Population Studies Division, Health Canada, Ottawa, ON, Canada.
Environ Res. 2012 May;115:51-8. doi: 10.1016/j.envres.2012.03.003. Epub 2012 Apr 6.
Parks and green space areas are important to human health for psychological and physiological reasons. There have been few evaluations of access to green space on mortality. This paper describes a cohort study of approximately 575,000 adults, 35 years of age and older, who resided in 10 urban areas in Ontario, Canada, between 1982 and 1986. Individuals were identified from income tax filings, and vital status was determined up to December 31, 2004 through record linkage to the Canadian Mortality Data Base. Place of residence was defined by postal code data that were extracted from income tax filings. Urban green space was defined by Landsat satellite retrievals with the Normalized Difference Vegetation Index and this was assigned to individuals' place of residence at inception into the cohort using both a 30 m grid cell and a 500 m buffer. The proportional hazards model was used to estimate rate ratios (RRs) and their corresponding 95% confidence intervals (CI) for selected underlying causes of death. The rate ratios were adjusted for income, marital status, ambient air pollution, and contextual neighborhood characteristics. About 187,000 subjects died during follow-up. An increase in the interquartile range of green space, using a 500 m buffer, was associated with reduced non-accidental mortality (RR=0.95, 95% CI=0.94-0.96). Reductions in mortality with increased residential green space were observed for each underlying cause of death; the strongest association was found for respiratory disease mortality (RR=0.91, 95% CI=0.89-0.93). Risk estimates were essentially unchanged after adjusting for ambient air pollution. Our study suggests that green space in urban environments was associated with long-term reduction in mortality although this finding should be interpreted cautiously as this association may be influenced by residual confounding of sociodemographic and lifestyle factors. Further research is needed to: confirm these findings, better understand the relationships between access to green space and behavioral risk factors for mortality, and identify what green space characteristics may confer the greatest health benefit.
公园和绿地对人类健康具有重要意义，无论是从心理还是生理方面来看。目前，关于绿地可达性与死亡率之间的关系评估较少。本文描述了一项对大约 575000 名成年人的队列研究，这些成年人年龄在 35 岁及以上，居住在加拿大安大略省的 10 个城市，时间为 1982 年至 1986 年。个人身份信息从所得税申报单中获取，截至 2004 年 12 月 31 日的生存状态通过与加拿大死亡率数据库的记录链接确定。居住地点根据从所得税申报单中提取的邮政编码数据来定义。城市绿地由陆地卫星检索的归一化差异植被指数来定义，并用 30 米栅格单元和 500 米缓冲区将其分配给队列中个体的居住地点。使用比例风险模型估计选定的潜在死因的死亡率比（RR）及其相应的 95%置信区间（CI）。RR 通过调整收入、婚姻状况、环境空气污染和背景邻里特征进行校正。在随访期间，约有 187000 人死亡。使用 500 米缓冲区，绿地范围每增加一个四分位间距，非意外死亡率降低（RR=0.95，95%CI=0.94-0.96）。随着居住绿地的增加，每种潜在死因的死亡率都有所下降；与呼吸道疾病死亡率的相关性最强（RR=0.91，95%CI=0.89-0.93）。调整环境空气污染因素后，风险估计基本保持不变。我们的研究表明，城市环境中的绿地与长期死亡率降低有关，尽管由于社会人口统计学和生活方式因素的残余混杂，这一发现应谨慎解释。需要进一步研究以：确认这些发现，更好地理解获得绿地与死亡率的行为风险因素之间的关系，并确定哪些绿地特征可能带来最大的健康益处。
