Arsenic intoxication is poisoning with the chemical element arsenic. Arsenic is a semimetal and is one of the trace elements. Poisoning is usually caused by trivalent soluble arsenic.
What is arsenic intoxication?
Trivalent arsenic compounds are highly toxic because they disrupt transport processes within the body, interfere with DNA repair, and negatively affect cellular energy metabolism. Arsenic poisoning can occur acutely or take a chronic course. Arsenic was already used medicinally in ancient times. It was part of the therapy against syphilis. In the form of the very toxic arsenic, arsenic became known as a murder weapon and suicide agent. Arsenic belongs to the group of trace elements. So it seems to perform useful tasks in the body in small doses. However, what function arsenic has in physiological dosage is not yet clear.
Causes
Acute arsenic poisoning is caused when large amounts of arsenic suddenly enter the body. A dose of 60 to 170 milligrams of arsenic can be fatal to humans. More common than acute arsenic intoxication, however, is chronic intoxication with arsenic. Arsenic in the form of arsenite or arsenate contaminates drinking water in many countries. Arsenic enters groundwater through leaching of arsenic-containing ores. Around 100 million people worldwide have access to arsenic-contaminated water. Especially in India, Thailand and Bangladesh, chronic arsenic poisoning can be increasingly observed due to these circumstances. The World Health Organization (WHO) recommends that an arsenic level of 10 micrograms per liter should not be exceeded in drinking water. In Germany, this value has been observed since 1996. However, many other European countries and the USA regularly exceed this limit. Rice is one of the foods most heavily contaminated with arsenic. Arsenic from groundwater accumulates in rice around ten times as much as in other cereals such as wheat or barley. Apple juice and beer are also frequently contaminated with arsenic. Soluble arsenic compounds are absorbed through the gastrointestinal tract and also through the skin. Arsenic is then stored in muscles, skin, hair, nails, bones, and lungs.
Symptoms, complaints and signs
Acute arsenic intoxication is noticeable within hours of ingestion. There is severe gastrointestinal inflammation with vomiting, severe pain, nausea and severe watery diarrhea. As a result, the body loses a lot of water and salt. The blood thickens and the function of the kidneys is reduced. To compensate, the pulse increases. Within a short time, sufferers go into shock. Death occurs within a few hours to days due to kidney failure or cardiovascular failure.The picture of chronic arsenic poisoning is very diverse. Characteristic of the poisoning is a strong callus formation on the soles of the feet and on the skin surfaces. Dark gray skin pigmentation and white bands on the fingernails are also typical. Furthermore, the hair of the affected persons falls out. Inflammation of the conjunctiva may occur. Brain and nerves can be damaged. The consequences are disturbances of sensitivity, movement disorders, paralysis or regression of the muscles. Sufferers are tired, dull and suffer from lack of drive and concentration. The respiratory tract suffers damage, as does the liver. After prolonged exposure to arsenic, the small blood vessels can become damaged. The resulting oxygen deficiency is initially manifested by drumbeat fingers and watch glass nails. In extreme cases, the affected regions or even the entire extremities die. This medical phenomenon is also known as Black Foot Disease. Chronic arsenic exposure also results in an increased risk of cancer. After a few years, malignant tumors of the skin, liver, lungs or urinary bladder may appear.
Diagnosis and progression
Arsenic intoxication can be detected by measuring arsenic blood levels. In addition, in cases of intoxication, arsenic is also found in the urine. Detection is by atomic absorption or atomic emission spectroscopy. Uncontaminated persons have an arsenic level in the blood of 5 to a maximum of 15 µg/l (micrograms per liter).Concentrations may increase slightly due to excessive consumption of arsenic-contaminated marine animals or plants and may subsequently be confused with chronic arsenic intoxication. In individuals who are not exposed to arsenic in their occupational environment, the concentration in urine varies between 5 and 20 picograms per liter. When arsenic-containing foods are ingested, the concentration can rise to as high as 1000 picograms per liter. Because of these food-dependent fluctuations, chronic arsenic poisoning is better diagnosed by analysis of hair or nails. Roughly speaking, a tenfold increase in the concentration of arsenic in drinking water will double the arsenic content in toenails in the long term.
Complications
In acute arsenic poisoning, depending on the level of the dose and the constitution of the poison victim, death is a likely outcome. Complications following chronic arsenic intoxication can vary in severity. The long latency period of up to thirty years is problematic. Typical of chronic arsenic poisoning are changes in the appearance of the skin, for example pigmentary disorders or increasing hornification of the skin. As a complication of long-term arsenic exposure – for example via drinking water – severe disfigurement can result. In addition, the fine blood vessels in the legs can be permanently damaged. This can go so far that the affected extremities die and have to be amputated. Initially, the affected legs turn blackish. This phenomenon is known in medicine as “black foot disease”. Previously, a limited region in Taiwan was known to have experienced an increased incidence of this type of disease in the 1990s. They were caused by the consumption of arsenic-contaminated groundwater. In more recent times, however, black foot disease has also been diagnosed in countries where wine is grown. In addition to “Black Foot Disease”, chronic arsenic intoxication can also cause cancers of the skin, lungs, liver or urinary bladder. Very rarely, arsenic poisoning results in neurogenic “Sudeck’s syndrome” or toxin-induced heart damage.
When should you see a doctor?
Arsenic intoxication must always be treated by a physician. In acute emergencies, an emergency physician should be called or the hospital should be visited directly. Arsenic intoxication represents a very serious complaint that, in the worst case, can lead to irreversible damage to the organs and, consequently, to death. The doctor should be consulted if the affected person has deliberately ingested a large amount of arsenic. Patients suffer from diarrhea and severe abdominal pain. Furthermore, there is also vomiting and nausea. If these complaints are also associated with paralysis or with movement disorders, a visit to the doctor is absolutely necessary. A doctor must also be consulted in case of muscle weakness or lack of concentration. Furthermore, arsenic intoxication leads to a high pulse and can thus lead to heart failure. Also complaints of the kidneys can indicate arsenic intoxication and should be examined by a doctor. In the worst case, this will lead to renal failure, which if left untreated will result in death. If arsenic intoxication does not occur acutely, the symptoms are usually gradual. However, they should still be examined by a doctor to avoid consequential damage.
Treatment and therapy
Sulfur-containing complexing agents such as dimercaptopropanesulfonic acid or dimercaptosuccinic acid are used to treat arsenic intoxication. Success with these complexing agents is still quite effective in acute arsenic poisoning, even at high doses of arsenic. A few hours after ingestion, activated charcoal can bind arsenic in the gastrointestinal tract and cause it to be excreted. However, the use of complexing agents in chronic arsenic intoxication is controversial.
Outlook and prognosis
The prognosis for arsenic intoxication depends on the dose, whether it is acute or chronic, and whether it is treated. For example, acute arsenic intoxication, such as can occur from ingestion of large amounts of arsenic compounds, is more severe. It will lead to death within hours or days if left untreated, as the arsenic causes shock, among other things. If emergency medical action is taken in good time (pumping out the stomach, administration of activated charcoal, etc.), there is a good chance of surviving arsenic intoxication.In many cases, there is no need to fear acute consequential damage after a phase of recovery. The situation is different in the case of chronic arsenic poisoning, which occurs much more frequently. In this case, the symptoms usually appear gradually, beginning with changes in skin appearance, general fatigue and other non-specific symptoms. Especially the skin changes, the increased risk of tumor formation and paralysis, can lead to death in affected persons or make amputations of dead limbs necessary. Years may pass from the time of exposure until the onset of serious symptoms. However, if a physician is consulted with the onset of symptoms, the prognosis is better. Success can be achieved by means of excretory therapies aimed at detoxifying the body. However, long-term damage is to be assumed, since detoxification only works in such a way that further poisoning is prevented. Damage that has already occurred in the organism remains.
Prevention
To prevent chronic arsenic intoxication, drinking water in affected countries should be depleted. For this purpose, there are methods based on activated carbon, iron hydroxide granules or aluminum oxide. Ion exchangers are also used. Another process for purifying drinking water is phytoremediation. Genetically modified plants are used for this purpose. These store arsenic in their leaves and thus remove it from the contaminated soil. The thick-stemmed water hyacinth can even remove arsenic from contaminated water.
Aftercare
When arsenic intoxication occurs, it depends on whether the poisoning is acute or chronic. Chronic poisoning results, for example, from drinking arsenic-containing mineral water or daily doses of arsenic ingested through arsenic-contaminated drinking water. Skin and vascular damage are the most common side effects of chronic arsenic intoxication. Follow-up care is essential for chronic arsenic intoxication. Basal cell carcinoma may develop from chronic intoxication. Basal cell carcinomas resulting from arsenic intoxication are mainly found on areas of the skin exposed to sunlight. Regular observation of all areas of the skin in question is essential. It is true that this cancer does not spread. But it does eat into the skin. All forms of basal cell carcinoma must be surgically removed. In addition, chronic arsenic intoxication also increases the risk of other types of cancer in the medium term. Without control examinations and follow-up care, the risks of disease are high for those affected. Latent arsenic poisoning can occur via certain foods. This primarily affects plants that obtain their fluids from arsenic-contaminated groundwater. Detoxification can be initiated with complexing agents and activated charcoal if necessary. Acute arsenic intoxication requires that large doses of arsenic enter the organism at one stroke. Depending on the level of the dose administered, follow-up care is unnecessary. Many affected persons die within a short time. Those who survive suffer secondary damage.
What you can do yourself
Activated charcoal can bind arsenic in the gastrointestinal tract for several hours after contamination and help excrete the toxin. Immediate administration of activated charcoal is therefore indicated as a first-aid measure for acute arsenic poisoning, but under no circumstances should affected individuals attempt to treat themselves exclusively. In the case of acute arsenic poisoning, the emergency physician must be called immediately or the patient must be taken to the nearest hospital. In the case of chronic arsenic intoxication, the patient can help to identify the cause of the poisoning. If symptoms occur during or shortly after travel to developing and emerging countries, two significant risk factors in particular exist – contaminated drinking water and household pesticides that have long since been banned in Europe. If drinking water is suspect, only mineral water should be consumed and this should also be used for preparing coffee, tea and other hot drinks as well as for ice cubes. In contrast to microbial contamination, boiling the water does not help if the arsenic concentration is too high, but special water filters can be helpful. If children and pets show corresponding symptoms during a trip to such countries, this may be due to contact with or consumption of ant baits or other pest traps heavily contaminated with arsenic.Under no circumstances should such products be purchased locally in exotic countries and, if necessary, removed from the hotel room.
