Introduction
What is pollution?
Pollution is the introduction of harmful materials into the
environment. These harmful materials are called pollutants. Pollutants can be
natural, such as volcanic ash. They can also be created by human activity, such
as trash or runoff produced by factories. Pollutants damage the quality of air,
water, and land.
Air Pollution:
Sometimes, air pollution is visible. A person can see dark
smoke pour from the exhaust pipes of large trucks or factories, for example.
More often, however, air pollution is invisible. Polluted air can be dangerous,
even if the pollutants are invisible. It can make people’s eyes burn and make
them have difficulty breathing. It can also increase risk of lung cancer. Air
pollution is caused by natural disasters, such as volcanoes, burning fossil
fuels, cars, factories, and greenhouse gases.
Water Pollution:
Some polluted water looks muddy, smells bad, and has garbage
floating in it. Some polluted water looks clean but is filled with harmful
chemicals you can’t see or smell. There are some natural sources of water
pollution. Oil and natural gas, for example, can leak into oceans and lakes
from natural underground sources. Human activity also contributes to water
pollution. Chemicals and oils from factories are sometimes dumped into
waterways. Mining and drilling, oil spills, buried chemical waste, sewage,
loose garbage, and fertilizer used in agriculture are all ways in which human
activity contributes to water pollution.
Land Pollution:
Many of the same pollutants that foul the water also harm the
land. Mining sometimes leaves the soil contaminated with dangerous chemicals.
Pesticides and fertilizers from agricultural fields are blown by the wind. A
pesticide called DDT, which is used to kill insects, is sprayed. This pesticide
destroys bird habitats and has also been linked to cancer in humans. Trash is
another form of land pollution. Litter
makes it difficult for plants and other producers in the food web to produce
nutrients. This litter often contains dangerous pollutants that can leech onto
the soil. Some cities incinerate their garbage. This gets rid of it, but it can
sometimes add to the problem of air pollution.
Reducing Pollution:
Around the world, people and governments are making efforts
to combat pollution. Recycling, for instance, is becoming more common.
Recycling reduces the amount of garbage that ends up in landfills,
incinerators, and waterways. Governments can combat pollution by passing laws
that limit the amount and types of chemicals that factories and agribusinesses
are allowed to use. The smoke from coal-burning power plants can be filtered.
People and businesses that illegally dump pollutants into the land, water or
air can be fined for millions of dollars. Some government programs can force
polluters to clean up the site they polluted. International agreements such as
the Kyoto Protocol, a U.N agreement, can help limit the emission of greenhouse
gases. Reducing pollution requires environmental, political, and economic leadership.
