Transcript Heavy Metals

Mineral Project
By: Michael Arpasi
Question
 How
do heavy metals (such as mercury,
arsenic, and lead) effect humans?
What is a heavy metal?

A heavy metal is any metal with a specific gravity of 5.0
kg/m^3 Some examples are lead, mercury, and arsenic.
Mercury (Hg)

Mercury is the 80th element on the periodic table of elements. Its
specific gravity is 13.59 kg/m^3. It is a liquid at room temperature.
Elemental mercury is poorly absorbed through the skin and gastrointestinal track. It is readily absorbed by inhalation, injection, or
ingestion of salts. It was a common ingredient in 19th century felt
production and exposure resulted in encephalopathy, aka “mad
hatter’s disease”.
Arsenic (As)

Arsenic is the 33rd element on the periodic table of elements. Its
specific gravity is 5.73kg/m^3. At room temperature it is a solid
state. Its most toxic forms are water soluble salts. Arsenic is readily
absorbed by groundwater, and enters humans by the gastro
intestinal track. It has been used as a murder weapon and is a
contaminant in ground water in some parts of India.
Lead (Pb)

Lead is the 82nd element on the periodic table of elements. Its specific gravity is
11.35 kg/m^3. At room temperature it is a solid state. Lead is most toxic as lead
salts. These were commonly used as pigments in paint. Its use was discontinued.
It is absorbed through the gastro-intestinal track.
Enzymes

An enzyme is a protein (made of
chains of amino acids) which when
folded has binding sites which
effect a substrate. A substrate is a
molecule which when bound, is
altered by the enzyme into a
product(s). Enzymes lower the
activation energy in a reaction,
and are responsible for most
complex chemical reactions which
occur in cells. The enzymes nature
is not changed by the reaction.
Heavy Metal Toxicity

Heavy Metals are non-competitive inhibitors in enzymes. They bind
to oxygen, nitrogen, and sulfur atoms within the protein amino
acids. This changes the shape of the binding sites, and renders them
unable to bind a substrate.
Normal Enzyme
Deactivated Enzyme
Enzyme Damage

Enzymes altered by the binding with heavy metals
function poorly, or not at all.

Poorly functioning enzymes cannot metabolize substrate
or produce desirable products.

This leads to cell damage, and ultimately tissue damage
and illness.
Exposure
Acute
Mercury
Arsenic
Lead
Elemental (inhaled):
Fever, Vomiting, and
Diarrhea
Nausea, vomiting,
diarrhea,
encephalopathy,
cardiac arrhythmia,
and painful
neuropathy.
Nausea, vomiting,
encephalopathy,
(headache, seizures,
ataxia, and
obtundation).
Diabetes,
hyperkeratosis/
hypopigmentation.
Encephalopathy,
anemia, abdominal
pain, nephropathy,
foot-drop/ wristdrop.
Inorganic salts
(indigestion): caustic
gastroenteritis
Chronic
Nausea, metallic
taste, gingivastomatitis, tremor,
neurasthenia, kidney
failure, and
hypersensitivity.
Cancer: lung,
bladder, and skin.
Treatment

Remove the source of the exposure.

A treatment used for heavy metal poisoning is called
chelation. It is a process of removing heavy metals from
the enzymes. It is injected into the blood stream, and
removes the heavy metals by allowing them to attach
onto the chelate. Once the heavy metals are attached the
body can work to excrete the heavy metals.
Questions?