Siderosis is the deposition of excess

iron Iron is a chemical element; it has symbol Fe () and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, forming much of Earth's o ...

in body tissue. When used without qualification, it usually refers to an environmental disease of the

lung The lungs are the primary Organ (biology), organs of the respiratory system in many animals, including humans. In mammals and most other tetrapods, two lungs are located near the Vertebral column, backbone on either side of the heart. Their ...

, also known more specifically as pulmonary siderosis or Welder's disease, which is a form of

pneumoconiosis Pneumoconiosis is the general term for a class of interstitial lung disease where inhalation of dust (for example, ash dust, lead particles, pollen grains etc) has caused interstitial fibrosis. The three most common types are asbestosis, silico ...

. 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 classical antiquity, ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Greek ...

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

suffix In linguistics, a suffix is an affix which is placed after the stem of a word. Common examples are case endings, which indicate the grammatical case of nouns and adjectives, and verb endings, which form the conjugation of verbs. Suffixes can ca ...

Signs and symptoms

Pulmonary siderosis does not 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 pulmonary fibrosis, scarring of the human lung, lungs due to asbestos fibers. Symptoms may include shortness of breath, cough, wheezing, and chest pain, chest tightness. Complications may include lung canc ...

for example, and has also been called "benign

". 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), 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 discomfort that c ...

coughing A cough is a sudden expulsion of air through the large breathing passages which can help clear them of fluids, irritants, foreign particles and microbes. As a protective reflex, coughing can be repetitive with the cough reflex following three ...

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 , commonly found in nature as quartz. In many parts of the world, silica is the major constituent of sand. Silica is one of the most complex and abundant f ...

, which upon repeated inhalation is known to cause dangerous

silicosis Silicosis is a form of occupational lung disease caused by inhalation of crystalline silica dust. It is marked by inflammation and scarring in the form of Nodule (medicine), nodular lesions in the upper lobes of the lungs. It is a type of pneum ...

. 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 (anatomy), lens of the eye that leads to a visual impairment, decrease in vision of the eye. Cataracts often develop slowly and can affect one or both eyes. Symptoms may include faded colours, blurry or ...

s and night blindness. This happens via the

corrosive Corrosion is a natural process that converts a refined metal into a more chemically stable oxide. It is the gradual deterioration of materials (usually a metal) by chemical or electrochemical reaction with their environment. Corrosion engine ...

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(OH) ...

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

welding Welding is a fabrication (metal), fabrication process that joins materials, usually metals or thermoplastics, primarily by using high temperature to melting, melt the parts together and allow them to cool, causing Fusion welding, fusion. Co ...

, grinding,

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 specialty that uses medical imaging to diagnose diseases and guide treatment within the bodies of humans and other animals. It began with radiography (which is why its name has a root referring to radiation), but tod ...

. 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, pulm ...

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, is a malignant tumor that begins in the lung. Lung cancer is caused by genetic damage to the DNA of cells in the airways, often caused by cigarette smoking or inhaling damaging chemicals. Damaged ...

, 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