Particulate matter (PM) is a chemical composition of smoke, including sulfates, carbon, nitrates, or mineral dusts. It stems from vehicle and industrial emissions and other fossil fuel burning, and researchers are now increasingly examining wildfires and the effects of longterm exposure to wildfire smoke that affect respiratory illnesses and other impacts to human health.
A subset of PM — fine particulate matter (PM2.5) — is especially dangerous to human health because it’s 30 times thinner than a human hair and can not only lodge in lung tissue but also cross into the brain after it’s inhaled.
Scientists from the University of Michigan have identified a link between agriculture and wildfire PM2.5 emissions and the onset of dementia among 27,857 adult Americans, with data drawn from the national Health and Retirement Study. Pollution estimates were based on the locations of the participants, who were older than 50 and did not have dementia at the outset. About 15 percent of the study participants developed dementia, but the rate of cognitive decline was significantly greater in the areas of high PM2.5 concentration between 1998 and 2016.
Air quality in the upper Mississippi River Valley, tainted Thursday by north winds blowing in smoke from Canadian wildfires, worsened from moderately affected in the morning to just plain unhealthy by afternoon. By 6:30 p.m. the Air Quality Index (AQI) was rated at Unhealthy for Sensitive Groups.
According to the National Weather Service (NWS) and AirNow.gov, smoke from fires burning in Ontario — north of Michigan, Wisconsin and Illinois — is forecast to cause a mix of air quality conditions into at least Saturday.
As of 4 p.m. Thursday, the AQI for northwest Illinois and eastern Iowa showed pollutants hovering between the conditions of unhealthy for those sensitive to pollution and unhealthy for anyone in the population. The Sterling Daily Gazette reported that sensitive groups include people with respiratory conditions or heart or lung disease — as well as children, teens, and seniors.
Those at risk are advised to stay indoors or at least shorten the time they are active outdoors.
The New York Times reported that smoke from Canada fires is returning to smoke-weary residents of New York; it’s expected to be heaviest on Friday morning, but forecasters said the region would be spared the orange haze that settled last week, when a thick plume of smoke choked the air in New York City, delaying flights, closing schools, and sending people to hospitals with respiratory issues. The NWS said smoke had temporarily settled in the Upper Midwest, causing unhealthy levels in much of Minnesota, including the Twin Cities.
Accu-Weather reports said Canadian smoke is now settling across the Midwest; it had started to drift over Minnesota and the Dakotas earlier in the week, and by Thursday morning, wind had carried high-altitude smoke as far south as Oklahoma and east to Pennsylvania and New York. The worst smoke stretched from southern Minnesota to central Ohio, and emergency room physicians and nurses cautioned those at risk to stay indoors if possible.
“With the air quality at its current levels, we are beginning to see a slight increase in emergency rooms visits for patients suffering from respiratory issues,” said Sarah Alvarez-Brown, director of Emergency Services and Behavioral Health at CGH Medical Center in Sterling, Illinois. “On average, 20 percent of emergency visits involve respiratory issues and difficulty breathing, but over the last couple of days, we have seen this jump to 30 or 40 percent of visits. No matter your age — from infants to older adults — if you have a pre-existing respiratory condition, asthma, heart or lung disease, or you are sensitive to changes in air quality, you may want to limit your time outside or stay indoors, in an air-conditioned or air-purified environment, until the smoke and haze pass.”
Check AirNow.gov for updates; the maps are interactive and can be zoomed or changed by zip code. Air quality levels are updated hourly.
Residents of eastern Canada and the United States shared unhealthy air quality as hundreds of northern wildfires burn. On June 7, unhealthy to hazardous air advisories were issued for the capital cities of Ottawa, Ontario, and Washington, D.C., and for populations along the smoke paths.
The Fire and Smoke Map from AirNow offers an interactive map-based tool with local precautions. For Ottawa on June 7, AirNow sensors identified a hazardous air quality index (AQI) in the 400s for PM 2.5 (particulate matter that is 2.5 micrometers or smaller; the average human hair is 30 times larger than the largest of PM 2.5 particulates). Due to the hazard of such a PM 2.5 loading, an advisory was issued to avoid all outdoor physical activity.
In Washington, the AQI was unhealthy on June 7, with advisories to keep outdoor activities short and light, and to go indoors if you have symptoms. Sensitive groups should consider moving all activities indoors.
By the evening of June 8, the plume of unhealthiest air had shifted predominantly to the Northeast coast. In New York City, producers cited the effects of smoke when cancelling two Broadway shows and a Shakespeare in the Park performance. On June 6, New York City Mayor Eric Adams cancelled outdoor school activities. “We are taking precautions out of an abundance of caution to protect New Yorkers’ health until we are able to get a better sense of future air quality reports,” he said. “We recommend all New Yorkers limit outdoor activity to the greatest extent possible. Those with preexisting respiratory problems, like heart or breathing problems, as well as children and older adults may be especially sensitive and should stay indoors at this time.”
To track smoke risk, the IQAir Earth Map and the associated World AQI Ranking offer another set of monitoring tools, based on their IQAir network. As of June 7, their World AQI Ranking listed New York City as #2 and Detroit, Michigan as #5 as global cities with the worst air, with Toronto as #15. By the evening of June 8, New York City had dropped to #6, Toronto to #10, and Detroit to #24.
in an article for The Conversation, Christopher T. Migliaccio, a research associate professor in toxicology at the University of Montana, wrote on smoke toxicity and precautions to consider when exposed to smoke:
If there is smoke in the air, you want to decrease your exposure.
Can you completely avoid the smoke? Not unless you’re in a hermetically sealed home. The PM levels aren’t much different indoors and out unless you have a really good HVAC system, such as those with MERV 15 or better filters. But going inside decreases your activity, so your breathing rate is slower and the amount of smoke you’re inhaling is likely lower.
We also tend to advise people that if you’re in a susceptible group, such as those with asthma, create a safe space at home and in the office with a high-level stand-alone air filtration system to create a space with cleaner air.
Some masks can help. It doesn’t hurt to have a high-quality N95 mask. Just wearing a cloth mask won’t do much, though.
The BlueSky Canada smoke forecast for June 8 through June 10 offers a specific two-day outlook that doesn’t promise an end to smoke, but indicates that the thickest production may alternate with lighter periods of smoke. By June 10, something like clear skies may appear over Detroit, and the thickest fingers of smoke, from the Quebec fires through Ottawa to New York City, will become more intermittent. A look at the timing of the heaviest smoke may help to plan outside activities during the hours of clearer air.
The BlueSky Canada forecast also shows continued fire and smoke in western Canada and Alberta.
Western Canadian communities and firefighters may catch a welcome break next week with a forecast for precipitation — perhaps a good amount. Over the next week, areas along the Canadian Rockies may receive more than 100 mm (3.9 inches) while the Alberta-Saskatchewan border area may receive 20 mm (less than an inch), with soil moisture predicted to rise throughout the fire-impacted areas. This will likely slow fire spread and smoke volume, though fires at such scale will continue to produce smoke. An overall increase in humidity should lower fire danger.
The western provinces have experienced weeks of active fire behavior and growth, with an intensity comparable to that seen in the 2016 fires that burned Fort McMurray, Alberta and the heat domes and fires of 2021, when fires burned Lytton, British Columbia.
Phys.org reported that some 2,500 firefighters from across Canada backed by 400 military personnel have been deployed across Alberta and that more foreign help has been requested — with crews and incident management teams from the United States, Mexico, Australia, and New Zealand.
At one point nearly 30,000 Alberta residents were evacuated from their homes. Hazardous air quality and low visibility due to smoke were reported from British Columbia to Saskatchewan and as far south as Colorado and northern Texas.
The Canadian Interagency Forest Fire Center Situation Report for May 20 indicated area burned to-date of 2.1 million hectares (nearly 5.2 million acres), with 15 new fires for a total of 226 currently active fires. Of those fires, 90 are identified as out of control. Canada is in its tenth day at its highest preparedness level of 5.
In the Climate Atlas of Canada, an article on “Forest Fires and Climate Change” examines the impacts of climate change on Canadian fires and summarizes studies by Mike Flannigan and other scientists who predict that by 2100, western Canada will see a 50 percent increase in the number of dry, windy days that let fires start and spread, whereas eastern Canada will see an even more dramatic 200 percent to 300 percent increase in this kind of fire weather. And by 2040, fire management costs are expected to double.
Flannigan, a professor of wildland fire at the University of Alberta, explores the impact in more detail on his website. “Fire is the major stand-renewing agent for much of the Canadian forest,” he says, “greatly influencing forest structure and function.”
The research he summarized indicates that the observed increases in area burned in Canada during the last four decades is the result of human-induced climate change. Additionally, he says it appears that temperature is the most important predictor of area burned in Canada with warmer temperatures associated with increased area burned.
Based on a 2005 analysis, Flannigan says current estimates are that an average of over 2 million hectares burn annually in Canada. Just shy of the third week of May, Canada has already recorded 2.1 million hectares burned.
The University of Oregon in Eugene is launching a new research program to study effects of wildfire smoke and examine options for reducing risks. UO research professor Cass Moseley told KGW News that the center’s launch is due in part to efforts by Oregon’s U.S. Senators Ron Wyden and Jeff Merkley, who secured $800,000 in funding from the U.S. Environmental Protection Agency.
Research will focus in part on new ways to protect homes from smoke infiltration, along with more efficient communication with communities in emergencies and developing community action plans tailored to different regions in the Northwest.
The new Wildfire Smoke Research and Practice Center builds on research already completed through the Ecosystem Workforce Program (EWP), a joint venture between the UO and Oregon State University. KLCC reported that the EWP’s senior policy advisor Cass Moseley will head up the new center; she said recent incidents in the Pacific Northwest, particularly the 2020 Labor Day fires, highlighted the need for new smoke research. Much of Oregon, particularly the southern Willamette Valley, was choked with wildfire smoke for weeks during the 2020 fire season.
Those fires and the severe levels of smoke really emphasized the need for new research, according to Moseley. “And we saw this fall in Oakridge, several weeks of highly dense smoke as the fire there settled into that valley and really stayed; that community spent a lot of time and energy responding to that smoke event.”
The center’s launch was announced by Merkley and Wyden, who secured the funding to help communities prepare for wildfire smoke. One area of interest is the toxins released when manmade structures burn, as these risks became obvious during western Oregon fires in wildland/urban interface areas over the last few years. Most smoke research has focused on burning timber and wooden structures, and part of the new planned research will study effects of smoke from burning plastics, glass, fuels, and other synthetic materials. Moseley said the center has three co-investigators and a principal investigator leading the group, along with research assistants and graduate and undergraduate student assistants.
When local residents who aren’t firefighters see summertime haze or clouds on the horizon, they often guess it’s smoke. Mid-summer they often think it’s wildfire smoke, and in the fall they suspect it’s a prescribed burn. This is a “common experience” with wildfire smoke, according to attorneys with Oregon OSHA, who successfully argued last week that it’s fairly easy to determine when the air is smoky and affecting air quality.
“Most times, it’s not obvious,” attorney James Anderson declared. “There’s no method to determine that air quality is due to wildfire smoke, or prescribed burn smoke, or other things that make up particulates.”
Magistrate Mark D. Clarke was not persuaded. “Why is it that complicated?” he asked. He said Oregonians are quite familiar with wildfire smoke. “I’m not sure any of us have any trouble knowing when wildfire smoke rolls in. I’m having trouble with that, factually.”
The lawsuit also claimed that OSHA’s rules to protect workers against extreme heat and smoke were too vague to be enforced. The new rules, as KGW-TV reported last July, took effect after recent heat waves in Oregon resulted in medical problems and deaths, prompting new requirements for employers to protect employees from heat-related illnesses. The new OSHA rules require, when the heat index hits or exceeds 80 °F, that employers provide shaded areas for workers to rest, more break time, and access to plenty of water. When temperatures exceed 90 then breaks must be longer, communication must be more frequent, and workers must be monitored more closely.
Dangerous heat exposure is risky especially for farm workers, according to Ira Cuello Martinez, policy director for Pineros y Campesinos Unidos del Noroeste (PCUN), Oregon’s farm worker union. “You’re constantly moving and doing repetitive motions, having to bend down, and there aren’t many shaded structures when it comes to the field or doing work in agriculture,” he said.