Take a deep breath and you’ll inhale an assortment of gases; (about 20% oxygen along with an assortment of inert gases such as nitrogen (78%), argon (0.9%), carbon dioxide, and so on. You’ll also breathe in a small number of toxins. Many tens of thousands – and potentially millions – of tiny microscopic particles cloud every breath you take.

Toxic chemicals in the air we breathe

There are several potentially harmful chemicals in the air we breathe. Here’s a look at the major ones:

We’re used to hearing about mercury in fish, but much of the mercury that gets into the water in the first place originates in our air. Coal-fired power plants and industrial facilities release this neurotoxin into the air your children breathe, and what’s left over settles into the ground or drops into lakes and streams, where it poisons fish.

Though lead is no longer used in gasoline, it is still a byproduct of other industrial processes and can be found in harmful amounts in many areas across the U.S.

This contributes to acid rain and respiratory ailments. Diesel sold in the U.S. contains 0.0015% sulfur, and “bunker fuel,” used by Cargo ships, is a whopping 4.5% sulfur by weight. (Mims, 2010) According to the World Health Organization, the concentration of S02 (sulfur dioxide) released by fossil fuels kills an estimated 500,000 people each year. (Kunzig, 2008)

Nitric acid
Another source of acid rain, this corrosive mist is released from smokestacks and farming operations. Fertilizer manufacture and concentrated animal feedings are a major culprit.

Nitrogen dioxides
Invisible to the naked eye, this air pollutant has been linked to a number of health problems, including asthma, lung disease, and even death if inhaled frequently enough. Diesel-powered cars are a major emitter of nitrogen dioxide.

Nitrogen oxides
Both NO and N02 occur whenever air is heated; cars are a major source (15-25%), as are fossil-fuel power plants (30-50%) and industrial facilities (25-35%). (Rohde & Muller, 2016)

  • There is also particulate matter, ozone, smog, and polycyclic aromatic hydrocarbons, which we’ll discuss separately in the next chapter.


Children breathing dirty air

Many families live in places with toxic air. The percentage of children living in counties in the U.S. in which levels of each air pollutant in 2006 rose above allowable EPA levels is as follows:

  1. Ozone: 52.55%
  2. Particulate matter: 12.63%
  3. Particulate matter over 10 ppm: 8:72%
  4. Carbon monoxide: 0.49%
  5. Lead: 0.07%

(Science News, 10-11-2008, p. 4; Childstats.gov)

Air pollution can still pose a health risk even when within the allowable limits set by the EPA. So even those children living in less polluted areas can suffer adverse effects and consequences from airborne toxins.