The effects of arsenic are dangerous, but overexposure to it is very rare.
Intake can result from swallowing, absorbing, or inhaling the chemical.
Arsenic poisoning can cause major health complications and death if it is not treated, so precautions exist to protect those who are at risk.
Arsenic is often implicated in deliberate poisoning attempts, but an individual can be exposed to arsenic through contaminated groundwater, infected soil and rock, and arsenic-preserved wood.
However, arsenic in the environment is not immediately dangerous, and it is rare to find toxic amounts of arsenic in nature.
- Arsenic is a natural metalloid chemical that may be present in groundwater.
- Ingestion only poses health problems if a dangerous amount of arsenic enters the body. Then, it can lead to cancer, liver disease, coma, and death.
- Treatment involves bowel irrigation, medication, and chelation therapy.
- It is rare to find dangerous amounts of arsenic in the natural environment. Areas with dangerous arsenic levels are usually well-known and provisions exist to prevent and handle the risk of poisoning.
- Anyone who suspects there may be high arsenic levels in their local environment should contact their local authorities for more information.
What is arsenic?
Arsenic is a naturally occurring, metalloid component of the Earth's crust. Minuscule quantities of arsenic occur in all rock, air, water, and soil. A metalloid is a substance that is not a metal but shares many qualities with metals.
The concentration of arsenic may be higher in certain geographical regions. This could be a result of human activity, such as metal mining or the use of pesticides. Natural conditions can also lead to a higher concentration.
It can be found combined with other elements in different chemical compounds. Organic forms of arsenic also contain carbon, but inorganic forms do not. Arsenic cannot be dissolved in water.
Inorganic arsenic compounds are more harmful than organic ones. They are more likely to react with the cells in the body, displace certain elements from the cell, and change the cell's function.
For example, cells use phosphate for energy generation and signaling, but one form of arsenic, known as arsenate, can imitate and replace the phosphate in the cell. This impairs the ability of the cell to generate energy and communicate with other cells.
This cell-altering ability may be useful in cancer treatment, as some studies have shown it can send the disease into remission and help thin the blood. Arsenic-based chemotherapy drugs, such as arsenic trioxide, are already in use for some cancers.
The symptoms of arsenic poisoning can be acute, or severe and immediate, or chronic, where damage to health is experienced over a longer period. This will often depend on the method of exposure.
A person who has swallowed arsenic may show signs and symptoms within 30 minutes.
These may include:
If arsenic has been inhaled, or a less concentrated amount has been ingested, symptoms may take longer to develop. As the arsenic poisoning progresses, the patient may start experiencing convulsions, and their fingernail pigmentation may change.
Signs and symptoms associated with more severe cases of arsenic poisoning are:
- a metallic taste in the mouth and garlicky breath
- excess saliva
- problems swallowing
- blood in the urine
- cramping muscles
- hair loss
- stomach cramps
- excessive sweating
Arsenic poisoning typically affects the skin, liver, lungs, and kidneys. In the final stage, symptoms include seizures and shock. This could lead to a coma or death.
Complications linked to long-term arsenic consumption include:
- liver disease
- nervous system complications, such as loss of sensation in the limbs and hearing problems
- digestive difficulties
Groundwater possesses trace amounts of arsenic. On occasion, these levels may exceed the amount a human can safely ingest.
The main cause of arsenic poisoning is the consumption of a toxic amount of arsenic.
Arsenic, consumed in large amounts, can kill a person rapidly. Consumed in smaller amounts over a long period, it can cause serious illness or a prolonged death.
The main cause of arsenic poisoning worldwide is the drinking of groundwater that contains high levels of the toxin. The water becomes contaminated underground by rocks that release the arsenic.
Medical News Today (MNT) asked Dr. Daniel E. Brooks MD, Medical Director of the Banner Poison and Drug Information Center (BPDIC) about the risk of poisoning from contact with arsenic-contaminated underground rock.
He told us:
"There is no risk from touching rocks that contain arsenic. Transient contact with arsenic-containing rocks will not lead to effect absorption or clinical concerns for arsenic poisoning."
The World Health Organization (WHO) estimate that more than 200 million people worldwide are exposed to water that contains potentially unsafe levels of arsenic.
Arsenic in the workplace
If proper safety measures are not taken, workers in certain industries may face a higher risk of toxicity.
These industries include:
- glass production
- wood treatment
- the production and use of some pesticides
The method through which arsenic enters the human body in these industries depends on the way the arsenic is being used.
For example, arsenic may be inhaled in the smelting industry, as there is inorganic arsenic in coke emissions. In the wood treatment industry, it may be absorbed through the skin if a chemical containing arsenic makes contact.
There may be traces of arsenic in some foods, such as meat, poultry, and fish. Normally, poultry contains the highest level of arsenic, due to antibiotics in the chicken feed. Rice has also been found to potentially contain higher levels of arsenic than water.
Pathological testing can confirm an instance of arsenic poisoning.
In areas and occupations with a risk of arsenic poisoning, it is important to monitor the levels of arsenic in the people at risk. This can be assessed through blood, hair, urine, and fingernail samples.
Urine tests should be carried out within 1 to 2 days of the initial exposure for an accurate measure of when the poisoning occurred. These tests can also be used to help diagnose cases of apparent arsenic poisoning.
Tests on hair and fingernails can determine the level of arsenic exposure over a period of up to 12 months. These tests can give an accurate indication of arsenic exposure levels, but they do not show what effects they may have on the person's health.
The treatment depends on the type and stage of the arsenic poisoning.
Some methods remove arsenic from the human body before it causes any damage. Others repair or minimize the damage that has already occurred.
Treatment methods include:
- removing clothes that could be contaminated with arsenic
- thoroughly washing and rinsing affected skin
- blood transfusions
- taking heart medication in cases where the heart starts failing
- using mineral supplements that lower the risk of potentially fatal heart rhythm problems
- observing kidney function
Bowel irrigation is another option. A special solution is passed through the gastrointestinal tract, flushing out the contents. The irrigation removes traces of arsenic and prevents it from being absorbed into the gut.
Chelation therapy may also be used. This treatment uses certain chemicals, including dimercaptosuccinic acid and dimercaprol, to isolate the arsenic from the blood proteins.
The following measures can be taken to protect people from the arsenic in groundwater:
- Arsenic removal systems in homes: If the levels of arsenic in an area are confirmed as unsafe, systems can be purchased for the home to treat drinking water and reduce the arsenic levels. This is a short-term solution until the arsenic contamination can be dealt with at the source.
- Testing nearby water sources for traces of arsenic: Chemically examining the water can help to identify poisonous sources of arsenic.
- Taking care when harvesting rainwater: In areas of high rainfall, arsenic poisoning can be prevented by ensuring the process of collection does not put the water at risk of infection, or cause the water to become a breeding ground for mosquitos.
- Considering the depth of wells: The deeper the well, the less arsenic its water is likely to have.
However, Dr. Brooks told MNT that arsenic poisoning from environmental causes is unlikely to affect a significant number of people.
[The risk is] minimal for the vast majority of humans. There are specific (and usually well-known) areas where ground water cannot be consumed due to risks of arsenic (or other heavy metals) but, on a global scale, this affects a small percentage of humans.
Daniel E. Brooks MD, Medical Director, Banner Poison and Drug Center, Phoenix, AZ
The Environmental Protection Agency (EPA) has set a limit of 0.01 parts per million (ppm) for arsenic in drinking water. In the workplace, the limit set by the Occupational Safety and Health Administration (OHSA) is 10 micrograms (mcg) of arsenic per cubic meter of air for 8-hour shifts and 40-hour weeks.
Dr. Brooks suggests that anyone who suspects arsenic poisoning in their area "should seek out the assistance of a poison center or medical toxicologist."
The Centers for Disease Control and Prevention (CDC) can assist with concerns about arsenic and other toxins.