Researcher Spotlight (first published in 2019): In 2008, as Shaojie Song was finishing his undergraduate studies at Tsinghua University in Beijing, the city was preparing to host the summer Olympics and struggling to contain its air pollution. “It was a big event,” says Shaojie, “and the city worked hard during that period to clean up the air. It was very impressive, and it was a success—but it took a lot of effort.”
Shaojie was studying environmental science at the time, an academic path influenced by his experience growing up in a small city in the Hebei province in northern China. (“There were environmental issues there, like wastewater, black rivers, solid waste—and plastic bags everywhere,” says Shaojie.) After watching Beijing tackle its air pollution issues, he decided to pursue a master’s in atmospheric chemistry at Tsinghua, spending much of his time measuring particulate matter in Beijing’s air and monitoring the impact of motor vehicle emissions.
During his PhD studies at MIT, he focused on the transfer and chemistry of trace metals in the ecosystem, specifically mercury. “Mercury in the air actually doesn't have a lot of human impacts,” says Shaojie. “But when the mercury gets into oceans, it can be converted to methyl mercury, which can have more serious human health impacts and also have impacts for wildlife, like birds and polar bears.”
He brought his interest in Chinese air quality to the Harvard-China Project in 2016, and has recently been focused on researching the makeup of small atmospheric particles and their role in creating smog. “We know that the chemical mechanism responsible for the haze [in Northern China] is tied to an important property of the particles—its acidity,” says Shaojie. In a recent study, Shaojie and his colleagues found that the wide variance in previous estimations of particle acidity were due to incorrect applications of models and even some coding errors. “We corrected those, and actually can now narrow down the particle acidity into a much smaller range than previously had been reported.”
These are the exactly the kinds of mysteries Shaojie strives to unlock. “I want my research to improve our understanding of the effects of chemistry on pollution,” says Song. “And I want to help the government more quickly control the pollution and improve the air quality.”
He credits the Harvard-China Project with widening the scope of his work. “It is not like my other academic groups, which focus on one issue like chemistry or physics,” he says. “It is more interdisciplinary.” The other important element, he says, is the access to resident scholars. “It is difficult for us to study Chinese issues without interacting with Chinese colleagues, and we have a lot of coverage in China here,” says. “We can share the data, we can share ideas, and we can work in tandem.”
(Written by Dan Morrell)