Wildfires are increasingly contributing to unhealthy air
Despite decades of environmental efforts, over 40% of Americans — more than 137 million people — live in cities and states with poor air quality, a new report says. And, in addition to cars and factories, wildfires are increasingly contributing to unhealthy air.
For the past 22 years, the American Lung Association has produced its annual State of the Air report, which analyzes the air quality on a local level for communities across the country. This year's study found that more Americans were exposed to unhealthy air, at times deemed hazardous, compared to previous years.
在过去22年里，美国肺脏协会（American Lung Association）每年都会发布一份《空气状况报告》，分析全国各地社区的地方空气质量。今年的研究发现，与前几年相比，更多的美国人暴露在不健康的甚至有时被视作有害的空气中。
In fact, more than 63 million people lived in counties that had dangerous levels of deadly particulate matter pollution — an increase of nearly 9 million over the last year. These particles are made up of dust, ash, soot and metals. They come from gas-powered vehicles and industrial plants, however in more recent years, dangerous spikes in particulate matter readings are coming from wildfires, which are burning hotter, faster and longer.
"The three years covered by [the report] ranked among the seven hottest years on record globally," the study said. "Spikes in particle pollution and high ozone days related to wildfires and extreme heat are putting millions more people at risk and adding challenges to the work that states and cities are doing across the nation to clean up air pollution."
Although wildfires take place all over the United States, the overwhelmingly majority happen in the West. That is why, according to the report, all but one of the top 25 worst cities with particulate matter pollution are west of the Rocky Mountains. The eastern outlier is Pittsburgh, which has historically had poor air quality because of its industrial facilities. That said, the city has been cleaning up its act and saw its lowest levels ever in this year's study.
Wildfires — which are burning hotter, faster and longer — are contributing to an increase in air pollution across the United States. The fires fill the air with particulate matter, made up of ash, soot, dust and more.
California on the other hand, topped the pollution charts. Fresno, Calif., unseated Fairbanks, Alaska, as the city with the worst short-term particulate matter pollution. A little more than 200 miles south, Los Angeles was dubbed the city with the worst ozone levels in the country, as it has reigned for all but one year since the study has been conducted. California also has 11 of the top 25 polluted cities.
The Environmental Protection Agency monitors six air pollutants — particulate matter, nitrogen oxides, sulfur dioxide, carbon monoxide, lead and ozone — as part of the Clean Air Act. The State of the Air report only focuses on two: particulate matter and ozone. It measures the daily and long-term levels of particulate matter and long-term ozone levels.
Ozone makes up Earth's stratosphere and protects the planet from ultraviolet rays beaming down from the sun. Unfortunately, it's also toxic. According to the EPA, ozone can damage the lungs when it's inhaled. Lower levels aggravate respiratory diseases such as asthma. It can also cause chest pain, coughing and shortness of breath in otherwise healthy people.
Fortunately, ozone levels across the country have been on the decline for the past four years. But more than 122 million Americans live in counties with failing ozone grades, the study found.
People of color were nearly four times more likely to live in a county with poor air quality compared to white people.
"People of color were 61% more likely than white people to live in a county with a failing grade for at least one pollutant, and 3.6 times as likely to live in a county with failing grades for all three pollutants," the report said.
On the flip side, people seeking pollutant-free air should more or less look to the East, where 14 of the top 25 cleanest cities lie, according to the study. Cheyenne, Wyo., was crowned the cleanest U.S. city, followed by Wilmington, N.C., and Honolulu.