Siderosis is the deposition of excess

iron Iron () is a chemical element with Symbol (chemistry), symbol Fe (from la, Wikt:ferrum, ferrum) and atomic number 26. It is a metal that belongs to the first transition series and group 8 element, group 8 of the periodic table. It is, Abundanc ...

in body tissue. When used without qualification, it usually refers to an environmental disease of the lung, also known more specifically as pulmonary siderosis or Welder's disease, which is a form of pneumoconiosis. Pulmonary siderosis was first described in 1936 from X-ray images of the lungs of arc welders. The name ''siderosis'' comes from

Ancient Greek Ancient Greek includes the forms of the Greek language used in ancient Greece and the ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Dark Ages (), the Archaic p ...

word for iron, ''sídēr(os)'', and has an -''osis'' suffix.

Signs and symptoms

Pulmonary siderosis doesn't usually cause harmful scar tissue formation within the lungs, which is why it said to be non-fibrotic condition, unlike

asbestosis Asbestosis is long-term inflammation and scarring of the lungs due to asbestos fibers. Symptoms may include shortness of breath, cough, wheezing, and chest tightness. Complications may include lung cancer, mesothelioma, and pulmonary heart d ...

for example, and has also been called "benign pneumoconiosis". Mild to moderate scarring of the lungs has been found in unusual cases of pulmonary siderosis. These people have had persistent

breathlessness Shortness of breath (SOB), also medically known as dyspnea (in AmE) or dyspnoea (in BrE), is an uncomfortable feeling of not being able to breathe well enough. The American Thoracic Society defines it as "a subjective experience of breathing dis ...

, coughing and decreased lung function. However, people in occupations where they are exposed to iron (or rust) dust are usually also exposed to other forms of dust such as

silica Silicon dioxide, also known as silica, is an oxide of silicon with the chemical formula , most commonly found in nature as quartz and in various living organisms. In many parts of the world, silica is the major constituent of sand. Silica is ...

, which upon repeated inhalation is known to cause dangerous silicosis. Because of this, it is not known for certain whether the inhalation of pure iron or rust can cause detrimental scarring of the lungs that has been seen in some cases of pulmonary siderosis. Still, studies have shown lack of silica in tissue samples collected from people with pulmonary siderosis. This indicates that iron alone is enough to cause damage to the lungs. Symptoms usually appear after a number of years, but may rarely appear within a year. Eye exposure to iron dust can also cause another form of siderosis, "ocular siderosis" or " siderosis bulbi", which can cause eye discoloration, but also eye damage, like

cataract A cataract is a cloudy area in the lens of the eye that leads to a decrease in vision. Cataracts often develop slowly and can affect one or both eyes. Symptoms may include faded colors, blurry or double vision, halos around light, trouble ...

s and

night blindness Nyctalopia (; ), also called night-blindness, is a condition making it difficult or impossible to see in relatively low light. It is a symptom of several eye diseases. Night blindness may exist from birth, or be caused by injury or malnutrition ...

. This happens via the

corrosive A corrosive substance is one that will damage or destroy other substances with which it comes into contact by means of a chemical reaction. Etymology The word ''corrosive'' is derived from the Latin verb ''corrodere'', which means ''to gnaw'', ...

effects of iron.

Cause

Pulmonary siderosis is caused by repeated inhalation of fine iron or

rust Rust is an iron oxide, a usually reddish-brown oxide formed by the reaction of iron and oxygen in the catalytic presence of water or air moisture. Rust consists of hydrous iron(III) oxides (Fe2O3·nH2O) and iron(III) oxide-hydroxide (FeO( ...

dust that happens usually over a number of years. This can happen during work consisting of

welding Welding is a fabrication process that joins materials, usually metals or thermoplastics, by using high heat to melt the parts together and allowing them to cool, causing fusion. Welding is distinct from lower temperature techniques such as bra ...

grinding Grind is the cross-sectional shape of a blade. Grind, grinds, or grinding may also refer to: Grinding action * Grinding (abrasive cutting), a method of crafting * Grinding (dance), suggestive club dancing * Grinding (video gaming), repetitive and ...

foundry A foundry is a factory that produces metal castings. Metals are cast into shapes by melting them into a liquid, pouring the metal into a mold, and removing the mold material after the metal has solidified as it cools. The most common metals pr ...

work, paint manufacture or iron ore mining among other similar occupations where a person is exposed to fine iron dust or fumes.

Diagnosis

Pulmonary siderosis causes changes within the lungs that are clearly visible in tissue samples, x-ray images and other

radiological studies Radiology ( ) is the medical discipline that uses medical imaging to diagnose diseases and guide their treatment, within the bodies of humans and other animals. It began with radiography (which is why its name has a root referring to radiat ...

. In a tissue sample from alveoli patchy deposits of iron can be seen throughout the sample.

Treatment

There is no cure for pulmonary siderosis or other

interstitial lung disease Interstitial lung disease (ILD), or diffuse parenchymal lung disease (DPLD), is a group of respiratory diseases affecting the interstitium (the tissue and space around the alveoli (air sacs)) of the lungs. It concerns alveolar epithelium, pu ...

s. Any damage is thus permanent. Symptoms can be treated.

Prognosis

Outcome of pulmonary siderosis is often good if the inhalation of iron or rust dust is permanently avoided. However,

has been associated with

lung cancer Lung cancer, also known as lung carcinoma (since about 98–99% of all lung cancers are carcinomas), is a malignant lung tumor characterized by uncontrolled cell growth in tissues of the lung. Lung carcinomas derive from transformed, malign ...

, a condition which may have a poor outcome. Still, it is not known if pulmonary siderosis causes cancer in welders specifically or if these cases of cancer appear due to entirely different factors.

References

External links

{{Respiratory pathology Iron metabolism Lung diseases due to external agents