Many years ago my parents took the family on a car trip from Louisville to New York City. Our route took us through Pittsburgh. When we reached the outskirts of the city, the sky turned gray. Downtown it looked like it was dusk in mid-afternoon. The unusually colored air was a result of the air pollution from the many factories and steel mills in the area. My parents marveled at the prosperity that resulted from the busy economy that brought on the pollution.

A few years later I returned to Pittsburgh and the air was clear. The polluting industry had either been closed or they had installed pollution control equipment. There were many shiny new skyscrapers built downtown. The economy was rolling along splendidly, and the air was cleaner. Bad air was not necessary for the city’s prosperity.

Recently there has been an epidemic of foul air in China. There have been reports that some days the air was so thick in Beijing that flights in and out of the city were cancelled. Fortunately the air in Shenzhen seems no worse than usual.

The word smog is a combination of the words smoke and fog. In the old days the smoke came from burning coal for industry and heating homes. In less industrialized times, it was the kind of air pollution most often encountered. It eased as industry began eliminating burning coal, and with the advent of scrubbers on smoke stacks and other air cleaning devices.

In more recent years photochemical smog has been most often encountered. It is a mixture of ozone and various carbon, nitrogen, and sulfur compounds combining within the air. The chemicals are released primarily by modern industrial processes, automobiles, and many smaller sources, including natural.

Bad air has bad health effects. There have been cases where the dirty air killed people directly, like the Great Smog in London in 1952. Then some 4000 people were killed in the four days it lasted. 60 people died in a suburb of Pittsburgh in 1948 during an especially severe smog. There are all sorts of estimates about how many people develop long term respiratory and other health problems from breathing polluted air.

Most western governments have passed laws and regulations aimed at cleaning the air. While not perfect, the air is much cleaner than it was even a few years ago. Things continue to improve as environmental science and technology advances.

Pollution is a product of prosperity. It is a symptom of good economic times. There is little air pollution in primitive and backward areas of the world.

Currently China finds itself where the west was a few years ago. Its young economy is coming on strong. It is developing quickly. Coal fired power plants are being built to supply the energy needed for the economic renaissance. Cars crowd the roads as people go about their business.

As China’s economy has flowered, so has its bad air. Once viewed as an inevitable product of a brisk and growing economy, air pollution is now seen as an unnecessary burden on everyone it effects. The government is starting to enact emission controls on automobiles, and is closing some of the worst polluting factories. There are also fledgling efforts to clean the waters of China.

In many ways bad air is similar to the childhood disease of measles, or Rubella. Measles are spread from person to person by a virus. Often the high fever and respiratory problems brought on by the disease are severe, even permanently damaging. Fortunately, most people recover from the illness completely.

While sick, the body develops immune tools to fend off future attacks from the virus. People usually get measles while young. Most recover and live strong and healthy lives, immune from further bouts of the illness.

Air pollution is like measles. It has attacked the young Chinese economy. At the present time the attack is very severe, even debilitating. China is like the Pittsburgh of my childhood, prosperous but dirty.

But China is beginning to fight back, much like the human body fights the measles virus. Now it looks like pollution is winning the battle, but China continues to strengthen its regulations and enforcement efforts. Eventually it will win the battle. It will emerge from this sickness and its overall economic health will be greatly improved.