Dust strontium

Half-lives span a very wide range (Table 17.5). Consider strontium-90, for which the half-life is 28 a. This nuclide is present in nuclear fallout, the fine dust that settles from clouds of airborne particles after the explosion of a nuclear bomb, and may also be present in the accidental release of radioactive materials into the air. Because it is chemically very similar to calcium, strontium may accompany that element through the environment and become incorporated into bones once there, it continues to emit radiation for many years. About 10 half-lives (for strontium-90, 280 a) must pass before the activity of a sample has fallen to 1/1000 of its initial value. Iodine-131, which was released in the accidental fire at the Chernobyl nuclear power plant, has a half-life of only 8.05 d, but it accumulates in the thyroid gland. Several cases of thyroid cancer have been linked to iodine-131 exposure from the accident. Plutonium-239 has a half-life of 24 ka (24000 years). Consequently, very long term storage facilities are required for plutonium waste, and land contaminated with plutonium cannot be inhabited again for thousands of years without expensive remediation efforts. 

In the other study. X-ray fluorescence spectroscopy was used to analyze trace element concentrations by observing dusts on 37 ram diameter cellulose acetate filters (20). Twenty-three elutriator and twenty-three area samples from 10 different bales of cotton were analyzed. The average fraction of total dust accounted for by the elements analyzed was 14.4% amd 7.6% for vertical elutriator and area samples, respectively. Although the variation in absolute quantity of atn element was high, the relative abundance of an element was consistent for measurements within a bale. Averaged over all the samples analyzed, calcium was the most abundant element detected (3.6%), followed by silicon (2.9%), potassium (2.7%), iron (1.1%), aluminum (1.1%), sulfur (1.0%), chlorine (0.8%) and phosphorous (0.6%). Other elements detected in smaller aunounts included titanium, manganese, nickel, copper, zinc, bromine, rubidium, strontium, barium, mercury amd lead. 

Lead chromates, lead molybdates, chrome greens, and fast chrome greens are supplied as pigment powders, low-dust or dust-free preparations, or as pastes. The anticorrosive pigments zinc chromate, zinc tetraoxychromate, and strontium chromate are described in Section 5.2.4.2. 

Eor chromate-containing anticorrosive pigments like zinc chromate, zinc potassium chromate, zinc tetraoxichromate and strontium chromate, the TRK value/TLV-TWA value for chromium(VI) compounds of 0.05 mg m calculated as CrOs in total dust has to be complied with [5.111]. 

Quantifying the sources and rates of input of base cation nutrients (calcium, magnesium, potassium, and sodium) to forest ecosystems is an important goal in forest biogeochemistry, particularly when seeking to understand the recovery from environmental disturbances such as acid rain and forest clear-cutting. The earliest study to use isotopes as an indicator of atmospheric inputs to soils was by Dymond et al. (1974), who used strontium isotope measurements of micas in Hawaiian soils to determine that a significant proportion of the potassium input to Hawaiian soils was from deposition of dust transported... 

Brimhall et al. (1991) used lead isotopes in zircons within a bauxite profile from Western Australia to differentiate between zircons derived from the underlying bedrock and zircons of eolian origin. Borg and Banner (1996) applied both neodymium and strontium isotopes to constrain the sources of soil developed on carbonate bedrock. Using these isotopes and Sm/Nd ratios, they were able to delineate the importance of atmospheric versus bedrock contributions in controlling the composition of the soil. Kurtz et al. (2001) used neodymium and strontium isotopes to determine the amount of Asian dust in a Hawaiian soil chronosequence. They found that the basaltic bedrock isotope signatures in soils had, in many cases, been completely overprinted by dust additions, demonstrating the profound effect of Asian dust on soil nutrient supplies. 

A mixture of strontium nitrate and aluminium often degenerates producing ammonia and NOx gas. This tendency is common with other nitrates except ammonium nitrate(see (31)). Dust which contains strontium nitrate is inflammable, and the same precautions must be taken as they are with other oxidizers. 

The potential of ultrasonic extraction for field-based extractions has been put into use in the industrial hygiene and environmental single-element analysis of, for example, lead from glass fibre filter ambient air samples [13,14] or from lead-based paint, urban dust and river sediment [15] hexavalent chromium from coal fly ash and paint chips [16] and strontium from river sediment [17]. Ultrasonic extraction has also proved effective as a prior step in multi-element determinations of heavy metals. 

Strontium is a naturally occurring element found in rocks, soil, dust, coal, and oil. Naturally occurring strontium is not radioactive and is referred to as stable strontium. Stable strontium in the environment exists in four stable isotopes, " Sr (read as strontium 84), Sr, Sr, and Sr. Twelve other unstable isotopes are known to exist. Its radioactive isotopes are Sr and °Sr. Strontium is chemically similar to calcium. It was discovered in 1790. The isotope Sr is a highly radioactive poison, and was present in fallout from atmospheric nuclear explosions and is created in nuclear reactors. Atmospheric tests of nuclear weapons in the 1950s resulted in deposits and contaminations. °Sr has a half-life of 28 years and is a high-energy beta emitter. Its common cationic salts are water soluble it forms chelates with compounds such as ethylenediaminetetraacetic acid strontium coordination compounds are not common. Powdered metallic strontium may constitute an explosion hazard when exposed to flame. 

Stable strontium is a dust in air. It eventually settles over land and water. Stable strontium dissolves in water and moves deeper in soil to underground water. 

Frumkin, A. Stein, M. (2004) The Sahara-East Mediterranean dust and climate connection revealed by strontium and uranium isotopes in a Jerusalem speleothem. Earth and Planetary Science Letters 217, 451-464. 

In air, strontium compounds are present mostly as dust. Emissions from burning coal and oil increase strontium levels in air. The amount of strontium that has been measured in air in different parts of the United States by the EPA ranges from not detected to 20 trillionths of a gram (g) per cubic meter (m3). Very small dust particles of strontium in the air fall out of the air onto surface water, plant surfaces, and soil either by themselves or when rain or snow falls. These particles of strontium eventually end up back in the soil or in the bottoms of lakes, rivers, and ponds, where they stay and mix with strontium that is already there. 

Most of the strontium in water is dissolved. Strontium in water comes from different sources. Most of it comes from dissolving strontium out of rocks and soil that water runs over and through. Only a very small part is from the settling of strontium dust out of the air. Some strontium is suspended in water, as in muddy water. The amount of strontium that has been measured in drinking water in different parts of the United States by the EPA is generally less than... 

If a person breathes in vapors or dust containing a strontium chemical that is soluble in water, then the chemical will dissolve in the moist surface inside the lungs and strontium will enter the bloodstream relatively quickly. If the strontium chemical does not dissolve in water easily, particles may rest inside of the lung for a time. When you eat food or drink water that contains strontium, only a small portion leaves the intestines and enters the bloodstream. In young people, a larger portion enters the bloodstream than in adults. If a fluid mixture of a strontium chemical is... 

Strontium is widely distributed in the earth s crust and oceans. It is released into the atmosphere as a result of natural processes such as entrainment of dust particles, resuspension of soil by wind, and sea spray. Strontium is released into surface water and groundwater from the natural weathering of rocks and soils. Human activities, including milling and processing of strontium compounds, burning of coal, land application of phosphate fertilizers, and use of pyrotechnic devices, release strontium into the atmosphere. Discharges of industrial waste water and runoff from land treated with phosphate fertilizers are human-related processes that release strontium into streams and aquifers. 

Strontium is widely distributed in the earth s crust and oceans. Strontium is released into the atmosphere primarily as a result of natural sources, such as entrainment of dust particles and resuspension of soil. Radioactive strontium is released into the environment as a direct result of anthropogenic activities. Stable strontium can be neither created nor destroyed. However, strontium compounds may transform into other chemical compounds. Radioactive strontium is formed by nuclear reactions. Radioactive decay is the only mechanism for decreasing the concentration of radiostrontium. The half-life of 90Sr is 29 years. 

At hazardous waste sites, radiostrontium that is found in excess of natural background levels is most likely to be in soil and presents a special hazard for young children. Hand-to-mouth activity resulting in inadvertent soil consumption or intentional consumption of soil (pica behavior) will result in oral exposure to radiostrontium. Young children often play close to the ground and frequently play in dirt, which increases their dermal exposure to radiostrontium in dust and soil. The degree of hazard in each case depends on the form of strontium present at the waste site. 

CHROMIC ACID, STRONTIUM SALT (7789-06-2) SrCrO A strong oxidizer accelerates the burning of combustible materials. Violent reaction with reducing agents active metals, cyanides, esters, and thiocyanates. Incongjatible with acids, bases, water, fluorine, hydrazine, zirconium dusts, potassiiun iodide, sodium tetraborate, sodium tetraborate decahydrate, sodium borohydride. 

Violent reaction with magnesiiun powders and dusts. Incompatible with aluminiun powders, arsenates, barium, calcium, ethoxy ethynyl alcohols, lead, strong oxidizers, phosphates, strontium, tartrates. MAGNETIC 70 or MAGNETIC 90 or MAGNETIC 95 (7704-34-9) see sulfur. MAGOX (1309-48-4) see magnesium oxide. 

CHROMIC ACID, STRONTIUM SALT (7789-06-2) Incompatible with fluorine, hydrazine, zirconium dusts, potassium iodide, sodium tetraborate, sodium tetraborate decahydrate, sodium borohydride. 

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