Oh, Beautiful for Smoggy Skies
Find out how your driving affects the air in your community.
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Oh, Beautiful for Smoggy Skies
Make-it-Green Girl here, with more tips for making your driving more green-ified. This week I’m going to be building on that ever present subject – driving – by submitting for your consideration the impact of the automobile on air quality.
Why is it called smog?
When humans discovered fire, it was already the beginning of the end for pristine air quality. In the 12th century, when the British ran out of timber and started burning coal instead, it was almost a death sentence. London is the first and most famous example of a city whose air quality deteriorated so badly that a new word had to be created to describe it.
The word smog is actually two words–smoke and fog put together in what’s called a portmanteau word. Smoke plus fog equals smog. This cute but fitting description attempted to capture the dual nature of smog–it was thick and brown like smoke, but it would also linger for a long time close to the ground like fog.
P.S. – If you want to learn more about portmanteau words, check out Grammar Girl’s Quick and Dirty Tips for Better Writing! In fact you will even be able to pick up a copy of the new book, Grammar Girl’s Quick and Dirty Tips for Better Writing by Mignon Fogarty wherever books are sold on July 8th. Reserve a copy now or preorder one from your favorite online retailer.
What makes up smog?
The components of smog are many, but a key few come from driving your gasoline powered car. The nastiest pollutants that come straight from your tailpipe are NOx, carbon monoxide, and VOCs.
Nitrous Oxides
Oxides of nitrogen are collectively referred to as N-O-subscript X, which is pronounced like “knocks.” These compounds are formed in car engines because there is nitrogen and oxygen in the air that your car uses to burn the gasoline. Nitrogen, which exists in the air as two nitrogen atoms bonded together is incredibly stable. So stable, in fact, that important historical documents like the U.S. Constitution are often preserved in a sealed box filled with nitrogen.
But, at the extremely high temperatures of your car’s internal combustion chamber, nitrogen can be broken apart and recombined with other elements in the chamber, usually oxygen, and voila! NOx is created. In fact, anything burned at high enough temperatures in air is going to produce NOx. NOx is particularly noxious as an air pollutant, because it has a lovely brown color that contributes to that dirty haze over our cities. It can also combine with water vapor in the atmosphere to form nitric acid, which falls back to Earth as acid rain.
Most car engines are designed with a lean fuel-to-air ratio, meaning there’s more air than is necessary to burn the fuel. One result of this is a lower combustion temperature, which helps lower the amount of NOx created. However, this does’nt eliminate it entirely, and further lowering the flame temperature makes your engine less and less efficient (read: more and more gas hungry)! Thankfully, the three-way catalytic converter in your car is a key weapon in fighting air pollution. It traps NOx on the surface of the catalyst long enough to reduce it back to nitrogen and oxygen.
Frequent tune-ups for your car, before it breaks down or fails a smog test, are a great idea to help keep your car’s smog emissions low. Have your mechanic check both your fuel to air ratio and your catalytic converter.
Carbon Monoxide
Carbon monoxide is a partially oxidized form of carbon that’s created when almost any carbon compound is burned in oxygen, from tobacco to natural gas. Some substances, when burned, produce more carbon monoxide than others. Your gasoline engine is surely not the worst offender, but with so many cars on the road, it can still leave a mark on your community’s air quality.
Carbon monoxide is particularly dangerous to your health. The one molecule of oxygen (hence ‘monoxide’) bonded to one carbon atom is a near perfect fit to your body’s hemoglobin. Hemoglobin is the molecule that transports oxygen through your bloodstream to your tissues. Carbon monoxide binds irreversibly to hemoglobin, rendering it useless to transport oxygen in your blood; if enough of your hemoglobin gets tied up, you essentially suffocate.
Automotive engineers have an answer for this problem as well. You guessed it–the three-way catalytic converter! The second “way” that it cleans your exhaust is by oxidizing carbon monoxide into carbon dioxide. Too much carbon monoxide in your ambient air can be deadly.
VOCs
Volatile organic compounds, or VOCs for short, are a large family of smallish hydrocarbon molecules that come from petroleum products, like benzene and toluene. “Volatile” means they evaporate at temperatures at or near ambient air temperatures. “Organic” means they contain carbon. “Compound” just means they are made of more than one species of atom, mostly carbon, hydrogen, nitrogen, and oxygen.
VOCs appear in car exhaust because they’re already present in the gasoline, and small amounts don’t burn in the engine. VOCs can also escape the nozzle of the gas pump when you fuel up, or out of the opening of your gas tank if you’re topping up your tank.
Your car is probably already equipped to deal with the VOCs sneaking out of your tailpipe. The last “way” the three-way catalytic converter protects our air is to fully oxidize unburned VOCs into carbon dioxide and water. So, keeping your car’s catalytic converter working and your smog checks updated can go a long way towards reducing VOC emissions.
To help reduce emissions from fueling, choose newer gas stations, whose pumps frequently have check valves to keep fuel from spilling when you stop fueling. Make sure to do your part, too, by waiting a few second after releasing the pumping handle before removing it from your tank, to allow excess gasoline to spill into the gas tank, not all over your shoes.
You Can Do It
I hope you feel more empowered to help clean up your local air quality by adopting good car maintenance habits. Of course, the easiest way to reduce emissions is to reduce them to zero… by not driving. But for many of you, this is not an option. [In a Yoda voic Drive you must. But save the air, you still can. Less often, you must drive. Maintain your car, you must. Then, a great eco-warrior will you be.
Thanks for listening to Make-it-Green Girl’s Quick and Dirty Tips for an Earth Friendly Life.Â