加拿大卫生部环境卫生科学与研究局Hong Chen团队研究了加拿大居民搬迁后暴露于环境细颗粒物和长期生存变化之间的相关性。相关论文于2021年10月8日发表在《英国医学杂志》上。
为了研究加拿大居民长期接触环境细颗粒物（PM2.5）与过早死亡之间的相关性，研究组进行了一项基于群体的准实验研究，招募了1996年、2001年和2006年在加拿大人口普查中的663100名年龄在25-89岁的受访者，他们在人口普查日前五年内一直居住在PM2.5水平较高或较低的地区，并在随后的五年内搬家。主要结局是自然死亡，次要结局是任何心脏代谢原因、任何呼吸原因和任何癌症原因的死亡。所有死亡结果均来自国家生命统计数据库。
使用与众多个人、社会经济、健康和环境相关的协变量相匹配的倾向得分技术，每个搬到不同PM2.5区域的参与者与最多三个搬到同一PM2.5区域的参与者相匹配。在从高PM2.5区域迁移到中等或低PM2.5区域的匹配组中，居住迁移与PM2.5年暴露量分别从10.6 μg/m3下降到7.4和5.0 μg/m3有关。相反，在从低PM2.5区域到中等或高PM2.5区域的匹配组中，年PM2.5暴露量从4.6 μg/m3增加到6.7和9.2 μg/m3。
搬家五年后，经历PM2.5暴露从高水平下降到中等水平的个体死亡率下降了6.8%。暴露于PM2.5大幅度下降的人群死亡率下降幅度更大。PM2.5暴露从低水平到高水平导致死亡率增加，但从低水平到中等水平增加的程度较低。此外，PM2.5暴露量的减少与心脏代谢死亡的减少密切相关，而PM2.5暴露量的增加主要与呼吸系统死亡有关。尚未发现PM2.5暴露变化与癌症相关死亡有关的强力证据。
研究结果表明，在加拿大，PM2.5的减少与较低的死亡率相关，而PM2.5的增加与较高的死亡率相关。这些结果是在PM2.5水平远低于许多其他国家的情况下观察到的，为持续改善空气质量提供了支持。
附：英文原文
Title: Changes in exposure to ambient fine particulate matter after relocating and long term survival in Canada: quasi-experimental study
Author: Hong Chen, Jay S Kaufman, Toyib Olaniyan, Lauren Pinault, Michael Tjepkema, Li Chen, Aaron van Donkelaar, Randall V Martin, Perry Hystad, Chen Chen, Megan Kirby-McGregor, Li Bai, Richard T Burnett, Tarik Benmarhnia
Issue&Volume: 2021/10/08
Abstract:
Objective To investigate the association between changes in long term residential exposure to ambient fine particulate matter (PM2.5) and premature mortality in Canada.
Design Population based quasi-experimental study.
Setting Canada.
Participants 663100 respondents to the 1996, 2001, and 2006 Canadian censuses aged 25-89 years who had consistently lived in areas with either high or low PM2.5 levels over five years preceding census day and moved during the ensuing five years.
Interventions Changes in long term exposure to PM2.5 arising from residential mobility.
Main outcome measures The primary outcome was deaths from natural causes. Secondary outcomes were deaths from any cardiometabolic cause, any respiratory cause, and any cancer cause. All outcomes were obtained from the national vital statistics database.
Results Using a propensity score matching technique with numerous personal, socioeconomic, health, and environment related covariates, each participant who moved to a different PM2.5 area was matched with up to three participants who moved within the same PM2.5 area. In the matched groups that moved from high to intermediate or low PM2.5 areas, residential mobility was associated with a decline in annual PM2.5 exposure from 10.6 μg/m3 to 7.4 and 5.0 μg/m3, respectively. Conversely, in the matched groups that moved from low to intermediate or high PM2.5 areas, annual PM2.5 increased from 4.6 μg/m3 to 6.7 and 9.2 μg/m3. Five years after moving, individuals who experienced a reduction in exposure to PM2.5 from high to intermediate levels showed a 6.8% (95% confidence interval 1.7% to 11.7%) reduction in mortality (2510 deaths in 56025 v 4925 deaths in 101960). A greater decline in mortality occurred among those exposed to a larger reduction in PM2.5. Increased mortality was found with exposure to PM2.5 from low to high levels, and to a lesser degree from low to intermediate levels. Furthermore, the decreases in PM2.5 exposure were most strongly associated with reductions in cardiometabolic deaths, whereas the increases in PM2.5 exposure were mostly related to respiratory deaths. No strong evidence was found for the changes in PM2.5 exposure with cancer related deaths.
Conclusions In Canada, decreases in PM2.5 were associated with lower mortality, whereas increases in PM2.5 were associated with higher mortality. These results were observed at PM2.5 levels considerably lower than many other countries, providing support for continuously improving air quality.
DOI: 10.1136/bmj.n2368
Source: https://www.bmj.com/content/375/bmj.n2368
BMJ-British Medical Journal:《英国医学杂志》，创刊于1840年。隶属于BMJ出版集团，最新IF：93.333
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本期文章：《英国医学杂志》：Online/在线发表
