Why is wildfire smoke potentially worse than other pollutants in the air?

Wildfires in the Western United States have spread smoke across the landscape, posing a rising hazard to public health. The 2020 fire season was so terrible, because of climate change, that it nearly quadrupled the previous record for acres burned in California, and at-home monitoring of the smoke’s impact on air quality became practically ubiquitous. This year’s season is off to a disastrous start, with smoke from West Coast wildfires already darkening skies on the East Coast.

Smoke isn’t your typical form of pollution. According to studies published in the journal Nature earlier this year, the small particles present in smoke can be up to ten times more hazardous to human health than soot from other sources such as tailpipes and factories.

Fine particles, also known as PM2.5, are 30 times smaller than the diameter of a human hair follicle and were studied by researchers. When a fuel, whether it’s gas or plant, burns, tiny particles are released into the air and occasionally into our bodies. According to the study, fine particles from wildfire smoke resulted in 10% more respiratory hospitalizations than they would have been without the smoke. While pollution from other sources is also hazardous, it only increased hospitalizations by around 1%.

Rosana Aguilera, the study’s primary author and a postdoctoral researcher at the University of California, San Diego, spoke in an interview. She explained what she and other academics are doing to learn more about the effects of wildfire smoke on human health.

The interview was slightly altered for clarity.

What are “fine particles,” and why are they a concern?

Fine particles were investigated by the research group I work in since they are one of the primary components of wildfire smoke. These particles are distinct from others. Their chemical makeup varies depending on the items being burned. There are a variety of chemicals that may be found in wildfire smoke and fine particles, including carbon and heavy metals.

We’re concentrating on these small particles found in wildfire smoke right now because wildfire smoke is becoming increasingly prevalent as a source of emissions in various parts of the United States and the world. It’s one form of air pollution in California that appears to be on the rise in the foreseeable future. Some articles support the notion that wildfire smoke will be one of the primary sources of fine particulate matter in areas such as the Western United States.

What kind of impact may such tiny particles have on people’s health?

Because it’s tiny enough to infiltrate our respiratory system and reach deep into the lungs, it’s one of the air pollutants to be concerned about. It might enter the circulation and spread to other organs from there. It can make breathing difficult. It can irritate the skin and aggravate illnesses such as asthma and other respiratory and cardiopulmonary problems.

We mostly deal with acute impacts, which are the reactions that occur after being exposed to wildfire smoke for a few days. My study group isn’t focusing on long-term impacts right now, but I believe it’s an issue that needs to be explored more. Long-term exposure is more difficult to study since it requires following individuals who have been exposed to several wildfires.

So, how does wildfire smoke compare to other sources of pollution like vehicles, trucks, and industry?

When comparing wildfire smoke to non-smoke fine particles, we discovered that wildfire smoke is more hazardous in terms of increased hospitalizations.

The mix of traffic emissions and wildfire smoke may be extremely different. We haven’t looked at the chemical makeup of these tiny particles concerning their origins. However, several toxicological studies have delved into this further and shown that wildfire smoke toxicity may be enhanced. If it passes through a structure, it may pick up pollutants from homes and other structures.

What do you want to achieve with your research?

We’d like to investigate these differential effects of fine particles concerning emission sources, as well as try to learn more about the chemical makeup of various wildfires.

If wildfire smoke has a higher impact, and if it will be one of the primary sources of this sort of pollution in the future — or if it currently is — we need to learn more about why it is more damaging. Then, what kind of long-term impact can we expect?