指定的流域内。我们发现在英国，每 1,000 单位/公里 在每个参与者的地理编码住宅的预先指定的流域内，还在个人层面测量了物理环境暴露（地形变异和绿地暴露，根据遥感数据建模）。我们发现在英国，每 1,000 单位/公里 在每个参与者的地理编码住宅的预先指定的流域内，还在个人层面测量了物理环境暴露（地形变异和绿地暴露，根据遥感数据建模）。我们发现在英国，每 1,000 单位/公里1 公里网络流域内住宅密度增加²与 2.8%（优势比：1.028，p = 0.0058）和 11.4％（OR：1.114，p < 0.0001）孤独和社会孤立的几率分别独立相关。这可以解释为孤独（社会隔离）的密度弹性，我们将其称为异常密度比（ADR）. 此外，就最低密度四分位数而言，第四四分位数与孤独和社会孤立的几率分别高出 14.4% 和 30.4%。这种关联在 2 公里的空间尺度上稍微更明显，表明在这种具有象征意义的城市病中可能存在尺度效应。独立屋的高密度与孤独和社会孤立呈负相关，而公寓的密度与这两种结果都呈正相关。在男性和退休人员中发现居住密度对孤独感的影响更显着，而对于社会孤立，在退休人员中观察到类似的影响。据我们所知，这是第一次使用大样本的个体（非生态）数据来衡量密度-孤独效应的研究，控制个人混杂因素并减轻绿色空间等环境因素。密度与孤独和社会孤立有关，独立于其他因素，这意味着城市设计和密度规划策略很重要；尤其是在郊区人口密集化加速的时代。