Seeing through Air Pollution in 2020

What is Air Pollution?

Air pollution is made up of particles and different kinds of gases both inside and outside our homes. The differentiating factor between air pollution and the air we want is just that air pollution is harmful. Air pollution can impact human health through increased risk factors while also impacting our world through rising temperatures.

How do we measure Air Quality?

Air quality is measured through an index known as the Air Quality Index (AQI). The AQI is a daily reporting on air quality that shares how clean or polluted the air is. The Environmental Protection Agency measures the AQI with all 5 major air pollutants in mind: particulate matter, ozone, nitrogen dioxide, carbon monoxide, and sulfur dioxide. The AQI runs on a scale, from 0 – 500. The higher you are on the scale, the more polluted the air. To check the air quality, go here.

The 5 Major Air Pollutants

*Air pollution includes greenhouse gases, like carbon dioxide and methane, but these are not the most common air pollutants*

1.       Particulate matter is just really, really tiny particles that can be solid or liquid. These particles are suspended in the air and we’re actively breathing them in. The issue is that these particles are made up of nitrates, sulphates, organic chemicals, soil or dust particles, and allergens, whether those be pollen fragments or mold spores. Particulate matter mostly comes from our cars, industry, and wood-burning heaters. These particles are broken down into two different sizes based on how they affect human health. Particles with a diameter of 10 micrometers or less are small enough that they pass through our nose and enter into our lungs. There are particles even smaller, with a diameter of 2.5 micrometers or less, that are able to pass through our lungs and into our bloodstream! Particulate matter has a range of health effects depending on type and size, but there is a known association between exposure to particles and an increase in hospital admissions and heart or lung disease-induced death.

2.       Ozone is a highly reactive gas that is both natural and man-made. The basic oxygen molecule (what we breathe) is made up of two oxygen atoms. When a third oxygen atom is introduced, we get ozone. Ozone exists in two distinct ways within Earth’s atmosphere; you have ozone in the upper atmosphere, where it acts as a shield between us and damaging ultraviolet light from the sun, and then you have ground-level ozone. The ground-level ozone is what’s concerning. Ground-level ozone is the main component in smog and it exists due to the interaction between sunlight and things like car emissions. Ozone is a massive irritant, causing potential inflammation in our eyes, noses, and throats. Ozone can exacerbate health issues like asthma and chronic respiratory diseases, like chronic bronchitis. The issue with ozone is that it travels long distances and accumulates in high concentrations, so we aren’t able to track down the original pollutant.

Per NASA

3.        Nitrogen dioxide (NO2), like ozone, is a highly reactive gas. NO2 finds its way into the air primarily through fuel burning (i.e. cars), but it also is emitted from industry and unflued gas-heaters and stoves – unflued just means that a heater/stove burns gas without having a chimney or other mechanism to carry the combustion products away. Since cars are the primary source of NO2, it makes sense that busy roads are where we find the highest concentration. NO2 is another respiratory irritant – causing increased susceptibility to health effects like lung infections and airway inflammation (even in healthy people). As if NO2 wasn’t bad enough on its own, it also contributes to the formation of ground level-ozone and particulate matter!

4.       Carbon Monoxide (CO) is yet another gas. This one, however, is both colorless and odorless. We get CO when carbon in fuels doesn’t have the chance to completely burn. Typically, CO comes from cars, industry, and bushfires but it can also come from unflued gas heaters, wood-burning heaters, and cigarette smoke. Cold temperatures make combustion more difficult and therefore less complete so it’s in the winter months that we see the highest CO levels. The harmful effects that come from CO occur because CO reduces the amount of oxygen that reaches the body’s organs and tissue. When there are really high levels of CO, it can actually cause death through carbon monoxide poisoning. You can learn about carbon monoxide detectors for inside your home here!

5.       Sulfur Dioxide (SO2) is a smelly gas that’s also highly reactive. We get SO2 mostly from fossil fuel combustion at power plants and industrial facilities. However, SO2 can be released through natural processes like decomposition and combustion of organic matter, sea spray, and volcanic eruptions. SO2 has been found to exacerbate cardiovascular diseases while also acting as a respiratory irritant.

How much Air Pollution do we have?

The Environmental Protection Agency released data in the summer of 2019 that showed air pollution is increasing and the air quality of the US is in definite decline. Compared to 2013-2016, 2017/2018 has increased in the average number of unhealthy air days. By 15% more days, to be exact. Though there isn’t a surefire explanation as to why the decline is happening, the EPA believes it may be related to the high number of wildfires, our warming climate, and our general increase in consumption (driven by both population growth and a well-off economy).

We’ve talked about the most common pollutants, but how bad is it?

We talked about the specific health risks with each pollutant, but air quality, in general, has been linked with higher rates of cancer, heart disease, stroke, and respiratory diseases like asthma. But worldwide, bad air quality is causing people to die. In 2016, there were an estimated 4.2 million premature deaths. Of those deaths, only 10% occurred in high-income countries. Just in the United States, the American Lung Association estimates that 134 million people (which is over 40% of our population!) are at risk of disease and premature death associated with air pollution.

There are also effects of air pollution that aren’t directly health-related.

Read: Climate Change

As I mentioned previously, air pollution includes greenhouse gases. An increase in greenhouse gases is related to heatwaves, extreme weather, and disruptions in our food supply – all of which can have indirect effects on human health. The fourth National Climate Assessment released by the United States in 2018 mentioned that a changing climate could “expose more people in North America to ticks that carry Lyme disease and mosquitoes that transmit viruses such as West Nile, Chikungunya, Dengue, and Zika.”

Quick Greenhouse Gas Snippet

Of the greenhouse gases, carbon dioxide is the most potent. Carbon dioxide contributes to climate change by trapping heat in the atmosphere. Over the past 150 years, humans have raised the amount of carbon dioxide in the atmosphere higher than it’s been in hundreds of thousands of years.

Methane is another top contender, coming primarily from landfills, the natural gas industry, and gas from livestock.

Sulfur dioxide (mentioned earlier!) mixes with other chemicals and is the primary cause of acid rain. When Sulfur dioxide is released into the environment, it reflects light to the point that the sunlight can’t reach us and we have a cooling effect. While cooling might sound like an ideal alternative in the time of global warming, it’s not quite that simple. Because Sulfur dioxide comes from both man-made and natural sources, we can’t keep a hold on how much Sulfur dioxide is entering into our atmosphere. The cooling effect can last for years, which has the potential to be detrimental to agriculture.

Particulate matter (mentioned earlier!) can potentially change or deplete the nutrients that we need in our soil and waterways. Particulate matter can also cause harm to our forests and crops as well as our monuments and statues.

What do Wildfires do?

Wildfires aren’t the leading cause of air pollution but they’re definitely a contributor. Wildfires consume everything in their path, traveling at speeds up to 14 miles an hour, and in the US the havoc caused by wildfires has only increased significantly over the last two decades. Each year since 2000, the US has been witness to an average of 72,400 wildfires. These wildfires were able to burn out an average of 7 million acres. These numbers are double what the US saw in the 1990s. The largest wildfire season that the US experienced was in 2015, where wildfires burned more than 10 million acres. Because of climate change, it’s only expected that the US will get hotter and drier thereby creating the perfect conditions for wildfires. 

What causes wildfires?

Wildfires occur across the globe but they are the most common in the US, occurring in nearly all 50 states. The EPA classifies wildfires as natural disasters but, unfortunately, most of the wildfires are caused by humans. In fact, only 10-15% of all wildfires occur on their own.

Wildfires happen naturally?

They do! There are actually a ton of benefits to wildfires. In dead or decaying matter, nutrients are sort of locked in. When a wildfire takes place, these nutrients are released back into the soil where they can be utilized again. There’s also a disinfectant quality to wildfires because they clean out plants and insects that are potentially harmful, while also removing underbrush that disinhibits new growth. Whether they occur naturally or because of human error, there are three conditions that have to exist for a wildfire to take place. There has to be fuel, air, and a heat source. Natural wildfires can occur through lightning and even the sun if there’s a sufficient amount of heat!

But there are places where clean air still exists… right?

Not exactly.

Our National Parks are what come to mind for many when we want to escape the smog-ridden cities. Unfortunately, 96% of our 416 National Parks are facing serious air quality issues. There are times where 85% of the parks have air that is unhealthy for visitors.

Most of the air pollution in our parks is ozone. It was recently discovered that 33 of our nation’s most visited parks have the same concentration as the 20 largest US urban areas, including Los Angeles. The air pollution is bad enough in our national parks that some people have just stopped going. This creates an economic concern, especially in one of the most popular national parks.

The Great Smoky Mountains

Over the past 50 years, the scenic overlooks in the GSM have decreased significantly due to air pollution. According to regional air reports, southern Appalachia’s visibility has decreased as much as 40% in the winter and 80% in the summer. For a lot of people in a 1996 survey (84%), the views of the Smoky Mountains were seen as being “extremely important.” Even clean air was extreme importance, with 74% of summer visitors ranking it so.

In the East, the GSM is among the highest in terms of ozone exposure. Recently, these levels have actually gone above what we deem acceptable for human health. Even beyond humans, these ozone levels are damaging, though! There are over 30 species of plants that have shown damage after being exposed to these ozone levels. Compared to all national parks, the GSM also receives the highest amount of sulfur and nitrogen deposits. This affects the rainfall in the mountains, making it more acidic. Compared to normal rainfall, the rainfall in the park is actually 5 – 10x higher in terms of acidity. There’s so much nitrogen in some of these high elevation soils, they’re actually suffering from advanced nitrogen saturation. The combination of sulfur dioxide and nitrogen saturation limits the availability of forest nutrients, which causes the release of toxic aluminum. Toxic aluminum can hurt both vegetation and stream life. The health of the park’s high elevation ecosystem is being put at high levels of risk due to mountain streams and forest soil being acidified.

What’s to be done?

Globally, countries are taking solo-initiatives to clean up the air. For example, China is currently working to handle smog in their cities by closing coal-fired power plants. In 1970 in the US, Congress passed the Clean Air Act. As a national policy, the Clean Air Act is meant to preserve, protect, and enhance air quality. As far as our Great Smoky Mountains go, a voluntary group started a multi-organizational initiative in 1992 known as the Southern Appalachian Mountains Initiative (SAMI). SAMI is meant to work as a comprehensive approach to improving regional air quality by curtailing the adverse effects of air pollution in the Southern Appalachia.

What can I do?

People can work against indoor air pollution just by being more mindful! We can keep our homes filled with clean air by increasing ventilation, by running exhaust fans in both the kitchen and the bathrooms, by using air purifiers, purchasing test kits (radon and carbon monoxide), by purchasing green seal products, and by opting not to smoke.

For the greater good, we can contribute to the decrease in air pollution by conserving our energy usage in both appliances and transportation, keeping our cars up to date and in good engine condition, and by letting our officials know air quality is important to us.