VOA健康报道2024--Study: Particles in Wildfire Smoke May Increase Dementia Risk

A new study suggests that particles found in wildfire smoke could increase the risk of getting dementia.

Dementia is a progressive brain condition that causes thinking problems and other health issues. There are several forms of dementia, including Alzheimer's disease.

Researchers reported the new findings about wildfire smoke at the recent Alzheimer's Association International Conference in Philadelphia, Pennsylvania.

The study centered on a substance called PM2.5. The substance is known as particulate¹ matter, a mixture of small, solid particles and water droplets² found in the air.

PM2.5 particles are about 30 times smaller than a human hair. They can be breathed into the lungs and then move on to the blood stream. Existing evidence shows this kind of pollution - from traffic, factories and fires - can cause or worsen heart disease. The new study finds it could also raise dementia risks.

Claire Sexton is the director of scientific programs for the Alzheimer's Association. She said in a statement the study shows that increasing wildfires, especially in the American west, are "an increasing threat to brain health." Sexton added that the findings demonstrate "the importance of enacting³ policies to prevent wildfires and investigating better methods to address them."

Researchers from the University of Washington and the University of Pennsylvania carried out the study. They examined health records of 1.2 million older adults in Southern California between 2009 and 2019. The scientists used air quality monitoring and other data to estimate how much PM2.5 was released from wildfire smoke or other ways over three years.

The study found the risk of being diagnosed with dementia increased about 21 percent for every 1 microgram increase in the concentration of wildfire particles. That compared with a 3 percent increased risk for every 3 microgram increase in non-wildfire particles.

It is not clear why this difference exists. But with wildfires increasing, this issue needs more study, said Alzheimer's Association chief science officer Maria Carrillo. She said it is especially important because the risk of Alzheimer's - the most common form of dementia - is higher for lower-income populations who may have a harder time avoiding unhealthy air.

Carrillo noted⁴ that health warnings urge staying indoors when air quality is poor. But she added, "there are a lot of people who don't have the option to stay home or they work outside."

Words in This Story

address - v. to speak about a particular subject or issue

monitor - v. to watch something carefully and record the results

diagnose - v. to say what is wrong with a person who is sick

concentration - n. a large number or amount of something in the same place

option - n. something that may be chosen

1 particulate   

adj.微小的；n.微粒，粒子

参考例句：

• A special group was organized to dig up the particulate of the case.成立了一个专门小组来查明该案件的各个细节。
• Lungs retain relatively insoluble particulate material.肺脏内留有不溶解的颗粒物质。

2 droplets   

n.小滴( droplet的名词复数 )

参考例句：

• Droplets of sweat were welling up on his forehead. 他额头上冒出了滴滴汗珠。 来自辞典例句
• In constrast, exhaled smoke contains relatively large water droplets and appears white. 相反，从人嘴里呼出的烟则包含相当大的水滴，所以呈白色。 来自辞典例句

3 enacting   

制定（法律），通过（法案）( enact的现在分词 )

参考例句：

• Generally these statutes apply only to wastes from reactors outside the enacting state. 总之，这些法令只适宜用在对付那些来自外州的核废料。 来自英汉非文学 - 环境法 - 环境法
• In addition, the complexion of enacting standards for live working is described. 另外，介绍了带电作业标准的制订情况。

4 noted   

adj.著名的，知名的

参考例句：

• The local hotel is noted for its good table.当地的那家酒店以餐食精美而著称。
• Jim is noted for arriving late for work.吉姆上班迟到出了名。