Metal fume fever
Encyclopedia
Metal fume fever also known as brass founders' ague, brass shakes, zinc shakes, Galvie Flu, or Monday morning fever is an illness caused primarily by exposure to certain fumes. Workers breathe in fumes from chemicals such as zinc oxide
Zinc oxide
Zinc oxide is an inorganic compound with the formula ZnO. It is a white powder that is insoluble in water. The powder is widely used as an additive into numerous materials and products including plastics, ceramics, glass, cement, rubber , lubricants, paints, ointments, adhesives, sealants,...

 (ZnO) or magnesium oxide
Magnesium oxide
Magnesium oxide , or magnesia, is a white hygroscopic solid mineral that occurs naturally as periclase and is a source of magnesium . It has an empirical formula of and consists of a lattice of Mg2+ ions and O2– ions held together by ionic bonds...

 (MgO), which are themselves created by heating or welding certain metals, particularly galvanized steel. Chromium
Chromium
Chromium is a chemical element which has the symbol Cr and atomic number 24. It is the first element in Group 6. It is a steely-gray, lustrous, hard metal that takes a high polish and has a high melting point. It is also odorless, tasteless, and malleable...

 is also a hazard, from stainless steel
Stainless steel
In metallurgy, stainless steel, also known as inox steel or inox from French "inoxydable", is defined as a steel alloy with a minimum of 10.5 or 11% chromium content by mass....

. Cadmium
Cadmium
Cadmium is a chemical element with the symbol Cd and atomic number 48. This soft, bluish-white metal is chemically similar to the two other stable metals in group 12, zinc and mercury. Similar to zinc, it prefers oxidation state +2 in most of its compounds and similar to mercury it shows a low...

, present in some older silver solder alloys can, in extreme cases, cause loss of consciousness within a matter of minutes. Iron itself, and so most simple steel
Steel
Steel is an alloy that consists mostly of iron and has a carbon content between 0.2% and 2.1% by weight, depending on the grade. Carbon is the most common alloying material for iron, but various other alloying elements are used, such as manganese, chromium, vanadium, and tungsten...

s, does not give rise to it, nor does aluminium.

Symptoms

The symptoms are nonspecific but are generally flu-like including fever
Fever
Fever is a common medical sign characterized by an elevation of temperature above the normal range of due to an increase in the body temperature regulatory set-point. This increase in set-point triggers increased muscle tone and shivering.As a person's temperature increases, there is, in...

, chills, nausea
Nausea
Nausea , is a sensation of unease and discomfort in the upper stomach with an involuntary urge to vomit. It often, but not always, precedes vomiting...

, headache
Headache
A headache or cephalalgia is pain anywhere in the region of the head or neck. It can be a symptom of a number of different conditions of the head and neck. The brain tissue itself is not sensitive to pain because it lacks pain receptors. Rather, the pain is caused by disturbance of the...

, fatigue
Fatigue (physical)
Fatigue is a state of awareness describing a range of afflictions, usually associated with physical and/or mental weakness, though varying from a general state of lethargy to a specific work-induced burning sensation within one's muscles...

, muscle aches, and joint pains. A sweet or metallic taste in the mouth which distorts the taste of food and cigarettes is also normally reported along with a dry or irritated throat which may lead to hoarseness. Symptoms may also include a burning sensation in the body, shock, no urine output, collapse, convulsions, shortness of breath, yellow eyes or yellow skin, rash, vomiting, watery or bloody diarrhea or low blood pressure, which require prompt medical attention. Milder flu-like symptoms will normally disappear within 24 to 48 hours, and someone suffering from metal fume fever will usually feel well enough to return to work the next day, despite the fact that they may still be feeling a little bit under the weather. It often takes 4 days to fully recover.

Cause

Metal fume fever is due to the inhalation of certain metals, either as fine dust or most commonly as fumes. Simple compounds of the metals, such as their oxides, are equally capable of causing it. The effects of particularly toxic compounds, such as nickel carbonyl
Nickel carbonyl
Nickel carbonyl is the organonickel compound with the formula Ni4. This pale-yellow liquid is the principal carbonyl of nickel. It is an intermediate in the Mond process for the purification of nickel and a reagent in organometallic chemistry...

, are not considered as a mere metal fume fever.

Exposure usually arises through hot metalworking processes, such as smelting and casting of zinc alloys, or welding of galvanized metals. If the metal concerned is particularly high-risk, then cold sanding processes may also cause it, even though the dose is lower. This may also occur with electroplated surfaces or metal-rich anti-corrosion paint, such as cadmium passivated steel or zinc chromate
Zinc chromate
Zinc chromate, ZnCrO4, is a chemical compound containing the chromate anion, appearing as odorless yellow solid powder. It is used industrially in chromate conversion coatings, having been developed by Ford Motor Company in 1920s...

 primer on aluminium aircraft parts. Exposure has also been reported in use of lead free ammunition, by the harder steel core stripping excess metal from the jacket of the bullet and barrel of the rifle.

The most plausible mechanism accounting for the symptoms involves an immune reaction which occurs when inhaled metal oxide fumes injure the cells lining the airways. This is thought to modify proteins in the lung. The modified proteins are then absorbed into the bloodstream, where they act as allergens.

Diagnosis

Physical examination findings vary among persons exposed, depending largely upon the stage in the course of the syndrome during which examination occurs. Patients may present with wheezing or crackles in the lungs. They may also have an increased white blood cell count, and urine, blood plasma and skin zinc levels may (unsurprisingly) be elevated. Chest X-ray findings are generally unremarkable.

Diagnosis of metal fume fever can be difficult, as the complaints are non-specific and resemble a number of other common illnesses. When respiratory symptoms are prominent, metal fume fever may be confused with acute bronchitis
Bronchitis
Acute bronchitis is an inflammation of the large bronchi in the lungs that is usually caused by viruses or bacteria and may last several days or weeks. Characteristic symptoms include cough, sputum production, and shortness of breath and wheezing related to the obstruction of the inflamed airways...

. The diagnosis is based primarily upon a history of exposure to metal oxide fumes. Cain and Fletcher (2010) report a case of metal fume fever that was diagnosed only by taking a full occupational history and by close collaboration between primary and secondary health care personnel.

An interesting feature of metal fume fever involves rapid adaptation to the development of the syndrome following repeated metal oxide exposure. Workers with a history of recurrent metal fume fever often develop a tolerance to the fumes. This tolerance, however, is transient, and only persists through the work week. After a weekend hiatus, the tolerance has usually disappeared. This phenomenon of tolerance is what led to the name "Monday Fever".

Treatment

Treatment of mild metal fume fever consists of bedrest, and symptomatic therapy (e.g. aspirin for headaches) as indicated.

A traditional remedy is to consume large quantities of milk, either before or immediately after exposure.

Prevention

Prevention of metal fume fever in workers who are at potential risk (such as welder
Welder
A welder is a tradesman who specializes in welding materials together. The materials to be joined can be metals or varieties of plastic or polymer...

s) involves avoidance of direct contact with potentially toxic fumes, improved engineering controls (exhaust ventilation systems), personal protective equipment (respirators), and education of workers regarding the features of the syndrome itself and proactive measures which can be taken to prevent its development.

Particularly for cadmium, the design of the product may be changed so as to eliminate it. NiCd rechargeable batteries are being replaced by NiMH
NIMH
NIMH or NiMH may refer to:*Nickel-metal hydride battery, a type of rechargeable battery*National Institute of Mental Health, a part of the United States National Institutes of Health...

. Cadmium plating is replaced with zinc or nickel. Silver solder alloys now rarely contain it.

External links

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