California Environmental Protection Agency, Office of Environmental Health Hazard Assessment, Oakland, California 94612, USA.
Environ Health Perspect. 2010 Mar;118(3):363-9. doi: 10.1289/ehp.0901181. Epub 2009 Oct 26.
Several studies have reported associations between long-term exposure to ambient fine particulate matter (PM) and cardiovascular mortality. However, the health impacts of long-term exposure to specific constituents of PM(2.5) (PM with aerodynamic diameter < or = 2.5 microm) have not been explored.
We used data from the California Teachers Study, a prospective cohort of active and former female public school professionals. We developed estimates of long-term exposures to PM(2.5) and several of its constituents, including elemental carbon, organic carbon (OC), sulfates, nitrates, iron, potassium, silicon, and zinc. Monthly averages of exposure were created using pollution data from June 2002 through July 2007. We included participants whose residential addresses were within 8 and 30 km of a monitor collecting PM(2.5) constituent data. Hazard ratios (HRs) were estimated for long-term exposure for mortality from all nontraumatic causes, cardiopulmonary disease, ischemic heart disease (IHD), and pulmonary disease.
Approximately 45,000 women with 2,600 deaths lived within 30 km of a monitor. We observed associations of all-cause, cardiopulmonary, and IHD mortality with PM(2.5) mass and each of its measured constituents, and between pulmonary mortality and several constituents. For example, for cardiopulmonary mortality, HRs for interquartile ranges of PM(2.5), OC, and sulfates were 1.55 [95% confidence interval (CI), 1.431.69], 1.80 (95% CI, 1.681.93), and 1.79 (95% CI, 1.582.03), respectively. Subsequent analyses indicated that, of the constituents analyzed, OC and sulfates had the strongest associations with all four outcomes.
Long-term exposures to PM(2.5) and several of its constituents were associated with increased risks of all-cause and cardiopulmonary mortality in this cohort. Constituents derived from combustion of fossil fuel (including diesel), as well as those of crustal origin, were associated with some of the greatest risks. These results provide additional evidence that reduction of ambient PM(2.5) may provide significant public health benefits.
多项研究报告了长期暴露于环境细颗粒物（PM）与心血管死亡率之间的关联。 然而，PM（2.5）（空气动力学直径≤2.5 微米的颗粒物）特定成分的长期暴露对健康的影响尚未得到探索。
我们使用了加利福尼亚教师研究的数据，这是一项针对在职和前女性公立学校专业人员的前瞻性队列研究。 我们估计了 PM（2.5）及其几种成分（包括元素碳、有机碳（OC）、硫酸盐、硝酸盐、铁、钾、硅和锌）的长期暴露水平。 每月暴露平均值是使用 2002 年 6 月至 2007 年 7 月的污染数据创建的。 我们纳入了其居住地址在距收集 PM（2.5）成分数据的监测器 8 至 30 公里范围内的参与者。 我们估计了长期暴露于所有非创伤性原因、心肺疾病、缺血性心脏病（IHD）和肺部疾病导致的死亡率的危险比（HRs）。
大约有 45000 名女性居住在距监测器 30 公里范围内，她们中有 2600 人死亡。 我们观察到 PM（2.5）质量及其所有测量成分与所有原因、心肺和 IHD 死亡率之间存在关联，并且与肺部死亡率与几种成分之间存在关联。 例如，对于心肺疾病死亡率，PM（2.5）、OC 和硫酸盐的四分位距 HR 分别为 1.55（95%置信区间[CI]，1.43-1.69）、1.80（95% CI，1.68-1.93）和 1.79（95% CI，1.58-2.03）。 随后的分析表明，在所分析的成分中，OC 和硫酸盐与所有四个结局的关联最强。
在该队列中，长期暴露于 PM（2.5）及其几种成分与全因和心肺疾病死亡率的增加风险相关。 源自化石燃料燃烧（包括柴油）的成分以及源自地壳的成分与一些最大的风险相关。 这些结果提供了额外的证据，表明减少环境 PM（2.5）可能会带来重大的公共健康益处。
