no but your still wrong Barium - Ba
Chemical properties of barium - Health effects of barium - Environmental effects of barium
Atomic number
56
Atomic mass
137.33 g.mol -1
Electronegativity according to Pauling
0.9
Density
3.5 g.cm-3 at 20°C
Melting point
725 °C
Boiling point
1640 °C
Vanderwaals radius
0.222 nm
Ionic radius
0.135
Isotopes
16
Electronic shell
[ Xe ] 6s2
Energy of first ionisation
502.7 kJ.mol -1
Energy of second ionisation
965 kJ.mol -1
Standard potential
- 2.90 V
Discovered by
Sir Humphrey Davy in 1808
Barium - Ba
Barium
Barium is a silvery-white metal that can be found in the environment, where it exists naturally. It occurs combined with other chemicals, such as sulfur, carbon or oxygen. Ii is very light and its density is half that of iron. Barium oxidizes in air, reacts vigoroulsy with water to form the hydroxide, liberating hydrogen. Barium reacts with almost all the non-metals, forming often poisouning compounds.
Applications
Barium is often used in barium-nickel alloys for spark-plug electrodes an in vacuum tubes as drying and oxygen-removing agent. It is also used in fluorescent lamps: impure barium sulfide phosphoresces after exposure to the light.
Barium compounds are used by the oil and gas industries to make drilling mud. Drilling mud simplifies drilling through rocks by lubricating the drill.
Barium compounds are also used to make paint, bricks, tiles, glass, and rubber. Barium nitrate and clorate give fireworks a green colour.
Barium in the environment
Barium is surprisingly abundant in the Earth's crust, being the 14th most abundant element. High amounts of barium may only be found in soils and in food, such as nuts, seaweed, fish and certain plants.
Because of the extensive use of barium in the industries human activities add greatly to the release of barium in the environment. As a result barium concentrations in air, water and soil may be higher than naturally occurring concentrations on many locations.
Barium enters the air during mining processes, refining processes, and during the production of barium compounds. It can also enter the air during coal and oil combustion.
The chief mined ores are barite, which is also the most common and witserite. The main mining areas are UK, Italy, Czech Republic, USA and Germany. Each year about 6 million tonnes are produced and reserves are expected to exceed 400 million tonnes.
Health effects of barium
The amount of barium that is detected in food and water usually is not high enough to become a health concern.
People with the greatest risk to barium exposure with additional health effects are those that work in the barium industry. Most of the health risks that they can undergo are caused by breathing in air that contains barium sulphate or barium carbonate.
Many hazardous waste sites contain certain amounts of barium. People that live near them may be exposed to harmful levels. The exposure will than be caused by breathing dust, eating soil or plants, or drinking water that is polluted with barium. Skin contact may also occur.
The health effects of barium depend upon the water-solubility of the compounds. Barium compounds that dissolve in water can be harmful to human health. The uptake of very large amounts of barium that are water-soluble may cause paralyses and in some cases even death.
Small amounts of water-soluble barium may cause a person to experience breathing difficulties, increased blood pressures, heart rhythm changes, stomach irritation, muscle weakness, changes in nerve reflexes, swelling of brains and liver, kidney and heart damage.
Barium has not shown to cause cancer with humans. There is no proof that barium can cause infertility or birth defects.
Environmental effects of barium
Some barium compounds that are released during industrial processes dissolve easily in water and are found in lakes, rivers, and streams. Because of their water-solubility these barium compounds can spread over great distances. When fish and other aquatic organisms absorb the barium compounds, barium will accumulate in their bodies.
Because it forms insoluble salts with other common components of the environment, such as carbonate and sulphate, barium is not mobile and poses little risk. Barium compounds that are persistent usually remain in soil surfaces, or in the sediment of water soils. Barium is found in most land soils at low levels. These levels may be higher at hazardous waste sites.
Read more:
Barium (Ba) - Chemical properties - Health and Environmental effects
Strontium - Sr
Chemical properties of strontium - Health effects of strontium - Environmental effects of strontium
Atomic number
38
Atomic mass
87.62 g.mol -1
Electronegativity according to Pauling
1.0
Density
2.6 g.cm-3 at 20°C
Melting point
769 °C
Boiling point
1384 °C
Vanderwaals radius
0.215 nm
Ionic radius
0.113 nm (+2)
Isotopes
14
Electronic shell
[ Kr ] 5s2
Energy of first ionisation
549.2 kJ.mol -1
Energy of second ionisation
1064 kJ.mol -1
Discovered by
A. Crawford in 1790
Strontium - Sr
Strontium
Strontium is a soft, silver-yellow, alkaline-earth metal. It has three allotropic crystalline forms and in its physical and chemical properties it is similar to calcium and barium. Strontium reacts vigorously with water and quickly tarnishes in air, so it must be stored out of contact with air and water. Due to its extreme reactivity to air, this element always naturally occurs combined with other elements and compounds. Finely powdered strontium metal will ignite spontaneously in air to produce both strontium oxide and strontium nitride.
Applications
Strontium has uses similar to those of calcium and barium, but it is rarely employed because of its higher cost. Principal uses of strontium compounds are in pyrotechnics, for the brilliant reds in fireworks and warning flares and in greases. A little is used as a getter in vacuum tubes to remove the last traces of air. Most strontium is used as the carbonate in special glass for television screens and visual display units. Although strontium-90 is a dangerously radioactive isotope, it is a useful by-product of nuclear reactors from whose spent fuel is extracted. Its high-energy radiation can be used to generate an electric current, and for this reason it can be used in space vehicles, remote weather stations and navigation buoys.
Strontium in the environment
Strontium is commonly occurs in nature, formung about 0.034% of all igneous rock and in the form of the sulfate mineral celestite (SrSO4) and the carbonate strontianite (SrCO3). Celestite occurs frequently in sedimentary deposits of sufficient size, thus the development of mining facilities attractive. The main mining areas are UK, Mexico, Turkey and Spain. World production of strontium ores is about 140.000 tonnes per year from an unassessed total of reserves.
Foods containing strontium range from very low e.g. in corn (0.4 ppm and oranged (0.5 ppm) to high, e.g. in cabbage (45 ppm), onions (50 ppm) and lattuce (74 ppm).
Health effects of strontium
Strontium compounds that are water-insoluble can become water-soluble, as a result of chemical reactions. The water-soluble compounds are a greater threat to human health than the water-insoluble ones. Therefore, water-soluble forms of strontium have the opportunity to pollute drinking water. Fortunately the concentrations in drinking water are usually quite low.
People can be exposed to small levels of (radioactive) strontium by breathing air or dust, eating food, drinking water, or by contact with soil that contains strontium. We are most likely to come in contact with strontium by eating or drinking.
Strontium concentrations in food contribute to the strontium concentrations in the human body. Foodstuffs that contain significantly high concentrations of strontium are grains, leafy vegetables and dairy products.
For most people, strontium uptake will be moderate. The only strontium compound that is considered a danger to human health, even in small quantities, is strontium chromate. The toxic chromium that it contains mainly causes this. Strontium chromate is known to cause lung cancer, but the risks of exposure have been greatly reduced by safety procedures in companies, so that it is no longer an important health risk.
The uptake of high strontium concentrations is generally not known to be a great danger to human health. In one case someone experienced an allergic reaction to strontium, but there have been no similar cases since. For children exceeded strontium uptake may be a health risk, because it can cause problems with bone growth.
Strontium salts are not known to cause skin rashes or other skin problems of any kind.
When strontium uptake is extremely high, it can cause disruption of bone development. But this effect can only occur when strontium uptake is in the thousands of ppm range. Strontium levels in food and drinking water are not high enough to be able to cause these effects.
Radioactive strontium is much more of a health risk than stable strontium. When the uptake is very high, it may cause anaemia and oxygen shortages, and at extremely high concentrations it is even known to cause cancer as a result of damage to the genetic materials in cells.
Effects of strontium on the Environment
Strontium in its elemental form occurs naturally in many compartments of the environment, including rocks, soil, water, and air. Strontium compounds can move through the environment fairly easily, because many of the compounds are water-soluble.
Strontium is always present in air as dust, up to a certain level. Strontium concentrations in air are increased by human activities, such as coal and oil combustion. Dust particles that contain strontium will settle to surface water, soils or plant surfaces at some point. When the particles do not settle they will fall back onto earth when rain or snow falls. All strontium will eventually end up in soils or bottoms of surface waters, where they mix with strontium that is already present.
Strontium can end up in water through soils and through weathering of rocks. Only a small part of the strontium in water comes from dust particles from the air. Most of the strontium in water is dissolved, but some of it is suspended, causing muddy water at some locations. Not much strontium ends up in drinking water.
When strontium concentrations in water exceed regular concentrations, this is usually caused by human activities, mainly by dumping waste directly in the water. Exceeded strontium concentrations can also be caused by settling of dust particles from air that have reacted with strontium particles from industrial processes.
Strontium concentrations in soil may also be increased by human activities, such as the disposal of coal ash and incinerator ash, and industrial wastes. Strontium in soil dissolves in water, so that it is likely to move deeper into the ground and enter the groundwater. A part of the strontium that is introduced by humans will not move into groundwater and can stay within the soil for decades.
Because of the nature of strontium, some of it can end up in fish, vegetables, livestock and other animals.
One of the isotopes of strontium is radioactive. This isotope is not likely to occur naturally in the environment. It ends up in the environment, though, as a result of human activities, such as nuclear bomb testing and radioactive storage leaking. The only way to decrease concentrations of this isotope is through radioactive decay to stable zirconium.
The concentrations of radioactive strontium in the environment are relatively low and the particles will always end up in soils or water-bottoms eventually, where they mix with other strontium particles. It is not likely to end up in drinking water.
Certain deep-sea creatures incorporate strontium into their shells as strontium sulphate, and stony corals require it, which is why it needs to be added in the water in aquaria.
Read more:
Strontium (Sr) - Chemical properties, Health and Environmental effects
nowhere in the usgs report does it state that those levels you quoted are toxic or linked to cancers at the wtc site.
it maybe odd but that's no evidence of anything but oddness.