Air Pollution. Biologists define pollution as an undesirable change in the physical, chemical, or biological characteristics of an ecosystem

Forms of pollution

Biologists define pollution as an undesirable change in the physical, chemical, or biological characteristics of an ecosystem. This means that pollution makes our environment unfit for use and can injure or kill living organisms. Industrialization and human population growth have been cited as the underlying causes of air, water, and land pollution, making it a global problem today.

Air Pollution

Air pollution often seems to be a personal or social issue – the displeasure of being in a smoke-filled coffee shop, the polluting smell of leaves burning or the frustration of sitting in a traffic jam amid trucks and cars spewing out toxic fumes. But air pollution today is a global problem that knows no borders.

Although air pollution has always existed in some form or other, pollution of the air has become a significant problem since the Industrial Revolution

Most air pollution today is generated by industry and motor vehicles. Industries using coal, oil, and other fossil fuels spew out large amounts of chemical compounds. Despite regulations imposed by many governments, we still witness smokestacks belching out clouds of soot and other pollutants in the early mornings and late afternoons, creating a blazing ball of red that is the sun filtered through the chemical compounds in our air. These compounds, once dissolved in water, shower pollutants back on earth in the form of acid rain. Acid rain damages crops and forests, kills fish, and makes water unfit for drinking.

Automobiles, a common necessity in most countries today, are an equally significant contributor to air pollution. A consumer born into a typical middle-class American home will purchase a dozen cars, use more than 28,000 gallons of gasoline, and drive more than 700,000 miles during his or her lifetime. Considering facts such as these for the United States alone, it is little wonder that cities around the world are experiencing the debilitating effects of automobile exhaust.

Despite air-pollution controls on motor vehicles in most environmentally conscious countries, the city dweller faces high risks of respiratory illnesses due to carbon emissions from vehicle exhaust. Cities in dry, sunny climates, and where motor vehicles are the main source of pollution, tend to suffer under a yellowish haze that lingers overhead – a form of air pollution known as photochemical smog. Cars and trucks give off nitric oxide which reacts with oxygen to produce a strong choking gas called nitrogen dioxide. As ultraviolet rays from the sun mix with nitrogen dioxide and oxygen, dangerous chemicals are produced. Add industrial solvents and spilled or unburned gasoline to the air as the temperature rises, and you'll see a dense, yellow-brown smog settle over the urban landscape. Photochemical smog, along with other forms of air pollution, has resulted in eye irritation, respiratory problems, and cancer in humans. More than 1.5 billion people worldwide breathe unhealthy city air daily, and at least 800 of them die prematurely because of that pollution.

Car pools, cleaner-burning engines, new fuels, and other personal and technological advances may begin to bring air pollution under control, but without global agreements on how to control and clean our air, the problem can only grow worse. Today, and every day, 140,000 new cars, trucks, and buses start their engines for the first time and add yet more pollutants to those belched out by the more than half billion vehicles already in use.

Дата добавления: 2015-10-30