ANNAPOLIS, Md. – Residents in the Chesapeake Bay region and across the country added another item to their checklist for heading outdoors this summer: How’s the air?
Wildfires burning across Canada combined with atypical weather patterns to deliver dense doses of smoky haze to the region on two occasions in June. Bay states were among those exposed to such poor air quality that it was considered unhealthy for most people to spend time outdoors.
We talked to local air quality experts to try to put these “bad air” days into context and to better understand their impact on human health, wildlife and the environment.
Dan Salkovitz is a meteorologist who’s been forecasting air quality for the Virginia Department of Environmental Quality for 40 years. He said the poor air quality numbers the region saw on June 7–9 and again on June 27–29 were “among the highest ever recorded” in the area for some pollutants.
Salkovitz remembers wildfire haze from Quebec making its way to the region in the early 2000s and the Great Dismal Swamp fire in 2011 causing localized haze in southeast Virginia. Still, the situation we’ve seen this summer, he said, is far from typical.
“It’s unequivocal that trends are phenomenally better,” he said, referring to overall air quality, compared with 20 years ago.
In 1998, for example, Virginia had 108 days in which the air quality index exceeded the standard for ozone, the major pollutant that the U.S. and much of the developed world was working to reduce at the time. Pollution controls for industry, vehicles and energy efficiency standards have all made an impact since then. Last year, there was one such day. By midsummer this year, there were five of them linked to wildfire smoke.
Jeremy Hoffman, director of climate justice and impact at Groundwork USA, began studying local air quality and its impact on human health when he was a scientist at the Science Museum of Virginia. He agreed that the trends are headed in the right direction, something he saw on the ground when he began installing air quality monitors in Richmond.
“We’re actually living in the best air quality in the observable time period,” Hoffman said. “So when something like [the wildfire haze] happens, it’s so much more noticeable.”
Meanwhile, he said, hotter and drier conditions brought on by a changing climate “are promoting these more intense and larger fires.”
When it comes to wildfire smoke, the most direct health threat is particulate matter. Air monitors that track this pollutant measure two sizes of it, which you might see labeled on tracking maps as PM2.5 and PM10.
PM2.5, referring to particles of 2.5 microns or less, are the smaller of the two. They are microscopic, inhalable particles that can contribute to cardiac and respiratory issues. Even in healthy individuals, these tiny particles in the air can irritate eyes, noses and throats, causing coughing, phlegm and tightness of breath, according to the federal government’s air quality tracking website, AirNow.gov.
Under the Clean Air Act, the U.S. Environmental Protection Agency regulates five major air pollutants, including particulate pollution, ground-level ozone, carbon monoxide, sulfur dioxide and nitrogen dioxide. All of these pollutants are measured to determine the “air quality index,” or AQI, on a given day. The AQI runs from 0 to 500, with values of 50 or below representing good air quality.
On some days in June, the air quality index for the region climbed over 200, rendering the air in some portions of the watershed “very unhealthy.”. In July, that index again reached into the orange and red zones of “unhealthy” as Canadian wildfires persisted.
Even when the air quality is known, it can be hard to decide how to act — especially in a region where wildfire haze is relatively new.
AirNow.gov offers guidance for how to act on the warnings they issue, based on a person’s health, age and other risk factors. People with heart and lung disease, older adults and children (who breathe more air per pound of body weight than adults), as well as pregnant women, should pay closer attention to the warnings and reduce their time outside. Other groups should also choose less strenuous activities, which increase inhalation of pollutants, during poor air quality days.
But staying indoors isn’t always an option. Outdoor workers and those who rely on public transportation or walking do not always have the luxury of reducing time outdoors, regardless of the day’s air quality. Hoffman found in his research in Richmond that people living in certain neighborhoods near industrial corridors and arterial roads already experience significantly worse air quality than those living on streets lined with more trees several blocks away.
Wildlife and pets are also impacted by wildfire haze. The Smithsonian National Zoo in the District of Columbia closed its doors on June 8, the region’s worst air quality day to that date, and brought animals indoors as much as possible.
Wildfires can also be a major source of nitrogen pollution in the atmosphere, which eventually settles on the ground and washes into local waters. Air pollution is already the source of up to a third of the nitrogen that enters the Chesapeake Bay. One study found that wildfires in California increased nitrogen deposition by an estimated 78% in 2020.
Although wildfires are expected to continue increasing in scale and frequency, it’s not clear if the unique weather patterns that brought Canada’s smoke to the Chesapeake Bay region will continue. But the smoky summer can remind residents of the ongoing impacts of an increasingly erratic climate, Hoffman said.
“When we think about the impacts of climate change, here they are at our front door. What do we do now?” he said. “We continue along with our lives as though this extreme air is normal, but it’s not.”
Now if the non-believers of the Earth’s meteorological history really want to help the atmosphere, they should teach Canada to manage their forests and outlaw volcanos global wide.