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‘We’ll be having more days with poor air quality.’ What fires out West could mean for Massachusetts

People fished under hazy skies in Squantum on Tuesday.Stan Grossfeld/Globe Staff

Hazy skies and poor air quality prompted the state to issue three air quality alerts in the past week. Meteorologists have attributed the murky air to the wildfires burning in Canada and the western U.S.

New Englanders should expect more hazy air in the future, as Western wildfires continue, according to scientists who study air quality. That means higher-than-normal levels of pollution, which can cause respiratory issues for some people.

Here are some answers to common questions about how the haze can affect your health.

What’s an air quality alert and why did Massachusetts have one?

Air quality alerts are issued when air pollution reaches a concentration that can make breathing more difficult, especially for people with respiratory issues or underlying conditions.


On Monday, state officials said that the air in most of Massachusetts was “unhealthy” for people with certain medical conditions. The DEP said Tuesday morning that fine particle levels were “moderate to unhealthy” for sensitive groups. Sensitive groups include people with heart or lung disease, older adults, children, teenagers, and people who are frequently active outdoors, according to the DEP.

There are six levels to the Air Quality Index, or AQI, each signaling a different AQI value. The index is color-coded and runs from 0 to 500. AQI values in the green and yellow categories, or values below 100 on the index, are generally safe for most people, according to the DEP website. Any values over 100 can have a greater impact on some people’s health.

Particle pollution within the past week led AQI values to rise to potentially dangerous levels. Two reporting areas in Massachusetts in Chelsea and Chelmsford reported air quality values of over 150 in the red “unhealthy” tier Monday, according to AirNow, a website that reports the official AQI. Other reporting areas in the state registered “unhealthy for sensitive groups” and “moderate” levels of pollution on Monday.


On Tuesday, the situation had improved: Areas around the state reported AQI values in the green “good,” yellow “moderate,” and orange “unhealthy for sensitive groups” levels of pollution.

Bill Simpson, a meteorologist with the National Weather Service in Boston, said last week that air quality alerts in Massachusetts are issued roughly “seven to 10 times a year.” On those days, air quality typically falls into the “unhealthy for sensitive groups” tier.

Steve Coughlin, an air quality meteorologist for the DEP, said the state usually reports “good” air quality levels on the index. And last year, the state had just three days where air quality was unhealthy for sensitive groups — all attributed to ozone pollution, he said.

Haze obscures the view of the Annisquam River and Lobster Cove in Gloucester, Mass.John Blanding/Globe Staff/The Boston Globe

Why was the air quality so bad?

Experts attributed the fine particle levels to the wildfires burning in Canada and the western United States. Coughlin said that the smoke plumes from the wildfires moved across the country and wafted into the New England area, which necessitated an alert on July 20.

The sustained wildfires also affected the air quality this week.

Like in Massachusetts, the Rhode Island Department of Environmental Management issued similar alerts due to the wildfires last week, as well as Monday and Tuesday.

Michael Page, a freelance meteorologist with the Weather Channel, said last week that the smoke from the fires traveled to a high level of the atmosphere to the jet stream, “a fast-moving ribbon of air that moves across the country, generally from west to east,” where it was propelled to the Northeast.


And those particles can keep traveling across the globe.

“The fires are so intense right now that they produce a vast amount of smoke very, very high up in the atmosphere, and it actually goes all the way to Europe and beyond sometimes,” Mathew Barlow, a professor of environmental earth and atmospheric sciences at the University of Massachusetts Lowell, said last week.

How unusual is an event like this?

While experts say they have seen similarly poor air quality in New England before, it is rare to have the issues caused by particle pollution during the summer months. That could mean more days with bad air.

Coughlin said if the DEP issues an air quality alert during the summer, it’s usually connected to harmful ozone levels. Harmful ozone gases are produced when air pollution reacts to sunlight, according to the Environmental Protection Agency.

“Boston residents might see air quality alerts due to ozone several times during the summer, so those happen occasionally,” said Amy Huff, a senior research scientist who works with the National Oceanic and Atmospheric Administration. “But air quality alerts from particle pollution like we’re seeing ... those are very rare.”

With more fires out west, should New England expect more air quality issues?

Pollution from wildfires could become more common, though, as California and other Western jurisdictions continue to struggle with wildfires. Such events can certainly lead to more severe air quality conditions in New England.


Page said trends show that the West is becoming drier, making it more susceptible to wildfires, which will affect other parts of the country.

The logic says that if there’s more smoke on more days out West, where our weather generally comes from, more and more of that smoke will eventually be making it to us,” he said. “So this is something that will become more common going forward, and as a result, we’ll be having more days with poor air quality.”

Barlow noted that New England can’t ignore the consequences of wildfires out West, even though they’re thousands of miles away.

“Sometimes people look at what’s going on in the West Coast and feel like it’s a real shame for people on the West Coast, but it doesn’t really affect us, that’s a remote effect of climate change,” Barlow said. “But I think, with events like this, we see that what goes on in Oregon and the Pacific Northwest, even in Canada, can affect us [in Massachusetts] pretty directly.”

Is this a consequence of climate change?

Scientists are hesitant to directly connect these wildfires, and the worsening air quality that follows, to climate without longer-term research, but they do say these events are indicative of a warming environment.

Shobha Kondragunta, a lead scientist at NOAA, said last week that the surface temperatures recorded in July had been “20 degrees higher” in southwestern Canada and the northwestern US than in past years. Hot temperatures dry out vegetation and leave it more susceptible to fire, she said. Kondragunta also noted that the intense fire activity sweeping through the western US and Canada is not typical until later in the summer.


“There are indications that maybe there is a climate change impact,” she said, “but we have to study long-term data sets.”

Barlow said this was a “wake-up call” that extreme events like this can happen more often as the earth gets warmer.

“This is what we’re seeing with the climate change that’s already occurred, let alone what we’re working on for the future,” he said.

What should people do when the air quality worsens? Do masks help?

Coughlin said during a more severe air quality alert, people in sensitive groups should avoid intense outdoor activities, take breaks, and “watch for symptoms, such as coughing and shortness of breath.”

As for masks, experts say it’s important to remember that, as we’ve learned, not all masks are the same. Masks that can filter very small particles such as N95s can provide protection, while the cloth or surgical masks we’ve worn on and off during COVID do not offer as much coverage.