Cadmium Nitrate Toxicity - Health Effects, Treatment, and Prevention

Introduction

Cadmium nitrate is a toxic chemical compound comprising cadmium, nitrogen, and oxygen, with the chemical formula Cd(NO3)2. Cadmium nitrate is a white, crystalline, odorless solid that is soluble in water. It is a toxic substance that can adversely affect human health and the environment. When subjected to high temperatures, it emits toxic fumes of cadmium oxides.

Cadmium nitrate finds its application in the manufacturing of cadmium hydroxide for use in alkaline batteries, photography, the coloring of glass and porcelain, and nuclear reactors. The substance has been identified as a carcinogen and is linked to an increased likelihood of lung cancer development. In addition to its role as a carcinogenic agent, it is also known to have hepatotoxic and genotoxic properties. Hepatotoxic and genotoxic refer to substances that are harmful to the liver and DNA (deoxyribonucleic acid), respectively.

What Are the Uses of Cadmium Nitrate?

The following are the uses of Cadmium nitrate:

• Cadmium nitrate is used as a corrosion inhibitor in several industrial applications. It is added to plating baths to prevent the corrosion of metal surfaces during the plating process.

• It is used in the production of pigments, including cadmium yellow and cadmium red. These pigments are used in the manufacture of paints, plastics, and other materials.

• It is used as a catalyst in organic synthesis, which is used to produce synthetic fibers.

• This compound is used as a stabilizer in the production of polyvinyl chloride (PVC) plastics. It improves the durability and resistance of the material to heat, light, and weather.

• Cadmium nitrate is used in the production of nickel-cadmium batteries, which helps to increase the battery's efficiency.

• Cadmium nitrate is used in scientific research as a reagent for several chemical reactions. It is also used as a precursor in the production of other cadmium compounds.

What Is Cadmium Nitrate Toxicity?

Cadmium nitrate is a toxic chemical compound that can cause harmful health effects if exposure occurs. Exposure to cadmium nitrate can occur through inhalation, ingestion, or skin contact. Cadmium is a heavy metal that is not naturally found in the human body and can accumulate over time, leading to toxic effects. This substance poses a risk to both aquatic and terrestrial ecosystems due to the presence of a heavy metal, which can be toxic to plants and animals. It is important not to release it into the environment. Smokers may be exposed to cadmium through cigarette smoke. Certain industries release cadmium into the environment, which can then contaminate soil and water sources, increasing the chances of toxicity.

According to Occupational Safety and Health Administration (OSHA) regulations, the permissible exposure limit (PEL) for airborne substances is 0.005 mg/m3 (milligram per cubic meter) on average over an eight-hour work shift. National Institute for Occupational Safety and Health (NIOSH) advises limiting exposure to occupational carcinogens to the lowest feasible level. The American Conference of Governmental Industrial Hygienists (ACGIH) recommends a threshold limit value (TLV) of airborne exposure as 0.002 mg/m3 for the eight-hour work shift. Additionally, the ACGIH recommends a total particulate fraction of 0.01 mg/m3 for the same period.

What Are the Symptoms of Cadmium Nitrate Toxicity?

Symptoms develop in individuals when cadmium nitrate is ingested, inhaled, or absorbed through the skin which include:

Acute Effects

• Coughing, chest pain, shortness of breath, and pneumonitis result from inhalation of cadmium nitrate.

• Exposure to this substance can result in a flu-like condition known as metal fume fever.

• Nausea, vomiting, abdominal pain, and diarrhea develop due to the ingestion of this compound.

• Skin irritation and allergic reactions when it comes into contact with the skin.

• Eye contact causes irritation of the eyes.

Chronic Effects

• Emphysema (a lung disease characterized by damage to the air sacs in the lungs) and pulmonary edema (an accumulation of fluid in the lungs).

• Prolonged exposure can damage the kidneys, causing symptoms such as proteinuria, hematuria, and decreased kidney function. Proteinuria is the presence of excess protein in the urine, while hematuria refers to the presence of blood in the urine.

• Liver damage, anemia, and loss of smell sensation occur in cases of repeated exposure to lower levels of this substance.

• Long-term exposure to cadmium nitrate can increase the risk of hypertension (high blood pressure), atherosclerosis (a gradual clogging and hardening of arteries due to plaque buildup), and heart disease.

• Reproductive problems may arise due to damage in the reproductive system, including decreased fertility. Developmental defects and low birth weight in infants may be present in cases of extended or repeated exposure to this substance.

What Are the Implications of Cadmium Nitrate Toxicity for Human Health?

Cadmium initially binds with metallothionein and is carried to the kidney. Once the cadmium concentration is higher than that of available metallothionein, toxic effects are observed, and the cadmium-metallothionein complex may become damaging. The accumulation of cadmium in the kidney leads to increased excretion of important low and high-molecular-weight proteins. Due to its high affinity with zinc, cadmium can interfere with biological processes that involve zinc. Moreover, cadmium can activate the estrogen receptor and potentially promote the growth of specific types of cancer cells while also causing reproductive dysfunction.

Nitrate toxicity arises from its conversion to nitrite within the body. Nitrite, in turn, triggers the autocatalytic oxidation of oxyhemoglobin to hydrogen peroxide and methemoglobin. This elevation of methemoglobin levels results in methemoglobinemia, a condition characterized by tissue hypoxia, as methemoglobin is unable to bind oxygen.

What Is the Treatment for Cadmium Nitrate Toxicity?

The treatments options for cadmium nitrate toxicity include:

• Chelation Therapy: Chelation therapy involves using chelating agents, which bind to heavy metals such as cadmium and help remove them from the body. Chelation therapy is often used in cases of severe cadmium toxicity.

• Supportive Care: Supportive care involves treating the symptoms of cadmium nitrate toxicity, such as respiratory problems, gastrointestinal problems, and kidney damage. This may include oxygen therapy, Bronchodilators, intravenous fluids, and medications to control nausea and vomiting.

• Methemoglobinemia Treatment: Supplemental oxygen and intravenously-administered methylene blue one percent solution, given slowly over a five-minute period followed by a normal saline IV (intravenous) flush, can be used to treat methemoglobinemia. This helps in restoring the iron in hemoglobin to its normal oxygen-carrying state.

• Medications: Proparacaine hydrochloride can be used to relieve eye irritation. Seizures can be managed using Diazepam or Lorazepam.

• Activated Charcoal: This compound is administered in cases of ingestion to remove the cadmium nitrate present in the bloodstream.

• Dialysis may be necessary to remove excess cadmium from the blood if the kidney is severely damaged.

How to Prevent Cadmium Nitrate Toxicity?

The following are the ways to prevent cadmium nitrate toxicity:

• Wear appropriate protective equipment such as gloves, goggles, and a respirator while working with cadmium nitrate or other sources of cadmium.

• Wash hands and face thoroughly after working with cadmium nitrate to remove any residue. Do not eat, drink, or smoke while working with the substance. Good hygiene practices should be implemented in the workplace.

• Ensure proper ventilation in workspaces where cadmium nitrate is used to prevent inhalation of the substance.

• Stop smoking as it worsens the respiratory issues caused by exposure to this compound.

• Dispose of cadmium-containing materials in accordance with local regulations to prevent contamination of the environment.

• Avoid eating foods that are high in cadmium, such as shellfish and organ meats.

Conclusion

Cadmium nitrate toxicity is a serious health and environmental concern that requires attention from regulatory agencies, industry, and individuals. Preventing exposure to cadmium nitrate involves implementing proper precautions to minimize exposure, providing personal protective equipment, and setting limits on the amount of cadmium released into the environment. Proper diagnosis and treatment can help to prevent further health effects and improve the prognosis.