Social Epidemiology and Health Policy, Department of Family Medicine and Population Health, University of Antwerp, Campus Drie Eiken, Doornstraat 331, BE-2610, Wilrijk, Belgium.
Interface Demography (ID), Department of Sociology, Vrije Universiteit Brussel, Pleinlaan 2, BE-1050, Brussels, Belgium.
Environ Res. 2023 Jan 1;216(Pt 1):114517. doi: 10.1016/j.envres.2022.114517. Epub 2022 Oct 8.
Exposure to green spaces is associated with improved mental health and may reduce risk of suicide. Here, we investigate the association between long-term exposure to residential surrounding greenness and suicide mortality.
We used data from the 2001 Belgian census linked to mortality register data (2001-2011). We included all registered individuals aged 18 years or older at baseline (2001) residing in the five largest urban areas in Belgium (n = 3,549,514). Suicide mortality was defined using the tenth revision of the World Health Organisation International Classification of Diseases (ICD-10) codes X60-X84, Y10-Y34, and Y870. Surrounding greenness was measured using the Normalized Difference Vegetation Index (NDVI) within a 300 m and 1,000 m buffer around the residential address at baseline. To assess the association between residential surrounding greenness and suicide mortality, we applied Cox proportional hazards models with age as the underlying time scale. Models were adjusted for age, sex, living arrangement, migrant background, educational attainment, neighbourhood socio-economic position. We additionally explored potential mediation by residential outdoor nitrogen dioxide (NO) concentrations. Finally, we assessed potential effect modification by various socio-demographic characteristics of the population (sex, age, educational attainment, migrant background, and neighbourhood socio-economic position). Associations are expressed as hazard ratios and their 95% confidence intervals (CI) for an interquartile range (IQR) increase in residential surrounding greenness.
We observed a 7% (95%CI 0.89-0.97) and 6% (95%CI 0.90-0.98) risk reduction of suicide mortality for an IQR increase in residential surrounding greenness for buffers of 300 m and 1,000 m, respectively. Furthermore, this association was independent of exposure to NO. After stratification, the inverse association was only apparent among women, and residents of Belgian origin, and that it was stronger among residents aged 36 or older, those with high level of education, and residents of most deprived neighbourhoods.
Our results suggest that urban green spaces may protect against suicide mortality, but this beneficial effect may not be equally distributed across all strata of the population.
暴露于绿色空间与改善心理健康有关，并且可能降低自杀风险。在这里，我们研究了长期居住环境绿化与自杀死亡率之间的关系。
我们使用了 2001 年比利时人口普查与死亡率登记数据（2001-2011 年）相关联的数据。我们将基线（2001 年）时居住在比利时五个最大城市地区的所有 18 岁或以上的登记个体（n=3549514）都包括在内。自杀死亡率是使用世界卫生组织第十次修订的《国际疾病分类》（ICD-10）X60-X84、Y10-Y34 和 Y870 代码来定义的。在基线时，使用归一化差异植被指数（NDVI）在居住地址的 300 m 和 1000 m 缓冲区中测量周围的绿化。为了评估居住周围绿化与自杀死亡率之间的关系，我们应用了 Cox 比例风险模型，年龄是基本时间尺度。模型根据年龄、性别、居住安排、移民背景、教育程度、社区社会经济地位进行了调整。我们还探索了住宅外二氧化氮（NO）浓度潜在的中介作用。最后，我们评估了人口的各种社会人口特征（性别、年龄、教育程度、移民背景和社区社会经济地位）对潜在的效应修饰作用。关联表示为居住环境周围绿化每增加一个四分位距（IQR）的风险比及其 95%置信区间（CI）。
我们观察到，居住环境周围绿化每增加一个 IQR，300 m 和 1000 m 缓冲区的自杀死亡率分别降低了 7%（95%CI 0.89-0.97）和 6%（95%CI 0.90-0.98）。此外，这种关联独立于 NO 的暴露。分层后，这种反比关系仅在女性和比利时裔居民中显现，并且在年龄为 36 岁或以上、教育程度较高、以及居住在最贫困社区的居民中更为明显。
我们的结果表明，城市绿地可能有助于预防自杀死亡率，但这种有益效果可能不会在人口的所有阶层中均等分布。
