15 Contaminants In Your Tap Water That Will Likely Scare You

22 min read

Is there a nightmare lurking in your pipes? From nuclear waste to farm runoff, there’s a laundry list of toxins found in drinking water across the country. Luckily, there are plenty of safe, easy solutions, but more on that later… For now, let’s keep scaring the pants off you with these 15 terrible toxins that will surely make your skin crawl.

Watch Out for These 15 Terrible Toxins

It’s easy to be grossed out by toxins and contaminants that turn your tap water yellow and stink up your pipes, but what about the ones you can’t see or smell? The fact is, the worst pollutants don’t always show themselves. You could be swishing them around your mouth and not even know it.

Even worse, you could raise your kids from toddlers to teenagers, all the while serving them tainted water. Chemical pesticides can cause hormone imbalances, reproductive problems, and kidney damage. Yikes!

Keep reading to learn more about the sources, side effects, regulations, and treatment methods of the world’s worst tap water contaminants.

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Aluminum is one of the most abundant metals on Earth, and it can leach from the soil into your tap water. One of the most common sources of contamination is aluminum sulfate, or alum, used to treat wastewater. Alum is added to water treatment plants to help solid waste particles clump together. The downside, though, is that trace amounts of alum inevitably make their way into the water you drink. If you’ve ever seen white gelatinous deposits forming in your pipes, it could very well be alum.

1. Aluminum

Aluminum Health Risks

Aluminum-tainted water won’t make your blood curdle or your eyeballs pop out, but it can be hazardous for patients on dialysis.

According to the Center for Disease Control (CDC): “Aluminum toxicity can cause osteomalacia, anemia, and dementia in hemodialysis patients and has historically been associated with exposure to contaminated water or dialysate preparations or ingestion of aluminum-containing phosphate binders.”

It’s clear that aluminum is a little rough around the edges, so regardless of your medical history, it’s best to steer clear of it if you can.

Aluminum Regulations

The Environmental Protection Agency (EPA) sets the maximum limit for aluminum in drinking water at 0.05 mg/L. However, it’s hard to achieve this in most areas due to alum’s widespread use in sewage treatment plants.

The question is, do you look the other way, or do you take matters into your own hands?

Aluminum Treatment Methods

Fortunately, aluminum is pretty easy to remove through methods like…

  • Reverse osmosis
  • Ion exchange resins
  • Distillation

Ion exchange resins soften the water and remove “hard” minerals like aluminum. At the same time, reverse osmosis can remove up to 98% of aluminum, and distillation can remove up to 99%. If you use distillation, just make sure to remineralize your water with essential electrolytes like calcium and magnesium --- they’re good for your health.

2. Arsenic

Arrrrrsenic! Nope, it’s not a drink for pirates...it’s actually one of the gnarliest pollutants known to man, and it could be hiding in your water.

Arsenic comes from natural deposits in the earth’s crust, and mankind’s industrial activities help it reach your tap. Erosion from manmade sources like petroleum, coal plants, and semiconductor manufacturing, as well as animal feed additives and pesticides, all bump-up arsenic levels in the water. This is bad news bears for you and your family, and here’s why:

Arsenic Health Risks

When it comes to your health, arsenic doesn’t play nice. Common side effects of arsenic exposure include:

  • Skin cancer
  • Bladder cancer
  • Lung cancer
  • Kidney cancer
  • Live cancer
  • Prostate cancer

In case you haven’t noticed, arsenic has a thing for cancer. Plus, arsenic disrupts hormone levels, harms the cardiovascular and nervous systems, and can lead to serious skin problems. In other words, it does its best to mess you up. As little as 100 mg of arsenic can lead to severe arsenic poisoning.

The gut soaks arsenic up like a sponge and quickly spreads throughout the body. More often than not, symptoms appear slowly, and it can sometimes take years to notice that something’s wrong. All the while, arsenic is gradually eating away your cells from the inside-out.

Arsenic Regulations

The EPA finally battened down the hatches on arsenic in 2001, when it reduced the maximum limit in drinking water from 50 ug/L to 10 ug/L. In other words, water systems are required by law to contain less than 10 ug/L of arsenic, but if you want to guarantee zero arsenic, you’ll still want to invest in an at-home treatment system like Cloud Filters.

When it comes to arsenic contamination, New England, Texas and the Midwest are the worst off --- many local water supplies in these areas contain arsenic levels greater than 10 ug/L.

Arsenic Treatment Methods

Some of the most effective treatment methods for removing arsenic include:

  • Reverse osmosis
  • Anion exchange resins
  • Distillation
  • Manganese greensand
  • Titanium hydroxide/oxyhydroxide
  • Iron-based media
  • Activated alumina

If you suspect arsenic contaminants in your water, you should hire a professional to test your tap water and determine the best removal technique.

3. Bacteria, Viruses, Parasites & Other Harmful Microbes

Microorganisms like bacteria, viruses, parasites, fungi, and cysts are everywhere, including your water. They can enter the water supply from sewer overflows, wastewater releases, and runoff from concentrated animal farming operations. However, most microbial infections are the result of undercooked or improperly stored food.

Some of these micro-buggers are harmless, some are beneficial, and others can make you downright ill, including:

  1. E.coli
  2. Giardia
  3. Shigella
  4. Norovirus
  5. Legionella
  6. Salmonella
  7. Hepatitis A
  8. Campylobacter
  9. Cryptosporidium

E. coli, for example, is a bacteria that lives in the intestines of healthy animals and people. However, in large amounts it can wreak havoc on your health.

Norovirus, on the other hand, is a virus that hijacks your cells, and no amount of it is good for you.

Then there are parasites --- microscopic creepy-crawlies that like to make a home in your gut.

Microorganism Health Risks

Now, let’s take a closer look at three of the most common types of waterborne illnesses: E. coli, giardia, and cryptosporidium. All three of these can cause gut problems and flu-like symptoms.

  1. E. coli: According to the Centers for Disease Control and Prevention (CDC), roughly 5% to 10% of infected people develop a red blood cell condition that can result in kidney failure. Other symptoms include diarrhea, abdominal pain and fever.
  2. Giardia: These nasty parasites thrive on contaminated food and water. Symptoms of giardiasis usually show up 1-2 weeks after exposure and can include fatigue, nausea, diarrhea, vomiting, abdominal cramps, bloating, gas, loss of appetite and headaches.
  3. Cryptosporidium: Called “Crypto” for short, cryptosporidiosis is another parasite infection that lives in the intestines and spreads through feces. According to the CDC, Crypto affects about 750,000 people a year. Common symptoms include diarrhea, nausea and abdominal cramps.

Young children, the elderly, and people with weakened immune systems are the most at risk for infections.

Microorganism Regulations

According to the EPA and the Revised Total Coliform Rule (RTCR),  the health-based standards for bacteria, viruses and parasites is zero. The regulation took effect in 1990, after several disease outbreaks occurred due to low levels of harmful microbes in the water.

Microorganism Treatment Methods

Physical and chemical disinfection methods for drinking water include:

  • Ultraviolet (UV) light
  • Ultrafiltration
  • Distillation
  • Chlorine
  • Bromine
  • Iodine
  • Ozone

These processes can kill up to 99.9% of harmful microorganisms.

Chlorination is the most common and cost-effective way to quickly kill a wide variety of pathogenic microorganisms. Plus, it also makes water clearer and softer by breaking down iron, manganese, and hydrogen sulfide. However, chlorine leaves a nasty taste and can damage the gut lining. Fortunately, activated carbon filters can remove chlorine like it ain’t no thang.

UV light treatment is a popular method for commercial use, and it blasts harmful microbes to smithereens without the use of harsh chemicals. UV treatment works by shining the right strength and intensity of light through the water. On its own, UV can’t remove heavy metals or other contaminants from your tap water, but it can make a great addition to any reverse osmosis system.

Ozone treatment works by exposing oxygen to a high-voltage current. The electrically-charged oxygen destroys microorganisms and removes manganese, sulfur, and iron. Ozone is just as effective as chlorine, but it’s also more costly and energy-consuming.

4. Barium

Barium is a heavy, highly-reactive metal. It can leach into the water supply from mineral deposits, drilling waste disposals, copper smelting, and motor vehicle parts manufacturing.

If you’ve ever had X-rays taken of your digestive system, barium is the white liquid that the doctor made you swallow. But wait, why would your doctor give you something that’s so toxic?

Barium Health Risks

As it turns out, barium is only toxic in water-soluble forms. Barium compounds that do not dissolve in water, like the type used for X-rays, are not harmful.

Water-soluble barium compounds, on the other hand, are dangerous tap water contaminants with nasty side effects, like:

  • Difficulty breathing
  • High blood pressure
  • Irregular heart beat
  • Upset stomach
  • Muscle weakness
  • Brain swelling
  • Liver, kidney, heart and spleen damage

For example, recent animal studies concluded that “Although the barium-induced increase in the blood pressure of rats was modest, comparable mild hypertension in humans would have major health implications.”

Barium Regulations

Based on these animal studies, and under the authority of the Safe Water Drinking Act, the EPA has set the maximum limit for barium in drinking water to 2.0 mg/L. However, the World Health Organization (WHO) disagrees --- their guidelines recommend a max level of only 0.7 mg/L, or less than half of the EPA’s guidelines.

So the question is, who do you trust? The EPA, the WHO, or you?

Barium Treatment Methods

The best treatment methods for removing barium from drinking water are:

  • Reverse osmosis
  • Ion exchange
  • Distillation

Ion exchange resins remove barium and soften the water by replacing calcium and magnesium with sodium.

Want to learn more about remineralization and the other steps that an in-home water filter takes to provide your family with clean, safe, and healthy drinking water? Take a look at our Ultimate Guide to Water Filtration Systems.

Once again, keep in mind that if your filtration system removes calcium and magnesium, it should also include a final remineralization step to add a healthy dose of these key nutrients back into the water.

5. Cadmium

In nature, cadmium is released during volcanic activity along with lead, zinc and copper. Under normal circumstances, cadmium isn’t a threat to the water supply, but mining and industrial waste can leach unsafe levels into surface waters.

Common sources of cadmium in the water supply include:

  • Mining operations
  • Erosion of natural deposits
  • Discharge from metal refineries
  • Corrosion of galvanized pipes
  • Contamination from certain fertilizers
  • Runoff from battery waste and paint manufacturing

Cadmium Health Risks

Cadmium consumption can lead to several short-term health issues, including:

  • Nausea
  • Vomiting
  • Diarrhea
  • Muscle cramps
  • Convulsions
  • Liver, kidney, blood and bone damage

However, regular cadmium exposure can potentially cause liver, kidney, blood and bone damage. With that said cadmium levels have to be pretty high above the maximum allowed level in order to cause side effects.

So, exactly where does the government draw the line?

Cadmium Regulations

The EPA sets the acceptable limits for cadmium concentration in drinking water at 0.005 mg/L. No negative health effects have been reported at levels of 0.01 mg/kg/day or lower, which is well above the legal limit. Drinking water levels are generally considered safe for short-term consumption at 0.04 mg/L, and for long-term exposure at 0.005 mg/L.

Although it might seem like the government is playing it safe with a limit of 0.005 mg/L, we still have no idea about the possible cancerous effects of lifetime exposure. Given how severe the short-term side effects of cadmium can be, it’s best to avoid this toxic mineral altogether.

Cadmium Treatment Methods

The best ways to remove cadmium from drinking water are:

  • Reverse osmosis
  • Ion exchange
  • Distillation
  • Coagulation/filtration
  • Lime softening

Reverse osmosis systems can reduce high concentrations of cadmium ions by 92-98%. However, in order to remove cadmium entirely, it takes an army of different treatments. Fortunately, Cloud Water Systems incorporate all of the most effective methods.

6. Chlorine & Chloramine

The government adds chlorine and chloramine to the water supply to kill harmful microorganisms. Like all potentially harmful chemicals, the EPA has set limits. However, in order to get around these limits, many municipal water supplies have switched to a similar chemical called chloramine.

Chlorine & Chloramine Health Risks

Current studies indicate that drinking small amounts of chloramine does not cause harmful side effects. However, long-term effects over the course of decades are still unknown.

Chlorine, on the other hand, is proven to be bad for your health. In water, chlorine combines with organic materials to form byproducts called trihalomethanes (THMs). Researchers think that these harmful byproducts are responsible for most of chlorine's side effects. Long-term exposure to THMs have been linked to an increased risk of cancer and infant complications during birth.

In fact, THMs may be responsible for as much as 2-17% of bladder cancer cases in the United States. And if THMs sneak into the dialysis water of kidney failure patients, it can lead to serious blood complications.

Chlorine & Chloramine Regulations

The EPA has set the maximum limit for chlorine byproducts to 0.08 mg/L.

As for chloramine, the tolerable level for drinking water is between 1.0 mg/L and 4.0 mg/L. Roughly 1 in 5 Americans use tap water that contains chloramine contaminants.

Chlorine & Chloramine Treatment Methods

Chloramines are difficult to remove with reverse osmosis, distillation and ion exchange resins.

Luckily, activated carbon works wonders. And carbon filtration doesn’t just protect against health risks, it also improves the taste and smell of your water.

7. Copper

Copper is a metallic element that’s healthy in small doses but harmful in large ones. In industry, copper is widely used to make electrical wires, and it can seep into your water through industrial discharges. At the same time, copper salts are often used to control algae in reservoirs. The real problem, though, is that copper is a common plumbing material, and corroded pipes can leach into the water.

Copper Health Risks

Adults need about 2 mg of copper a day in order to strengthen connective tissues and repair damage to the heart and arteries. Under no circumstances, however, should you ingest more than 12 mg/day for men and 10 mg/day for women. Doses this high can cause copper poisoning.

Symptoms of copper poisoning include:

  • Nausea
  • Vomiting
  • Diarrhea
  • Upset stomach
  • Abdominal muscle pain

In severe cases, copper poisoning can cause anemia, liver poisoning, and kidney failure. Concentrations of just 2.8 mg/L to 7.8 mg/L can trigger vomiting and diarrhea.

In general, young children are more sensitive to copper than adults. If your baby gets diarrhea or vomits shortly after drinking their formula, it could be a sign of high copper levels in the water.

There is also a rare genetic disorder called Wilson’s Disease that affects roughly 30,000 people worldwide. Wilson's Disease causes copper to gather in the liver, brain, and other organs, eventually leading to hepatitis and severe neurological issues.

The Centers for Disease Control (CDC) documented several copper outbreaks in the 1990s, including one in Florida where 37 people became ill after drinking smoothies made with contaminated tap water. At the time of this incident, copper levels in the pipes were measured at 3.6 mg/L.

Copper Regulations

The maximum limit set by the EPA for copper in drinking water is 1.3 mg/L. Municipal utilities must ensure that at least 90% of the homes they service do not exceed this limit, otherwise, they have to notify the public.

Copper Treatment Methods

The best ways to remove copper contaminants from your tap water are:

  • Reverse osmosis
  • Ion exchange
  • Distillation

Ion exchange resins soften the water and remove copper along with other heavy metals.

When copper contamination comes from corroded pipes, there's also a possibility of lead poisoning. In that case, you’ll also need to treat your water with reverse osmosis to remove the lead.

Cloud Water Filters use both ion exchange resins and reverse osmosis to remove all heavy metals, including lead and copper.

8. Fluoride

It’s in your toothpaste and it’s in your drinking water...

For the past 40+ years, fluoride exposure has been on the rise. Why?

Because the government adds it to the municipal water supply as either hydrofluosilicic acid, sodium silicofluoride, or sodium fluoride. Oftentimes, too much fluoride enters the water due to malfunctioning equipment or poor monitoring.

Although low levels of fluoride have been shown to prevent cavities, moderate-to-high levels can lead to some undesirable side effects…

Fluoride Health Risks

The negative side effects of fluoride start to kick in at concentrations of roughly 2 mg/L. At this point, fluoride can discolor and disfigure children's teeth. In some cases, the teeth turn a chalky white color.

At 4 mg/L, long-term fluoride consumption can cause skeletal fluorosis, a disorder where the bones become extremely dense, hard, and fragile. Also called “marble bones,” this disease can be crippling in severe cases.

Worst of all, studies show that fluoride can cause memory deficits and other cognitive delays in young children.

Fluoride Regulations

According to the EPA, the safe daily limit of fluoride in drinking water is 0.08 mg/day per kilogram of body weight. Under the Safe Drinking Water Act, federal regulations set the maximum limit of fluoride in drinking water is 4.0 mg/L. However, the US Department of Health and Human Services (HHS), which oversees that national fluoridation program, recommends a concentration of 0.7 mg/L to prevent tooth decay.

The powers that be are a tad all over the place when it comes to fluoride regulations, and it may be time to treat your water yourself.

Fluoride Treatment Methods

The most common treatment methods for fluoride removal are:

  • Reverse osmosis
  • Distillation
  • Activated alumina absorption
  • Anion exchange
  • Bone charcoal

Alumina absorption is used for large municipal treatment systems, but when it comes to at-home water treatment, reverse osmosis (RO) is the way to go. Thankfully, with most high-quality RO systems, you can remove up to 95% of fluoride from your water.


Unlike a simple carbon water filter, a reverse osmosis membrane can separate and dissolve fluoride and other dangerous inorganic contaminants like lead and arsenic from your tap water. Check out this article to read more about how a reverse osmosis water filter works to provide the best drinking water for your family.

Bone charcoal and ion exchange are other effective ways to remove residual amounts of fluoride.

9. Lead

First word: Lead. Second word: Poisoning.

Lead is a notoriously dangerous substance, and it could be lingering in your water as we speak. Most of the lead toxins found in drinking water come from corroded pipes, service lines, and brass fixtures.

This is exactly what happened in Flint, Michigan when corroded lead pipes exposed 140,000 individuals and caused an estimated 6,000 to 12,000 cases of lead poisoning. The incident also triggered an outbreak of Legionnaires disease that killed 12 people.

Lead Health Risks

Side effects of lead exposure can include:

  • Irritability
  • Weight loss
  • Vomiting
  • Constipation
  • Stomach pain
  • Coma
  • Convulsions
  • Brain damage
  • Impaired hearing
  • Reduce intelligence
  • Decreased bone growth in children
  • Damage to the kidneys, bone marrow and red blood cells

Children are the most at risk, especially when it comes to effects on the nervous system. Side effects can occur at blood levels as low as 10 micrograms per deciliter (g/dL). Shockingly, children can lose as much as 2 IQ points at this level of lead exposure. Unlike adults, who only absorb about 11% of lead when ingested, children can absorb up to 75%.

More often than not, lead exposure shows no early warning signs and can gradually undermine your health behind the scenes.

Lead Regulations

The EPA has set the maximum limit for lead in drinking water at zero. At the same time, the Safe Drinking Water Act requires the use of lead-free plumbing in all new construction. However, there is a catch...

Some new plumbing parts that are considered “lead-free” still contain up to 0.2% lead, and up until 2013, pipes and fittings with up to 8% lead were also considered “lead-free.” Pipes installed before 1986, however, are the worst of the worst --- they typically contain a whopping 50% lead!

Lead Treatment Methods

Some of the most effective treatment methods for removing lead are:

  • Reverse osmosis
  • Cation exchange
  • Precoat adsorption filters
  • Distillation

In order to remove lead entirely, you need to hit it with everything you’ve got. Lead that’s dissolved in water can be removed through reverse osmosis, ion exchange, adsorption, and distillation, and lead that’s in sediment can be removed with fine filtration and adsorption. Reverse osmosis is particularly effective because it removes soluble lead by up to 95% and also acts as a barrier against lead that’s trapped in sediment.

10. Mercury

Mercury is an OG on the contaminant scene. In nature, it combines with carbon to make several different mercury compounds, including methyl mercury. Methyl mercury is found in soil and fish, mercuric salt compounds are found in water, and metallic mercury is a vapor that travels through the air.

Mercury is used to make light bulbs, batteries, thermometers and dental fillings, as well as some antiseptic creams and ointments.

The earth’s crust naturally releases up to 150,000 tons of mercury a year, but an extra 20 tons are released through industrial runoff and fossil fuels. Mercury can quickly travel through the atmosphere, across oceans, and around the globe, eventually ending up in lakes, rivers, and drinking water supplies.

Mercury Health Risks

The most common reasons for mercury exposure are dental fillings and other medical procedures. Direct water contamination is also a significant health issue that should not be ignored. Inhaling mercury vapors is the most dangerous form of exposure because it travels straight to the brain.

However, the biggest concern is mercury poisoning in fish. As mercury passes through the food chain, it becomes more concentrated.

By the time it reaches your body, mercury can cause severe side effects, including:

  • Irritability
  • Shyness
  • Tremors
  • Kidney damage
  • Memory problems
  • Permanent brain damage
  • Vision and hearing impairment
  • Damage to babies in the womb

Even short-term exposure to low levels of mercury toxins in drinking water can cause kidney damage, but not enough evidence exists to link mercury to cancer.

Mercury Regulations

The EPA has set the maximum limit for mercury in drinking water at 0.002 mg/L. When mercury levels rise above this line, it can increase the risk of kidney damage.

Mercury Treatment Methods

Mercury levels can be reduced by…

  • Reverse osmosis
  • Ion exchange
  • Distillation
  • Activated carbon

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The combination of reverse osmosis and activated carbon can remove up to 97% of the mercury in water, and specialty types of ion exchange resins can take care of the rest. Cloud Water Filters incorporate all three of these treatment methods for maximum mercury removal.

11. Nitrates

Nitrates and nitrites are the most common inorganic man-made water pollutants. The main sources of nitrates and nitrites in the water supply are human sewage and livestock manure. Potassium nitrate and ammonium nitrate are widely used in fertilizers, another major source of contamination.

Care to take a guess at what part of the country has it the worst? And the answer is…


This farm-heavy state has some of the highest rates of groundwater contamination by a long shot. But honestly, any agricultural area can be at risk.

What happens to your body when the s**t hits the fan?

Nitrates Health Risks

Babies are the most at risk when it comes to nitrate contamination. Nitrate toxins in drinking water can cause methemoglobinemia, a blood disorder in infants also known as “blue baby syndrome.” The babies turn blue as a result of nitrates interfering with the oxygen-carrying capacity of the blood.

Fortunately, this condition is easily reversed. Cases are most common in children under 6 months old. For the most part, adults are in the clear, although extremely high levels have been linked to central nervous disorders.

Nitrates Regulations

The EPA sets the maximum limit of nitrates and nitrites in drinking water to 10.0 mg/L. Below this level, you shouldn’t have to worry about methemoglobinemia in infants or nervous system disorders in adults.

Nitrates Treatment Methods

The best techniques for removing nitrates from drinking water are:

  • Reverse osmosis
  • Ion exchange
  • Distillation
  • Electrodialysis

Out of these methods, reverse osmosis, ion exchange, and distillation are the most effective for in-home use. Pump-driven reverse osmosis systems can reduce nitrates by up to 95%, and nitrate-selective ion exchange cartridges work as effective nitrate polishers. The best part is, Cloud Water Systems has you covered on all fronts.

12. Uranium

Uranium is a radioactive substance found naturally in rocks, soil, air, and water. It can enter the water supply by leaching from the soil and rocks, but the main source of contamination is nuclear waste. What does this mean for your health?

Uranium Health Risks

Long-term uranium exposure can cause kidney damage and increase the risk of cancer. According to the Agency for Toxic Substances and Disease Registry, human and animal studies show that uranium can lead to respiratory diseases like fibrosis and emphysema. However, the majority of these patients are uranium miners and mill workers.

Uranium Regulations

The EPA has set the maximum limit of uranium in drinking water at 0.030 mg/L. Above this line, you may start to see side effects like kidney toxicity and cancer.

Uranium Treatment Methods

Potential treatment methods for removing uranium from drinking water include:

  • Reverse Osmosis
  • Anion exchange resins
  • Distillation

These treatment methods are able to reduce uranium levels to below the EPA’s legal limit of 0.030 mg/L.

13. Radium

Radium is a byproduct of the radioactive decay of uranium and thorium. This occurs naturally in rocks and soil, but most of the radium that ends up in drinking water comes from nuclear power plants. Deep water wells tend to have the highest concentrations of radium compared to surface water.

Radium Health Risks

Radium emits energy as gamma rays and alpha particles, and exposure to these forms of energy can cause…

  • Cancer
  • Kidney damage
  • Birth defects

As a matter of fact, radium is so cancerous that it’s the second-leading cause of lung cancer to cigarettes.

Radium Regulations

Under the Safe Drinking Water Act, the maximum contaminant limit goal is zero.

Radium Treatment Methods

The best treatment methods for removing radium contaminants from tap water are:

  • Reverse osmosis
  • Distillation
  • Cation exchange softening
  • Lime softening

Ion exchange methods can remove radium along with other minerals like calcium and magnesium. Reverse osmosis and distillation are also effective methods of removal. Luckily, several reverse osmosis devices are certified by third-party testing organizations to remove radium, and Cloud is one of them.

14. Selenium

In the right doses, selenium is a powerful antioxidant that can help prevent cancer. However, in the wrong doses, it can cause several negative side effects.

Selenium compounds are widely used in photocopiers and other electronic devices. In Utah, between the years of 1987 and 1993, large amounts of selenium were released into the water supply from copper smelting operations.

Selenium Health Risks

In food sources like Brazil nuts, selenium helps protect the cells from oxidation and inflammation. However, human beings are only designed to process small amounts of selenium. When large amounts of selenium leach into the drinking water, it can spell bad news for your health.

Common side effects of selenium toxicity are:

  • Fatigue
  • Irritability
  • Nervous system damage
  • Damage to the hair and fingernails

Lifetime exposure to high selenium levels can also lead to kidney, liver and circulatory problems.

Selenium Regulations

The EPA sets the maximum limit of selenium in drinking water at 0.05 mg/L. Your water supplier must notify you if selenium levels exceed this limit.

The World Health Organization, however, recommends a slightly lower limit of 0.04 mg/L. Signs of selenium toxicity can begin at doses of 0.7 mg or more a day.

Selenium Treatment Methods

The best treatment methods for removing selenium from drinking water are:

  • Reverse osmosis
  • Activated alumina adsorption
  • Anion exchange
  • Distillation

Anion exchange and alumina adsorption can remove up to 95% of selenium, distillation can remove up to 98%, and reverse osmosis up to 90%. Several residential treatment systems are approved by accredited third-party organizations for selenium reduction, including Cloud Filters.

15. Silver

Silver might be good for your bank account, but it’s bad for your health. Studies show that naturally-occurring sources of silver don’t cause any health issues. However, the silver used in some carbon-containing filters to kill bacteria can have undesirable health effects.

Silver Health Risks

When ingested or absorbed through the skin, silver can turn your organs, skin, and hair a metallic grey color. So, if you don’t want to start looking like the Tin Man from the Wizard of OZ, then it’s best not to consume silver. Fortunately, though, it’s just a cosmetic issue and doesn’t impair organ function.

Silver Regulations

Because silver doesn’t pose any serious health risks other than discoloration, the EPA hasn’t set any enforceable limits for drinking water. However, they do recommend that levels be kept below 0.10 mg/L. Above this level, skin, hair, and organ discoloration may occur.

Silver Treatment Methods

The best treatment methods for removing silver from drinking water are:

  • Reverse osmosis
  • Distillation
  • Cation exchange

Reverse osmosis can reduce silver concentration by up to 90%, and distillation by up to 98%.

Is Your Family’s Water At Risk?

Roughly 20% of the lakes and reservoirs in the U.S. contain high levels of pollutants that exceed the EPA’s guidelines. Two of the worst states are Texas and California. Altogether, about 170 million Americans drink contaminated water every day.

Fortunately, at-home water filtration systems can eliminate almost all of the scariest contaminants from your tap water.

In order to find out if your drinking water contains high levels of certain toxins and pollutants, visit the Natural Resources Defence Council (NRDC) website. You can also call the Environmental Protection Agency (EPA) hotline for more information.


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