Fluorine (Symbol= F, From fluorospar the minteral from which fluorine is derived.)- A non-metallic gasieous element. Note: keep in mind that although fluorine is a gas, it can act as a solid if combined with other elements. Fluoride, the binary compound of the element flourine, is incorportated into the structure of teeth and bones, and has a cariostatic effect. Cariostatic is simply the inhibiting of dental caries or "cavities". In reality, fhuorine does not inhibit dental caries, but rather inhibits the bacteria that may cause them. Fluorine is not a guarantee against caries but does help. The problem is that fluorine also has side effects over time. The question is: is the prevention of tooth decay wotth the risks of fluorine accumulation in bones?

Excesses of fluorine cause what we call fluorosis. Fluorosis is characterized by skeletal changes such as osteomalacia (inadequate mineralization of the bones), osteosclerosis (hardening, or abnormal density of the bone) and "mottled" teeth enamel (if exposure occurs during enamal formation). The exposure to sufficient enough amounts of fluortde to cause fluorosis can be achieved by breathing in industrial gases, ingestion of flouride containing compounds (toothpastes, insecticide) and water with large amounts of fluoride.

 

There is no known RDA for fluoride. since it plays no part in human metabolism.

 

We read about excesses of fluorine and the effects it can have on skeletal tissue. Upper limits in the amounts of fluorine contained in drinking water have been imposed in many countries. The terms used to describe the amounts of a substance in water are PPM, PPB, etc. PPM stands for "parts per million" and refers to the amount of substance contained in one-million parts water. For example, if we divided a sample of water into one-million drops, and one of those drops was pure chlorine, then we would say that the water contained 1 PPM of chlorine. The amount of chlorine can be expressed as 1/1,000,000. Accordingly, if there was one drop of chlorine in one-billion drops of water, then we would have a sample of water with 1 PPB chlorine. Most developed countries have limits of substances allowed in the drinking water. Limits on chlorine, flouride, other minerals, and even microorganisms have been imposed in many countries. Some elements are even added to the drinking water in many countries to render it more safe. For example, by adding fluoride to the public drinking water, many officials are simply trying to help prevent decrease the incidence of dental caries in the population. Adding chlorine also inhibits many microorganisms, so we can understand the strategy. Flouride and chlorine, like some of the other elements also have their risks as well. Therefore, this is the ebb and flow of our never-ending debate and decision as to whether we include them in many of the products we come into contact with on a daily basis, especially the ones that we consume.

Cadmium (Symbol= Cd, Greek kadmia earth)-A bivalent metal similar in properties to Tin. However, cadmium and its salts are poisonous. Cadmium and its compounds are used in photography, engraving and many other industrial processes.

 

Cadmium, its salts and other cadmium contaioing compounds or mixtures are poisonous. For example, if cadmium bromide (CdBr₂), is ingested, it causes abdominal pain, choking, increased salivation, tenesmus, and other painful symptoms. Inustrial cadmium can also cause bronchitis. The problem with cadmium is that it tends to accumulate in tissues over time. The organ that seems to be affected the most is the kidneys. In the diet cadmium is poorly absorbed, but once absorbed, it is difficult to get rid of. Vegetables and plants growing near mining villages may have increased amounts of cadmium in the soil. This can be taken up by plants via their roots. There have been a few reports of villages or towns that have suffered because of increased amounts of cadmium placed into the soil. In these areas, there was an increase in osteomalacia (inadequate mineralization of the bone) and other side effects.

Lead (Symbol= Pb, Latin plumbum)-A soft, grey- blue metal. Lead, its salts and and other compounds, or mixtures are poisonous. Lead was known to be harmful hundreds of years ago. Lead poisoning may even have contributed to the downfall of Rome. Lead can cause poisoning not only through ingestion, but additionally via absorption through the skin. Use of lead is popular in industry and many harmful lead-containing products have been manufactured. Tetra-ethyl lead, the "anti-knocking" agent added to petrol (gasoline) can be absorbed through the skin causing mental symptoms and death. Lead, once popular in pencils, caused illness in many children and unfortunately, death on occasion. During the Roman Empire, lead was used to make cooking vessels. Being unaware of the effects of lead contamination, many people must have suffered during this time.

 

Toxicity of lead causes anorexia (loss of apetite), constipation, decreased body weight, decreased libido, headache, dizzines, hypertension, mood changes, irritability, insomnia, and other symptoms. A classic sign indicating lead poisoning is the development of blue-coloured goms in the area bordering the teeth.

Arsenic (Symbol= As , Latin arsenium, arsenum, arsenicum from Greek arsen strong)- Nonmetallic element, occurring as a grey, brittle and shiny solid with a "garlicky" odour. It is harmful by ingestion and inhalation. Arsenic is also a carcinogen. Arsenic has been used in medicinal compounds over the ages. "Flower of arsenic" or arsenic trioxide is a sweet tasting arsenic compound that was taken in small doses. It causes an increase in the red blood cell mass and was used to increase the performance of workers. This practice however, is dangerous.

 

As with flower of arsenic, the user developed a reddish appearance, probably from the increase in absolute red cell mass and thus, the increase in haemogobin. The idea behind this was increased oxygen delivery, similar to "blood doping" for increased athletic ability. this of course, is only tmemporary. Side effects may include increased clotting, and increased blood viscosity, which has an affect on vessel walls. Also, increases in blood pressure occur. Interestingly, pokeweed also stimulates erythropoiesis (red blood cell production).

Acute or immediate arsenic poisoning, which usually results in hypotension and death depending on dose, is characterised by severe stomach pain, cramps, erythematous skin eruptions, nausea, vomiting, swollen eyelids, and peripheral extremities.

Chronic exposure to arsenic results in headaches, peripheral neuropathy, confusion, white lines in the fingernails, pigmentation of the skin, scaling and increased thickness of the skin on the hands and soles.

 

Mercury (Symbol= Hg , Latin hydrargyrum or mercurius) - A metallic element. Unlike other metals, mercury is liquid at room temperatures. Mercury and its salts have been used as antiseptics, purgatives, astringents, antisyphilitics, as well as for other uses. Mercury is toxic to the human. Therefore, use in therapy is becoming less frequent.

Industrial uses of mercury include the manufacture of batteries, explosives, thermometers, paint, and electrical apparatus. Dimethyl and diethyl mercury is used in the the treatment of seeds.