Ecology: Menace in the Skies

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Authorities in the German state of North Rhine-Westphalia are so concerned about the dangers of smog in 15 Ruhr districts that they have posted warning signs that will bar traffic from roads in the event that air pollution becomes extreme. And out in space last September, after other astronauts had repeatedly failed to photograph Houston because of the dense brown disk of smog that usually hangs above it, Gemini 11 Command Pilot Pete Conrad finally shot a picture of the city on one of its better days. Discussing the photograph after his return to earth, Conrad pointed to the reduced but ever present pall over the city. "Notice the air pollution drifting out there," he said, "in case anybody thinks we don't have it."

Smog disintegrates nylon stockings in Chicago and Los Angeles, eats away historic stone statues and buildings in Venice and Cologne. Rapidly industrializing Denver, which for many years boasted of its crystalline air, is now often smogbound. In Whiting, Ind., a concentration of fog and pollution from an oil refinery produced a chemical mist that one night last year stripped paint from houses, turned others rusty orange, and left streets and sidewalks covered with a greenish film.

Pollution's First Victim. Air pollution, commonly thought to be a result of the industrial revolution, actually preceded man himself. Nature has long contaminated the air with sand and dust storms, with forest fires and volcanic eruptions that spew tons of particles and gases into the atmosphere. When Krakatoa, a volcano in the East Indies, blew up in 1883, the debris and dust it hurled into the air spread around the globe, darkening daytime skies for hundreds of miles. Krakatoa dust, suspended in the atmosphere, produced spectacularly ruddy sunsets and sunrises the world over for months after the blast.

Nature even produces its equivalent of smog. Over large fir forests, there is a continuous bluish haze produced by terpenes—volatile hydrocarbons that are emitted by the trees. Decaying animal and vegetable matter give off gases. Flowers saturate the nearby air with pollen that causes such allergic reactions as hay fever in man. It was natural air pollution rather than the man-made kind that claimed the man who is probably the first recorded human victim; Pliny the Elder died in 79 A.D. after breathing in an overdose of sulphur oxides emanating from erupting Vesuvius.

Once man mastered fire, however, he was superbly equipped to surpass nature's contribution to air pollution. The burning process—combustion—powers most transportation in the U.S., plays a vital role in its manufacturing, generates electric power, heats homes and buildings, and consumes much of its refuse. But this year it will also pour 140 million tons of pollutants into the air. And as population, industrial production, number of automobiles, and other indices of U.S. prosperity increase, the upward flow of contaminants will increase correspondingly.