Abstract

Background:

We do not currently understand how spatiotemporal variations in the composition of fine particulate air pollution [fine particulate matter with aerodynamic diameter $\le 2.5\mathrm{\mu }\mathrm{m}$ (${\mathrm{PM}}_{2.5}$)] affects population health risks. However, recent evidence suggests that joint concentrations of transition metals and sulfate may influence the oxidative potential (OP) of ${\mathrm{PM}}_{2.5}$ and associated health impacts.

Objectives:

The purpose of the study was to evaluate how combinations of transition metals/OP and sulfur content in outdoor ${\mathrm{PM}}_{2.5}$ influence associations with acute cardiovascular events.

Methods:

We conducted a national case-crossover study of outdoor ${\mathrm{PM}}_{2.5}$ and acute cardiovascular events in Canada between 2016 and 2017 (93,344 adult cases). Monthly mean transition metal and sulfur (S) concentrations in ${\mathrm{PM}}_{2.5}$ were determined prospectively along with estimates of OP using acellular assays for glutathione (${\text{OP}}^{\text{GSH}}$), ascorbate (${\text{OP}}^{\text{AA}}$), and dithiothreitol depletion (${\text{OP}}^{\text{DTT}}$). Conditional logistic regression models were used to estimate odds ratios (OR) [95% confidence intervals (CI)] for ${\mathrm{PM}}_{2.5}$ across strata of transition metals/OP and sulfur.

Results:

Among men, the magnitudes of observed associations were strongest when both transition metal and sulfur content were elevated. For example, an OR of 1.078 (95% CI: 1.049, 1.108) (per ${10\mathrm{\mu }\mathrm{g}/\mathrm{m}}^3$) was observed for cardiovascular events in men when both copper and S were above the median, whereas a weaker association was observed when both elements were below median values ($\text{OR}=1.019$, 95% CI: 1.007, 1.031). A similar pattern was observed for OP metrics. ${\mathrm{PM}}_{2.5}$ was not associated with acute cardiovascular events in women.

Discussion:

The combined transition metal and sulfur content of outdoor ${\mathrm{PM}}_{2.5}$ influences the strength of association with acute cardiovascular events in men. Regions with elevated concentrations of both sulfur and transition metals in ${\mathrm{PM}}_{2.5}$ should be examined as priority areas for regulatory interventions. https://doi.org/10.1289/EHP9449

中文翻译：

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室外 PM2.5 的硫、过渡金属和氧化电位与急性心血管事件的关联：加拿大成年人的病例交叉研究

摘要

背景：

我们目前不了解细颗粒物空气污染[具有空气动力学直径的细颗粒物$\le 2.5\mathrm{\mu }\mathrm{米}$(${\mathrm{下午}}_{2.5}$)] 影响人口健康风险。然而，最近的证据表明，过渡金属和硫酸盐的联合浓度可能会影响氧化电位 (OP)${\mathrm{下午}}_{2.5}$以及相关的健康影响。

目标：

该研究的目的是评估过渡金属/OP 和硫含量的组合如何在户外${\mathrm{下午}}_{2.5}$影响与急性心血管事件的关联。

方法：

我们进行了一项全国性的户外案例交叉研究${\mathrm{下午}}_{2.5}$2016 年至 2017 年间加拿大的急性心血管事件（93,344 例成人病例）。月平均过渡金属和硫 (S) 浓度${\mathrm{下午}}_{2.5}$与使用谷胱甘肽的无细胞测定法估计的 OP 一起前瞻性确定（${\text{OP}}^{\text{谷胱甘肽}}$), 抗坏血酸 (${\text{OP}}^{\text{AA}}$）和二硫苏糖醇耗尽（${\text{OP}}^{\text{数字地面电视}}$）。条件逻辑回归模型用于估计优势比 (OR) [95% 置信区间 (CI)]${\mathrm{下午}}_{2.5}$跨越过渡金属/ OP和硫的地层。

结果：

在男性中，当过渡金属和硫含量都升高时，观察到的关联程度最强。例如，OR 为 1.078（95% CI：1.049, 1.108）（每${10\mathrm{\mu }\mathrm{G}/\mathrm{米}}^3$) 在铜和 S 均高于中值时观察到男性心血管事件，而当两种元素均低于中值时观察到较弱的关联 ($\text{要么}=1.019$, 95% CI: 1.007, 1.031)。对于 OP 指标也观察到类似的模式。${\mathrm{下午}}_{2.5}$与女性急性心血管事件无关。

讨论：

室外过渡金属和硫的总含量${\mathrm{下午}}_{2.5}$影响与男性急性心血管事件的关联强度。硫和过渡金属浓度升高的地区${\mathrm{下午}}_{2.5}$应作为监管干预的优先领域进行审查。https://doi.org/10.1289/EHP9449