Health Analysis Division, Statistics Canada, Ottawa, Ontario.
Health Effects Institute, Boston, Massachusetts, United States.
Health Rep. 2021 May 19;32(5):3-14. doi: 10.25318/82-003-x202100500001-eng.
Residential greenness has been associated with health benefits, such as lower risk of mortality, cardiovascular disease, obesity, adverse birth outcomes and asthma and better psychological health. However, the variation in greenness across socioeconomic and demographic characteristics in urban areas of Canada has not been well documented.
Respondents to the 2016 Census long-form questionnaire were assigned estimates of exposure to residential greenness based on the mean Normalized Difference Vegetation Index (NDVI) (from 2012 or the most recent year available) within a 500 m buffer around their home, based on postal code. Census weights were used to determine differences in average exposure to greenness according to selected demographic and socioeconomic characteristics.
Mean residential greenness among the 5.3 million census respondents in urban Canada was 0.44 units of the NDVI (standard deviation = 0.18 units). Greenness was lower among immigrants (particularly recent immigrants), some groups designated as visible minorities (particularly people of Filipino ancestry), lower-income households and tenants (i.e., NDVI values ranging from 0.40 to 0.43 units). Greenness values were highest among White non-immigrants and higher-income households (i.e., NDVI values ranging from 0.46 to 0.47 units).
Given the potentially multifaceted role that greenness plays in health outcomes, the inequalities in residential greenness described here may contribute to producing or exacerbating existing health inequalities in the Canadian population.
住宅绿化与健康益处相关,例如降低死亡率、心血管疾病、肥胖、不良生育结果和哮喘的风险,以及改善心理健康。然而,加拿大城市地区的社会经济和人口特征的绿化差异尚未得到充分记录。
根据邮政编码,将 2016 年人口普查长表问卷的受访者的住所周围 500 米缓冲区的住宅绿化暴露量估计值分配给基于归一化差异植被指数(NDVI)(来自 2012 年或可用的最近一年)的平均值。使用人口普查权重来确定根据选定的人口统计学和社会经济特征,平均绿化暴露量的差异。
加拿大城市中 530 万普查受访者的平均住宅绿化为 NDVI 的 0.44 个单位(标准差=0.18 个单位)。移民(特别是新移民)、一些被指定为可见少数民族(特别是菲律宾裔)、低收入家庭和租户的绿化程度较低(即 NDVI 值范围从 0.40 到 0.43 个单位)。非移民白人、高收入家庭的绿化值最高(即 NDVI 值范围从 0.46 到 0.47 个单位)。
鉴于绿化在健康结果中可能具有多方面的作用,这里描述的住宅绿化不平等可能会导致或加剧加拿大人口中现有的健康不平等。