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10 Most harmful pollutants you’re breathing every day

Air pollution causes harmful health effects, ranging from irritating to life-threatening. Here are the 10 most harmful pollutants and what you can do about them.

Here’s a disturbing fact — 9 out of 10 people breathe air contaminated with high levels of pollutants.1 

We all begrudgingly accept air pollution as an aspect of modern life that’s as unavoidable as taxes, but what exactly are we breathing every day? How does it affect our health? And what can we do about it?

Air pollutants are incredibly diverse in terms of composition, health effects, and sources, ranging from the thick brown smoke belched out of monolithic mega-factories to invisible and insidious threats to your health and well-being. 

In this article, you’ll learn about: 

  • The 10 most harmful types of air pollutants 
  • How they impact your health
  • What you can do to protect yourself and your loved ones. 

Let’s do a deep dive into the most common and dangerous air pollutants that you’ll likely encounter:

1.Particulate matter (particle pollution)

Particulate matter (also called airborne particles or PM) consists of particles in the air, including dirt, dust, and smoke, and tiny drops of liquid.2 Airborne particles come in three sizes: PM10, PM2.5, and ultrafine.

PM10 (Coarse particles)

Coarse particles, or PM10, are inhalable particles with a diameter ranging between 2.5 and 10 microns.

All that dust floating around your attic or the ominous smoke billowing from a wildfire are great examples of PM10 particles that you can see. These airborne particles can affect your throat, eyes, and nose, and can cause serious health effects.

PM2.5 (Fine particles)

Fine particles, or PM2.5, are inhalable particles with a diameter of less than 2.5 microns, which means they can only be seen underneath a microscope. Common sources of fine particulate matter include pet dander, dust mites, bacteria, and dust from construction and demolition sites. PM2.5 particles are small enough to potentially lodge into your lung tissue, causing respiratory illnesses like asthma, bronchitis, and emphysema.

Long-term exposure to PM2.5 can also reduce both your lung function and life expectancy.3

Ultrafine Particles (UFPs)

Ultrafine particles (UFPs) are less than 0.1 microns in diameter and make up roughly 90% of all airborne particles.4

UFPs are the most dangerous particulate matter because their tiny size makes them extremely inhalable. Once inhaled, they get deposited into your lungs and absorbed directly into your bloodstream — providing a fast-track to any organ within your body.

The health effects of ultrafine particles are particularly nasty, increasing your risk for heart attacks and strokes and reducing your life expectancy.5

2. Pet Dander

We all love our furry friends, but for millions afflicted with pet allergies, it can be a stressful (and stuffy) friendship.

The culprit? Animal dander, the microscopic flecks of skin shed by birds, cats, dogs, rodents, and other cuddly critters with fur or feathers.

Pet dander is easily spread through your home and out to schools, hospitals, and other public places — even if there aren’t any animals present.6 Exposure to pet dander can trigger pet allergies, which can cause symptoms like:7

  • sneezing
  • runny nose
  • itchy, red, or watery eyes
  • nasal congestion

Additionally, if you have asthma, exposure to pet dander can exacerbate your symptoms.

3. Pollen

Pollen is one of the most notorious triggers of seasonal allergies.

Every spring, summer, and fall, plants release tiny pollen grains to fertilize other plants of the same species. Once airborne, these pesky pollen grains can infiltrate your respiratory system, where your body identifies them as invaders and releases antibodies to attack them.

Most pollens that spur allergic reactions derive from trees, grasses, and weeds, such as ragweed.8 People with pollen allergies experience symptoms that are similar to pet allergies, including sneezing, runny nose, and nasal congestion.

4. Mold

Simply put, molds are fungi.

Most people associate mold with that icky green fuzz on spoiled bread, but there are more than 100,000 identified species of mold.;

There are three types of mold species: allergenic, pathogenic, and toxigenic. While allergenic molds can aggravate mild allergies, and pathogenic molds can spur infection in people with compromised immune systems, toxigenic molds cause a toxic response in humans and animals.

Common sources of mold in homes, business, and schools include:9

  • leaks through roofs, walls, and basements
  • condensation on windows and in bathrooms
  • standing water in drains, on floors, and in dehumidifying equipment
  • wet floors and carpets

5. Lead

Since leaded gasoline has been phased out, airborne lead concentrations decreased in the US by 94% between 1980 and 2007; however, industrial processes such as lead-acid battery manufacturing have become a significant source of airborne lead.10

Lead exposure has a cumulative effect on your long-term health, meaning the more you’re exposed to lead over time, the greater the likelihood that you’ll experience serious health issues later on in your life. Chronic exposure to lead may result in:11

  • severe damage to your blood-forming, nervous, urinary, and reproductive systems
  • severe damage to your central nervous system and brain
  • kidney disease
  • death from lead poisoning

6. Volatile Organic Compounds (VOCs)

Volatile Organic Compounds (VOCs) are indoor gases emitted from solids or liquids, which significantly contribute to indoor air pollution. 

VOCs are emitted from a dizzying array of everyday items found in your home, including:12

  • building materials and furnishings
  • paints, paint strippers, and other solvents
  • cleaners and disinfectants
  • air fresheners and aerosol sprays
  • pesticides
  • dry-cleaned clothing

Exposure to VOCs can have a host of short and long-term health effects, such as:

  • irritation to eyes, nose, and throat
  • headaches, loss of coordination, and nausea
  • damage to liver, kidneys, and central nervous system
  • fatigue
  • allergic skin reaction
  • cancer (the VOC formaldehyde is a known human carcinogen)

7. Carbon Monoxide (CO)

Carbon monoxide (CO), known as the “invisible killer,” is an odorless, colorless gas that frequently goes undetected, killing more than 400 people in the U.S. every year.13 

Carbon monoxide is typically created from combustion processes, like the burning of wood, oil, coal, charcoal, natural gas, and propane, but it can also be found indoors from:

  • unvented kerosene and gas heaters
  • leaking chimneys and fireplaces
  • back-drafting from furnaces and water heaters

Mild to moderate carbon monoxide poisoning is characterized by:

  • headaches
  • fatigue
  • shortness of breath
  • nausea
  • dizziness

Severe carbon monoxide poisoning results in:

  • mental confusion
  • vomiting
  • loss of muscular coordination
  • loss of consciousness
  • death

Since you cannot see or smell carbon monoxide, it’s crucial that you install a carbon monoxide detector in the hallway near each separate sleeping area in your home. 

Check or replace the batteries when you change the time on your clocks each spring and fall, and replace the detector(s) every five years.

The Centers for Disease Control and Prevention (CDC) also provides these tips:14

  • Have your chimney checked and cleaned every year, and make sure your fireplace damper is open before lighting a fire and well after the fire is extinguished.
  • Have your furnace, water heater, and any other gas or coal-burning appliances serviced by a qualified technician every year.
  • Do not use portable flameless chemical heaters indoors.
  • Never use a gas oven for heating your home.
  • Never use a generator inside your home, basement, or garage, or less than 20 feet from any window, door, or vent; fatal levels of carbon monoxide can be produced in just minutes, even if doors and windows are open.
  • Never run a car in a garage that is attached to a house, even with the garage door open; always open the door to a detached garage to let in fresh air when you run a car inside.

8. Ozone (O3)

Ozone is a naturally occurring gas found in both the Earth’s upper atmosphere, where it helps block out harmful ultraviolet light from the sun. However, when ozone is found at ground level, it’s toxic to human beings. 

Ground-level ozone is formed when pollutants emitted by cars, power plants, refineries, and other sources chemically react in the presence of sunlight. Ever wonder why there’s more of that unsightly smog during hot summer days? That’s because the hotter the day and the stronger the sun, the more ozone is formed.15 

Exposure to ozone pollution can cause a multitude of alarming health effects, including:16

  • shortness of breath, wheezing, and coughing
  • asthma attacks
  • increased risk of respiratory infections
  • increased risk of stroke
  • increased risk of premature death 

9. Nitrogen Dioxide (NO2)

Nitrogen dioxide (NO2) is a harsh-smelling gas formed as a result of road traffic and other fossil fuel combustion processes. 

To make matters more malicious, nitrogen dioxide is also a precursor for ozone and particulate matter, and it plays a role in the formation of acid rain.17 

You’ll encounter nitrogen dioxide indoors if your heater or gas stove is unvented (also carbon monoxide as previously mentioned). Nitrogen dioxide can cause such health effects as:

  • irritation to lungs
  • lower resistance to respiratory infections

10. Sulfur Dioxide (SO2)

Sulfur dioxide (SO2) is a colorless gas or liquid with a strong, pungent odor. 

Unfortunately, the presence of sulfur dioxide in the air is almost exclusively man-made. Sulfur dioxide is produced when fossil fuels such as coal and oil are burned in industrial processes, and when mineral ores like aluminum are smelted. 

This noxious gas is also frequently responsible for causing poor visibility and acid rain. The short-term health effects of sulfur dioxide exposure include:18

  • irritation to nose and throat
  • shortness of breath
  • death (short-term exposure to high levels of SO2)

Long-term health effects of sulfur dioxide exposure include:

•    permanent changes to lung function
•    acute respiratory illness

Let’s clear the air: Pollution isn’t going away, so here’s
how to deal with it

You may not be able to singlehandedly stop pollutants, but you can follow these realistic, actionable steps to protect yourself and your loved ones from being exposed to dangerous air pollutants:

  1. Use an air quality monitor. Lightweight, ultra-precise, and powered by the world’s largest air quality data network, the AirVisual Pro lets you know exactly how clean or hazardous your air is. Take charge of your health and use the free Air Quality app to get real-time forecast and historical air pollution data. 
  2. Use a high-performance air purifier to clean your indoor air. Only IQAir’s patented HyperHEPA filtration technology is certified and proven to filter harmful ultrafine particles down to 0.003 microns — that’s ten times smaller than a virus and 100 times smaller than what a HEPA filter can capture.
  3. Properly maintain your gas appliances. Make sure your stove, heater, and other gas-powered appliances are regularly maintained by a trained professional. 
  4. Consider switching to gas logs instead of wood. Even when properly maintained, wood-burning stoves and fireplaces produce a significant amount of combustible pollutants such as CO, NO2, and ultrafine particles. 
  5. Ditch toxic synthetic cleaners, paints, and other household chemicals. Replace them with eco-friendly, naturally-derived products to reduce your exposure to harmful VOCs.
  6. Remove mold and allergy sources from your home. Make sure your home is well ventilated, regularly cleaned, and has a relative humidity of 30%-60% to reduce your exposure to these biological pollutants.
  7. Reduce your exposure to in-car pollution with a car air purifier. In-car pollution is far more hazardous than you think, with over 275 dangerous chemicals creeping around in the cabin of new cars.19 The Atem Car eliminates 99% of particle pollutants in your car cabin up to 20 times per hour, so you can enjoy odor, gas, chemical, and particle-free air wherever the road takes you.

With these seven powerful tips, you can make your air cleaner for yourself and for your family.

Article Resources

[1] Air pollution. (2019).
[2] Air contaminants. (2019).
[3] Particulate matter (PM10 and PM2.5). (2013).
[4] Stanier C, et al. (2004). Ambient aerosol size distributions and number concentrations measured during the Pittsburgh Air Quality Study (PAQS). DOI: 10.1016/j.atmosenv.2004.03.020
[5] Brook R, et al. (2010). Particulate Matter Air Pollution and Cardiovascular Disease. DOI: 10.1161/CIR.0b013e3181dbece1
[6] Kanchongkittiphon W, et al. (2015). Indoor environmental exposures and exacerbation of asthma: An update to the 2000 review by the Institute of Medicine. DOI: 10.1289/ehp.1307922
[7] Pet allergy symptoms and causes. (2019).
[8] Pollen allergies. (2015).
[9] Soloway, R. (2014). Mold 101: Effects on human health.
[10] Airborne lead. (2008).
[11] Substance data sheet for occupational exposure to lead. (1991).
[12] Volatile Organic Compounds’ impact on indoor air quality. (2017).
[13] Carbon monoxide: The invisible killer. (2019).
[14] Carbon monoxide poisoning: Frequently Asked Questions. (2018).
[15] Ozone facts. (2014).
[16] Ozone. (2019).
[17] Nitrogen dioxide. (2019).
[18] Sulphur dioxide. (2018).
[19] Jaslow R. (2012, February 15). New car smell is toxic, study says: Which cars are the worst?

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