Air and water pollution

What is air pollution?

Air pollution (say: po-loo-shun) occurs when gases, dust particles, fumes (or smoke) or

odour are introduced into the atmosphere in a way that makes it harmful to humans,animals and plant. This is because the air becomes dirty (contaminated or unclean).

The Earth is surrounded by a blanket of air (made up of various gases) called theatmosphere. The atmosphere helps protect the Earth and allow life to exist. Without it, wewould be burned by the intense heat of the sun during the day or frozen by the very lowtemperatures at night.

Any additional gas, particles or odours that are introduced into the air (either by nature orhuman activity) to distort this natural balance and cause harm to living things can be calledair pollution.

Air pollution for children

Things that pollute the air are called pollutants. Examples of pollutants include nitrogen

oxides, carbon monoxides, hydrocarbons, sulphur oxides (usually from factories), sand or

dust particles, and organic compounds that can evaporate and enter the atmosphere.

There are two types of pollutants:

Primary pollutants are those gases or particles that are pumped into the air to make it unclean.

They include carbon monoxide from automobile (cars) exhausts and sulfur dioxide from the

combustion of coal.

Secondary pollutants: When pollutants in the air mix up in a chemical reaction, they form an

even more dangerous chemical. Photochemical smog is an example of this, and is a secondary

pollutant.

Air pollution typically separated into two categories: outdoor air pollution and indoor air

pollution.

Outdoor air pollution involves exposures that take place outside of the built environment.

Examples include:

Fine particles produced by the burning of fossil fuels (i.e. the coal and petroleum used in traffic andenergy production). Noxious gases (sulfur dioxide, nitrogen oxides, carbon monoxide, chemicalvapors, etc.)

Ground-level ozone (a reactive form of oxygen and a primary component of urban smog)Tobacco smokeIndoor air pollution involves exposures to particulates, carbon oxides, and other pollutantscarried by indoor air or dust. Examples include:

Gases (carbon monoxide, radon, etc.)Household products and chemicalsBuilding materials (asbestos, formaldehyde, lead, etc.)Outdoor indoor allergens (cockroach and mouse dropping, etc.)Tobacco smokeMold and pollen

Please note: In some instances, outdoor air pollution can make its way indoors by way of open windows, doors, ventilation, etc.

Some air pollutants are poisonous. Inhaling them can increase the chance you'll have healthproblems. People with heart or lung disease, older adults and children are at greater risk from airpollution. Air pollution isn't just outside - the air inside buildings can also be polluted and affectyour health.

What causes air pollution?Air pollution can result from both human and natural actions. Natural events that pollute the airinclude forest fires, volcanic eruptions, wind erosion, pollen dispersal, evaporation of organiccompounds and natural radioactivity. Pollution from natural occurrences are not very often.Human activities that result in air pollution include:

1. Emissions from industries and manufacturing activities

Consider a typical manufacturing plant: You will notice that there are long tubes (calledchimneys) erected high into the air, with lots of smoke and fumes coming out of it. Wasteincinerators, manufacturing industries and power plants emit high levels of carbon monoxide,organic compounds, and chemicals into the air. This happens almost everywhere that people live.Petroleum refineries also release lots of hydrocarbons into the air.

2. Burning Fossil FuelsAfter the industrial age, transportation has become a key part of our lives. Cars and heavy dutytrucks, trains, shipping vessels and airplanes all burn lots of fossil fuels to work. Emissions fromautomobile engines contain both primary and secondary pollutants. This is a major cause ofpollution, and one that is very difficult to manage. This is because humans rely heavily onvehicles and engines for transporting people, good and services.

Fumes from car exhauts contain dangerous gases such as carbon monoxide, oxides of nitrogen,hydrocarbons and particulates. On their own, they cause great harm to people who breath them.Additionally, they react with environmental gases to create further toxic gases.

3. Household and Farming ChemicalsCrop dusting, fumigating homes, household cleaning products or painting supplies, over thecounter insect/pest killers, fertilizer dust emit harmful chemicals into the air and cause pollution.In many case, when we use these chemicals at home or offices with no or little ventilation, wemay fall ill if we breathe them.

What are the common air pollutants around?

Carbon Monoxide (CO)Fuel combustion from vehicles and engines.

Reduces the amount of oxygen reaching the body’s organs and tissues; aggravatesheart disease, resulting in chest pain and other symptoms.

Ground-level Ozone (O3) Secondary pollutant formed by chemical reaction of volatile organic compounds (VOCs) and

NOx in the presence of sunlight. Decreases lung function and causes respiratory symptoms, such as coughing and shortness of

breath, and also makes asthma and other lung diseases get worse.

Lead (Pb) Smelters (metal refineries) and other metal industries; combustion of leaded gasoline in

piston engine aircraft; waste incinerators (waste burners), and battery manufacturing. Damages the developing nervous system, resulting in IQ loss and impacts on learning,

memory, and behavior in children. Cardiovascular and renal effects in adults and early effectsrelated to anaemia.

Nitrogen Dioxide (NO2)Pollutants factsFuel combustion (electric utilities, big industrial boilers, vehicles) and woodburning.Pollutants factsWorsens lung diseases leading to respiratory symptoms, increased susceptibilityto respiratory infection.

Particulate Matter (PM) This is formed through chemical reactions, fuel combustion (e.g., burning coal, wood, diesel),

industrial processes, farming (plowing, field burning), and unpaved roads or during roadconstructions.

Short-term exposures can worsen heart or lung diseases and cause respiratory problems.Long-term exposures can cause heart or lung disease and sometimes premature deaths.

Sulfur Dioxide (SO2) SO2 comes from fuel combustion (especially high-sulfur coal); electric utilities and industrial

processes as well as natural occurances like volcanoes. Aggravates asthma and makes breathing difficult. It also contributes to particle formation

with associated health effects.

What are the effects of air pollution?Below are a few key effects of air pollution. The last page on FactSheet has some specific airpollution incidents that are worth checking out.

Acidification:Chemical reactions involving air pollutants can create acidic compounds which can cause harm tovegetation and buildings. Sometimes, when an air pollutant, such as sulfuric acid combines with

the water droplets that make up clouds, the water droplets become acidic, forming acid rain.When acid rain falls over an area, it can kill trees and harm animals, fish, and other wildlife.

Acid rain destroys the leaves of plants.When acid rain infiltrates into soils, it changes the chemistry of the soil making itunfit for many living things that rely on soil as a habitat or for nutrition. Acid rain alsochanges the chemistry of the lakes and streams that the rainwater flows into, harmingfish and other aquatic life.

Eutrophication:Rain can carry and deposit the Nitrogen in some pollutants on rivers and soils. Thiswill adversely affect the nutrients in the soil and water bodies. This can result in algaegrowth in lakes and water bodies, and make conditions for other living organismharmful.

Ground-level ozone:Chemical reactions involving air pollutants create a poisonous gas ozone (O3). GasOzone can affect people’s health and can damage vegetation types and some animallife too.Particulate matter:Air pollutants can be in the form of particulate matter which can be very harmful toour health. The level of effect usually depends on the length of time of exposure, aswell the kind and concentration of chemicals and particles exposed to. Short-termeffects include irritation to the eyes, nose and throat, and upper respiratory infectionssuch as bronchitis and pneumonia. Others include headaches, nausea, and allergicreactions. Short-term air pollution can aggravate the medical conditions of individualswith asthma and emphysema. Long-term health effects can include chronic respiratorydisease, lung cancer, heart disease, and even damage to the brain, nerves, liver, orkidneys. Continual exposure to air pollution affects the lungs of growing children andmay aggravate or complicate medical conditions in the elderly.

Air pollution preventionSolution efforts on pollution is always a big problem. This is why preventioninterventions are always a better way of controlling air pollution. These preventionmethods can either come from government (laws) or by individual actions.

Why is Air Pollution such an important issue?

bulletYour HealthDangerous chemicals such as benzene or vinyl chloride in the air causes cancer, birthdefects, long term injury to the lungs, as well as brain and nerve damage when people breath it. And insome cases, breathing these chemicals can even cause death. Breathing contaminated air can make your eyesand nose burn and trigger respiratory problems, especially for people with asthma. In recent years,scientists have shown thatair pollution from cars, factories and power plants is a major cause of asthma attacks.

Water pollution: an

introduction

Over two thirds of Earth's

surface is covered by water;

less than a third is taken up by

land. As Earth's population

continues to grow, people are

putting ever-increasing pressure

on the planet's water resources.

In a sense, our oceans, rivers,

and other inland waters are

being "squeezed" by human

activities—not so they take up

less room, but so their quality

is reduced. Poorer water quality

means water pollution.

We know that pollution is a human problem because it is a relatively recent development in the planet's history: before the 19th century Industrial Revolution, people lived more in harmony with their immediate environment. As industrialization has spread around the globe, so the problem of pollution has spread with it. When Earth's population was much smaller, no one believed pollution would ever present a serious problem. It was once popularly believed that the oceans were far too big to pollute. Today, with around 7 billion people on the planet, it has become apparent thatthere are limits. Pollution is one of the signs that humans have exceeded those limits.

How serious is the problem? According to the environmental campaign organization WWF: "Pollution from toxic chemicals threatens life on this planet. Every ocean and every continent, from the tropics to the once-pristine polar regions, is contaminated."

What is water pollution?

Water pollution can be defined in many ways. Usually, it means one or more substances have built up in water to such an extent that they cause problems for animals or people. Oceans, lakes, rivers, and other inland waters can naturally clean up a certain amount of pollution by dispersing it harmlessly. If you poured a cup of black ink into a river, the ink would quickly disappear into the river's much larger volume of clean water. The ink would still be there in the river, but in such a low concentration that you would not be able to see it.

At such low levels, the chemicals in the ink probably would not present any real problem. However, if you poured gallons of ink into a river every few seconds through a pipe, the river would quickly turn black. The chemicals in the ink could very quickly have an effect on the quality of the water. This, in turn, could affect the health of all the plants, animals, and humans whose lives depend on the river. Photo ofair pollution from a smokestack , Thus, water pollution is all about quantities: how much of a polluting substance is released and how big a volume of water it is releasedinto. A small quantity of a toxic chemical may have little impact if it is spilled into theocean from a ship. But the same amount of the same chemical can have a much biggerimpact pumped into a lake or river, where there is less clean water to disperse it. Water pollution almost always means that some damage has been done to an ocean, river, lake, or other water source. A 1969 United Nations report defined ocean pollution as:

"The introduction by man, directly or indirectly, of substances or energy into the marine environment (including estuaries) resulting in such deleterious effects as harm to living resources, hazards to human health, hindrance to marine activities, including fishing, impairment of quality for use of sea water and reduction of amenities."

Fortunately, Earth is forgiving and damage from water pollution is often reversible.

Read more at: http://www.niehs.nih.gov/health/topics/agents/air-pollution/