Pollution
In the mid-1900s, a biologist named
Rachel Carson was afraid that some day there might be no more birds. Farmers
were spraying a chemical called DDT on their fields to kill insects. But DDT was
also keeping birds such as the bald eagle and peregrine falcon from having
babies. DDT prevented the babies from hatching. She wrote a book called
Silent Spring to warn about the dangers of DDT.
Pollution happens when chemicals
that are harmful to living things get into the environment. Rachel Carson feared
that DDT would get into the food people ate. Her book scared a lot of people.
Governments banned the use of DDT. People then began to worry about other kinds
of pollution. They worried that pollution could harm people’s health.
WHAT DOES POLLUTION DO?
Pollution can kill or sicken
plants, animals, and people. Pollution can change the environment. Things that
cause pollution are called pollutants.
Pollution can get into the air.
Air pollution can irritate people’s lungs. Polluted air can mix with rain to
make acid rain. Acid rain kills trees and harms fish in lakes.
Pollution can also get into soil
and water. From there, pollutants can get into the food chain. Plants take in
the pollution from the ground. Animals that eat the plants can be harmed, too.
Bigger animals and even people might eat the damaged animals.
WHERE DOES POLLUTION COME FROM?
Air pollution comes from
factories and power plants that burn coal and oil. Smoke from factories and
power plants can mix with water in the air to make acid rain. Air pollution also
comes from cars and other vehicles that burn gasoline.
Soil pollution can come from
chemicals used on farms to kill insects and other pests. Pollutants can also
seep from garbage dumps into the nearby soil and water.
Water pollution comes from
factories that dump poisonous chemicals into lakes and rivers. Water pollution
can also come from farms. Farmers put chemicals on the ground to help crops grow
and to kill insects. Rain can wash these chemicals into lakes and rivers.
Big ships called oil tankers can
pollute the ocean if the oil leaks out of the tankers. There can be a huge oil
spill if a tanker has an accident and sinks at sea.
A special kind of pollution comes
from nuclear power plants. Nuclear power plants produce radioactive waste. This
waste lasts for thousands of years and can cause cancer and other deadly
illnesses if it is not properly stored.
IS POLLUTION CHANGING EARTH’S CLIMATE?
Many scientists think that
pollution is changing Earth’s climate. They think the change is coming from
gases in the air called greenhouse gases. Carbon dioxide and other gases trap
heat from the Sun. They trap heat the way glass walls and ceilings in
greenhouses trap heat. It stays warm inside a greenhouse even when it is cold
outside.
Greenhouse gases in the air make
Earth warm enough for life. But scientists think that people are putting too
much carbon dioxide and other greenhouse gases into the air. These extra
greenhouse gases come from burning coal and oil in factories and power plants.
They come from burning gasoline in cars. Too much of them will make Earth
warmer. This warming could cause disastrous changes on the planet.
HOW CAN WE STOP POLLUTION?
Chemicals that cause pollution are
not easy to get rid of. They stay in the air and ground and water for a long
time. The best way to fight pollution is to stop producing it in the first
place. Governments can pass laws that forbid or limit the use of chemicals that
cause pollution. Laws can stop factories from dumping poisonous chemicals in
lakes, rivers, and the ocean. Factories and power plants can clean up the smoke
that they give off.
Engineers can build cars that burn
less gasoline. They can find ways for cars to give off cleaner exhaust
gases.
Scientists are looking for fuels to
replace coal and oil. They are looking for ways to use the power in wind and in
rays from the Sun. They are also looking for safe ways to get rid of nuclear
waste.
You can help cut down on the amount
of garbage you make. You can recycle paper, plastic, glass bottles, and metal
cans. Recycled material gets used over again. Recycling helps cut down on
pollution.
Tags
The Environment
