Hazardous Elements - Heavy Metal Ions
Name_______________________________
The REAL World of Chemistry Measurement and Matter
Period_______Date____________________
Although 22 elements are known to be required to support human life, other elements can endanger your
health. Some metals are listed by the United States Environmental Protection Agency (EPA) as
extremely hazardous: antimony, arsenic, beryllium, barium, cadmium, copper, lead, manganese,
mercury, nickel, tin, vanadium, and zinc.
Hg
Mercury can enter your body if you breathe its vapors, or it can enter through your skin if you
touch mercury. Once mercury vapor is in the lungs, it enters the blood stream and is deposited in the
kidneys, liver and brain. Effects of mercury poisoning are irritability, loss of memory, impaired vision
and hearing, insanity, and even death. The Mad Hatter in Lewis Carroll’s Alice in Wonderland suffered
from mercury poisoning. In the 1800s, mercury compounds were used to make rabbit fur into felt for
top hats. People who worked in the hat industry, hatters, were known as “mad hatters” because they
developed severe nervous system disorders from the mercury. Today OSHA requires employers to
inform employees of health hazards to which they are exposed and requires the use of respirators and
other safety equipment when handling hazardous chemicals.
Mercury has been used in many ways in our society, but most are in sealed containers. These would
include light switches, thermometers, thermostats and fluorescent bulbs. But, for 150 years, silvermercury amalgam fillings have been used by dentists for cavities. Now dentists are encouraged to stop
using the amalgams because fillings contain about 50% mercury and may be a health risk. Dr. Murry
Vimy of the University of Calgary Medical School in Alberta says that mercury from amalgam comes
off and accumulates in tissues when the teeth are brushed or when gum is chewed. Legislation has been
introduced to require dentists to inform their patients and gain their consent before using silver-mercury
amalgams. There are new polymer products that can be used in place of amalgams. These new fillings
actually make the tooth stronger than the original tooth. You might talk to your dentist about these new
products if you ever need a filling.
In the past, mercury was also added to paints to make them resistant to mold and mildew. Mercury
fumes from paint can be hazardous to your health if you breathe them. An article in the Minneapolis
Star tribune, said that a four-year-old boy was severely disabled after he breathed mercury fumes while
the interior of his Detroit home was being painted. This incident triggered an urgent federal
investigation to find out if similar cases were occurring elsewhere. As a result of the study, The EPA
banned the use of mercury in indoor paint in 1990, and in exterior paints in 1991. If you have cans of
old paint, do not use them. Periodic collections of hazardous materials occur in most areas so that
proper disposal of such chemicals may be accomplished.
Pb
Lead has been used for over 4,000 years. Romans used lead pipes in their plumbing fixtures.
Evidence of these lead pipes can still be seen in ruined Roman baths throughout Europe. The words
“plumbing,” “plumber,” and “plumb” (a weight suspended from the end of a line) come from the Latin
word for lead, plumbum. The words “lead” and “leader” come from the word “plumb,” meaning exactly
vertical, which is a line by which others are measured. The word lead means to guide or direct as well
as identifying the element Pb. Some historians believe that lead poisoning led to the downfall of the
Roman Empire.
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Lead has been used in the production of many products. It was commonly used in paints, gasoline,
batteries, and glass. Exposure to lead causes irreversible brain damage, lowers intelligence and
produces deficiencies in reading, writing, spelling, and abstract reasoning. Contrary to popular belief,
lead poisoning can occur in upper and middle-class homes as well as in inner-city neighborhoods. The
question is, “If lead is so bad, why aren’t half of today’s adults suffering the effects of childhood lead
poisoning?” The answer is that they probably are. In fact, David Bellinger, a lead researcher at Harvard
University says, “I guess we all might have been a little smarter than we turned out” (Waldman 46).
The greatest risk of lead exposure is to young children and unborn babies in pregnant women. The
child’s body mistakes lead for calcium. The lead attaches to enzymes essential to the functioning of the
brain and other cells. Most lead that is absorbed will stay in the child’s brain forever.
Because lead accumulates in the body, the health effects depend on the level and duration of exposure to
lead. Symptoms of lead poisoning do not show up until the child has been exposed for a long period of
time. The symptoms after long exposure are irritability, lack of coordination, memory lapses, lethargy,
and headaches because lead targets the brain. In addition, lead poisoning may cause anemia by
damaging the red blood cells. This causes abdominal pain and colic accompanied by nausea and
vomiting. Care should be taken to ensure that children are not exposed to lead.
One possible source of ingesting lead is drinking water. Although most homes have very low levels of
lead in the drinking water, some older homes have levels above the EPA action levels. The EPA action
level is 15 parts per billion or 0.015 mg/L. Since June 1, 1985, the State of Minnesota “banned the use
of lead pipe and solders containing more than 0.2% lead to be used in any plumbing installation which
conveys potable water.” But, if your home was built before 1985, chances are you have some lead
contamination in your drinking water. Lead levels in your drinking water are likely to be highest if your
home has copper pipes with lead solder or if your home or water system has lead pipes. From the 1800s
to about 1930, lead was a common material used for water-service pipes and interior plumbing. Since
that time, copper and galvanized steel pipe have been used more extensively in residential plumbing
systems. Lead-based solders were commonly used to join copper to steel pipes. Lead from pipes and
lead-based solders enter the drinking water through corrosion of pipes and solder. Corrosion can occur
when the water sits in the pipes for several hours. Soft and hot water dissolve even more lead in your
water. The only way to measure the lead level is to have the water analyzed.
By law, plumbers are not even allowed to fix leaking lead plumbing. It must be replaced. Plumbers are
not even allowed to repair lead sewage waste systems. Even plumbing that was replaced in 1983 may
have lead-based solder joints! Currently plumbers use solder that is made from an alloy of tin and
antimony and contains no lead.
There are ways to minimize the exposure to lead in your drinking water:
1) Do not drink or cook with water that has been in contact with your home’s plumbing for more than a
few hours.
2) Flush the cold water faucet by allowing the water to run for 2-3 minutes. If your home has a lead
service pipe or connection, allow an additional 15-30 seconds to flush the service line as well. If you
live in a high-rise building, flushing the system may not decrease the risk of lead in water since high-rise
buildings have larger pipes. You should ask your landlord for advice on reducing lead levels.
3) Do not cook with or drink hot tap water.
Lead-based paints are also a significant contributor to lead poisoning in children. In 1990, the EPA
banned lead-based latex interior home paints. Although latex paints no longer contain lead, if you live
in a home or apartment that was built before 1950, the walls and woodwork were probably painted with
lead-based paint. The common belief is that children pick off flakes of lead-containing paint and eat it,
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but pediatricians at the University of Rochester Medical Center have shown that lead-containing dust
was found on the hands of children who lived in rooms which were painted with lead-based paint.
Deteriorating lead-based paint produces lead-laden dust. Children with high levels of lead in their
systems performed worse on IQ tests than those with less lead. A 1987 study of 249 middle and upperclass infants in Boston reported that those who were exposed to very small amounts of lead lost four to
six points on developmental tests measuring memory. The exposure to lead resulted from renovation of
the family home. Exposure can result from sanding paint in both the interior and exterior of the home.
Old paint sitting around your home may contain lead. Whatever you do, do not paint a child’s room
with paint that contains lead. Also, do not sand old lead based paint on wood work or walls because
sanding puts lead dust into the air.
Lead emissions from motor vehicles used to be one of the primary sources of lead pollution. Efforts
began in the 1970s to reduce the amount of air pollutants emitted from automobiles. By 1980, almost all
cars used lead-free gasoline. As a result, the amount of lead in the air has been greatly reduced.
Each year a number of people die or become seriously ill from lead poisoning caused by lead that
leaches out of improperly glazed kitchenware. The U.S. law says that glazed pottery designed for
culinary use must be fired at high enough temperatures to fuse the lead component of the glaze into the
container permanently. Some glazed kitchenware that is bought outside the U.S. or is made in schools
or in private homes may fall short of the federal standards. If these pieces are used to store or cook
foods (especially highly acidic foods), the lead may leach out of the pottery into the food. A California
family was severely stricken by lead poisoning after storing orange juice in a ceramic pitcher purchased
in Tijuana, Mexico. In 1992 a senior at Breck University did a research project on lead levels in leadedcrystal goblets used for water and wine. Lead oxide (up to 24-32%) is added to glass to give it a special
brilliance. She found dangerous levels of lead, so high that her research advisor decided not to use his
own leaded crystal any more.
Humans are not the only victims of lead poisoning. In 1988 an epidemic of lead poisoning killed many
of the endangered trumpeter swans in Minnesota. The Raptor Center at the University of Minnesota
warns that their survival is gravely threatened. Swans are lake-bottom feeders. Because of extremely
low water levels caused by drought conditions in Minnesota, the swans fed off the bottoms of lakes
which had been previously inaccessible. Even though these feeding areas had not been hunted in many
years, tons of lead shotgun pellets can be found there. While they fed, the swans ate the lead and fell
victim to lead poisoning. More than fifty trumpeter swans were brought to the Raptor Center for
treatment. Twelve died. As a result there are only about 200 trumpeter swans left in Minnesota today.
Cd
The Impressionists were the first painters to use cadmium paints. Sherry French, a Manhattan
gallery owner, says, “You wouldn’t be able to paint Van Gogh’s ‘Sunflowers’ without cadmium”.
Contemporary artists say the intensity of the yellow, orange, and red cadmium colors cannot be replaced
by other pigments. Although not all artists work with cadmium paint, which is available in oils,
acrylics, and watercolors, many say they could not do without it. Cadmium pigments are also known for
their resistance to fading. According to Rene de la Rie, Head of the Science Department at
Washington’s National Gallery of Art, these paints have helped the cause of art conservation. To
illustrate the problem with other paints, de la Rie says that green colors in many 17th century paintings
have turned blue over time because yellow pigments that were mixed with blue to produce green have
faded. When humans consume cadmium, it builds up in the kidneys and liver. Elevated levels can
cause problems ranging from kidney malfunction to death according to the EPA.
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Heavy Metal Article Questions
Name_______________________________________
Version A
Period______Date_____________________________
______ 1. Which of the following statements supports the author’s purpose?
A. heavy metals can quickly kill their victims
B. heavy metal exposure is only a problem for children
C. heavy metals are a major cause of cancer
D. we are exposed to heavy metals all around us
______ 2. Which of the following are heavy metals mentioned in the article?
A. calcium, magnesium, iron
B. mercury, lead, cadmium
C. radon, radium, polonium
D. sodium, potassium, rubidium
E. none of the above
______ 3. Lead has been used in
A. gasoline
B. paint
C. ceramics
D. batteries
______ 4. Heavy metal poisoning has all of the following effects except
A. lower intelligence B. death
C. irritability
D. cancer
E. all of the above
E. memory loss
______ 5. To reduce exposure to lead in your home, you could do all of the following except
A. use cold water because it does not dissolve as much lead
B. run the water for 2-3 minutes to flush the water lines
C. sand and remove old lead paint from woodwork
D. replace old solder joints
______ 6. Which type of container may leach lead into your drink?
A. plastic cup
B. pewter tankard
C. crystal goblet
D. aluminum cup
______ 7. The article discussed that humans aren’t the only victims of lead poisoning. What else are affected?
A. rabbits
B. squirrel
C. deer
D. swans
______ 8. In the story, Alice in Wonderland, what was wrong with “The Mad Hatter?”
A. He was insane from exposure to mercury used in the hat making industry.
B. He had poor digestion due to arsenic on the powered doughnuts at the picnic.
C. He had a large, heavy hat made of felt that gave him a headache.
D. He ate heavy metals which weighed him down making him lethargic.
______ 9. Mercury has been used in all of the following except
A. fluorescent bulbs B. tooth fillings
C. plastic
D. paint
______ 10. Cadmium has been most important to
A. hatters
B. glass blowers
C. plumbers
D. artists
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Heavy Metal Article Questions
Name_______________________________________
Version B
Period______Date_____________________________
______ 1. Which of the following statements supports the author’s purpose?
A. heavy metal exposure is only a problem for children
B. heavy metals can quickly kill their victims
C. we are exposed to heavy metals all around us
D. heavy metals are a major cause of cancer
______ 2. Which of the following are heavy metals mentioned in the article?
A. sodium, potassium, rubidium
B. calcium, magnesium, iron
C. mercury, lead, cadmium
D. radon, radium, polonium
E. none of the above
______ 3. Lead has been used in
A. batteries
B. gasoline
C. paint
D. ceramics
______ 4. Heavy metal poisoning has all of the following effects except
A. memory loss
B. lower intelligence C. death
D. irritability
E. all of the above
E. cancer
______ 5. To reduce exposure to lead in your home, you could do all of the following except
A. replace old solder joints
B. use cold water because it does not dissolve as much lead
C. run the water for 2-3 minutes to flush the water lines
D. sand and remove old lead paint from woodwork
______ 6. Which type of container may leach lead into your drink?
A. crystal goblet
B. plastic cup
C. pewter tankard
D. aluminum cup
______ 7. The article discussed that humans aren’t the only victims of lead poisoning. What else are affected?
A. rabbits
B. swans
C. squirrel
D. deer
______ 8. In the story, Alice in Wonderland, what was wrong with “The Mad Hatter?”
A. He ate heavy metals which weighed him down making him lethargic.
B. He had poor digestion due to arsenic on the powered doughnuts at the picnic.
C. He had a large, heavy hat made of felt that gave him a headache.
D. He was insane from exposure to mercury used in the hat making industry.
______ 9. Mercury has been used in all of the following except
A. paint
B. plastic
C. tooth fillings
D. fluorescent bulbs
______ 10. Cadmium has been most important to
A. artists
B. hatters
C. glass blowers
D. plumbers