Until now, measuring levels of air pollution around the world has been difficult, but since new satellite-based imaging has been implemented, researchers are able to determine the extent of pollution in particular areas of the world that previously could not be measured. Satellites are making it possible for experts to get a glimpse of how and where matter settles around Earth, and is also providing a clearer understanding of pollution and the problems it creates.
The harmful level of particulate matter begins at 2.5 micrometers in diameter. Researchers know that material of this size can become embedded in the lungs and will contribute to asthma or other serious health issues. Without the satellite imagery, chances of measuring harmful pollutants around the world have been slim, but now, scientists can begin to measure the quality of air worldwide.
NASA is instrumental in operating the satellites from space and determining levels of pollution at or near the planet’s surface. NASA gathered the information, and researchers Asron van Donkelaar and Randall Martin, both from Dalhousie University in Canada, were able to implement computer models that generated a global map showing where the pollution matter was heaviest.
Western Europe, in the areas of China have seen increases in levels of aerosol pollution since the implementation of satellite imagery, much because of the rapid increase of industrialization. India’s levels have also increased due to the heavy areas of black carbon that could, according to some scientists, eventually alter the seasonal cycles of monsoon climates.
No part of the Earth is without some level of pollution, due to winds that naturally scatter the pollutants and dust from urbanized areas of the world to the seemingly lifeless Saharan deserts. Eastern China and northern India produce pollutants through power plants and factories that are allowed to burn coal without filters. According to the imagery, pollution levels in the United States were relatively low, but were still visible on the satellite models, mostly in the Midwest and in the eastern parts of the country.
Motorized vehicles are blamed for producing particles and nitrates throughout the world, and diesel engines yield increasing levels of soot into the air that are constantly carried through the wind. Researchers are working to update the satellite imagery on an ongoing basis in order to determine pollution that is human-caused or is naturally occurring. The imagery also suggests that 80-percent of the world’s population is now breathing polluted air that exceeds what experts recommend. World Health Organization’s have determined that healthy levels should not exceed 10 micrograms per cubic meter.
Countries that are still developing previously had no way of measuring the amounts of pollutants in the air without surface-based pollution sensors that help measure airborne particles, known as PM2.5, or particulate matter that are 2.5 micrometers or less in diameter. These particles are smaller than a human hair and can easily go undetected by human defenses. Satellites of the past could not determine whether particles were close to the ground or high into the atmosphere. Many times, clouds will still block the views, as will snow-covered land or desert areas. Researchers have created the imagery maps from the NASA satellites and information on aerosol amount levels from computer programs.
The American Heart Association estimates that air pollution in excess of PM2.5 levels is responsible for more than 60,000 deaths each year in the United States. Experts have determined that once pollution is in the lungs, the particles can enter the bloodstream contributing to a wide range of life-threatening illnesses, including heart disease and bronchitis. With the information gathered from the imagery, how pollutants affect human health can be more easily determined, as well as be more accurate.
Scientists at NASA are planning to continue satellite imagery studies, as well as participate in other studies relating to satellite missions. The satellite imagery and resulting knowledge gained from the maps are both important to realizing how pollution impacts every corner of the earth, and how it can be accurately measured.
In the ongoing effort to measure pollutants, scientist will begin to study data from NASA satellites carrying innovative instrumentation known as a polarimeter. This instrument is designed to measure properties in new and different ways, and working with current instruments will measure aerosol pollutants from space.