Exhaust fumes and industrial emissions have long been recognized as the primary sources of air pollution. However, there are other hidden but significant factors that contribute to air pollution. These include droughts and wildfires. Recent research led by Professor Hyung Joo Lee (DESE), Na Rae Kim, and Min Young Shin (Integrated Ph.D. candidate) has revealed how droughts and wildfires comprehensively influence the level of Particle Matter 2.5 (hereafter PM2.5) air pollution. The research has been published in the international environmental science journal Environment International.
PM2.5, or fine particles of radius 2.5µm or less, is a serious concern in the air environment, since it can penetrate deeply inside the lungs, causing respiratory or cardiovascular diseases. The research team looked into the data of PM2.5 concentration in California, USA over the past 15 years, to analyze the impact of droughts and wildfires on PM2.5 concentration. They classified the level of droughts into four levels, and analyzed changes in PM2.5 concentration on each level.
As a result, the team was able to find out that the concentration level of PM2.5 increases by 1.5µg/m3 on average as the level of drought increases. In addition, the potential danger of wildfires increases as droughts worsen, raising the probability of wildfires by 90%p on average as drought gets worse by one level. Furthermore, extreme drought cases, together with wildfires, were confirmed to have increased the level of PM2.5 concentration by 9.5µg/m3 on average. The team also revealed that the change in PM2.5 concentration depends mainly on wildfires, and that PM2.5 concentration does not change noticeably without wildfires.
Prof. Lee explained that the research succeeded in identifying the complex relationship between droughts, wildfires, and air pollution quantitatively with long-term data. He also pointed out the increasing number of massive wildfires and repeated droughts in Korea to emphasize the implications of the research. He also added, “Now the prevention and management of wildfires will play a pivotal role in improving air quality and protecting public health.”
