Karalee Jarvill, age ll, of So. Sioux City,Nebraska, for her question:
How does air pollution get started?
The complicated process begins with waste materials poured into the air from man made engines and industrial plants. Many of these emissions, though unhealthy, are not downright dangerous. However, serious pollution builds up when these original emissions are changed by sunlight and by various gases in the atmosphere.
Someday historians will look back and wonder how our atmosphere got into such a state of unhealthy pollution. Moat likely they will decide that the Industrial Age happened too fast. Machines and factories were designed, built and put to work in a great hurry. The population increased at a great rate and everybody demanded every new gadget T right this minute. Nobody had time to consider what all this extravagant use of energy would do to the world of nature.
For example, most air pollution starts with wasteful burning processes. The rest starts with carelessly designed chemical plants. The automobile gets a lot of the blame.
Auto emissions are the unburned, wasted gasoline poured into the air as exhaust gases. Most of this material is hydrocarbon chemicals, which are not poisonous in small quantities. However, our streaming traffic pours forth countless tons of these auto emissions. And some of them react with the atmosphere to form destructive nitrogen compounds. Cars also emit quantities of carbon monoxide. When people breathe this gas in large quantities, they get headaches and fatigue and high concentrations can be fatal.
Some of the worst air pollutants are the nitrogen oxides. Most of them start out as waste emissions from autos, petroleum plants and from factories that burn, or partly burn, fossil fuels. One of these emissions is nitric oxide, a colorless gas. In the atmosphere, nitric oxide forms the stifling, reddish brown pollutant called nitrogen dioxide.
Nitrogen dioxide harms plant life and hamper the breathing of people and animals. Even worse, in certain weather conditions, it reacts with the air to form more dangerous pollutants. One of these is sulfur dioxide, which is destructive to all living tissue. And sometimes this pollutant combines with atmospheric moisture to form deadly droplets of sulphuric acid. When things get this bad, it's time to issue a red alert.
The worst kind of air pollution, of course, builds up around crowded cities, The mixture varies from place to place and changes with the weather.
With the Age of Industry, air pollution crept up on us unawares. When we realized how serious it was becoming, steps were taken to reduce it. This was helped somewhat, at least to stop pollution from getting worse. But ahead of us lies the enormous task of stopping it entirely. This will succeed when we control the emissions that start it.