Public Health Professor Kari Nadeau Discusses Wildfire Research at Climate Health Event

Kari C. Nadeau, professor of climate and population studies at the Harvard School of Public Health, discussed the increasing severity of wildfires and their detrimental effects on human health at a virtual presentation Thursday evening.

The event was held on the eve of COP28, a United Nations climate change conference that will focus entirely on health for the first time.

The Salata Institute for Climate and Sustainability and the University’s Vice Provost for Advances in Learning co-hosted the talk. It was the second event in a series called “Harvard Speaks on Climate Change,” which features Harvard faculty from various departments engaging in climate change research and solutions.

“We’re going across the campus and looking at what various faculty members are doing,” James H. Stock, event moderator and vice provost for climate and sustainability, said in an interview after the event.

Nadeau said her research examines the consequences wildfires can have on human health through the release of particulate matter and heavy metals that get deposited in humans’ respiratory tracts.

Nadeau said emergency room visits in New York City this summer peaked due to asthma and chronic obstructive pulmonary disease, attributed to the wildfire smoke that enveloped the city.

“You can see within those small amount of days the increase in asthma visits to the emergency room,” she said. “It’s about zero to four to five days, on average; four to five days of constant exposure will increase the rates of asthma.”

Nadeau also spoke about the importance of the types of particles that are released into the air by wildfires, adding toxic “products” such as microplastics and dioxins have increased in prevalence in wildfire smoke.

“Wildfire smoke isn’t really wild anymore,” she said. “About 50 percent of it in the western part of our country is made up of commercial buildings, as well as residential homes.”

“What I look at is how that smoke affects the immune cells,” she added.

Through her research, Nadeau also looks for solutions to climate change that focus on education.

“We want to focus on solutions at the individual as well as the population level,” she said. “I’m going to make sure, as a physician, that I can let patients know how they are going to do in the next wildfire smoke exposure.”

“I’d like to also be able to tell people — on a population level — what’s best to do during a wildfire or during heat stress or another climate change event,” she added.

Nadeau pointed to her research on the benefits of prescribed burns — deliberate burnings that can allow for new vegetation growth, reallocation of soil nutrients, and a reduction in the intensity of wildfires — as an example of a way to mitigate wildfires.

“We were the first group ever able to show that prescribed burns were less toxic to humans than wildfires. That makes sense, because people are allowed to leave their homes beforehand,” she said.

Through tracking blood cells of individuals exposed to prescribed burns versus wildfires, Nadeau’s research team quantified the differences in ingested particulate matter between the two types of fire.

“Prescribed burns emit a lot less smoke, but no one had actually calculated that or measured it,” she said.

“That led to policy change, which we’re really humbly happy to be part of,” she added, referencing the inclusion of prescribed burns in the Biden administration’s climate change management plan.