Global climate change is making warm, drought like conditions across the globe more common. A contributing factor to the change in global climate is deforestation of rainforests for agricultural use in Indonesia and the Amazon. The deforestation process involves burning away native vegetation, which releases carbon dioxide (CO2) stored in the vegetation and in turn contributes to global greenhouse gas emission. This last year, 2015, Indonesia and Borneo had intense weather patterns that reduced the amount of rain falling on the forests and contributed to the widespread fires that ravaged the landscape. These fires caused the largest release of CO2 from Equatorial Asia in 28 years. Forest fires release copious amounts of fine particulate matter into the air. This particulate matter is known to contribute to worsening of lung conditions like asthma and COPD, exacerbate heart conditions leading to heart attacks, and make people more susceptible to viral and bacterial infections. For this reason, the WHO sets limits to the amount of particulate matter that should be allowed in the air. During these fires, the amount of particulate matter in the air was 10 times higher than the recommended guidelines. To assess the health impact of these fires, an international team of researchers collected satellite and meteorological data during the fires to model the spread of the particulate matter and estimate the impact on human health.
The team found that levels of PM10 and PM2.5 (two sizes of particulate matter) were significantly elevated from September to October, the same period over which the wild fire was active. The levels of both sizes of particulate matter greatly exceed the WHO standards across almost all of Equatorial Asia. In the provinces of Jambi and South Sumatra, and Central Kalimantan, PM concentrations were up to 100 times higher than normal. An estimated 69.3 million people were exposed to unhealthy levels of particulate matter, levels that would cause most people to experience negative health effects and would cause more serious health complications in those with pre-existing disease. An additional 5.6 million people were exposed to very unhealthy levels of particulate matter and 2.0 million people were exposed to hazardous levels of particulate matter. Hazardous levels are defined as those that could cause serious health effects in everyone and it is advised that everyone stay indoors. During the course of the wildfires, it was estimated that between 6,100 and 17,200 people died prematurely due to particulate matter exposure. That is a large number considering the relatively short term exposure (2 months). This model estimates that if the population of Equatorial Asia were exposed long term to the level of particulate matter seen with this fire we could expect an additional 75,600 pre-mature deaths per year.
This research highlights a couple key points. First, exposure to particulate matter from fire or urban pollution is a serious health concern that needs serious attention from the government and health organizations across the world. Second, global warming will only serve to worsen the burden of poor air quality specifically in poorer parts of the world where wild fire control is inadequate. Controlling our CO2 and pollution levels will not only stave off global warming, it will also save millions of lives per year.
Image Credit: Flikr Dan Pearce