Arsenic

It has the atomic number 33 in the periodic table of elements and is abbreviated to As. As a trace element, it is found everywhere in the environment, in organic compounds and therefore also in living organisms. It is primarily known for its toxic properties (for example in numerous Agatha Christie novels). However, arsenic is also a normal component of the metabolism of plants, animals and humans. It binds to certain enzymes, especially those that are important for oxygen utilization. Elemental arsenic (the gray metallic form) is only slightly toxic. Toxic are the arsenic-oxygen compounds, such as arsenic III-oxide (arsenicic), which can be fatal in quantities as low as 60 to 120 mg. Arsenic is also the substance predominantly used in homicides. Arsenic is an odorless and tasteless white powder that dissolves well in alcoholic beverages. Due to the accumulation and secretion in nails and hair, arsenic can also be detected in exhumed corpses, making this murder weapon obsolete. In ancient times, arsenic was not only used as a murder poison, but also, in smaller quantities, as a "beauty product" and to improve performance. The "mild poisoning" temporarily dilated the capillaries.

Functions in the body

The actual functions of arsenic in the metabolism have not yet been clearly clarified. It is not even clear whether arsenic is an essential, i.e. indispensable, trace element. Most of the literature even describes arsenic as a toxic trace element. In any case, arsenic protects against selenium poisoning due to its chemical relationship.

Main suppliers

Traces of arsenic are found in practically all foods and drinks.

Deficiency symptoms

In animal experiments, growth disorders and changes in the myocardium, i.e. the heart muscle, have been observed with arsenic deficiency.

Overdose/acute poisoning

Acute poisoning causes nausea, vomiting and, after a few hours, severe diarrhea. Death then usually occurs due to the subsequent loss of electrolytes and water, which can trigger a state of shock. Kidney failure can also occur.

Chronic poisoning

Chronic arsenic poisoning causes certain skin discolorations. On the one hand, pigment shifts occur, on the other hand hyperkeratosis, i.e. excessive keratinization of the skin. This can lead to skin tumors. Furthermore, disorders of the nerve tracts occur, which manifest themselves, for example, in the form of skin paresthesia and paralysis. Headaches, concentration disorders, weakness and exhaustion have also been described. Muscle atrophy (regression of the muscles) can also occur.

Daily requirement

Animal studies have shown that the daily requirement of arsenic is 10 to 25 µg. With a normal diet, about 10 to 50 µg of arsenic are ingested per day.

Safety and side effects

The form of arsenic that occurs naturally in food and is known as organic arsenic appears to be safe and harmless when ingested in normal amounts.

Arsenic trioxide, which is available as a prescription drug, is safe and harmless when administered intravenously by a physician.

Other forms of arsenic, known as inorganic arsenic, can be very toxic even in small amounts. Ingesting 10 mcg of arsenic per kilogram of body weight per day over an extended period of time can cause symptoms of arsenic poisoning. An intake of 5 mg of arsenic, or sometimes less, can cause symptoms in the digestive tract. Higher doses can cause serious poisoning and can be fatal. Inorganic arsenic is classified as a carcinogenic agent.

There are laws that regulate the permitted amount of arsenic in drinking water. The maximum amount allowed in drinking water is 10 mcg of arsenic per liter. Prolonged consumption of drinking water containing 50 mcg of arsenic per liter has been linked to a deterioration of intelligence tests in children.

Precautions and warnings

Pregnancy and lactation: Trace amounts of arsenic naturally occurring in food are considered safe and harmless for pregnant and lactating women, but arsenic supplements should be avoided during pregnancy and lactation. Arsenic has been linked to birth defects and other serious harm in animals.

Low folic acid levels: There is evidence that a lack of folic acid could affect the way the body processes and excretes arsenic and contribute to higher levels of arsenic in the body.

Heart problems: The prescription form of arsenic - arsenic trioxide - can affect heart rhythms in some patients.

Drug interactions

You should not use arsenic in combination with the following medications:

Medications that can cause an irregular heartbeat (QT interval prolonging drugs).

Some forms of arsenic can cause an abnormal heartbeat. Taking arsenic in combination with drugs that can cause an irregular heartbeat could lead to serious side effects including arrhythmias.