The recent massive wildfires in Australia have killed more than 30 people and an estimated 1 billion animals, and burned 2,500 homes and millions of acres. And the human toll is expected to rise even after the blazes wind down. According to Harvard scientist Loretta Mickley, senior research fellow in atmospheric chemistry at the Harvard John A. Paulson School of Engineering (SEAS), long-term exposure to the smoke-filled air hanging over much of the country could lead to many premature deaths in Australia. In 2015, Mickley and a team of experts estimated that the air polluted by large forest fires in Indonesia had caused more than 100,000 premature deaths in that region. “The air quality across a large area of Australia has been very poor over a sustained amount of time, and the net health effects could last for several months to a year,” said Mickley, who spoke with the Gazette about her research.
GAZETTE: What are the short-term versus the long-term effects of exposure to this kind of smoke?
MICKLEY: We do see acute health effects from fires. For example, someone may have an asthma attack from high levels of smoke in her neighborhood, or we might see an increase in hospital admissions for lung complaints or similar conditions. But what people don’t always realize is that the particles in the smoke can affect chronic conditions like heart or pulmonary diseases, and the current thinking is that the long-term health effects can be quite severe over a period of a year or even more. So someone may get a stroke next June in that region and not realize that it can be traced back to smoke exposure. I think that effect has not been widely reported with the fires in Australia.
GAZETTE: Can you talk about the findings from your earlier work around fires and health outcomes and if they might apply here?
MICKLEY: A few years ago we did a big project involving researchers from SEAS [the School of Engineering and Applied Sciences], the [Harvard T.H. Chan] School of Public Health, the Department of Earth and Planetary Sciences, and fire experts at Columbia University. Our team, led by Harvard principal research scientist Sam Myers, wanted to know about fires in Equatorial Asia, mainly in Indonesia where they have periodic strong smoke events lasting weeks. In that part of the world, many fires are deliberately set to clear the tropical forests in order to plant oil palm or other trees that are valuable in the marketplace. Farmers also use fire to reduce pests and clear debris in agricultural fields. In very dry years, which come periodically, these fires can get out of control; they escape, and the smoke can linger over a broad area for weeks at a time. And 2015 was particularly bad, with very heavy smoke comparable, I would say, to what at least some areas of southern Australia are experiencing now. Our team determined that the smoke that people in Equatorial Asia experienced in 2015 led to 100,000 premature deaths, with most of those deaths occurring in the one-year aftermath of the fires.