How air pollution affects health and the environment. Scientists have long known the air we breathe can be hazardous to our health. The World Health Organization estimates that more than 90 percent of the world’s population breathes air containing harmful levels of pollutants. Airborne particulate matter (PM) is especially dangerous. Breathing these tiny, floating solid and/or liquid particles of organic and inorganic matter, also known as aerosols, results in more than 4 million premature deaths each year due to cardiovascular, respiratory, and other illnesses, according to a major international health study called the Global Burden of Disease.
What is an Air Pollutant?
The US Clean Air Act was incorporated into the United States Code of Federal Regulations, Title 42, Chapter 85. Its Title III, Section 7602(g) defines an air pollutant:
The term “air pollutant” means any air pollution agent or combination of such agents, including any physical, chemical, biological, radioactive (including source material, special nuclear material, and byproduct material) substance or matter which is emitted into or otherwise enters the ambient air. How air pollution affects health and the environment.
Clearly this is a very broad definition. More importantly, its Title 42, Section 7408 states that the US Environmental Protection Agency (EPA) Administrator must publish a list of certain air pollutants:
“emissions of which, in his judgment, cause or contribute to air pollution which may reasonably be anticipated to endanger public health or welfare”
Thus legally in the USA, CO2 is an air pollutant which must be regulated if it may endanger public health or welfare. And according to the encyclopedic definition, CO2 is a pollutant unless our emissions can be stored “harmlessly.”
How does air pollution affect Earth’s climate?
Aerosols can impact how the Sun’s light hits Earth. For example, some aerosols reflect sunlight while others absorb sunlight. It depends on the color of the particle.
Credit: NASA/JPL-Caltech
Dark surfaces—whether it’s a black t-shirt or a dark particle in the atmosphere—absorb the Sun’s heat. Lighter-colored surfaces reflect heat from the Sun.
A white t-shirt reflects the Sun on a hot day, making you feel cooler. In the same way, light-colored particles that reflect the Sun’s light and heat away from Earth can make the global temperature cooler. Dark-colored particles that absorb the Sun’s light can make the global temperature warmer.
How does air pollution affect our health?
Breathing in polluted air can be very bad for our health. Long-term exposure to air pollution has been associated with diseases of the heart and lungs, cancers and other health problems. That’s why it’s important for us to monitor air pollution.
How is NASA monitoring air pollution?
NASA uses satellites orbiting Earth to keep an eye on air pollution. In fact, air quality forecasters use information about aerosols from NASA’s Aqua, Terra and Suomi-NPP satellites.
NASA also is developing a new instrument called the Multi-Angle Imager for Aerosols, or MAIA, to fly aboard a future spacecraft mission. MAIA will help scientists understand the size, makeup and quantity of aerosols in our air. Eventually, scientists will be able to compare this information with health records. This can help us better understand the relationship between aerosol pollution and human health.
