Environmental Impact and Health Effects of the Alkali Metals

Lithium				it is now suspected of being more plentiful than
Like all alkali metals, lithium reacts easily in water				previously calculated. It is not found in large
and does not occur freely in nature due to its				deposits but occurs in small amounts in certain
activity. Lithium is a moderately abundant element				mineral waters and in many minerals usually
and its present in the Earth’s crust in 65 ppm				associated with other alkali metals. It is also found
(parts per million). Lithium is easily adsorbed by				in small quantities in tea, coffee, tobacco, and
plants and the amount of lithium in plants varies				other plants, and trace quantities of the element
widely. While the lithium surface becomes coated				may be required by living organisms. Rubidium is
with a mixture of lithium hydroxide, lithium				used in making certain catalysts. The rate of
carbonate, and lithium nitride (Li3N), lithium				radioactive decay of the rubidium-87 can be used
hydroxide represents a potentially significant				in geologic age determination. It is very like
hazard because it is extremely corrosive. Special				potassium and there are no environments where
attention should be given to water organisms.				it is seen as a threat. No minerals of rubidium are
Many reactions of lithium may cause fire or				known, but rubidium is present in significant
explosion when exposed to Lithium. It gives off				amounts in other minerals such as lepodite (1.5%),
irritating or toxic fumes (or gases) in a fire. There				pollucite and carnallite. It is also present in traces in
is risk of fire and explosion on contact with				trace amounts in other minerals such as
combustible substances and water. On inhalation it				zinnwaldite and leucite. The amount of rubidium
gives burning sensation, coughs, labored breathing,				produced every year is small, and what demand
shortness of breath, and sore throat. However,				there is can be met from a stock of a mixed
the symptoms may be delayed. When it comes in				carbonate by-product that is collected during the
contact of the skin, the skin becomes red. On				extraction of lithium from lepodite. The little
ingestion, there are chances of abdominal cramps,				rubidium that is produced is used for research
abdominal pain, burning sensation, nausea, shock				purposes only, these is no incentive to seek
or collapse, vomiting, and weakness. The				commercial outlets for the material.
substance is corrosive to the eyes, the skin and				Rubidium has no known biological role but has a
the respiratory tract. Inhalation of the substance				slight stimulatory effect on metabolism, probably
may cause lung oedema. The symptoms of lung				because it is like potassium. The two elements
oedema are often not manifested until a few				are found together in minerals and soils, although
hours have passed and they are aggravated by				potassium is much more abundant than rubidium.
physical effort.				Plant will adsorb rubidium quite quickly. When
Rest and medical observation is, therefore,				stresses by deficiency of potassium some plants,
essential in all cases of probable actions of lithium.				such as sugar beet, will respond to the addition of
Immediate administration of an appropriate spray,				rubidium. In this way rubidium enters the food
by a doctor or a person authorized by him/her,				chain and so contributes to a daily intake of
should be considered. The substance can be				between 1 and 5 mg. No negative environmental
absorbed into the body by inhalation of its aerosol				effects have been reported.
and by ingestion. Inhalation due to evaporation at				It is moderately toxic by ingestion. If rubidium
20°C is negligible; a harmful concentration of				ignites, it will cause thermal burns. Rubidium readily
airborne particles can, however, be reached				reacts with skin moisture to form rubidium
quickly when dispersed. Heating the element may				hydroxide, which causes chemical burns of eyes
cause violent combustion or explosion. The				and skin. Signs and symptoms of overexposure
substance may spontaneously ignite on contact				to this element are skin and eye burns, failure to
with air when finely dispersed. Upon heating, toxic				gain weight, ataxia, hyper irritation, skin ulcers, and
fumes are formed. It reacts violently with strong				extreme nervousness. Medical condition is
oxidants, acids and many compounds causing fire				aggravated by exposure to heart patients due to
and explosion hazards. It also reacts violently with				potassium imbalance. In case of exposure to
water, forming highly flammable hydrogen gas and				eyes immediately flush with running water for 15
corrosive fumes of lithium hydroxide.				minutes while holding eyelid. Obtain medical
Sodium				attention immediately. In case of skin exposure
Sodium is the most abundant element in the				remove material and flush with soap and water.
Earth’s crust and is found in nature only in the				Remove contaminated clothing. Get medical
combined state ranking sixth or seventh in order				attention promptly. In case of inhalation move to
of abundance of the elements. It occurs in the				fresh air immediately. If irritation persists, get
ocean and in salt lakes as sodium chloride, NaCl,				medical attention. In case of ingestion do not
and less often as sodium carbonate, Na2CO3, and				induce vomiting. Rather try to get medical
sodium sulfate, Na2SO4. Sodium is the second				attention immediately.
most abundant element after chlorine (as chloride				Cesium
ions) dissolved in seawater. The most important				Although cesium is much less abundant than the
sodium salts found in nature are sodium chloride				other alkali metals, it is still more common than
(halite or rock salt), sodium carbonate (trona or				elements many important elements. Few cesium
soda), sodium borate (borax), sodium nitrate and				mineral are know, pollucite is the main: they are
sodium sulfate. Sodium salts are found in all water				silicate magmas cooled from granites. Cesium
bodies. A huge amount of this salt is extracted				ranks about 46th in natural abundance among the
mainly from salt deposits by pumping water down				elements in crustal rocks. The natural source
bore holes to dissolve it and pumping up brine.				yielding the greatest quantity of cesium is the
The sun and many other stars shine with visible				rare mineral Pollux (or pollucite). Ores of this
light in which the yellow component dominates and				mineral found on the island of Elba contain 34
this is given out by sodium atoms in a high-energy				percent of cesium oxide; American ores of Pollux,
state. Sodium's powdered form is highly explosive				found in Maine and South Dakota, contain 13
in water and a poison combined and uncombined				percent of the oxide. It is extracted by separating
with many other elements. This chemical is not				the cesium compound from the mineral,
mobile in solid form, although it absorbs moisture				transforming the compound thus obtained into the
very easily. Once liquid, sodium hydroxide leaches				cyanide, and electrolysis of the fused cyanide.
rapidly into the soil				Cesium can also be obtained by heating its
				hydroxides or carbonates with magnesium or
Sodium salts are important ingredients of many				aluminum and by heating its chlorides with calcium.
foodstuffs (for instance common salt) as besides				Commercial cesium usually contain such elements
imparting salty taste, it is necessary for humans				with which it usually occurs in minerals and which
to maintain the balance of the physical fluids				resembles it so closely that no effort is made to
system. Sodium is also required for nerve and				separate them.
muscle functioning. However, too much sodium				Cesium occurs naturally in the environment mainly
can damage our kidneys and increases the				from erosion and weathering of rocks and
chances of high blood pressure. The amount of				minerals. It is also released into the air, water and
sodium a person consumes each day varies from				soil through mining and milling of ores. Radioactive
individual to individual and from culture to culture.				isotopes of cesium may be released into the air
Some people get as little as 2 g/day, some as				by nuclear power plants and during nuclear
much as 20 grams. Sodium is essential, but				accidents and nuclear weapons testing. The
controversially surrounds the amount required.				radioactive isotopes can only be decreased in
Contact of sodium with water, including				concentration through radioactive decay.
perspiration causes the formation of sodium				Non-radioactive cesium can either be destroyed
hydroxide fumes, which are highly irritating to skin,				when it enters the environment or react with
eyes, nose and throat. This may cause sneezing				other compounds into very specific molecules.
and coughing. Very severe exposures may result				Both radioactive and stable cesium act the same
in difficult breathing, coughing and chemical				way within the bodies of humans and animals
bronchitis. Contact to the skin may cause itching,				chemically. Cesium in air can travel long distances
tingling, thermal and caustic burns and permanent				before settling on earth. In water and soils most
damage. Its contact with eyes may result in				cesium compounds are very water-soluble. In
permanent damage and loss of sight.				soils, however, cesium does not rinse out into the
Potassium				groundwater. It remains within the top layers of
Most potassium occurs in the Earth's crust as				soils as it strongly bonds to soil particles and as a
minerals, such as feldspars and clays. Potassium is				result it is not readily available for uptake through
leached from these by weathering, which explains				plant roots. Radioactive cesium does have a
why there is quite a lot of this element in the sea				chance of entering plants by falling on leaves.
(0.75 g/liter). Minerals mined for their potassium				Animals that are exposed to very high doses of
are pinkish and sylvite, carnallite and alunite. The				cesium show changes in behavior, such as
main mining area used to be Germany, which had				increased or decreased activity.
a monopoly of potassium before the First World
War. Today most potassium minerals come from				Humans may be exposed to cesium by breathing,
Canada, USA and Chile. The world production of				drinking or eating. In air the levels of cesium are
potassium ores is about 50 million tonnes, and				generally low, but radioactive cesium has been
reserves are vast. Potassium is a key plant				detected at some level in surface water and in
element. Although it is soluble in water, little is lost				many types of foods. The amount of cesium in
from undisturbed soils because as it is released				foods and drinks depends upon the emission of
from dead plants and animal excrements, it				radioactive cesium through nuclear power plants,
quickly become strongly bound to clay particles,				mainly through accidents. These accidents have
and it is retained ready to be readsorbed by the				not occurred since the Chernobyl disaster in 1986.
roots of other plants.				People that work in the nuclear power industry
Together with nitrogen and phosphorous,				may be exposed to higher levels of cesium, but
potassium is one of the essential macro minerals				many precautionary measurements can be taken
for plant survival. Its presence is of great				to prevent this. It is not very likely that people
importance for soil health, plant growth and animal				experience health effects that can be related to
nutrition. Its primary function in the plant is its role				cesium itself. When contact with radioactive
in the maintenance of osmotic pressure and cell				cesium occurs, which is highly unlikely, a person
size, thereby influencing photosynthesis and				can experience cell damage due to radiation of
energy production as well as stomatal opening and				the cesium particles. Due to this, effects such as
carbon dioxide supply, and translocation of				nausea, vomiting, diarrhoea and bleeding may
nutrients. As such, the element is required in				occur. When the exposure lasts a long time
relatively large proportions by the growing				people may even lose consciousness. Coma or
plant. The consequences of low potassium levels				even death may than follow. How serious the
are apparent in a variety of symptoms: restricted				effects are depends upon the resistance of
growth, reduced flowering, lower yields and lower				individual persons and the duration of exposure
quality produce. High water soluble levels of				and the concentration a person is exposed to.
potassium cause damage to germinating seedlings				Francium
inhibits the uptake of other minerals and reduces				Francium is the heaviest of the alkali metals and
the quality of the crop.				the most electropositive or the least
				electronegative of all the known elements. All its
Potassium can be found in vegetables, fruit,				isotopes are radioactive and short-lived. The
potatoes, meat, bread, milk and nuts. It plays an				element is extremely rare, though its atoms have
important role in the physical fluid system of				been detected in uranium ores. It is because of its
humans and assists nerve functions. Potassium, as				extreme rarity that its chemical and physical
the ion K+, concentrate inside cells, and 95% of				properties are not known. It has been studied by
the body's potassium is so located. When our				radiochemical techniques, which show that it’s
kidneys are somehow malfunctioning, an				most stable state is the ion Fr+. Francium is.
accumulation of potassium will take place. This can				Francium is the second rarest element in the
lead to disturbing heartbeats. Potassium can affect				crust, after astatine.
us when breathed in. Inhalation of dust or mists				No use has been found for what little francium
can irritate the eyes, nose, and throat, lungs with				can be produced. No doubt Francium occurs
sneezing, coughing and sore throat. Higher				naturally to a very limited extent in uranium
exposures may cause a build up of fluid in the				minerals. Nevertheless it has been estimated that
lungs, this can cause death. Skin and eye contact				there might be from 340 to 550 grams of
can cause severe burns leading to permanent				francium in the earth's crust at any one time. Due
damage.				to its extremely short half-life, there’s no
Rubidium				reason for considering the effects of francium in
Rubidium is a widely distributed element, ranking				the environment. As it is so unstable, any amount
about 16th in order of abundance of the elements				formed would decompose to other elements so
in Earth’s crust. The relative abundance of				quickly that there’s no reason to study its
rubidium has been reassessed in recent years and				effects on human health.

Study Committee

Environmental Impact and Health Effects of the Alkali Metals