As the climate warms, wildfire activity is increasing, posing a risk to human health. Studies have reported on particulate matter (PM) in wildfire smoke, yet the chemicals associated with PM have received considerably less attention. Here, we analyzed 13 years (2006–2018) of PM_2.5 chemical composition data from monitors in California on smoke-impacted days. Select chemicals (e.g., aluminum and sulfate) were statistically elevated on smoke-impacted days in over half of the years studied. Other chemicals, mostly trace metals harmful to human health (e.g., copper and lead), were elevated during particular fires only. For instance, in 2018, lead was more than 40 times higher on smoke days on average at the Point Reyes monitoring station, due mostly to the Camp Fire, burning approximately 200 km away. There was an association between these metals and the combustion of anthropogenic material (e.g., the burning of houses and vehicles). Although still currently rare, these infrastructure fires are likely becoming more common and can mobilize trace metals in smoke far downwind, at levels generally unseen except in the most polluted areas of the country. We hope a better understanding of the chemicals in wildfire smoke will assist in the communication and reduction of public health risks.

中文翻译：

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超越颗粒物质量：与加州破坏性火灾事件相关的铅和其他污染物水平升高

随着气候变暖，野火活动正在增加，对人类健康构成威胁。研究报告了野火烟雾中的颗粒物 (PM)，但与 PM 相关的化学物质受到的关注要少得多。在这里，我们分析了 13 年（2006-2018 年）的 PM _2.5在受烟雾影响的日子里，来自加利福尼亚州监测器的化学成分数据。在超过半数的研究年份中，选择的化学品（例如铝和硫酸盐）在受烟雾影响的日子里在统计上有所升高。其他化学物质，主要是对人体健康有害的微量金属（例如铜和铅），仅在特定火灾期间升高。例如，2018 年，Point Reyes 监测站在烟雾日平均铅含量高出 40 多倍，这主要是由于 Camp Fire 在大约 200 公里外燃烧。这些金属与人为材料的燃烧（例如，房屋和车辆的燃烧）之间存在关联。虽然目前仍然很少见，但这些基础设施火灾可能会变得越来越普遍，并且可以在远在下风处的烟雾中移动微量金属，除了该国污染最严重的地区外，一般都处于看不见的水平。我们希望更好地了解野火烟雾中的化学物质将有助于沟通和减少公共卫生风险。