Chromium Toxicity- Symptoms, Sources, and Mechanism of Exposure

Introduction:

Chromium is one of the common skin sensitizers that cause skin-sensitizing effects in the general public. A possible source of exposure is waste dumps for chromate-producing plants that cause water or air pollution. It occurs in an environment in two phases such as trivalent and hexavalent chromium. Exposure occurs from industrial and natural sources of chromium. The respiratory tract is the target organ for chromium toxicity. Shortness of breath and coughing are observed in cases of acute chromium toxicity. Perforation, ulceration, decreased pulmonary function, bronchitis (refers to inflammation of the bronchial tube lining, which carries air to and from the lungs), and pneumonia (refers to an infection that leads to inflammation in one or both lungs)are seen in chronic exposure to chromium. It is a mineral that affects the body's carbohydrate, fat, protein, and insulin levels.

What Is Chromium?

Chromium is a naturally occurring element in animals, plants, rocks, volcanic dust, soil, and gasses. It is used for making steel and other alloys. It occurs in an environment in two forms. The two forms of chromium are trivalent chromium (Cr III) and hexavalent chromium (Cr VI).

Chromium (IV) is considered more carcinogenic than chromium (III). Hexavalent chromium usually exists in strongly oxidizing environments, readily soluble in water and alkaline in nature. It is used on a large scale in chemical and metallurgy industries. High concentration of chromium leads to DNA (deoxyribose nucleic acid) damage.

What Is Chromium Toxicity?

Chromium toxicity refers to any toxic effects in an individual that occurs due to exposure to specific forms of chromium, especially hexavalent chromium. Hexavalent chromium and its other products are toxic when ingested or inhaled. It can be absorbed by the gastrointestinal and lungs.

What Is Trivalent Chromium?

Trivalent chromium is a chemically stable form of chromium that occurs naturally in the earth’s crust. It is an essential nutrient for normal functioning and regulation of the body. It helps in the regulation of fat and sugar metabolism. Trivalent chromium deficiency is rare and is seen in a patient who gets intravenous nutrition for a longer period of time. It is usually low in toxicity and does not cause much harm to the body. Dietary supplements with trivalent chromium are usually not associated with any adverse reactions or effects.

What Is Hexavalent Chromium?

Hexavalent chromium does not occur naturally and is released into the environment by human activities. It can be generated in industrial processes that involve stainless steel (cutting, casting, and welding). Food and water contaminated with hexavalent chromium lead to adverse health effects. Workers who work with high levels of hexavalent chromium may experience health issues such as nose ulcers, running nose, irritation to the nose lining, shortness of breath, and cough. Skin contact with the corresponding hexavalent chromium irritates the stomach and intestinal lining and damages male reproductive organs. They are classified as human carcinogens. It can lead to lung cancer in workers exposed to high-level hexavalent chromium in drinking water over a long period.

What Are the Symptoms of Chromium Toxicity?

Occupational exposure occurs due to the presence of chromium (III) and chromium (VI). Exposure to chromium leads to the following symptoms such as:

• Asthma (refers to a condition in which the airway of a person becomes narrow, and swelled, leading to difficulty in breathing).

• Chronic bronchitis (refers to a productive cough that lasts more than three months for at least two consecutive years).

• Chronic pharyngitis (refers to a sore throat that persists for a few weeks and is caused by allergies, environmental pollutants, infections, acid reflux, or allergies).

• Chronic rhinitis (refers to an allergic response that causes sneezing and itchy and watery eyes).

• Congestion (refers to a stuffy nose when nasal and adjacent blood vessels become swollen with the presence of excess fluid).

• Hyperemia (refers to the increased amount of blood in the vessels of a tissue or an organ in the body).

• Polyps of the upper respiratory tract.

• Ulceration of nasal mucosa.

• Dryness.

• Erythema (refers to redness of the skin).

• Fissuring (refers to crack or split to form a narrow opening).

• Scaling.

• Small vesicles.

• Nasal irritation.

• Sneezing.

• Itching and soreness.

• Rhinorrhea (refers to excessive drainage that ranges from clear fluid to thick mucus from the nasal passages).

• Nose bleeds.

• Septum atrophy.

• Ulcerations and perforation.

• Reduced lung function.

What Are the Sources of Chromium Exposure?

Chromium is present naturally in the Earth’s crust, mostly in chromium III form. Chromium (VI) compounds are anthropogenically produced and do not occur naturally. A large amount of chromium is produced through various activities such as :

• Production of bichromates and chromates.

• Stainless steel.

• Welding.

• Chromium plating.

• Ferrochrome alloys and chrome pigment production.

• Material tanning.

• The combustion of oil and coal.

• Cement work.

• Water incineration.

How Does Chromium Exposure Occur?

Exposure to chromium occurs through ingestion, inhalation, and direct contact with the skin. The sources of exposure may include food, water, air, groundwater, and contaminated soil. In food, chromium is present in the form of chromium III. It is rare to find traces of hexavalent chromium in the food supplement. Hexavalent chromium is present in smoking, and smoking tobacco in enclosed spaces is the source of exposure to airborne hexavalent chromium.

How to Reduce Chromium Exposure?

• Smoking should be avoided in enclosed spaces to limit the exposure to chromium present in cigarette smoke.

• Contaminated groundwater should not be used for cooking, bathing, gardening, and washing.

• It is suggested to avoid excessive use of dietary supplements as they may contain trivalent chromium.

Conclusion:

Chromium enters the water, soil, and air mostly in chromium (III) and chromium (VI) forms. There are various studies conducted on chromium and its health effects. It is concluded that chromium is responsible for toxic reactions and effects in humans. It is carcinogenic in nature. Hexavalent chromium is mostly responsible for carcinogenic activity as compared to trivalent chromium. These toxic effects are the main source of health problems such as asthma. Several studies suggest that chromium (VI) compounds can elevate cancer risk. The World Health Organisation (WHO) has determined chromium (VI) a human carcinogen. Chromium exposure can be avoided by using fresh water for household purposes and limiting the dietary products that contain trivalent chromium.