野火烟雾中含有有毒化学物质——它们是如何到达那里的—

: By 约书亚·傅

感谢造访 InnerSelf.com，哪里有 20,000+ 宣传“新态度和新可能性”的改变生活的文章。所有文章均翻译为 30多种语言. 订阅每周出版的《内在自我》杂志和玛丽·T·拉塞尔的《每日灵感》。 InnerSelf杂志 自 1985 年起出版。

2020年XNUMX月上旬的一天中午，野火烟雾使旧金山的天空变成橙色。 雷·查韦斯/媒体新闻集团/水星新闻通过盖蒂图片社

当您从野火中吸入烟雾时，可能吸入的有毒化学物质超出您的想象。

Pollution from power plants and vehicles, pesticides, fertilizers and chemicals in waste can all make their way into trees and plants.发电厂和车辆产生的污染，废物中的农药，化肥和化学药品都可能进入树木和植物。 When those trees and plants burn, chemicals are released along with health-harming particulate matter in the smoke, gas and ash.当这些树木和植物燃烧时，化学物质会与烟雾，气体和灰烬中的有害健康的颗粒物一起释放出来。

Millions of people have been breathing that smoky air this year as the western US experiences another extreme fire year.由于美国西部经历了又一个极端火灾年，今年有数百万人一直呼吸着黑烟。 By Oct. 1, 2020,到XNUMX年XNUMX月XNUMX日，加利福尼亚州几乎翻了一番之前的纪录面积被烧毁，还有数周的野火危险仍在继续。

As 研究空气污染的工程师和科学家，我一直在研究这些化学物质如何加剧火灾中颗粒物质的健康影响，从而引起呼吸系统和心血管疾病，包括哮喘和心脏骤停。 To understand the risks, it helps to understand what chemicals people are breathing and how those chemicals get into smoke in the first place.要了解风险，它有助于了解人们呼吸的化学物质以及这些化学物质如何首先进入烟雾。 Here are answers to four key questions.以下是对四个关键问题的解答。

化学品如何进入野火烟雾？

Several factors affect the toxicity of wildfire smoke.有几个因素会影响野火烟雾的毒性。 These include the这些包括燃烧的燃料类型，火灾情况，例如无论是闷烧还是燃烧，以及野火与呼吸烟雾的人之间的距离以及该人暴露的时间。

The chemicals involved also make a difference.涉及的化学品也有所作为。 The chemicals that end up in wildfire areas can come from fertilizers and pesticides from farms, waste and sewage from factories and communities, vehicle exhaust and many other sources.最终在野火地区产生的化学物质可能来自农场的化肥和农药，工厂和社区的废物和污水，汽车尾气和许多其他来源。 It's well known that trees absorb large amounts of carbon dioxide from the air.众所周知，树木会吸收空气中的大量二氧化碳。 But ground-level pollution can also be但是地面污染也可能是被微生物分解 in the soil and taken up through the roots.在土壤中并通过根部吸收。 And chemicals from pesticides or fertilizers can collect on leaves and plants, as can农药或化肥中的化学物质也可以收集在叶子和植物上颗粒物来自车辆和工厂。

When trees and plants burn, chemical reactions create and release many different pollutants that are harmful to human health.当树木和植物燃烧时，化学反应会产生并释放出许多对人体健康有害的污染物。 Among them:其中：

一氧化碳和氮氧化物与呼吸和心血管问题.
挥发性有机化合物 like benzene, cresols, diphenyl, hydrogen cyanide, naphthalene and polycyclic aromatic hydrocarbons can cause difficulty breathing, headache, fatigue, nausea, vomiting and corneal damage.如苯，甲酚，联苯，氰化氢，萘和多环芳烃会导致呼吸困难，头痛，疲劳，恶心，呕吐和角膜损害。 Most of these are not regularly monitored, even during wildfires.其中大多数都没有定期监控，即使在野火期间也是如此。
Fine particulate matter, or PM2.5, is one of the biggest wildfire concerns in terms of health, and the most prevalent.就健康而言，细小颗粒物或PMXNUMX是最令人关注的野火之一，也是最普遍的问题。 The tiny particles become suspended in the air and can penetrate deep into the lungs.微小的颗粒悬浮在空气中，可以深入到肺部。 Depending on the dose, frequency and duration, the inhaled particles can cause conditions such as asthma, bronchitis and heart failure.根据剂量，频率和持续时间的不同，吸入的颗粒可能引起哮喘，支气管炎和心力衰竭等疾病。流行病学研究已将野火烟雾中PM2.5的暴露与早期死亡，呼吸系统疾病和心血管疾病联系起来。

当房屋和其他建筑物中的材料燃烧时，这会增加更多不健康的污染物。

旷野消防员经常接触烟雾会增加他们受到健康伤害的风险。 Josh Edelson / AFP / Getty Images

这些污染物不仅对敏感人群有害，例如老年人，幼儿和慢性病患者； they are also a他们也是消防员的危险他们日复一日地暴露在烟雾中。

我们还不知道的是，许多化学物质和污染物（例如苯，多环芳烃和氰化氢）对健康的影响程度没有像臭氧和PM2.5那样受到定期监测。

远距离冒烟是否仍然有害？

空气污染物可以传播数百英里，即使看不见野火烟雾也会影响人们。

Wildfire smoke can also grow more toxic as it ages, creating a higher risk for people downwind.野火烟雾随着年龄的增长也可能会产生更多的毒性，给顺风人士带来更高的风险。 When smoke is in the air, its particles chemically react with other molecules through oxidation, creating more reactive compounds called free radicals that can damage human cells.当烟雾在空气中时，其颗粒会通过氧化与其他分子发生化学反应，生成更多反应性化合物，称为自由基，会损害人体细胞。 Researchers in Europe found the toxicity doubled within about five hours and became as much as欧洲的研究人员发现，毒性在大约五个小时内增加了一倍，并达到了效力提高四倍随着时间的推移。

The fine particulate matter in wildfire smoke is easily inhaled deep into the lungs and embedded in the tiny air sacs there called alveoli.野火烟雾中的细颗粒物很容易吸入到肺部深处，并埋藏在称为肺泡的微小气囊中。 It can cause inflammation and oxidative stress, leading to lung damage and worsening of various respiratory diseases, including asthma.它会引起炎症和氧化应激，导致肺部损伤和各种呼吸系统疾病（包括哮喘）恶化。

到2020年XNUMX月中旬，来自加利福尼亚州野火的烟雾传遍了全国。 美国宇航局世界观

为什么野火烟会加剧哮喘？

When there are enough wildfire smoke particles in the air, human airways are prone to inflammation.当空气中有足够的野火烟尘颗粒时，人的呼吸道容易发炎。 That's a problem for people with asthma.对于哮喘患者来说这是一个问题。

哮喘的特征是胸闷和疼痛，咳嗽，疲劳，头痛，呼吸急促，心跳加快和喘息。

In 最近的一项研究，我和我的同事使用化学传输模型，遥感和地面测量来将野火烟雾中的PM2.5与其他来源的PM2.5分开。 We found a substantially stronger association between smoke and asthma than previously reported.我们发现烟雾和哮喘之间的关联比以前报道的要强得多。 The toxicity of the smoke, including chemicals not often measured in ambient air, like benzene, formaldehyde and nitrogen cyanide, likely has something to do with it.烟雾的毒性，包括在环境空气中不经常测量的化学物质，例如苯，甲醛和氰化氮，可能与它有关。

烟熏地区的人们如何确保安全？

人们在烟雾弥漫的空气中可以采取几个步骤来保护自己的健康。

（1）注意当地的空气质量指数。 Avoid spending too much time outdoors when there is a lot of smoke, and minimize strenuous activities outdoors.避免在有大量烟雾的户外花费太多时间，并尽量减少户外的剧烈活动。

（2）保持室内空气清洁。 Close doors and windows when there is smoke, and use a free-standing indoor air filter that can remove particles.冒烟时请关闭门窗，并使用可去除颗粒物的独立式室内空气过滤器。 Do not increase indoor pollution by using candles and fireplaces, and avoid using vacuum cleaners that can stir up dust.不要使用蜡烛和壁炉来增加室内污染，并避免使用会引起灰尘的真空吸尘器。 Do not smoke.不吸烟。

（3）遵照医生的建议。 If you have asthma or other lung or cardiovascular diseases, make sure you have an emergency plan.如果您患有哮喘或其他肺部或心血管疾病，请确保您制定了应急计划。

（4）使用N-95口罩。 If there is a wildfire in your area or wildfire smoke, you should wear a mask when you go out to prevent harmful particles from entering your lungs.如果您所在地区有野火或野火烟雾，则外出时应戴口罩，以防止有害颗粒进入肺部。