by Dr. Mark Edwards

Editor’s note: Mark Edwards’ Algae Secrets column continues with a series of articles on Algae Solutions to Heavy Metal Poisons and Pesticides, offering fascinating insights into how algae offer solutions to:

  • Reduce the ecological load of natural and man-made poisons in our ecosystems.
  • Minimize residual poisons in and on our foods.
  • Provide higher nutralence — nutrient density and diversity — for human foods and feeds.
  • Anchor or stabilize poisons locally so they do not migrate to air, water and soils.
  • Clean air, water and soils polluted with natural and pesticide poisons.
  • Provide therapeutics to soften and, in some cases terminate, the severe pain and agony caused by natural poisons and pesticides.
  • Create alternative foods that are grown with not pesticides, carry no pesticide residuals and free rural environments from pesticide plumes.  

This Algae Secrets series focuses not only on novel methods to minimize poison exposure, but also to reverse the epidemics of:

  • Autism and Autism Spectrum Disorders among our children and too many adults.
  • Arsenic poisoning of our children, adults and elderly that causes horrific suffering.
  • Pesticide poisoning of our wild animals and pets, as well as people who happen to live within a few miles of pesticide treated fields.
  • Cancers, heart disease, neurological disorders, dementia and Alzheimer’s disease.

Anyone concerned about losing our children’s brainpower will find valuable information in this article set. Those who want to save our children will help make these strategies happen.

The prior Algae Secrets post on Flint’s lead crisis focused on lead poisoning. The CDC estimates that at least four million households with children are being exposed to high levels of lead daily.

Approximately half a million U.S. children under five years of age have been tested with blood lead levels exceeding five micrograms per deciliter (µg/dL), the reference level at which CDC recommends public health actions be initiated. The number of children and adults at risk from the broader array of heavy metals is probably 10x in the U.S. and greater than 100x globally. Scientific and medical research suggest that various algae species offer a safe, inexpensive yet effective chelation solution for heavy metals.

Several common and inexpensive algae species have been granted GRAS (Generally Recognized As Safe) by the FDA. Therefore, the benefits of reducing heavy metals from the body far outweigh the negligible risk from ingesting a natural product.

Heavy metal bioaccumulation

Heavy metal bioaccumulation operates as a stealth predator as it builds up in vital organs. Exposure often occurs with no obvious immediate symptoms and frequently goes unrecognized. If unrecognized, or inappropriately treated, heavy metal exposure can degrade major organs, cause severe pain and suffering, and can lead to death.

Heavy metals, especially arsenic, have been used effectively as instruments of murder. Arsenic poisoning has been implicated in the death of prominent people throughout history, including Napoleon Bonaparte, Simón Bolívar, Guangxu, the Emperor of China and King Faisal I of Iraq. White arsenic, a common rat poison, was used so often to poison rich relatives in late 17th-century France that it was nicknamed “inheritance powder.”

The main threats to human health from heavy metals are associated with exposure to lead, cadmium, mercury and arsenic, all of which appear in the World Health Organization’s list of 10 chemicals of major public concern.

These metals have no known use in the human body and are classified as “toxic metals.” Other metals are essential to human biochemical processes. Zinc is an important cofactor for several enzymatic reactions in the human body, vitamin B-12 has a cobalt atom at its core, and iron is important for hemoglobin regulation. Copper, manganese, selenium, chromium, and molybdenum are all trace elements, which are important in the human diet. Most elements may have pernicious effects if taken in quantity or if the usual body mechanisms of elimination are impaired.


Lead poisoning gained center stage in January 2016 when a state of emergency was declared over the Flint, Michigan’s lead-contaminated water supply nearly a year after government officials switched the city’s water source to the Flint River. Parents are concerned about the severe long-term effects of lead poisoning on youth and lack of action by city, state and federal officials. Two EPA officers resigned over the Flint water crisis.

An advocacy group found that children in 11 New Jersey cities and two counties have higher lead levels than those in Flint. Lead poisoning in New Jersey came not from poisoned water but exposure to paint in windows, doors and other woodwork found in older homes. Advocates estimate that about 225,000 young children in New Jersey have been affected with elevated lead levels since 2000.

The Pennsylvania Department of Health’s 2014 report revealed that 18 major cities, including Pittsburgh, Philadelphia and Scranton, have rates of people with blood level rates higher than five µg/dL, ranging up to 23% of the population. Overall, the Pennsylvania report found that the state has a lead exposure rate of 9.37%. A Wisconsin study found similar exposure in that state primarily from old lead pipes.

The CDC reports that even low levels of lead in blood have been shown to affect IQ, ability to pay attention, and academic achievement. Children under the age of six are especially vulnerable to lead poisoning, which can severely affect mental and physical development and lead to disorders such as attention-deficit/hyperactivity disorder, or ADHD. Lead poisoning drops a child’s IQ three to seven points; degrades brain development, leads to abnormal behavior such as impulse control and has been linked to criminality. Even more damaging, lead poisoning imposes serious multigenerational impacts according to the U.S. Centers for Disease Control and Prevention. The Mayo Clinic provides a long list of terrible lead poisoning symptoms for children and adults.


Naturally occurring cadmium-sulfide based pigments were used as early as 1850 because of their brilliant red, orange and yellow colors. Cadmium appeared prominently in the paintings of Vincent Van Gogh in the 1800s. Cadmium compounds are currently mainly used in re-chargeable nickel-cadmium batteries. Cadmium emissions from the environment have increased dramatically during the 20th century because cadmium-containing products are rarely re-cycled, but often dumped with household waste. Cigarette smoking provides a major source of cadmium exposure. In non-smokers, food is the most important source of cadmium exposure. Recent data indicate that adverse health effects of cadmium exposure may occur at lower exposure levels than previously considered, primarily in the form of kidney damage but also bone defects and fractures.


Mercury in any form is poisonous, with mercury toxicity most commonly affecting the neurologic, gastrointestinal and renal organ systems. Poisoning can result from mercury vapor inhalation, ingestion, injection and absorption through the skin. Mercury has 3 forms: (1) elemental mercury, (2) inorganic salts, and (3) organic compounds. Perhaps the most deadly form of mercury is methylmercury. Only 2-10% of the ingested mercury is absorbed from the gut, and ingested elemental mercury is not absorbed at all. However, 90% of any methylmercury ingested becomes absorbed in the bloodstream from the GI tract.

The EPA provides a list that shows the amount of various types of fish that a woman who is pregnant or planning to become pregnant can safely eat. Long-living fish tend to bio-accumulate mercury from their diet, including king mackerel, marlin, orange roughy, shark, ahi tuna and swordfish.


Classic examples of environmental contamination include the Minimata Bay disaster and the current epidemic of arsenic poisoning in Southeast Asia. In the 1950s, industrial effluent was consistently dumped into Japan’s Minimata Bay. Local fish bio-accumulated arsenic and mercury at exceedingly high concentrations. Some adults developed toxicity signs and symptoms. The greatest impact was on the next generation, where many babies were born with severe neurologic deficits.

Currently, millions of people living in Bangladesh are at risk for organ dysfunction and cancer from chronic arsenic poisoning from the water supply. In an effort to bypass ground water sources rife with bacterial contamination, tube wells were sunk throughout that area, deep into the water table. Bedrock rich in arsenic gives these deeper water stores — and the crops they irrigate — a high concentration of arsenic, and toxicity is epidemic throughout the area. Childhood lead poisoning linked to the ingestion of old paint chips in North American is another good example of environmental contamination.

A 2007 study found that over 137 million people in more than 70 countries are at risk from arsenic poisoning from drinking water.

This table summarizes the typical presentation of the most commonly encountered toxic metals.

Typical Presentation and Symptoms from Heavy Metals

Typical Presentation and Symptoms from Heavy Metals

OSHA regulations guide the surveillance of workers at risk and suggest exposure limits for metals of industrial importance.


Biosorption is the process whereby treatment by a biological material removes chemical molecules. Bioaccumulation of heavy metals in seaweeds has long been a concern for largely Asian societies that consume substantial amounts of seaweed. Consumption of 8.5 g/day of seaweed represents only 0.2-6.7% of the respective provisional tolerable weekly intakes established by the World Health Organization. Therefore, even if people eat considerable seaweed, they have a low probability of health risks from heavy metals via seaweed consumption.

Commercial algae producers know that algae may bioaccumulate metals at 1,000x ambient levels. Therefore, U.S. algae producers do not use coastal or estuary water because these waters are often contaminated by industrial and residential pollution.

Numerous studies have shown that both green and brown algae such as Ulva fasciata and Sargassum sp bioaccumulate heavy metals such as lead, cadmium and arsenic from aqueous solutions.

Animal studies

Several studies have demonstrated the blue-green algae spirulina acts as an effective chelator for lead in animals. Experimental animals with lead poisoning were fed on a standard laboratory diet with or without spirulina 5% for several weeks. The results showed that spirulina prevented the expected lead acetate-induced changes on plasma and liver lipid levels. Spirulina succeeded to improve the biochemical parameters of the liver and kidney towards the normal values of the control group. Spirulina demonstrated protective effects on lead acetate-induced damage.

Chlorella vulgaris extract (CVE) has been shown to have strong chelating effects on the myelosuppression induced by lead in Listeria monocytogenes-infected mice. Treatment with CVE, given simultaneously or following lead exposure, restored to control values the myelosuppression observed in infected/lead-exposed mice and produced a significant increase in serum colony-stimulating activity.

The benefits of the CVE treatment were also evident in the recovery of thymus weight, since the reduction produced by the infection was further affected by lead exposure. Therefore, CVE administration indicated that the immunomodulation effect of CVE plays an important role in the ability of these algae to reduce blood lead levels.

The only human subjects algae treatment study for heavy metals found in the medical literature targeted chronic arsenic poisoning patients in Bangladesh. The fact that no human trials have proven the efficacy of spirulina as a lead chelator does not diminish the probability that human trials will succeed.

The reason there are no human studies comes down to money. Human clinical trials may cost several hundred thousand dollars and medical research sponsors want a return on their investment. Companies cannot patent a naturally occurring organism. In addition, medical school faculty members are judged not only on their publications but also on how much they receive in grant support.

Spirulina and other algae species are excellent candidates for heavy metal removal from human tissues but no company wants to sponsor such research. Algae natural products can be gathered or grown on every continent. Therefore, clinical trials will benefit all people because the findings are not protectable.

Path forward

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 metals in the brains and body tissues of children and adults. The algae taken orally should act as an effective biosorbent, chelate with the poisonous heavy metal, and allow it to pass harmlessly out of the body in the urine.

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