Pollution and its effects

Pollution is defined as contamination to natural environment causing adverse effects. Pollutants, the components of pollution, can be either foreign substances/energies or naturally occurring contaminants. Pollution is often classed as point source ornonpoint source pollution.

Types of pollution

Pollution can be classified into following

Air pollution

The air we breathe is polluted through both natural and manmade substances. Common gaseous pollutants include carbon monoxide, sulphur dioxide, chlorofluorocarbons (CFCs) and nitrogen oxides produced by industry and motor vehicles. Photochemical ozone and smog are created as nitrogen oxides and hydrocarbons react to sunlight. Particulate matter or fine dust is characterized by their micrometre size PM10 to PM2.5.

Light pollution

This includes light trespass, over-illumination and astronomical interference.

Littering

Throwing of manmade objects into the natural resources and on public and private properties.

Noise pollution

Un bearable noise produced by vehicles, aircrafts, industries and etc account for noise pollution.

Soil contamination

Soil is full of nutrients and continuous and uncontrolled usage of chemicals and pesticides decrease its quality resulting in pollution. Most significant soil contaminants are - hydrocarbons, heavy metals, MTBE, herbicides, pesticides and chlorinated hydrocarbons.

Radioactive conta mination

Radioactive contamination is a result of the development of 20th century activities in atomic physics, such as nuclear power generation and nuclear weapons research, manufacture and deployment.

Thermal pollution

It is a temperature change in natural water bodies caused by human influence, such as use of water as coolant in a power plant.

Water pollution

most of the water bodies around the world are getting polluted through human activities which include- commercial and chemical waste, discharges of untreated domestic sewage, and chemical contaminants, such as chlorine, from treated sewage; release of waste and contaminants into surface runoff flowing to surface waters; waste disposal and leaching into groundwater; eutrophication and littering.

Sources of pollution

• Air pollution comes from both natural and human-made sources. However, globally human-made pollutants from combustion, construction, mining, agriculture and warfare are increasingly significant in the air pollution equation.
• Principal stationary pollution sources include chemical plants, coal-fired power plants, oil refineries, petrochemical plants, nuclear waste disposal activity, incinerators, large livestock farms, PVC factories, metals production factories, plastics factories, and other heavy industry.
• Agricultural air pollution comes from contemporary practices which include clear felling and burning of natural vegetation as well as spraying of pesticides and herbicides.
• Some of the more common soil contaminants are chlorinated hydrocarbons (CFH), heavy metals (such as chromium, cadmium–found in rechargeable batteries, and lead–found in lead paint, aviation fuel and still in some countries, gasoline), MTBE, zinc, arsenic and benzene.
• Pollution can also be the consequence of a natural disaster. For example, hurricanes often involve water contamination from sewage, and petrochemical spills from ruptured boats or automobiles. Larger scale and environmental damage is not uncommon when coastal oil rigs or refineries are involved. Some sources of pollution, such as nuclear power plants or oil tankers, can produce widespread and potentially hazardous releases when accidents occur.

Effects on human health

• Adverse air quality can kill many organisms including humans. Ozone pollution can cause respiratory diseases, cardiovascular disease, throat inflammation, chest pain, and congestion.
• Water pollution causes approximately 14,000 deaths per day, mostly due to contamination of drinking water by untreated sewage in developing countries. Oil spills are another cause of water pollution.
• Noise pollution induces hearing loss, high blood pressure, stress, and sleep disturbance.
• Mercury has been linked to developmental deficits in children and neurologic symptoms. Older people are majorly exposed to diseases induced by air pollution.
• Lead and other heavy metals have been shown to cause neurological problems.
• Chemical and radioactive substances can cause cancer and as well as birth defects.

Environmental Degradation

• Bio magnification describes situations where toxins may pass through tropic levels, becoming exponentially more concentrated in the process.
• Carbon dioxide emissions cause ocean acidification, the ongoing decrease in the pH of the Earth's oceans as CO2
• becomes dissolved.
• The emission of greenhouse gases leads to global warming which affects ecosystems in many ways.
• Smog and haze can reduce the amount of sunlight received by plants to carry out photosynthesis and leads to the production of troposphere ozone which damages plants.
• Soil can become infertile and unsuitable for plants. This will affect other organisms in the food web.
• Sulphur dioxide and nitrogen oxides can cause acid rain which lowers the pH value of soil.

Important facts

• About 400 million metric tons of hazardous wastes are generated each year. The United States alone produces about 250 million metric tons.
• In 2007, China has overtaken the United States as the world's biggest producer of CO2, while still far behind based on per capita pollution - ranked 78th among the world's nations.
• China, United States, Russia, India, Mexico and Japan are the world leaders in air pollution emissions.
• In February 2007, a report by the Intergovernmental Panel on Climate Change (IPCC), representing the work of 2,500 scientists, economists, and policymakers from more than 120 countries, said that humans have been the primary cause of global warming since 1950.
• Humans have ways to cut greenhouse gas emissions and avoid the consequences of global warming, a major climate report concluded.