Category: Illness or disabilities
Introduction and description
The uses of chromium in the human body are still under discussion but there is recognition that Trivalent chromium (Cr(III) or Cr3+) occurs in trace amounts in foods and waters, and is “required in for sugar and lipid metabolism”. More details are provided in the Chromium section and some extra details are provided in the detail of this section.
Chromium deficiency, involving a lack of Cr(III) in the body, or perhaps some complex of it, such as glucose tolerance factor is “extremely rare”. Chromium deficiency has been attributed to only three people, all on long-term parenteral nutrition, which is when a patient is fed a liquid diet through intravenous drips for long periods of time. If chromium is required, deficiency is not the problem.
Overdose of chromium, however, is a serious problem. Water insoluble chromium(III) compounds and chromium metal are much less of a health hazard, while the toxicity and carcinogenic properties of chromium(VI) have been known for a long time.
Because of the specific transport mechanisms, only limited amounts of chromium(III) enter the cells. Several in vitro studies have indicated that high concentrations of chromium(III) in the cell can lead to DNA damage. Acute oral toxicity ranges between 1.5 and 3.3 mg/kg.
In contrast to Trivalent chromium, hexavalent chromium (Cr(VI) or Cr6+) is not only toxic when ingested but mutagenic when inhaled. Chromium VI behaves like a heavy metal and thus we suffer all the effects of heavy metal poisoning.
The acute oral toxicity for chromium(VI) ranges between 50 and 150 µg/kg and is due to its strong oxidational properties. After it reaches the blood stream, it damages the kidneys, the liver and blood cells through oxidation reactions. Hemolysis, renal and liver failure are the results of these damages.
The present study analyzed the feature of occupational chromium poisoning in China since the 1980s. The collected data were acquired from 18 previous surveys of chromium poisoning in 14 cities of China. The method of risk assessment was applied to calculate the relative risk and 95% CI, p < 0.05 was considered as a significant risk. The results showed that nasal disease was the most common sign of occupational chromium poisoning, and the prevalence rate of nasal disease was 17.83% in total population of 6,998. Further, the risk analysis showed that occupational chromium poisoning led to an increased risk of lung or liver cancer in male workers due to the definite carcinogenicity of hexavalent chromium. Significantly, an increased risk of spontaneous or threatened abortion was also found in female workers. In conclusion, these studies suggest that early detection of impaired reproductive function or impaired lung or liver function in female or male workers is essential for controlling occupational chromium poisoning in China. PMID: 23604023
The carcinogenity of chromate dust has been known for a long time, and the first publication to describe the elevated cancer risk of workers in a chromate dye company. was published way back in 1890.
Chromium salts (chromates) are also the cause of allergic reactions in some people. Chromates are often used to manufacture, amongst other things, leather products, paints, cement, mortar and anti-corrosives. Contact with products containing chromates can lead to allergic contact dermatitis and irritant dermatitis, resulting in ulceration of the skin, sometimes referred to as "chrome ulcers". This condition is often found in workers that have been exposed to strong chromate solutions in electroplating, tanning and chrome-producing manufacturers.
Mineral supplements and dietary supplements – unbelievable though it may be, dietary supplements for chromium are available for sale apparently unregulated and principally in the USA. They include chromium(III) picolinate, chromium(III) polynicotinate, and 'related materials'. As Wikipedia carefully words it “The benefit of those supplements is questioned by some studies.” Even if trace amounts of chromium are needed, they are freely available in food. The subject is made more extraordinary because these supplements are expensive and their use complex.
Chromium has been known to be a micronutrient for mammals for four decades, but progress in elucidating the role of chromium has proceeded slowly. However, recent studies have shed light on a potential role of chromium in maintaining proper carbohydrate and lipid metabolism at a molecular level.
The oligopeptide chromodulin binds chromic ions in response to an insulin-mediated chromic ion flux, and the metal-saturated oligopeptide can bind to an insulin-stimulated insulin receptor, activating the receptor's tyrosine kinase activity. Thus, chromodulin appears to play a role in an autoamplification mechanism in insulin signaling.
The molecular agent responsible for transporting chromium from mobile pools to insulin-sensitive cells is probably the metal transport protein transferrin.
Chromium from the popular dietary supplement chromium picolinate enters cells via a different mechanism. Release of chromium from chromium picolinate for use in cells requires reduction of the chromic center, a process that can lead potentially to the production of harmful hydroxyl radicals. PMID: 10736319
Food chain and water supplies - The food chain may be another source of overdose, if animals are grazed on polluted land. As chromium compounds were used in dyes and paints and the tanning of leather, these compounds are often found in soil and groundwater at abandoned industrial sites, now needing environmental cleanup and remediation. The same chemicals can leech into water supplies. According to Wikipedia for example
“In 2010, the Environmental Working Group studied the drinking water in 35 American cities. The study was the first nationwide analysis measuring the presence of the chemical in U.S. water systems. The study found measurable hexavalent chromium in the tap water of 31 of the cities sampled, with Norman, Oklahoma, at the top of list; 25 cities had levels that exceeded California's proposed limit.”
Paints and pigments - Chromium minerals as pigments came to the attention of the west in the 18th century. The name of the element is derived from the Greek word χρῶμα, chrōma, meaning colour, because many of its compounds are intensely coloured. 'Siberian red lead' - in reality lead chromate was discovered in 1761. After a synthesis method became available chrome yellow was, together with cadmium yellow, one of the most used yellow pigments. It has a strong colour, and was used for school buses in the US and for Postal Service (for example Deutsche Post) in Europe. The use of chrome yellow declined due to environmental and safety concerns and was replaced by organic pigments or alternatives free from lead and chromium. Other pigments based on chromium are, for example, the bright red pigment chrome red, which is a basic lead chromate (PbCrO4·Pb(OH)2). A very important chromate pigment, which was used widely in metal primer formulations, was zinc chromate, now replaced by zinc phosphate. In effect another source may be anything still having this paint on it. Chrome green is a mixture of Prussian blue and chrome yellow, while the chrome oxide green is chromium(III) oxide. One is tempted again to think of all the artists and their use of these vibrant colours – yet another source for heavy metal poisoning.
Primer paint containing hexavalent chromium is still widely used for aerospace and automobile refinishing applications.
Manufacturing and metal industries - Chromium metal has proved to be of high value due to its high corrosion resistance and hardness. A major development was the discovery that steel could be made highly resistant to corrosion and discolouration by adding metallic chromium to form stainless steel. This application, along with chrome plating (electroplating with chromium) currently comprise 85% of the commercial use for the element. Chromium is also known for its luster when polished. It is used as a protective and decorative coating on car parts, plumbing fixtures, furniture parts and many other items, usually applied by electroplating. Chromium was used for electroplating as early as 1848, but this use only became widespread with the development of an improved process in 1924. Those in these industries thus suffer high exposure to the metal and the danger comes principally from the inhalation of dust.
Glass making - Chromium oxides are also used as a green colour in glassmaking and as a glaze in ceramics. People in the glassmaking industry are at risk, but there are interesting cases on Pubmed of chromium leaching out of ceramic glazes and poisoning people.
Reflective paints and cladding - Green chromium oxide is extremely light-fast and as such is used in cladding coatings. It is also the main ingredient in IR reflecting paints, used by the armed forces, to paint vehicles, to give them the same IR reflectance as green leaves.
Wood preservative - Because of their toxicity, chromium(VI) salts are used for the preservation of wood. For example, chromated copper arsenate (CCA) is used in timber treatment to protect wood from decay fungi, wood attacking insects, including termites, and marine borers. The formulations contain chromium based on the oxide CrO3 between 35.3% and 65.5%. In the United States, 65,300 metric tons of CCA solution have been used in 1996. Anyone using these preservatives is thus at risk. As are those who subsequently burn the wood.
Arsenic, chromium, and copper poisoning from burning treated wood. Peters HA, Croft WA, Woolson EA, Darcey BA, Olson MA. N Engl J Med. 1983 Jun 2;308(22):1360-1. PMID: 6843624
Tanning - Chromium(III) salts, especially chrome alum and chromium(III) sulfate, are used in the tanning of leather. The chromium(III) stabilizes the leather by cross linking the collagen fibers. Chromium tanned leather can contain between 4 and 5% of chromium, which is tightly bound to the proteins. “Although the form of chromium used for tanning is not the toxic hexavalent variety, there remains interest in management of chromium in the tanning industry such as ….use of less chromium or "chrome-less" tanning ”.
Refractory material - The high heat resistivity and high melting point makes chromite and chromium(III) oxide a material for high temperature refractory applications, like blast furnaces, cement kilns, moulds for the firing of bricks and as foundry sands for the casting of metals. In these applications, the refractory materials are made from mixtures of chromite and magnesite. The use is declining because of the environmental regulations due to the possibility of the formation of chromium(VI). Anyone making or using these materials is thus at risk.
Catalysts - Several chromium compounds are used as catalysts for processing hydrocarbons. For example the Phillips catalysts for the production of polyethylene are mixtures of chromium and silicon dioxide or mixtures of chromium and titanium and aluminium oxide.
Magnetic tape - Chromium(IV) oxide is used to manufacture magnetic tape used in high-performance audio tape and standard audio cassettes.
Drilling for oil and gas - Chromates can prevent corrosion of steel under wet conditions, and therefore chromates are added to drilling muds.
Metal polish - Chromium(III) oxide is a metal polish known as green rouge.
Laboratory - Chromic acid is a powerful oxidizing agent and is a useful compound for cleaning laboratory glassware of any trace of organic compounds. It is prepared in situ by dissolving potassium dichromate in concentrated sulfuric acid, which is then used to wash the apparatus. Sodium dichromate is sometimes used because of its higher solubility (50 g/L versus 200 g/L respectively). The use of dichromate cleaning solutions is now phased out due to the high toxicity and environmental concerns.
The only known treatments are chelating agents and these may be too late for some people, although they will at least halt the damage. Some scientists have suggested that Vitamin C can act as a chelating agent, but studies seem to indicate that it does NOT work.
.....Based on experimental studies, substantial amounts of ascorbic acid would need to be administered, preferably parenterally, soon after exposure to prevent systemic toxicity from chromium(VI) in humans. However, as ascorbic acid is a metabolic precursor of oxalate, the administration of ascorbic acid in high dose could lead to acute oxalate nephropathy, particularly in the presence of renal failure. While smaller doses of ascorbic acid (e.g., 10 g intravenously) are not toxic, such doses probably will not reduce the mortality from systemic chromium poisoning. CONCLUSION: There is currently insufficient evidence to advocate the use of ascorbic acid in the management of systemic chromium toxicity. Topical ascorbic acid may reduce dermal hexavalent chromium exposure, but this observation must be confirmed in controlled studies. PMID: 10382555
In contrast, there are some promising developments occurring in Russia
Hexavalent chromium compounds exhibit higher toxicity than its trivalent compounds since chromium ions in the +6 oxidation state easily cross biological membranes. It has recently been proposed that substances reducing chromium ions from the +6 to the less toxic +3 oxidation state can be beneficial in management of acute chromium poisoning. In vitro studies also demonstrated quercetin-5 '-sulfonic acid sodium salt (NaQSA) to reduce chromium ions from the +6 to the +3 oxidation state. The aim of the study was to determine efficacy of NaQSA in treatment of acute poisoning with a hexavalent chromium compound. …...The results of the study suggest the usefulness of NaQSA in the treatment of poisoning with hexavalent chromium compounds. PMID: 14730106
This study was achieved using Wistar rats, so its efficacy with humans has still to be tested.
- Accumulation and distribution of trivalent chromium and effects on hybrid willow (Salix matsudana Koidz x alba L.) metabolism 020525
- Bioaccumulation of heavy metals in plant leaves from Yan׳an city of the Loess Plateau, China 018313
- Chromium, insulin and diabetes 006887
- Croll, Oswald - Preface of Signatures – 15 016033
- Dandelion (Taraxacum officinale) and Agrimony (Agrimonia eupatoria) as Indicators of Geogenic Contamination of Flysch Soils in Eastern Slovakia 019200
- Phytoremediation of urban wastewater by model wetlands with ornamental hydrophytes 027987
- Protective effect of curcumin against heavy metals-induced liver damage 017774
- Role of Carum copticum seeds in modulating chromium-induced toxicity on human bronchial epithelial cells and human peripheral blood lymphocytes 027886
- The effect of substrates on the removal of low-level vanadium, chromium and cadmium from polluted river water by ecological floating beds 027988
- Auditory hallucinations, children and heavy metals 006885
- Chromium supplements 020737
- Cobalt poisoning and hip replacement 006878
- Contamination of Haiti's drinking water 008323
- Cr [chromium supplements] 018227
- Metal on metal hip replacement and cobalt poisoning 006877
- Toxins in eye shadow - Cosmetic companies 014503
- Toxins in lipstick - Cosmetic companies 014502