The World Health Organization (WHO) estimates over 200 million people worldwide are exposed to arsenic concentrations in drinking water that exceed the guideline limit of 10 µg/L. This threshold may also be expressed as 10 parts per billion (ppb). The majority of arsenic exposure lies in southern Asian countries such as Bangladesh, Cambodia, India, China, Taiwan and Viet Nam. Millions more are at risk in Argentina, Peru, Chile, Central America and Mexico. WHO estimates 13 million people are at risk in the USA.

Over half the population in Bangladesh – 57 million people – are at immediate risk of arsenic poisoning. WHO labeled Bangladesh arsenic poisoning problem the “largest mass poisoning of a population in history.” Unfortunately, millions in other countries are silently exposed to dangerous levels of arsenic without awareness of the risk.

Arsenic sources

Arsenic contamination of drinking water occurs naturally, or as a consequence of human activities such as mining. Studies often show ground and surface water within 5 km of active or historical mining operations experience elevated arsenic, copper and lead concentrations. Many mines operate with no systematic environmental surveillance or data collection despite the scientific evidence that mining activities can damage human health.

Arsenic in groundwater occurs from minerals dissolving from weathered rocks and soils. Human actions such as fracking, overdrafting aquifers and digging deeper wells accelerate the migration of arsenic to groundwater. Coal fired power plants, copper and gold mines, fierce storms, and wild fires release arsenic to the atmosphere, and then distribute the poison across ecosystems.

Unless action occurs quickly, human actions are likely to double the number of people at risk or arsenic poisoning within a decade. estimates over 1.1 million active oil and gas wells in the US, with about 65,000 fracking sites. Several studies have shown significantly elevated arsenic levels in ground water wells near fracking sites.

Methane used in fracking enhances heavy metal transport to water supplies, including arsenic, selenium and strontium. Heat and pressure from fracking can change redox conditions, creating new chemical reactions that may release arsenic that was previously bound in rock. Some fracking companies actually inject fluid containing additional arsenic. These companies argue that the injection fluid arsenic will not migrate to drinking water but they have not presented convincing proof.

Global warming and surface water shortages force communities to overdraft aquifers. Removing water from aquifers faster than the replacement rate causes migration of heavy metals into the remaining water supply. When water is pumped from an aquifer, surrounding layers are squeezed and compact. As the water is expelled, the land sinks. If the expelled water contains toxic heavy metals such as arsenic, the groundwater can become contaminated. Land subsidence, the gradual sinking of land due to excessive pumping is common in California and across the Southern States.

San Joaquin Valley California Land Subsidence — 1 foot per year

San Joaquin Valley California Land Subsidence — 1 foot per year

Similarly, digging deeper wells accelerates the movement of arsenic and other heavy metals to the bottom of the well. A series of Stanford University studies has shown that deeper wells may contain seven times higher arsenic concentration than shallow wells. Unless wells are tested regularly, consumers may be silently accumulating arsenic in their bodies.

Silent killer

Arsenic acts as a poison to biologic systems because the heavy metal inactivates cellular functions. Arsenic reacts with proteins, mainly the thiol portions, and uncouples the process of oxidative phosphorylation. Many thiols have strong odors resembling the pungent aroma of garlic. A strong symptom of arsenic poisoning is garlic breath from oxidized thiols.

Arsenic poisoning from drinking water is a stealth disease that quietly accumulates in the body over years, causing first modest and then severe symptoms. By the time symptoms appear, arsenic probably has already severely damaged the victim’s health. Arsenic accumulates and then attacks critical body organs. Arsenic poisoning causes health problems more ugly, painful and quickly fatal than leprosy. The EPA classifies arsenic as a carcinogen, and warns that long-term exposure can cause cancer, cardiovascular disease, immunological disorders, diabetes and other medical issues.

(L) Arsenic contamination in well water, (R) Arsenic-laden mine tailings are spread by wind

(L) Arsenic contamination in well water, (R) Arsenic-laden mine tailings are spread by wind

Stealth disease

Arsenic is a silent poison that accumulates in primary body organs and causes severe pain. Arsenic contaminated water tastes no different from clean water, unless other chemicals are present, such as in the case of frack ponds. Arsenic poisoning sufferers tend to keep building their body’s store of arsenic from their drinking water while experiencing terribly painful symptoms.

Arsenic symptoms begin with headaches, confusion, diarrhea, loss of night vision and drowsiness. Sufferers experience skin lesions that often develop into cancers of the liver, lung, bladder and major organs. As the poison accumulates, those afflicted may develop convulsions and changes in fingernail pigmentation called leukonychia striata and black foot disease. Maternal arsenic exposure is associated with fetal loss, stunting, infant morbidity and mortality.

Arsenic poisoning expressions

Arsenic poisoning expressions

As the poisoning becomes acute, symptoms may include cognitive impairment, diarrhea, vomiting, blood in the urine, cramping muscles, hair loss, stomach pain, and more convulsions. Critical organs are adversely affected including the brain, heart, lungs, skin, kidneys and liver. Eventually, major organs fail, leading to a coma or death.



Arsenic detection

People may be unaware of arsenic contaminated water until it is too late. Rural water wells are most often not tested, leaving families and communities vulnerable to unseen and undetected arsenic poisoning. Many states with known elevated arsenic levels such as Michigan offer free testing through the county or state health department.

An inexpensive field test unit, Arsenic Econo-Quick™ measures water arsenic concentrations between 0 and 1000 µg/l in a 12-minute reaction. It sells for less than $20. If arsenic is present in the water, the reaction produces arsine gas, which reacts with a reaction strip containing mercuric bromide present in the bottle. This results in a colored end product ranging from light yellow to brown. The color of the reaction strip is then compared to the reference scale given by the manufacturer, Industrial Test Systems.

Diagnosis and treatment

Arsenic poisoning can be identified by the symptoms that start within 30 minutes to two hours of exposure. Acute arsenic ingestion is typically followed by a severe gastroenteritis, garlic odor and hypersalivation. There is a characteristic sequence of multi-organ failure, with neurological symptoms and cardiac features, succeeded by respiratory distress syndrome and renal/liver dysfunction.

Long-term exposure, such as from tainted drinking water creates stomach pain, degradation of major organs, especially the liver and kidneys and often garlic breath. Confirmation occurs from blood, urine or tests of hair, nail and skin-scale samples. Hair, nails and skin store trace elements from the blood and provide a bioindicator for arsenic exposure. Incorporated elements maintain their position during hair growth and remain sequestered.

A 2004 study used preserved hair samples to suggest that Napoleon died of arsenic poisoning in 1821. Intentional arsenic poisoning has been a favored quiet killer for centuries and includes Socrates (who intentionally drank hemlock) and Alexander the Great.

Arsenic treatment is problematic. Chemical and synthetic methods such as Dimercaprol and dimercaptosuccinic acid, which are chelating agents, sequester arsenic away from blood proteins. Unfortunately, these treatments are expensive and impose unpleasant side effects. Major drawbacks include a tendency to redistribute arsenic to the brain and testes, the need for painful intramuscular injection, and an unpleasant garlic odor. The other problem is that the treatments may not work if certain organs are already riddled with arsenic. Supplemental potassium decreases the risk of experiencing a life-threatening heart rhythm problem from arsenic trioxide.

Since no good medicine currently exists for arsenic poisons, scientists and public policy leaders globally should consider arsenic a major challenge and find ways to save the affected populations. The economic and social costs of arsenic poisoning are horrific – and growing.


Phytoremediation, bioremediation mediated by plants has been proposed as an effective tool in arsenic cleanup from poisoned soil and water. Some plants, most notably, the Chinese brake fern Pteris vittata have been reported to be suitable for arsenic phytoremediation. In this respect, transgenic plants are being developed to improve their capacity to accumulate arsenic.

Rhizofiltration, the use of plants to absorb or adsorb pollutants from water has been used for the ex situ and in situ remediation of arsenic-contaminated water. Similarly, some terrestrial plants show great potential to remove arsenic from polluted soil.

Microcrops such as algae offer substantial competitive advantages for phytoremediation compared with terrestrial plants with roots. Algae grow 20 to 50 times faster than land plants, which allow substantially more biomass. Algae have no roots, so the plants do not die quickly as wastewater salinity rises. Algae’s major advantage is cell size, which creates 100x more surface area for adsorption than land plants. Algae have been used successfully for phytoremediation in wastewater for over 50 years in the US.

Algae nano chelator

A 2006 report shows promise for an algae chelator. Forty-one chronic arsenic poisoning patients in Bangladesh were randomly treated orally by placebo (17 patients) or spirulina extract (250 mg) plus zinc (2 mg) (24 patients) twice daily for 16 weeks. Each patient was supplied with arsenic-safe drinking water by installing a locally made water filter at household level. Effectiveness of spirulina extract plus zinc was evaluated by comparing changes in skin manifestations, (clinical scores), arsenic contents in urine and hair, between the placebo-and spirulina extract and zinc-treated groups.

High arsenic intake results in increased excretion of arsenic in the urine. There was a sharp increase in urinary excretion of arsenic at 4 weeks following spirulina plus zinc administration and the effect was continued for another 2 weeks.

Spirulina extract plus zinc removed 47% of the arsenic from scalp hair. Spirulina extract had no noticeable side effects that required a physician’s attention. The clinical scores for melanosis before and after treatment with placebo was not statistically significant (p > 0.05). In spirulina extract plus zinc-treated group, clinical scores were statistically significant (p < 0.01). Results showed that spirulina plus zinc offers a natural treatment of chronic arsenic poisoning.

Path forward

The potential for algae serving as a safe, inexpensive and effective chelation therapy is much larger than arsenic. The longer heavy metals stay in the human body, the more damage they inflict on vital organs. If my child had exposure risk to lead, cadmium, mercury and arsenic, I would supplement their daily diet with algae.

Spirulina and other algae species appear to offer a simple, safe and inexpensive solution for reducing the heavy metal load in the brains and body tissues. The algae taken orally should act as an effective biosorbent and chelate with the poisonous heavy metal and allow it to pass harmlessly out of the body.

If you have ideas on how algae improves our world, please contact Mark Edwards, Professor Emeritus, Arizona State University, at: