MAIA’s measurements of sunlight reflecting off airborne particles will help researchers determine the abundance, size, and optical properties of certain pollutants in the atmosphere. Using such data in conjunction with surface-based measurements will help researchers decipher the particles’ chemical composition.
Particles that are 10 micrometers or less in diameter (PM10) are small enough to be inhaled, potentially causing tissue damage and inflammation in the nose, throat, and lungs. Particles less than 2.5 micrometers (PM2.5) can penetrate deeper into the lungs and be absorbed into the bloodstream, where they can cause more serious health problems.
The composition of such particles depends on how they were formed. For example, black carbon results from the burning of fossil fuels and trees, while mineral dust comes from soil and sand. Other particles – organic carbon, sulfates, and nitrates – can form through chemical reactions between gases in the atmosphere. MAIA’s main objective is to study whether exposures to these different types of particle pollution have differing health impacts.
Over the course of its three-year mission, MAIA will focus on 11 primary target areas that cover major urban centers around the globe: Los Angeles, Atlanta, and Boston in the United States; Rome; Addis Ababa, Ethiopia; Barcelona, Spain; Beijing; Johannesburg; New Delhi; Taipei, Taiwan; and Tel Aviv, Israel. While orbiting 460 miles (740 kilometers) above Earth’s surface, the mission will also collect some data over 30 secondary target areas throughout the world.
Epidemiologists on the science team intend to study the effects of short-term exposure to particulate pollution over the course of days, as well as chronic exposure, which can last many years. Also of interest is “sub-chronic” exposure, such as the monthslong inhaling of pollutants that might occur during pregnancy, which can lead to adverse health effects for a mother and infant.