Final Exam Flashcards
How much of the worlds copper does Chile produce?
1/3
What are some of the copper companies?
BHP Billiton, Anglo American and Japan’s Sumitomo Corp
What are some of the jobs available at the US Borax mine?
Chemists, geologists, engineers, environmental scientists, milwright, electrician, equipment operators, senior quality advisor, business planning and analysis
What are four conflict minerals used in your cell phone
W (tungsten), Ta (tantalum), Au (gold), Sn (tin)
What does W (tungsten) do in your cell phone?
Makes your phone vibrate
What does Ta (tantalum) do in your cell phone?
Stores electricity for its battery
What does Au (gold) do in your cell phone?
Coats the wires
What does Sn (tin) do in your cell phone?
Solders the circuit board
What can precious metals be used for?
Military weapons,leading to war and human rights abuses
Where is Boron mined in the USA?
Boron California
Who mines boron in the USA?
Rio Tinto, US Borax
Where are the largest producers of boron?
Turkey and USA
What happens in the oxidation of Pyrite?
4FeS2 + 15O2 + 14H2O → 4Fe(OH)3 + 8SO4
2- + 16H+
Fe experiences a change in valence # from +2 in pyrite to +3 in ferric hydroxide.
The Fe is getting OXIDIZED, because it’s valence # increases
What is the most common oxidizing agent in enviornemnts in contact with the atomosphere?
Oxygen (O2)
How can the oxidation of pyrite be accelerated?
Mining or quarrying
What effect does Fe(OH)3 have?
It smothers organisms living on the stream bottom
How does Fe(OH)3 present?
Insoluble yellow-orange precipitate, also known as ferric hydroxide or yellow iron oxide.
Where can pyrite occur?
Shales that may be interbedded with coal seams, especially those that formed in marine coastal swamps.
What does strip mining of coal seams commonly cause?
Acidification of local surface waters because of the oxidation of pyrite by exposure to O2 and H2O.
What do Thiobacillus ferrooxidans do?
Catalyzes the oxidation of FeS2 to ferric ions and hydrogen ions. Convert insoluble metals to their soluble state.
What kind of bacteria is Thiobacillus ferrooxidans?
Acidophilic bacterium that obtains its energy through the oxidation of iron.
What are well known coal and metalliferous sulphide depoists around the world associated with?
Acid mine drainage
The pH scale is logarithmic.
This means that a small change
in pH represents a —— change in H+ concentration.
Large
What are solutions that resist changes to pH called?
Buffers
What do buffers do?
Act like sponges to absorb excess H+
Fluids in living organisms and seawater have strong ———–
capacity. In contrast, rainwater does not.
Buffereing
Where are acid soils commonly found?
Rainforests, jungles
Where are alkaline soils commonly found?
Deserts
The natural pH range for most plants is ——–, between ——–
acidic, 5.5 - 7.
True or false: sulfide minerals like pyrite that are underwater will not weather significantly. Explain!
True
What is the geological name for a rusty exposure of rock?
Gossan
What are some treatments for acid mine drainage?
- add a buffer material like limestone
- limit the area of exposed rock
- compacting acid-generating rock
- covering the rock with sealing layers
What common aspect do current aprroaches to AMD have?
They delay or
prevent oxidation
Physical barriers for AMD
Such as wet or dry cover have slowed sulfideoxidation in several studies; however, both wet and dry barriers
exhibit only short-term effectiveness. Wet cover is suitable atspecific sites where complete inundation is established, but thisapproach requires high maintenance costs. When using dry cover,plastic liners are expensive and rarely used for large volumes of waste.
Bactericides for AMD
can suppress oxidation, but are only effective on fresh tailings and short-lived, and do not serve as a permanent solution to AMD. In addition, application of bactericides may be toxic to aquatic organisms.
Chemical barriers for AMD
on sulfide surfaces (applying organic and/or inorganic coatings) are effective in preventing AMD. Among inorganic coatings, silica is the most promising, stable, acid-resistant and long lasting.
How long can the effects of AMD be present?
Hundreds, even thousands of
years
What health impacts is AMD reposbible for?
Physical, chemical, and biological degradation of stream habitat. It jeopardizes not only fish, but also the animals who feed on them.
What are some physical properties of gold
Soft, malleable, pounded thin, drawn out to make a thin wire, made into shapes, doesn’t rust or tarn
Gold is usually bonded to other metals such as?
Silver
What role does cyanide play in gold processing?
Cyanide helps extract the gold from the other metals, and leach it into the surrounding water
What temperature is the smelter?
1600 degrees C
What are impurities in the smelting process called?
Slag
Gold cyanidation is used in –% of gold production
90
Why is gold cyanization controversial?
The toxic nature of cyanide
Where was the Baia Mare cyanide spill?
Baia Mare, Romania
What were the effects of the Baia Mare cyanide spill
The polluted waters eventually reached the Tisza and then the Danube, killing large numbers of fish in Hungary and Romania. The spill has been called the worst environmental disaster in Europe since theChernobyl disaster
What is the toxicity of cyanide tpically ecpresses as?
The concentrationthat is lethal to 50% of the exposed population (LC50)
What is the LC50 of cyanide via inhalation?
LC50 for gaseous hydrogen cyanide is 100-300 parts per million. Inhalation of cyanide in this range results in death within 10-60 minutes.
What is the LC50 of cyanide via for ingestion?
LC50 for ingestion is 1-3 milligrams per kilogram of
body weight
What is the LC50 of cyanide via absorption through the eyes and skin?
LC50 is 100 milligrams per kilogram of body weight
How does cyanide effect the body?
Cyanide interferes with the cell’s ability to use oxygen, causing cellular suffocation. This leads to depression of the central nervous system and respiratory arrest.
How does Mercury get into the environment?
Mercury is a chemical element that can be found in small concentrations in many rocks and is the main component of the mineral cinnabar (HgS). Natural background levels can be detected in soils, air, and water around the world.
Mercury is present in gases emitted by volcanoes. Mining and industrial applications for the metal have increased significantly since the industrial revolution. Base metal smelting and gold mining both create mercury vapor, which is a potential hazard.
What thrtee industry sectors make up 2/3 of the totalUS mercury emissions?
medical waste incinerators, municipal waste combustors, and coal-fired power plants
Although cyanide is cheap, effective, and biodegradable (it degrades in sunlight), why has it been banned for gold extraction in the US states of Montana and Wisconsin, the Czech Republic, and Hungary
High toxicity
What are the three chemicakl forms of mercury?
Elemental
Inorganic
Organic
Elemental mercury
liquid metal
Inorganic mercury
Mercuric chloride
Mercuric sulfide (cinnabar)
Organic mercury
Methyl, ethyl, dimethyl mercury
Phenyl organic groups
How is mercury converted to methylmercury?
By bacteria in
sediments
What happens to methylmercury?
It biomagnifies in aquatic animals,
and the concentrations can increase by a million fold in animals at the top of the food chain
Where is methylmercury absored 100%?
Through the gastrointestinal tract and distributed through the body
What is the major source of organic mercury for humans?
Methylmercury
What is the formula for methylmercury?
[H3CHg]+
What are the health affects of mercury?
As a reproductive toxin and a potent neurotoxin, mercury affects the brain and the central nervous system.
Who is at greatest risk to mercury?
Pregnant women, women of childbearing age, and small children are at greatest risk because mercury can cross the placenta and cause irreparable neurological damage to the fetus
What is paresthesia
numbness of skin
What is ataxia
lack of coordination of muscle movements
What was the Irraq grain disaster?
A mass methylmercury poisoning incident that began in late 1971
What was grain treated with that caused the grain disaster?
A methylmercury fungicide
Where was the toxic grain imported to?
Imported into Iraq as seed grain from Mexico and the United States
What is Minamata disease?
A neurological syndrome caused by severe mercury poisoning
What are the symptoms of Minamata disease?
ataxia, numbness in the hands and feet, general muscle weakness, loss of peripheral vision, and damage to hearing and speech.
What was Minamata diseased caused by?
The release of methylmercury in the industrial wastewater from the Chisso Corporation’s chemical factory, which continued from 1932 to 1968. This highly toxic chemical accumulated in shellfish and fish in Minamata Bay, which, when eaten by the local population, resulted in mercury poisoning
Other than Japan where else did MInamata disease appear?
It severely affectedtwo First Nation communities (Grassy Narrows and Whitedog) in Northwestern Ontario following consumption of local fish contaminated with mercury, and one First Nation in Southern Ontario due to illegal disposal of industrial chemical waste
What percentage of the population in Japan showed signs of poisoning?
90%
What is dental amalgam?
A dental filling material used to fill cavities caused by tooth decay
What percentage of dental amalgam is elemental mercury by weight?
50%
What does a dental amalgam consist of?
A mixture of metals, consisting of liquid (elemental) mercury and a powdered alloy composed of silver, tin, and copper
What are dental amalgams also know as?
“silver fillings” because of their silver-like appearance
How do dentists make dental amalgam?
The dentist mixes the powdered alloy with the liquid mercury to form
an amalgam putty
Is the mercury in dental amalgam the same as the mercury in some types of fish?
NO! The form of mercury associated with dental amalgam is elemental mercury, which can slowly release mercury vapor. The form of
mercury found in fish is methylmercury, a type of organic mercury.
Mercury vapor is mainly absorbed by the _____
lungs
Methylmercury is mainly
absorbed through the ____
Digestive tract
Benefits of dental amalgam fillings?
Strong and long-lasting
Lest expensive
Risks of dental amalgam fillings?
Contain elemental mercury so it releases low levels of mercury in the form of a vapor that can be inhaled and absorbed by the lungs
Are dental amalgam fillings dangerous?
The FDA considers dental amalgam fillings safe for adults and children
ages 6 and above
Where was the deepwater horizon oil spill?
Gulf of Mexico near Mississippi Delta, U.S.
What was the estimated total dischrage of the deepwater horizon oil spill?
4.9 million barrels
What was the cause of the deepwater horizon oil spill?
Wellhead blowout
Causalities from the deepwater horizon oil spill?
11 killed 17 injured
Who was at fault for the deepwater horizon oil spill?
mostly BP, but also rig operator Transocean and contractor Halliburton. Blamed for gross negligence, a series of cost-cutting decisions and an inadequate safety system.
What are the health effects on wildlife from the deepwater horizon oil spill?
Extensive damage to marine and wildlife habitats and fishing and tourism industries was reported. Oil is embedded in the sand.
What animals does the video mention as a “poster animal” for the spill? The oil affects the animal at every stage of life.
Turtles
What are the main effects of oil on birds?
Can’t thermoregulate, spend all their time preening
What is meant by the term “baseline data”?
Data about the area prior to an event or disaster
What is Corexit?
chemical dispersant, sinks to sea floor
when mixed with oil. Dispute about
toxicity.
What is some physical evidence of the spill still found on beaches in the Gulf Coast?
oily sea foam, tar balls
What are some medical issues mentioned in this video about the Deepwater Horizon disaster, five years later?
chronic cough, skin rash, memory loss
What did the spill do to the real estate market?
Houses spend long time on market
Methods Used to Contain/Eliminate Oil
A massive response ensued to protect beaches, wetlands and estuaries from the spreading oil by utilizing:
a) skimmer ships
b) floating containment booms
c) controlled burns
d) oil-eating microbes
e) 1.84 million US gallons (7,000 m3) of oil dispersant (Corexit)
Containment booms
deployed, either to corral the oil or as barriers to protect marshes, mangroves, and shrimp/crab/oyster farms. Booms extend 18–48 inches above and below the water surface
How does Corexit work?
A mixture of emulsifiers and solvents that helps break oil into small droplets following an oil spill. Small droplets are easier to disperse throughout a water volume, and small droplets may be more readily biodegraded by microbes
Concerns with Corexit
Contains possible cancer-causing agents, hazardous toxins and endocrine-disrupting chemicals
Excessive exposure may cause central nervous system effects, nausea, vomiting, anesthetic or narcotic effects
How did the blowout occur?
high-pressure methane gas from the well expanded into the drilling riser and rose into the drilling rig, where it ignited and exploded, engulfing the platform.
What is a kick?
An unplanned flow of well fluids (water, oil, gas) into the wellbore
What is a blowout?
an uncontrolled release of flammable oil and gas from the well
What features does a blowout preventer have?
can close pipe rams, has circular annular preventers, blind shear rams
Why did the drill pipe buckle? What consequence did this have?
Effective compression. Large pressure difference between inside the pipe and outside. The pipe was closed at the top, but oil continued to flow in from the bottom. Buckling caused the blind shear rams to fail.
Financial Consequences for BP
BP pleading guilty to 11 counts of
manslaughter, two misdemeanors, and a felony count of lying to Congress
$18.7 billion in fines, the largest corporate settlement in U.S. history
The oil reservoir was about
18,360 ft below sea level what is this area reffered to as?
Macondo well, or Macondo prospect.
What is asbestos?
Asbestos is a general name for a number of fibrous minerals that
are all hazardous to human health
Chrysotile is in the ——– group of minerals: curly fibers
Serpentine
All other types of aesbestos are in the ——- group of minerals: straight fibers
amphibole
Properties that make asbestos so versatile and cost effective are:
1) high tensile strength
2) chemical and thermal stability
3) high flexibility
4) low electrical conductivity
5) large surface area
6) fire resistance
Uses of asbestos
Insulation, cement building materials, fibre cement boards, roofing, textiles, gaskets and pads for cars, brake linings, and other applications around the world.
Chrysotile “white asbestos”
accounts for >90% of asbestos used in U.S. buildings. Chrysotile fibers are white, flexible, and curly. A wide range of workers still come into contact with chrysotile asbestos today.
Chrysotile breaks down the easiest in the human body. Only rarely are high levels found in the body, even in chrysotile miners. Whether chrysotile can cause mesothelioma has been debated in the literature. It can cause lung cancer.
Crocidolite
takes the form of blue, straight fibers. It is is considered to be the most dangerous type of asbestos due to its physical properties. It is very hard to break down in the human body, and is no longer mined. Crocidolite has a high resistance to acid, making it a useful industrial substance
Tremolite and Actinolit
Tremolite and actinolite fibers differ from chrysotile asbestos fibers in their shape and color.
Tremolite is commonly milky white colour, while actinolite can be light to dark green.
They are sharp fibers that are easyt o inhale and ingest, making them one of the most dangerous asbestos types.
While tremolite and actinolite asbestos is no longer mined or used in commercial products, they are responsible for many individuals’
asbestos-related illnesses.
In the past, many miners came into contact with the substance while on the job.
Amosite
Amosite fibers are also sharp. Their needle-like
shape makes it easy for the fibers to become trapped within lungs and other parts of the body after inhaling or ingesting.
Next to chrysotile asbestos, amosite is the second most common type of asbestos found in buildings and different products.
Anthophyllite
Found their way into products made with vermiculite and talc.
The miners of vermiculite and talc are at high risk for developing asbestos-related diseases because of anthophyllite contamination within
the substances they mined.
Anthophyllite asbestos can range in color
from white to gray to brown
What type of asbestos is mained on a large scale?
Chrysotile
What are the top chrysotile producers?
In order: Russia, China, Brazil and Kazakhstan
Where are asbestos minerals found?
Metamorphic rocks
Asbestos Mining in Quebec
In late 2011, Canada’s remaining two asbestos mines (both in the Province of Quebec), Lac d’Amiante du Canada and the Jeffrey mine,
halted operations. Until then, the Jeffery mine was the world’s largest asbestos mine (2 hours east of Montreal).
Health Impacts of Asbestos
Non-cancerous
Cancerous
Asbestosis is?
When the lung becomes fibrotic and stiff, scars form, gas exchange capacity decreases. Shortness of breath, becomes worse. No cure
What are pleaural plaques?
Most common effect of asbestos inhalation. White raised patches on the inside of the chest cavity, made of connective tissues. Most appear 30+ years after exposure. Slowly grow larger.
Lung cancer from aesbestos
cumulative effect with smoking. Smokers are more likely to develop lung cancer if exposed to asbestos. Risk of lung cancer for non-smokers is smaller
Mesothelioma from aspestos
No correlation to smoking. Nearly all cases are due to asbestos. Cancerous tumors grow in pleura (tissues that surround the lung). Even slight exposures can cause mesothelioma. Can manifest 20+ years after exposure.
Asbestos and lung disease progression
- Inhaling the fibres
- Asbestosis
- Mesothelioma
What is mesothelioma?
Rare cancer of the tissues that surround the lung caused by asbestos
Kills 60% of sufferers within a year after their
symptoms appear
Has a five-year survival rate of less than 7%
Where is asbestos still used?
It continues to be used around the world, especially in Asia and Russia, and in small amounts in the US
Is asbestos banned in Canada?
Canada finally moved ahead with a full ban on the use, sale, import and manufacture of all asbestos products in 2018.
Do houses in Calgary contain asbestos?
Homes built before 1990 possibly contain asbestos materials somewhere. Homes built before 1980 almost always contain asbestos
materials somewhere. Asbestos may be contained within building materials:
Pipes and drywall
Insulation
Floor tiles
Roofing and siding
Heating systems (air ducts)
Plumbing
Do I need to remove asbestos from my house?
If you are not going to disturb the material through renovation or demolition, and it is not damaged, it poses minimal health risk and does not need to be removed
What is silicosis?
lung fibrosis caused by the inhalation of dust containing silica
What is silica
Crystalline SiO2 (also known as quartz)
Quartz is a very common mineral in the Earth’s crust, and is found in sedimentary, igneous, and metamorphic rocks. It is the main mineral in desert sand and on many beaches.
What are some building products that contain silica?
Concrete, brick
What are the immune system cells called that attack the silica?
Macrophages
What do macrophages do?
- engulf and try to dissolve the silica crystals
- carry silica into the walls of the lung
——- forms around the dead cells. This can
continue even after exposure has stopped.
Scar tissue
What is pulmonary fibrosis?
A progressive, fatal lung disease that few
survive more than 3-5 years after diagnosis.
Particles smaller than—— are absorbed into the bloodtream
1um
Particles smaller than—— will be trapped in the lungs
10um
What Causes Silicosis?
Silicosis is caused by exposure to crystalline silica, which comes from chipping, cutting, drilling, or grinding soil, sand, granite, or other
minerals. Any occupation where the earth’s crust is disturbed can cause silicosis.
What Are the Symptoms of Silicosis?
Symptoms of silicosis can appear from a few weeks to many years after exposure to silica dust. Symptoms typically worsen over time as scarring in the lungs occurs.
Main early symptom:
Cough
Acute silicosis:
fever and sharp chest pain along with breathing difficulty. These symptoms can come on suddenly.
Chronic silicosis:
-develops slowly
-abnormal chest X-ray
-development of cough and breathing difficulty
-excess phlegm production
-bronchitis-like symptoms
-wheezing
How do I prevent exposures and control the dust?
Water can be used to suppress the dust and
vacuums can be used to capture it at the source. When water or vacuums are not feasible, or if the exposures are still high even with these controls, an approved respirator should be used
Is silicosis reversible? Is there a cure?
NO
Where is the silica is found in relation to the coal?
In the sandstone and shale layers (below the coal)
What is Black Lung?
Coal workers’ pneumoconiosis, also known as black lung disease or black lung, is caused by long-term exposure to coal dust. It is similar to both silicosis from inhaling silica dust and asbestosis from inhaling asbestos dust. Inhaled coal dust progressively builds up in the lungs and leads to inflammation, fibrosis, and in the worst cases, death. There is no cure.
Symbol for fluorine
F
Symbol for fluoride
F-
How is water fluoridation usually accomplished?
by adding sodium fluoride (NaF), fluorosilicic acid (H2SiF6), or sodium fluorosilicate (Na2SiF6) to drinking water
What are some non-drinking water sources of F- in our diet?
fish, tea, gelatin
Natural F- gets washed into our drinking water supply by:
erosion
In the 1940’s, scientists found that people living near water sources with 1ppm F- had fewer:
Cavities
Today, —– of Americans have fluorinated public drinking water.
2/3
A study of medieval skeletons showed that people who lived in coastal areas and ate more —– had fewer ———.
Fish, cavities
A CDC study compared kids in the late 1960’s to kids in the early 1990’s, and found a 68% drop in:
Cavities
This drop in cavaities could be attributed to either:
drinking fluorinated water, or using fluoride toothpaste
What is the recommended amount of daily fluoride during tooth enamel growth?
0.8 – 1.2 ppm
What benefit does fluoride give during tooth enamel formation?
F- helps reduce enamel solubility during its formation. This results in stronger enamel that is more resistant to bacteria
> 1.5 ppm F- per day can cause:
tooth decay, pitting
3-6 ppm F- per day can cause:
skeletal fluorosis
The World Health Organization states that the most effective public health measure for the prevention of dental decay is
fluorinated drinking water.
Why the concern about fluoride
in drinking water?
Some studies have suggested a link between
fluorinated drinking water and lower IQ
What is the latest on Calgary’s municipal drinking water?
Calgary is adding fluoride into water in 2024
When can dental fluorosis occur?
Can only happen during tooth formation, when
excessive fluoride exposure occurs in childhood. Between birth to 6 years old
What can cause dental fluorosis
exposure to water that is naturally fluorinated to levels above the recommended levels, or
by exposure to other fluoride sources such pollution from high fluoride coal
What us the main mineral in tooth enamal?
calcium phosphate.
Hypomineralized enamel has altered optical properties and
appears?
opaque and lusterless relative to normal enamel.
Skeletal Fluorosis
- high fluoride concentration in the body results in hardening of bones,
making them lose elasticity and increasing the frequency of fractures. - thickening of the bone structure
- impaired joint mobility
- ligaments and cartilage can become ossified
Where is fluorosis most severe and widespread?
India and China because groundwater is
naturally highly fluorinated (~6-8 ppm fluoride)
Process of dental fluorosis
If there is an excess of F-, it can combine
with Ca to produce CaF2. This results in
inadequate calcium phosphate production, which means less mineralization in the growing enamel.
Process of skeltal fluorosis
If there is too much F- in the blood, the F- will leach the Ca2+ out of the bones to form CaF2, which is insoluble. This solid is then flushed out by the body
Geographic areas associated with ——— having over 1.5 mg/L of naturally occurring fluoride, which is above recommended levels.
Groundwater
Geological Sources of Fluoride in Groundwater
Minerals, rocks, hydrogeological conditions, irrigation and fertilizers
Rock types as source of fluoride
Igneous rocks that crystallize underground (e.g. granite) can sometimes contain fluorite and fluorapatite.
Hydrogeological conditions as source of fluoride
Alkaline groundwater generally tends to increase the solubility of fluoride minerals. Fluoride rich groundwater also generally has more Mg than Ca
Irrigation and fertilizers as source of fluoride
Phosphate (PO43-) fertilizers contain high levels of fluoride. Consequently, the widespread use of phosphate fertilizers has increased soil fluoride concentrations in many areas.
What did researchers in the UK develope
a fast colorchanging test that detects fluoride in drinking water. The test could help prevent the crippling bone disease skeletal fluorosis in developing countries.
How is radon formed?
A radioactive decay product of uranium and thorium
What is the stable end product of radon decay?
Lead
Similarities between radon and radium
both in the U-Pb decay series
both are radioactive
both are known to cause cancers
Differences between radon and radium
Radium is a solid. Radon is a gas.
What kind of particles does radon emit
alpha
What are some properties of radon that make it hard to detect?
colourless, odorless
What is the #2 cause of lung cancer after smoking
Excess Rn exposure
How long does Mike Holmes recommend to leave Rn testing units in place for?
91 days
What is the maximum acceptable level of Rn according to Health Canada?
200Bq/m^3
About how much does a Rn test cost?
$250
What is Bq?
It is a measure of radioactivity. One becquerel is defined as the activity of a quantity of radioactive material in which one nucleus decays per second.
What fraction of homes in Calgary have Rn higher than theHealth Canada limit?
1/8
Studies have found that homes built in the last 25 years have higher Rn content, on average. What are some reasons for this?
More square footage, taller, more airtight
What is the approximate cost of Rn remediation?
$2500
What percent of lung cancer in Canada is attributed to radon?
16%
What minerals contain U and Th?
Zircon, Monazite, Uranite
These minerals are usually mm-size and are found in igneous, sedimentary, and metamorphic rocks
WHY IS RADON HIGHER IN SOME AREAS THAN IN
OTHERS?
1) Abundance of uranium and thorium minerals in the bedrock
2) Grain size and permeability of the bedrock
3) Amount of fractures in the bedrock
4) Abundance of uranium and thorium minerals in glacial sediments
What kind of rock do we have in southern Alberta?
Sandstone, siltstone, mudstone
Was southern Alberta glaciated in the past?
Yes
Where was the glacial material that covers Calgary was sourced from?
The West (Rocky Mountains)
and North/East (Canadian Shield)
The strong positive associations between the estimated soil radon potential and the percentage of homes above the guideline of 200 Bq/m3 demonstrate that
SRP can be an effective predictor of areas prone to elevated indoor radon
concentrations.
What does the graph showing a positive linear slope on a soil radon potential indix vs percentage of homes above 200 Bq/m^3 indicate
These data indicate that radon in soil is the main source of radon in homes, and
that soil permeability also plays an important role in soil radon potential and, ultimately, in indoor radon potential.
What is geophaphy
the practice of eating soil or soil-like
substances such as clay or chalk.
Where does geophagy occur?
Occurs most often in rural or pre-industrial societies among
children and pregnant women, and those from a poor
socioeconomic background in developing countries.
What is pica
an eating disorder in the Diagnostic and Statistical Manual of Mental Disorders (DSM) characterized by abnormal
cravings for non-nutritive items.
According to Wikipedia, human geophagia may be related to?
Pica
Geophagy in Primates
widespread amongst nonhuman primates, suggesting that the practice predates human evolution, and that soil ingestion has continued for a variety of reasons
Possibly the oldest evidence for geophagy:
calcium-rich white clay found alongside bones of Homo habilus at Kalambo Falls near the border of Zambia and Tanzania
Pliny is said to have noted the ingestion of soil on
Lemnos, an island of Greece, and the ingestion of the soils from this island was noted until the 14th century
Historical evidence from South America
The German explorer and naturalist
Alexander von Humboldt was
fascinated by the practice of some
tribes to eat earth, mostly from want,
but sometimes by choice or custom.
What follows is an account by
Humboldt of the geophagy of the
Otomacs, a tribe inhabiting the
banks of the Orinoco River.
The setting is in what is now
Venezuela, c. 1800
“The Otomacs eat earth; that is, they swallow every day, during several
months, very considerable quantities, to appease hunger. The earth is a
very fine clay, of a yellowish gray color; and, being slightly baked in the
fire, the hardened crust has a tint inclining to red, owing to the iron oxides
which are mingled with it. The Otomacs do not eat every kind of clay
indifferently; they choose the smoothest to the feel.”
Historical evidence from Indonesia
“In the Indian archipelago, at the island of Java, we saw little square
and reddish cakes exposed to sale. These cakes, called taanampo,
were cakes of clay, slightly baked, which the natives eat with appetite.
The reddish and somewhat iron-rich clay, which the inhabitants of Java
are fond of eating occasionally, can be also spread on a plate of iron,
and baked, after having been rolled into little cylinders in the form of the
bark of cinnamon. In this state, it takes the name of ampo, and it is sold
in the public markets.”
Historical evidence from Africa
In Africa, David Livingstone wrote about slaves eating soil in Zanzibar in the mid 1800’s. It is thought that large numbers of slaves brought with them soil-eating practices when they were shipped to the New World as part of the transatlantic slave trade.
Who wrote about slaves eating soil in Zanzibar
David Livingstone
Why did slaves in America continue to practice geophagy?
- soils were ingested for medicine and perceived nutrition
- cultural reasons
- large numbers of slaves indulged in excessive soil eating** to make themselves ill **so they couldn’t work
- to commit suicide in the belief that their spirit would return to their African homeland (Hunter, 1973).
Who was geophagia also common amongst in Southern USA
poor whites
What is kaolin
A type of klay
In africa —- is eaten for pleasure or to supress hunger
kaolin
Where is kaolin sold for human consuption?
At most markets in Cameroon
What is kaolin often flavoured with
Spices such as black pepper and cardamom
Why is clay consumed by preganat or lactating women in Africa
In order to reduce nausea and supplement a mineral deficient diet.
Where did Geissler et al. investigate the prevelance of geophagy?
In parts of Kenya
What did the Geissler et al. study find
They studied 285 school children aged 5-18 years old, and found that 73% ate soil.
These authors found that 154 out of 275 pregnant women they surveyed reported eating soil regularly.
The median soil intake by the school children was measured at 28 g/day.
Summary of reasons why people eat soil:
1) Consumption of soil in times of famine. Laufer (1930) commented that hunger will be relieved by eating soil, as it will give a sensation of fullness to the stomach.
2) As a digestive aid for detoxifying food. e.g. Nearly all of the 160 wild potato species growing in the Andes contain toxic chemicals. Indigenous people eat the potatoes with a dip made of clay and
a mustard-like herb. Studies suggest that the fine clay particles may help prevent intestinal absorption of toxic materials or promote the body’s excretion of them.
3) Consumption of soil as a pharmaceutical. Used in treating nausea, intestinal upset, antidote to poison, and traditional remedy.
4) Psychological reasons. Layman et al. (1963) suggests that people may ingest soil to help handle anxiety.
5) Intentional illness or suicide.
6) Perceived nutritional benefit. This is questionable, but possible.
Conclusions about the nutritional benefit of geophagy cannot be drawn until it is know —–
What proportion of the nutrients consumed are actually absorbed and used by the body
What are the reuirements of a mineral
Naturally occuring
Solid crystalline stucture
Inorganic
Specific chemical composistion
What are kidney stones
A kidney stone is a hard, crystalline
mineral material formed within the
kidney or urinary tract. Between 1% and 15% of people develop a kidney stone at some point in their life. Kidney stones form when there is a decrease in urine
volume and/or an excess of stoneforming substances in the urine.
Kidney stones can cause blockage of the ___
Ureter
Symptoms of kidney stones
1) severe pain in the lower back or abdomen
2) blood in the urine
3) painful urination
4) nausea
5) vomiting
6) urinary urgency
7) restlessness
8) sweating
What happens if a stone is more than 5mm
It can cause blockage of the ureter
Kidney stones: risk factors
Most stones form due to a combination of genetics and environmental
factors.
1) high urine calcium levels
2) obesity
3) certain foods
4) some medications
5) calcium supplements
6) hyperparathyroidism
7) gout
8) not drinking enough fluids
How much urine do doctors reccomend producing in a day
2L
What are the 5 types of kidney stones made of?
- calcium oxalate (most common)
- calcium phosphate
- struvite
- uric acid
- cystine
What are the stages of formation of a kidney stone?
a) nucleation (chemical elements joining together) homogeneous (all crystal) vs. hetero (cell debris)
b) growth
c) aggregation
d) retention in the kidney, continue to grow
e) move into the ureter
In the U.S., what percent of men and what percent of women are estimated to produce a kidney stone in their lifetime?
men: 13% women: 7%
What percent of kidney stones need no surgical intervention?
78%. Most kidney stones will pass through the ureter to the bladder on their own with time.
If a kidney stone becomes lodged in the ureter, what are two possible medical interventions?
lithotripsy, endoscopic removal
If a person forms a kidney stone, what is the likelihood that they will form another one in the next four years?
50%
What causes kidney stones to form?
- supersaturation of urine with stone-forming elements
- deficiency of inhibitors (such as citrate) that prevent crystallization
What are two dietary habits that can lead to kidney stone formation?
- too much sodium in diet
- too much animal protein in diet
What percentage of kidney stones are calcium stones
75%
How does lithotripsy work?
uses sound waves to break up large kidney stones into smaller pieces. These sound waves are also called high-energy shock waves
What is the most common form of lithotripsy
extracorporeal
shock wave lithotripsy (ESWL)
What other treatment choices for kidney stones are available?
Drug treatment and endoscopic stone removal, a technique that goes through the bladder or through a small incision in the back to reach the stone.
Bone consists mainly of collagen fibres and small crystals of _____
calcium phosphate
What is the composition of a bone?
In vivo bone (living bone in the body)
contains between 10% and 20% water. Of its dry mass, approximately 60-70% is calcium phosphate. Most of the rest
is collagen, but bone also contains a small amount of other substances such as proteins and inorganic salts
The harder, outer layer of your bone is called:
Compact bone
The inner part of your bone is called:
spongy bone
What are the cells called that break down bone tissue?
Osteoclasts
What are the cells called that make new bone tissue?
osteoblasts
At what age is peak bone mass in humans?
in your 30’s
What is osteoporosis?
weakened bones due to low bone density
What are the most common fracture locations related to osteoporosis?
wrist, spine, hips
What is the main mineral in human teeth
hydroxyapatite, which is a crystalline calcium phosphate.
What is the hardest substance in the human body?
Tooth enamel
What is. agallstone made of
A gall stone is made of bile components. The bile components that form gallstones include cholesterol, bile salts, and bilirubin
Risk factors for gallstones include:
- birth control pills
- pregnancy
- a family history of gallstones
- obesity
- diabetes
- liver disease
- rapid weight loss
The risk of gallstones may be decreased by:
- maintaining a healthy weight through sufficient exercise
- eating a healthy diet that is high in fibre and low in sugar
Rare earth minerals from China
China’s Control Of Rare Earth
Minerals Threatens The United States
WOLFRAMITE: TUNGSTEN
GRAPHITE: CARBON
QUARTZ : SILICON
MONAZITE: RARE EARTH ELEMENTS
Where was the boron that we focused on from
Boron, California, USA
Where was the tantalum that we focused on from
Congo
Where was the active copper mine that we focused on in class
In chile
