Km. 14, Central Highway, Tawala, Panglao,
Name: Robert Trinidad, Jr.
Course and Year: BSMT-I (HC)
Instructor: Ms. Bueneventurada Libot, Ph. D.
Topic: Harmful Effects of Chlorine to the Environment
Define the definition of chlorine.
Explain the chlorine’s discovery.
Discuss the positive as well as the negative effects of chlorine in the body
and the environment.
Chlorine is a natural element, a yellow-green gas at room temperature. It is
heavier than air, but under the correct pressure and temperature, it can be converted
into liquid. Chlorine is found in the earth and can also be found in the sea. It is essential
to the life of animals and plants.
Chlorine is widely used as a bleaching agent in the manufacturing process of
paper and cloth. When released into the air, it reacts with water to make hydrochloric
acid. When this acid breaks down, the products that are left can lower the pH of water.
Because chlorine is a gas, it is rarely found in soil and it does not accumulate in the
You are generally not in danger of exposure to chlorine. The most common place
you will come into contact with it is at public swimming pools. It is used as a disinfectant
in pools, as well as in public drinking water. You can also find it in everyday household
bleach. Workers who make products such as bleach and disinfectants may have a
higher risk of exposure and may inhale chlorine gas.
Chlorine gas can affect your health, depending on how much of it you have been
exposed to and for how long. It is corrosive and irritating to the eyes, skin and
respiratory tract. Exposure to low amounts may cause a sore throat, eye and skin
irritation and coughing. Exposure to higher amounts of the gas can cause narrowing of
the bronchi, burning of the eyes and skin and a blue coloring of the skin. It can also
cause a build up of fluid in the lungs and pain in the chest.
Over 25,000 people worldwide die each day as a result of waterborne diseases.
Water chlorination is one of the most widely used safeguards for drinking water
supplies. In 1991, a Peruvian government decided to remove the chlorine in its
country’s water supply. The results were devastating and led to a cholera epidemic that
spread across South America and claimed the lives of tens of thousands of people.
Chlorine is one of the components in a wide variety of pharmaceuticals.
Pharmaceuticals containing chlorine include those for treating malaria, whooping cough,
typhoid fever and leukemia. The federal government has set legal safety limits
regarding water and chlorine. There should only be four milligrams of chlorine per one
liter of drinking water, and ten milligrams of chlorine to one liter of lake and stream
Chlorine is a poisonous, greenish-yellow gas described as having a choking
odor. It is a very corrosive, hazardous chemical. Usually combined with other chemicals,
it is used to disinfect water, purify metals, bleach wood pulp and make other chemicals.
Household bleach, used to whiten fabrics or remove mold from surfaces, is a 5%
solution of a stabilized form of chlorine.
DISCOVERY OF CHLORINE
Chlorine was produced first in 1774 by Carl Wilhelm Scheele, who collected the
gas released by the reaction of pyrolusite (manganese dioxide) with the substance we
now call hydrochloric acid. It had, according to Scheele, "a very perceptible suffocating
smell, which was most oppressive to the lungs... and gives the water a slightly acidic
taste... the air in it acquires a yellow color..." Scheele also noted the reactivity and
bleaching qualities of the new gas he had made: "all metals were attacked... fixed alkali
was converted into common salt... all vegetable flowers - red, blue, and yellow - became
white in a short time; the same thing also happened with green plants, insects
Despite the accuracy of his observations, Scheele mistakenly thought the
resulting gas was a compound that contained oxygen.
Sir Humphry Davy in 1810, however, found he could not get the new gas to react
with a charcoal electrode, which caused him to believe it may not contain oxygen. In
reactions with phosphorus and ammonia, he demonstrated the new gas could not
contain oxygen. He used a huge, 2000 plate voltaic pile (battery) to see whether he
could get oxygen out of the gas's compounds with phosphorus and sulfur, but again
found no oxygen.
In 1811, Davy concluded the new gas was in fact a new element. He named it
chlorine, from the Greek word 'chloros', meaning pale green.
THE PRESENTATION OF DATA
Problem 1. What are the useful effects of Chlorine?
Chlorine has a huge variety of uses; as a disinfectant and purifier, in plastics and
polymers, solvents, agrochemicals and pharmaceuticals, as well as an intermediate in
manufacturing other substances where it is not contained in the final product.
Chlorine is used worldwide to purify water supply as the ultimate defense against
waterborne microbiological infection. Modern day cholera epidemics in Peru, China,
India or Africa exemplify the devastating consequences of poor sanitation.
Chlorine also plays a critical role in the productions of thousands of commercial
Products reliant on chlorine’s unique properties include every household item
such as bleach and disinfectant to bullet-resistant vests, computer hardware, silicon
chips and automotive parts.
Problem 2: How can people be exposed to Chlorine?
Because of its widespread use in industrial and commercial locations, exposure
to chlorine could occur from an accidental spill or release, or from a deliberate terrorist
attack. The most harmful route of exposure is from breathing chlorine gas. Exposure
may also result from skin contact or eye contact with chlorine gas or by swallowing
chlorine-contaminated food or water.
Chlorine gas is heavier than air and will initially remain in low-lying areas unless
wind or other conditions provide air movement.
Exposures to chlorine gas are usually due to industrial processes or accidental
spills. Chlorine is added in small amounts to some municipal water supplies when
bacteria contamination threatens public health. When chlorine combines with lake or
river water, a class of chemicals that includes chloroform can be formed.
Most high-level exposure occurs in workplaces where chlorine is used. People
may inhale chlorine by using chlorine bleach or by living near an industry that uses
chlorine. The smell from treated drinking water or swimming pools may be irritating but
isn’t usually harmful.
Low level exposure can occur when water containing chlorine is used for drinking
or for food preparation.
Problem 3. What are the harmful effects of Chlorine?
Short-term, high-level exposures:
Immediately or shortly after exposure to 30 ppm or more of chlorine gas, a
person may have chest pain, vomiting, coughing, difficulty breathing, or excess fluid in
their lungs. Exposure to 430 ppm in air for 30 minutes will cause death.
The health effects of breathing air that has less than 30 ppm of chlorine are the
same as listed below for inhaling liquid bleach vapors.
Liquid chlorine bleach and its vapors (at levels of 3-6 ppm in air) are irritating to
eyes. At levels of 15 ppm in air people experience nose and throat irritation. Touching
liquid chlorine bleach can cause skin irritation. Drinking levels over 4 ppm can cause
throat and stomach irritation, nausea and vomiting.
Long-term, low-level exposure (e.g. several years of exposure to chlorine):
The main effects of exposure to chlorine gas include diseases of the lung and
tooth corrosion. People with previous lung disease, smokers, and those with breathing
problems are more sensitive to chlorine.
There is no information currently available about whether chlorine causes cancer.
No reproductive effects from chlorine exposure have been reported.
In general, chemicals affect the same organ systems in all people who are
A person's reaction depends on several things, including individual health,
heredity, previous exposure to chemicals including medicines, and personal habits such
as smoking or drinking.
It is also important to consider the length of exposure to the chemical; the
amount of chemical exposure; and whether the chemical was inhaled, touched, or
eaten. People with preexisting lung or heart disease may be particularly sensitive to the
effects of chlorine.
Problem 4. What happens to Chlorine in the body?
When chlorine enters the body as a result of breathing, swallowing, or skin
contact, it reacts with water to produce acids. The acids are corrosive and damage cells
in the body on contact.
Problem 5. What are the immediate health effects of Chlorine exposure?
Most harmful chlorine exposures are the result of inhalation. Health effects
typically begin within seconds to minutes. Following chlorine exposure, the most
common symptoms are:
The severity of health effects depend upon the route of exposure, the dose and
the duration of exposure to chlorine. Breathing high levels of chlorine causes fluid build-
up in the lungs, a condition known as pulmonary edema. The development of
pulmonary edema may be delayed for several hours after exposure to chlorine. Contact
with compressed liquid chlorine may cause frostbite of the skin and eyes.
Problem 6. What can you do if you think you may have been exposed to a release
If you have been exposed to a release of chlorine, take the following steps:
Quickly move away from the area where you think you were exposed. If the
release was indoors, go outdoors. If you are near a release of chlorine, emergency
coordinators may tell you to either evacuate the area or to "shelter in place." To "shelter
in place" means to remain indoors to avoid being exposed to the chemical. While
indoors, shut and lock all doors and windows, turn off air conditioners, fans and heaters,
and close fireplace dampers.
Quickly remove any clothing that may have chlorine on it. If possible, clothing
that is normally removed over the head (like t-shirts and sweaters) should be cut off the
body to prevent additional contact with the agent.
Place your clothing inside a plastic bag and seal the bag tightly.
Do not handle the plastic bag, and wait for instructions on proper
Disposing of your clothing in a sealed bag helps protect you and
other people from additional exposure.
Store the bagged clothing in a secure location away from people,
Quickly wash any chlorine from your skin with large amounts of
soap and water, and flush your eyes with large amounts of water.
Remove and dispose of contact lenses.
Wash eyeglasses with soap and water before wearing.
If needed, seek medical attention right away.
Problem 7. How is chlorine exposure treated?
To limit health effects from exposure to chlorine, wash eyes and skin as quickly as
possible with large amounts of water.
There is no antidote for chlorine poisoning, but chlorine's effects are treatable, and most
people recover. People who experience serious health effects (such as severe eye or
airway irritation, severe coughing, difficulty breathing, pulmonary edema) may need
Chlorine is widely used in making many everyday products. It is used for
producing safe drinking water the world over. Even the smallest water supplies are now
It is also extensively used in the production of paper products, dyestuffs, textiles,
petroleum products, medicines, antiseptics, insecticides, food, solvents, paints, plastics,
and many other consumer products.
Most of the chlorine produced is used in the manufacture of chlorinated
compounds for sanitation, pulp bleaching, disinfectants, and textile processing. Further
use is in the manufacture of chlorates, chloroform, carbon tetrachloride, and in the
extraction of bromine.
Moreover, chlorine is used almost universally in the treatment of public drinking
water because of its toxic effect on harmful bacteria and other waterborne, disease-
causing organisms. But there is a growing body of scientific evidence that shows that
chlorine in drinking water may actually pose greater long term dangers than those for
which it was used to eliminate. These effects of chlorine may result from either ingestion
or absorption through skin. In other words, chlorine gives us not only its beneficial
effects but also its negative effects. It depends upon a user on how he/she will use the
said element/chemical to help him/her.
Scientific studies have linked chlorine and chlorination by-products to cancer of
the bladder, liver, rectum, and colon, as well as heart disease, atherosclerosis
(hardening of the arteries), anemia, high blood pressure, and allergic reactions. There is
also evidence that shows that chlorine can destroy protein in our body and cause
adverse effects on skin and hair. The presence of chlorine in the water may also
contribute to the formation of chloramines in the water, which can cause taste and odor
Nevertheless, I do believe that chlorine itself is not believed to be the problem.
Scientists suspect that the actual cause of the bladder cancers, etc. in the body is a
group of chemicals that form as result of reactions between the chlorine and natural
substances and pollutants in the water. That’s why, it of great care in us, so that
chlorine will be prevented in order to give us hazards.
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m/chlorine_general.htm. 03 July 2010.
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http://library.thinkquest.org/C004050F/use.htm. 3 July 2010.
Health Effects of Chlorine in Drinking Water. Retrieved from:
http://www.ewaterfilters.com/chlorine.html 3 July 2010.