The Jones Road fire in New Jersey scorched 15,300 acres for nearly three weeks this spring. Its sickly orange haze vanished hours after the blaze was doused, but a stench from the blackened landscape, including parts of the Pine Barrens, lingered for days.

New Jersey public health experts now are trying to understand what, if any, health risks are hidden in the smoke from wildfires, whether they originate at home or faraway forests. They have limited resources for the task, but a small core of health researchers and academics are starting to gather data about illnesses related to days of uncontrolled burns.

Last week, they found a fresh motivation: fire broke out Friday in Wharton State Forest, prompting evacuations in southern New Jersey. Within days, 6,400 acres had burned. The blaze was reported 90 percent contained as of Wednesday, according to New Jersey Fire Service social media posts.

Brian Lippai, public information office for the Ocean County Health Department, said information about potential related hospitalizations from the Jones Road Fire, named for a street where it was first sighted, aren’t yet available. That would require some cross-coordination between emergency rooms across the state, he said, which doesn’t routinely happen.

We’re hiring! Please take a look at the new openings in our newsroom. See jobs

The hope, Lippai said, is that studies might emerge “once the dust settles—no pun intended.” Air pollution levels near the Jones Road fire, which burned in April, were recorded at more than 10 times the limit recommended by the World Health Organization, according to the U.S. Air Quality Index.

Experts don’t know how these fires are affecting long term health—and it could take some time to find out. The New Jersey Department of Health Environmental and Occupational Health Surveillance Program recently published a 15-page report that examines medical needs from air pollution that drifted from wildfires in Canada in 2023. A record-number of fires charred 18 million acres from March to June, and eight firefighters died.

But most important for New Jersey health authorities, visible smoke billowed over the border and across the Northeast United States for days, and the “wildfire smoke event caused the Air Quality Index (AQI) to reach “unhealthy” and “very unhealthy” levels across the state.”

The state study, released in March, collated billing data and diagnoses codes from Jersey hospitals including emergency visits and inpatient care.

Researchers found asthma-related emergency visits increased significantly on June 7. The number was 112 percent higher than the daily average of asthma patients who sought care two weeks before skies filled with Canada’s smoke. The study also notes that emergency visits likely underestimate how many individuals sought help in other ways, through their primary care physicians, urgent care clinics or with home remedies.

The National Oceanic and Atmospheric Agency, in a June monitoring report on Canada, pointed to climate change as affecting the vitality of the northern boreal forest. “As global temperatures continue to rise, wildfires in these regions are becoming more frequent, intense, and longer-lasting.” As of June 5, NOAA said, 1,746 fires have erupted in Canada this year, consuming about 10,000 square miles, or an area larger than Vermont.

In New Jersey, firefighters, too, have found that wildfires were no longer just a summer risk.

The Jones Road fire broke out days after New Jersey Forest Fire Service officials had warned they had delayed prescribed burns, routine for clearing brush, because of an unusually dry spring. A lack of rain and snow for some months had left the region and the expansive Pine Barrens woodlands, parts of which are a natural reserve, particularly vulnerable.

The county health department quickly issued public health advisories as the fire, apparently traced to a bonfire that had not been fully extinguished, spread and endangered main traffic arteries including the Garden State Parkway. Authorities warned of deteriorating air quality.

Smoke from the Jones Road fire is seen over homes on April 23 in Ocean County, N.J. Credit: Matthew Hatcher/AFP via Getty Images

NOAA tracked the blaze via satellite and later characterized it as one of the worst fires in the state’s history. Five thousand people were evacuated in its early hours. About 25,000 households lost power in the first week.

Residents soon posted on social media—including the state fire service Facebook page—their fears about health risk and whether New Jersey was turning into a “little California,” as one writer said, referring to catastrophic wildfires in Los Angeles County months earlier.

Medical professionals are still sorting through the public health effects. Peter Saccone, a local pulmonologist from Sewell, N.J., estimated his office experienced an estimated 20 percent increase in patients after and around the time of the fire. Patients reported feeling sick, with running noses, dry coughs and mucus. But tests revealed no infection.

Saccone said the symptoms were likely related to poor air quality exposure, either from wildfire smoke or allergies. It was difficult to distinguish between the sources, he said, because New Jersey then was also experiencing higher-than-normal pollen counts from warmer temperatures.

“Pollen, smoke, dust, etc. can trigger it the same way,” Saccone said. “There’s just so much of an overlap between symptoms.”

Philip Demoktritou, a professor in Nanoscience and Environmental Bioengineering at the Rutgers School of Public Health, pointed out that wildfire risk doesn’t stop at a property line. New Jersey, like other states, will have to reconsider what may be new and recurring safety risks from faraway conflagrations, he said.

Demokritou and other Rutgers researchers found that during the 2023 Canada fires there was a 3-degree Celsius drop in temperature in New York City. The phenomenon, known as global dimming, occurs when smoke and pollutants get trapped near the ground, and particulates within that smog are worth further study, he said.

“These particles, they don’t know boundaries,” said Demoktritou, one of a dozen authors of the study, published in April in the journal Nature. A rise in particulate matter is now a more common public health concern as a result of “an increased intensity and frequency of these extreme events.” And, he said, current ways of measuring particulates in the air are not ideal for the evolving wildfire scenario.

Particulate matter is a mixture of several chemicals, solids and liquids in the air and is measured for air quality reporting. There are two main standards known as National Ambient Air Quality PM10 and PM2.5. The latter measure accounts from generally smaller and more dangerous particulates that are able to penetrate the bloodstream.

This story is funded by readers like you. Our nonprofit newsroom provides award-winning climate coverage free of charge and advertising. We rely on donations from readers like you to keep going. Please donate now to support our work. Donate Now

Demokritou said wildfire particles are measured primarily in the nanoscale. The PM2.5 standard, he said, does not fully grasp the scale of the smaller particles from wildfire smoke on health. More precise measures are needed. Measuring the number and surface area per cubic meter of air rather than their mass would provide a more accurate metric for human health implications, he said.

“You cannot really compare apples with oranges,” he said. “So we have a problem, because the PM2.5 standard is not adequate to capture these wildfire nanoparticles.”

The Jones Road fire unleashed its chemical mix from trees and the ruin of multiple vehicles and buildings that burned hot with man-made plastics and petroleum-based equipment, according to the New Jersey Forest Fire Service.

Forest wildfires complicate risks for people with respiratory and heart disease, but urban fires that blend with forest burns are more complex and infused with chemicals from tars, metals, fabrics or building materials, said Savannah D’Evelyn, an environmental health scientist and bio-social scientist with the University of Washington, who has studied air quality, community health and climate adaptation.

Tiny particles from smoke can enter the bloodstream through the lungs and pass the blood-brain barrier—a membrane that protects the central nervous system from toxic substances and pathogens in blood, she said. Particles can also move through the nose and head directly to the brain. There are all sorts of health implications from days of soupy air, she said.

“There’s just kind of the domino effect,” D’Evelyn said. “If there’s impact on your lungs, that would maybe be increasing blood pressure, then that changes how things are working throughout your body.”

She added that health professionals have to consider what an expanded fire risk means for treatment, particularly in regions unfamiliar with repeated bouts of smoke. “Wildfire doesn’t really have a season anymore,” she said. “It hasn’t had a season for a long time in the west, but even in places like New Jersey and New York, fires are reaching all parts of the year.”

A NOAA report in 2024 found that fires within a wildlife urban interface, or WUI, which is the meeting point between human development and undeveloped land, are on the rise. In New Jersey and other urban-adjacent areas where fires are becoming more frequent, more than 50 million U.S. homes lie within a WUI.

D’Evelyn said wildfires, in particular, gush pollutants into the air. A fast-moving blaze will spiral pollution levels within hours and emergency room visits can spike from patients downed by asthma attacks and other breathing difficulties.

More research is needed to explore whether wildfire smoke triggers an onset of a multitude of disease or health complications, D’Evelyn said. People most directly exposed—such as firefighters—are prime for study.

“It’s impossible that we’re going to live in a world without smoke, and so what we need to do is figure out how to live with it,” D’Evelyn said.

About This Story Perhaps you noticed: This story, like all the news we publish, is free to read. That’s because Inside Climate News is a 501c3 nonprofit organization. We do not charge a subscription fee, lock our news behind a paywall, or clutter our website with ads. We make our news on climate and the environment freely available to you and anyone who wants it. That’s not all. We also share our news for free with scores of other media organizations around the country. Many of them can’t afford to do environmental journalism of their own. We’ve built bureaus from coast to coast to report local stories, collaborate with local newsrooms and co-publish articles so that this vital work is shared as widely as possible. Two of us launched ICN in 2007. Six years later we earned a Pulitzer Prize for National Reporting, and now we run the oldest and largest dedicated climate newsroom in the nation. We tell the story in all its complexity. We hold polluters accountable. We expose environmental injustice. We debunk misinformation. We scrutinize solutions and inspire action. Donations from readers like you fund every aspect of what we do. If you don’t already, will you support our ongoing work, our reporting on the biggest crisis facing our planet, and help us reach even more readers in more places? Please take a moment to make a tax-deductible donation. Every one of them makes a difference. Thank you,