A Pediatrician's Guide to Air Quality

The grandparents of today lived through the days of smog, when soot thickened the air and cities were blanketed with car exhaust haze. 

Then came the landmark Clean Air Act of 1970 and increasingly strict vehicle emission standards. Cars don’t spew out thick clouds of noxious smoke anymore, and it seems like our air is so much cleaner. 

One can be forgiven for believing that the breath you are taking right now is clean and safe. (And maybe it is!) But over half of all cities in the United States continue to have air pollution severe enough to cause serious harm to health. 

You may not see or smell air pollution, but your lungs, heart, brain and body can feel it – and be hurt by it. To know if the air you are breathing could hurt or shorten the lives of your children, you have to know what to look for, measure and see how your air rates.

Most air pollution comes from burning things like:

• Gasoline
• Wood
• Natural gas
• Coal

When you burn these once-living substances, you release three things into the air that can hurt you: nitric oxide, PAHs and particulate matter.

Nitrous oxide traps heat from the sun, just like its partner, carbon dioxide. This is one of the big causes of climate change, a massive threat to humanity.  But beyond climate change, nitrous oxide can damage brain development before birth, cause asthma and lead to impaired lung ability later in life.

PAHs are a group of chemicals called polycyclic aromatic hydrocarbons. These chemicals are released in smoke when you burn wood or fossil fuels like coal, natural gas and gasoline. The problem with PAHs is that they cause cancer and they can damage the development of your baby’s brain. Given that they destroy nerve cells necessary for normal brain development, the chance they could accelerate the dysfunctions of the mind later in life – such as dementia and Parkinson’s – is worth considering.

When you burn wood or fossil fuels like coal, gas and gasoline, you always create smoke. The reason smoke isn’t clear is because it has particles in it. If these particles are black and are larger than dust, they’re called soot. 

These days, most factories and cars burn or filter out the smoke enough that they don’t spew out as much soot as they did in the days of our grandparents. But there still are many particles in smoke that are smaller than soot. The most worrisome ones are a tiny 2.5 microns in diameter (a human hair is about 50 microns across, for comparison). These tiny particles are called “PM2.5.,” and they’re a high-priority issue when it comes to air pollution and health, because PM2.5 hurts people in so many ways. 

Air pollution can cause serious health problems affecting your:

• Brain: air pollution can affect brain development, which has been linked to developing ADHD, autism spectrum disorder and learning disorders
• Lungs: damaging the lungs causes asthma, and later in life COPD and emphysema
• Heart: breathing polluted air increases the risk of heart attack
• Blood vessels: breathing polluted air increases risk of stroke
• Uterus: air pollution is strongly associated with increased risk of miscarriage
• Cells: air pollution is strongly associated with increased risk of cancer

Putting it all together, just the PM2.5 portion of air pollution causes over four million deaths around the world, and over 50,000 deaths in the United States, every year

The international standard for measuring how polluted our air is is the Air Quality Index (AQI). AQI standards are set by each nation. In the United States, the EPA measures five elements of pollution: 

• Particulate matter
• NO2
• Ozone
• Sulfur dioxide
• Carbon monoxide

The numbers assigned to the AQI across the world range from 0 to 500, and lower is better. There are six categories of status:

• Good (0-50)
• Moderate (51-100)
• Unhealthy for Sensitive Groups (101-150)
• Unhealthy (151-200)
• Very Unhealthy (201-300)
• Hazardous (301-500)

As of the time of this post, the most polluted major city in the world is New Delhi with an AQI of 201. The next eight cities are in the 150-200 range and include cities across southeast Asia, one in China, another in India, one in Mexico and Berlin in Germany. 

The level at which our air quality damages our brains and shortens our lives is a choice we make as a nation. When we pass laws and enact regulations to clear our air, the air gets cleaner. When we don’t, air pollution worsens, and more of us are damaged and more of us die at younger ages.

And so the most important decision each of us can make for our babies, our kids, ourselves, is to decide whether insisting that the air we breathe will not hurt us is a priority – or not. If it isn’t, the air will never stop hurting us. If it is, we can keep it clean.

Since burning wood and fossil fuels, by choice or wildfire, is the number one source of pollution, the move to generating our energy by renewable fuels (wind, solar, geothermal, etc.) is the most powerful step that can be taken to slow climate change. 

Many nations have taken these steps already, and they now rank as the countries with the cleanest air. They include many Scandinavian countries, New Zealand, our territory of Puerto Rico, Austria and Ireland. Want to see our United States on that list, too? Spread the word, get involved, vote – be the change you want to see!

Did you know? Most of our homes’ indoor air quality is worse than our outdoor air quality (and your mattress might be part of the problem!). Here’s how to improve indoor air quality.