Contaminants of Water
The U.S. Environmental Protection Agency (EPA) sets standards for
drinking water. It allows approximately 90 contaminants in our water
(including bottled water). Drinking water from municipal systems, wells
and even bottled water may reasonably contain at least small amounts of
contaminants.
Contaminants are listed below. They include microbes, radionuclides,
inorganics, volatile organics, disinfectants, disinfectant byproducts
and MTBEs (fuel additives). Microbes and coliform bacteria are frequent
in the environment, but are usually not harmful. By if these bacteria
are found in our drinking water, it often means there is a problem with
the treatment system or pipes. The presence of these bacteria may
indicate that the water is contaminated with human or animal wastes and
may cause diseases due to the fecal coliform and E coli bacteria which
may be present in the water. The microbes in these waste products may
cause diarrhea, cramps, nausea, headaches and other symptoms.
There are no health effects from Turbidity, although it can impede
disinfection and cause microbial growth. The presence of organisms which
causes diseases may be indicated by turbidity. As a result of the
organisms, a person may have symptoms such as cramps, diarrhea,
nausea and headaches.
One type of parasite that may find its way into rivers and lakes through
sewage and animal waste is called cryptosporidium, which causes
cryptosporidiosis, a gastrointestinal disease. This particular disease
is usually mild, but it may be severe or even fatal in people with
severely weakened immune systems. If a person has such an immune system,
he should obtain information from the EPA and CDC if he is concerned
about cryptosporidium.
Another parasite that enters lakes and rivers through sewage and animal
waste is called giardia lamblia. It may result in a gastrointestinal
sickness with symptoms of diarrhea, cramps and vomiting.
There are certain minerals that are radioactive and may emit a form of
radiation known as alpha radiation. This form of radiation is termed an
alpha emitter. People may have an increased risk of cancer if, over many
years, they drink water containing alpha emitters in excess of the EPA's
standard.
Other minerals are
radioactive and may emit forms of radiation known as photons and beta
radiation. These are known as photon emitters. There may also be an
increased risk of cancer for people who, over the years, drink water
containing beta and photon emitters in excess of the EPA's standard.
There is the same risk of cancer with combined radium 226/228, which is
in excess of the EPA's standard.
Underground water sources, as well as the air in our homes may contain
radon gas which dissolves and accumulates in our air and water. People's
risk of lung cancer may be increased from breathing air containing
radon. The risk of cancer may also be increased from drinking water that
contains radon. However, radon in the air is more dangerous than radon
in water.
Inorganic Contaminants include the following: Antimony, Asbestos,
Barium, Beryllium, Cadmium, Chromium, Copper, Cyanide, Lead, Mercury,
Nitrate/Nitrite Selenium, and Thallium.
People may acquire skin
damage or problems with their circulatory system, and an increased risk
of getting cancer from drinking water through the years that contains
arsenic in excess of the EPA's standard.
Fluoride is added to
the drinking water in many communities to promote good dental health. It
is up to each community to make the decision as to whether or not to add
fluoride to its water supply. The EPA has set standards for fluoride in
drinking water at 4 mg/L. It is possible for some people to get bone
disease, including pain and tenderness, if they drink water with
fluoride in excess of this level.
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A condition called dental fluorisis
may result in a brown staining and/or pitting of the permanent teeth
even with a level of 4 mg/L. Therefore a secondary fluoride standard has
been set by the EPA of 2 mg/L to protect against dental fluorosis.
Although this disease only occurs in developing teeth, before they erupt
from the gums. Therefore, it is recommended that children under nine
years of age not drink water that has more than 2 mg/L of fluoride.
Since 1998 lead pipes and plumbing fixtures have been outlawed. The lead
may seep into water from older plumbing, especially in older buildings.
This lead may be dangerous to children and pregnant women, as they are
most vulnerable to lead health risks. The EPA has prepared a fact sheet
with advice on how to remove lead in your drinking water. Volatile
Organic Contaminants (VOCs) include Benzene, Carbon Tetrachloride,
Chlorobenzene, a variety of Dichlorobenzenes and Dichloroethylenes,
Ethylbenzene, Styrene, a variety of Tetrachloroethylenes, Toluene, Vinyl
Chloride and Xylenes.
Disinfectants may be
added to the water supply to kill germs such as Giardia and E coli. More
disinfectants than normal may be added to the water system after heavy
rainstorms to assure that these germs are killed.
When disinfectants are added to drinking water to kill germs and it
reacts with organic matter in water, it causes byproducts from
disinfectants to form. Some of these by products include total
trihalomethanes, haloacetic acids, bromate and chlorite.
Water containing chlorine in excess of EPA standards could cause
irritating symptoms of the eyes and nose, as well as stomach discomfort
and disorders. The same effects, in addition to anemia, may be caused
from water that contains an excess of chloramine.
Chlorine dioxide in water that is in excess of the EPA standards may
cause nervous system effects. These same effects may occur in fetuses of
pregnant women who drink this water. Some people may also experience
anemia.
If people drink water contaminated with total trihalomethanes for a
period of years and in excess of the EPA standards, they may experience
problems with their liver, kidneys or central nervous systems. They also
may have an increased risk of cancer.
People who drink water containing haloacetic acids in excess of the EPA
standards, may have an increased risk of cancer.
Bromate could cause cancer in drinking water containing this byproduct,
especially if the water is in excess of EPA standards and consumed over
a period of years.
Nervous system effects may be the result of infants and young children
drinking water through the years that contains chlorite in excess of the
EPA standards. The same or similar effects may occur in fetuses of
pregnant women who drink water containing chlorite in excess of EPA
standards. Anemia may also result in some people.
A fuel additive known as MTBE is widely used in the U.S. in order to
decrease carbon monoxide and ozone levels caused by auto emissions.
Reports of MTBE detections in the nation's ground and surface water
supplies are increasing because of its prevalent use. Some of the EPA
departments are discussing the concerns of the continued use of MTBE as
well as other oxygenates used in gasoline. The EPA is currently deciding
whether to set water standards for MTBE.
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