Professional Reference articles are designed for health professionals to use. They are written by UK doctors and based on research evidence, UK and European Guidelines. You may find one of our health articles more useful.
Treatment of almost all medical conditions has been affected by the COVID-19 pandemic. NICE has issued rapid update guidelines in relation to many of these. This guidance is changing frequently. Please visit https://www.nice.org.uk/covid-19 to see if there is temporary guidance issued by NICE in relation to the management of this condition, which may vary from the information given below.
Tungsten, chemical symbol W (for Wolframite, its mineral form's German name) - atomic number 74 - is a widely used metal that has a very high tensile strength and melting point. It is used in its elemental form in military guns and projectiles, wear-resistant machinery/products, lightbulb filaments and electron and television tubes. Compounds of tungsten are used in fluorescent lighting tubes, in the chemical and tanning industries and, as tungsten disulfide, in industrial lubricants.
Although the medical literature on the toxic effects of tungsten is limited, reviews of available literature reveal concerns about the long-term risk to health of tungsten and tungsten compounds[1, 2]. Tungsten may have carcinogenic potential.
Most tungsten is rapidly eliminated from the body in the urine and faeces but a small amount can be retained in the bones.
Acute tungsten poisoning
This is an extremely rare presentation. Toxicological analysis confirmed grossly elevated levels of tungsten in blood, urine, hair and nails. Clinical features of this acute episode include:
- Acute nausea within 15 minutes of ingestion.
- Sudden onset of seizures.
- Rapid onset of clouded consciousness leading to coma with evidence of encephalopathy.
- Initial moderate kidney failure progressing to acute tubular necrosis with anuria within 24 hours.
- Gradual symptomatic recovery over weeks with complete resolution of biochemical/metabolic abnormalities after five months.
Elemental tungsten is often produced in a powdered form so there is a theoretical risk of acute toxicity from inhaling the substance in this form or from machine wear/artillery disruption, although there are no reports of this form of acute poisoning.
Chronic tungsten poisoning
- Hard-metal workers (involved, for example, in grinding metals) and soldiers with embedded shrapnel may be exposed to the risk of long-term tungsten exposure.
- Tungsten may be implicated in cases of pulmonary fibrosis due to hard-metal lung disease. This giant cell interstitial pneumonitis is contracted from inhaling the dust formed from the manufacture, utilisation or maintenance of hard metal, a material composed of tungsten carbide and cobalt. It may be that the majority of the toxicity is attributable to the effects of cobalt on respiratory tissues in susceptible individuals.
- A 2009 study revealed that hard-metal plant workers co-exposed to tungsten carbide and cobalt displayed an increased risk to lung cancer compared to a control group.
- Hard-metal workers have also shown evidence of mild-to-moderate neuropsychological impairment, particularly with regard to memory function.
- Tungsten was introduced in America as an environmentally-friendly alternative to lead in the manufacture of bullets for the military. In certain circumstances - eg, low pH, low oxygen concentration, the presence of iron - it can dissolve. There is a potential for leakage into soil and drinking water. Animal research suggests that long-term exposure can be carcinogenic but more research is needed to determine whether this is relevant to humans.
- The long-term exposure risk of embedded shrapnel containing tungsten is a cause for concern.
- There is some evidence that some forms of tungsten may be more toxic than others.
- Individuals with higher urinary tungsten concentrations have been found to have double the odds of reported stroke.
Medical use of tungsten arterial embolisation coils
It has been noted that tungsten coils used in interventional radiology may be subject to degradation so embolisation coils and methods now use alternative inert materials.
- Suspect if there are symptoms of acute poisoning, as outlined above, in industrial workers or soldiers who may be exposed to tungsten.
- Inductively coupled plasma-mass spectrometry (ICP-MS) may be used to detect and determine the concentration of tungsten in body fluids/tissues. The following is a guide:
- In cases of acute poisoning initial blood levels of 5 mg/L have been detected. In patients with degraded embolisation coils in situ, blood levels of 0.47-1.51 mg/L have been detected.
- Average blood levels in controls (those who had undergone aortic aneurysm grafting without coil embolisation) were 0.044 mg/L.
- The probable minimum lethal exposure range is 0.5-5 g/kg.
- Get expert toxicological and ITU advice if tungsten poisoning is suspected.
- Treatment is mainly supportive.
- Charcoal may be given if it is not contra-indicated.
- In addition, oxygen should be given for respiratory symptoms.
- Benzodiazepines may be given for seizures.
- Haemodialysis has been used for kidney failure and its sequelae but with limited effect on tungsten clearance.
From the limited information available it appears that patients who survive an acute tungsten poisoning episode have a good chance of short- and long-term recovery if they receive appropriate supportive therapy and haemodialysis.
Further reading and references
van der Voet GB, Todorov TI, Centeno JA, et al; Metals and health: a clinical toxicological perspective on tungsten and review of the literature. Mil Med. 2007 Sep172(9):1002-5.
Wasel O, Freeman JL; Comparative Assessment of Tungsten Toxicity in the Absence or Presence of Other Metals. Toxics. 2018 Nov 96(4). pii: toxics6040066. doi: 10.3390/toxics6040066.
Laulicht F, Brocato J, Cartularo L, et al; Tungsten-induced carcinogenesis in human bronchial epithelial cells. Toxicol Appl Pharmacol. 2015 Oct 1288(1):33-9. doi: 10.1016/j.taap.2015.07.003. Epub 2015 Jul 9.
Naqvi AH, Hunt A, Burnett BR, et al; Pathologic spectrum and lung dust burden in giant cell interstitial pneumonia (hard metal disease/cobalt pneumonitis): review of 100 cases. Arch Environ Occup Health. 2008 Summer63(2):51-70. doi: 10.3200/AEOH.63.2.51-70.
Wild P, Bourgkard E, Paris C; Lung cancer and exposure to metals: the epidemiological evidence. Methods Mol Biol. 2009472:139-67. doi: 10.1007/978-1-60327-492-0_6.
Tungsten Issues Paper; Association of State and Territorial Solid Waste Management Officials, 2011
Kalinich JF, Emond CA, Dalton TK, et al; Embedded weapons-grade tungsten alloy shrapnel rapidly induces metastatic high-grade rhabdomyosarcomas in F344 rats. Environ Health Perspect. 2005 Jun113(6):729-34.
Tyrrell J, Galloway TS, Abo-Zaid G, et al; High urinary tungsten concentration is associated with stroke in the National Health and Nutrition Examination Survey 1999-2010. PLoS One. 2013 Nov 118(11):e77546. doi: 10.1371/journal.pone.0077546. eCollection 2013.
Hu J, Albadawi H, Chong BW, et al; Advances in Biomaterials and Technologies for Vascular Embolization. Adv Mater. 2019 Aug31(33):e1901071. doi: 10.1002/adma.201901071. Epub 2019 Jun 6.