Acid Rain-A Worrisome Threat

At one time, people in England used to die because of breathing the air-or, rather, the smog. Today, deaths from such pollution are rare. London's smog, which killed an estimated 4,000 in 1952, is no longer a threat. Some coal-burning power stations that contributed to the smog have been transferred to the countryside and equipped with high chimneys and, in some cases, scrubbers to remove a large percentage of the most deadly gases.

This has not, however, stopped the polluting of the atmosphere. Tall chimneys may have eliminated the danger from the immediate area. But now, prevailing winds transport the pollutants far afield-often to other countries. As a result, Scandinavia suffers from British pollution, and many people refer to Britain as the "Dirty Old Man of Europe." In a similar way, Midwestern industry in the United States causes much of Canada's acid rain problem.

For years, scientists have pointed an accusing finger at sulfur dioxide as the main culprit responsible for the air pollution that causes acid rain. In 1985 Drew Lewis, a U.S. presidential envoy on Canadian-American concerns about acid rain, claimed: "Saying that sulphates do not cause acid rain is the same as saying that smoking does not cause lung cancer." Seemingly, when it comes in contact with water vapor, sulfur dioxide produces sulfuric acid, which may acidify the rain or collect in the droplets of clouds, thus bathing upland forests with deadly moisture.

As the acid rain falls or, worse, as the acid snow melts, the soil beneath is affected. Swedish scientists who repeated a 1927 study concluded that at a depth of 28 inches [70 cm], the acidity of forest soil had risen tenfold. This chemical change seriously affects a plant's ability to take up vital minerals, such as calcium and magnesium.

What effect does all of this have on man? He suffers when lakes and rivers formerly teeming with life become acidic and lifeless. Moreover, Norwegian scientists conclude from their studies that the increased acidity of the water, whether in lakes or soil, dissolves aluminum. This poses a definite health hazard. Scientists have noted "a clear relationship between higher mortality statistics and increasing aluminum concentrations" in the water. Possible links between aluminum and Alzheimer's disease and other ailments of the aged continue to cause alarm.

True, in areas like Britain's Mersey River and France's Entressen garbage dump, efforts have been made to improve the situation. However, this type of problem does not go away. It reappears all over the world. But there is yet another kind of pollution-invisible.

Ozone-The Unseen Enemy

Burning fossil fuels, whether in power stations or in domestic furnaces, produces other pollutants in addition to sulfur dioxide. These include oxides of nitrogen and unburned hydrocarbons.

Scientific opinion now places increasing blame for air pollution on these nitrogen oxides. Under the effect of sunlight, they help produce a deadly gas, ozone. "Ozone is the most important air pollutant affecting vegetation in the US," stated David Tingey of the U.S. Environmental Protection Agency. He estimated that this was costing his country $1,000 million a year in 1986. Europe's loss was then put at $400 million annually.

Hence, while acid rain is killing waterways, many feel that ozone, linked ultimately to automobile exhausts, is more to blame than acid rain for the death of trees. The Economist stated: "Trees [in Germany] are being prematurely killed not by acid rain but by ozone. Though the death blow may be delivered by frost, acid mist or disease, it is ozone that makes the trees vulnerable." And what is happening in Europe merely mirrors the conditions on other continents. "Trees in the national parks of California are being damaged by air pollution that may be coming from as far away as Los Angeles," reported New Scientist.

There is, however, a worse kind of pollution defiling the earth. It is a fundamental causative factor in the physical polluting of the land, water, and air of our planet.