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7 Heavy Metals Everyone Should Test For

7 Heavy Metals Everyone Should Test For


Over the last decade, lead contamination has sprung to the forefront of national consciousness following the onset of the Flint, Michigan drinking water crisis. While lead is certainly one of the most talked about threats (and for good reason), it isn’t the only player in the dangerous game of toxic drinking water contamination. 

Several other major metals can (and do) find their way into your tap water. Many of these naturally occurring contaminants are covert threats that cannot be smelled, tasted, or seen in drinking water. Further, they can bioaccumulate, leading to detrimental health impacts, especially for the brain and nervous system.

Even if you are confident that your water is not affected by heavy metal contamination, we have created a short—but crucial—list the seven heavy metals that should be on your radar when it comes to drinking water risks, why you should be concerned, and what you can do about it.

Table of Contents:

Manganese in tap water

What Is Manganese and How Does it Get into Drinking Water?

Manganese is a naturally occurring metal used in steel and corrosion-resistant aluminum alloys. It is also an additive in unleaded gasoline, pigment, plumbing materials, battery cells, matches, fireworks, fertilizer, a reagent in organic chemistry, an oxidizing agent, and a component of tobacco smoke.

How Much Manganese Is Safe in Drinking Water?

The US EPA recommends maintaining a manganese concentration at or below 50 parts per billion (PPB) in drinking water.

What Are the Health Effects of Manganese in Drinking Water?

While manganese is an essential nutrient required by the human body in small amounts, exposure to high concentrations of manganese over many years has been associated with toxicity to the nervous system.

How Do I Know if There Is Manganese in My Drinking Water? 

You may notice a metallic taste, brownish-red color (that can stain clothing or appliances), or a black slime if your water contains manganese at concentrations over 50 PPB. 

What’s the Black Gunk on My Fixtures!?—SimpleLab Tap Score

How to Remove Manganese from Drinking Water 

Successfully removing manganese from water depends on its state of oxidation, the pH of the water, the presence and concentration of other minerals, as well as the concentration of total dissolved solids (TDS). Testing your water is an important first step to determining these key factors. Depending on the results, common solutions may include:

Lead in Drinking Water

What Is Lead and How Does it Get into Drinking Water?

Lead is a bluish-silver, naturally occurring metal that is fairly soft, highly malleable, and very resistant to corrosion. It is toxic to humans, animals, and most other lifeforms. It can enter your tap water three ways:

  • When household plumbing systems corrode
  • When natural deposits erode into your water source
  • When industrial activity leaks lead into your water source

How Much Lead Is Safe in Drinking Water?

No amount of lead is considered safe according to health research. 

While the EPA enforces a 15 PPB limit on lead in drinking water, the public health goal (i.e. Maximum contaminant level goal (MCLG)) is zero.

What Is The Difference Between MCLG and MCL?—SimpleLab Tap Score

Health Effects of Lead in Drinking Water

Even low levels of lead exposure can be dangerous. It accumulates in your body and has several toxic effects on your brain, liver, kidney, and bones. Children are especially vulnerable to the damaging effects of lead poisoning.

Lead exposure can lower a child's IQ, negatively impact behavior, and result in lifelong disabilities. Despite your best efforts to protect your children at home, it has been found that school water may be a significant culprit when it comes to increasing exposure risks. 

How Do I Know if There Is Lead in My Drinking Water? 

You cannot see, taste, or smell lead in your drinking water, but the age of your home can be a clue to your risk level.

If you live in a house built prior to 1986, laboratory testing is a wise investment. It is also important to note that lead is legal in many fixtures and pipes. While permitted lead concentrations are lower than they were pre-1986, differences in water quality could lead to leaching.

Lead leaching occurs when corrosive water enters an old pipeline and easily reacts with the metal pipes. How do you know if your water is corrosive? Again, the only way to know is to test your water. 

The corrosive-potential of your water is determined by its Langelier Saturation Index (LSI). This calculation examines a variety of water chemistry parameters–including pH, conductivity, total dissolved solids, alkalinity, and total hardness–and evaluates whether your water is more like to form scale or corrode your home's plumbing. 

The Ultimate Guide to Lead—SimpleLab Tap Score

Water testing is easyHow to Remove Lead From Drinking Water 

Because lead contamination can often enter water directly from the plumbing and fixtures within your own home, point-of-use (POU) filters are often suggested to filter out lead–such as an under-sink reverse osmosis system. 

Cold water often has a lower concentration of lead than hot water, as hot water may increase the ability of your water to leach metals from your pipes and fixtures. 

It’s also important to note, that like all metals on this list, boiling water will not remove lead. In fact, it will have the opposite effect and will concentrate the lead contamination.

Chromium in drinking water

What Is Chromium and How Does it Get into Drinking Water?

Chromium occurs in both natural deposits, as well as in manufacturing processes such as electroplating and pigment factories. It can enter groundwater through erosion, mining waste, and industrial waste. The most common forms of chromium that occur in natural waters in the environment are: trivalent chromium (CrIII) and hexavalent chromium (CrVI)—the former of which is an essential nutrient, and the latter a potent human carcinogen.

How Much Chromium Is Safe in Drinking Water?

While we are most concerned with hexavalent chromium due to its carcinogenic potential, there is no federal or state Maximum Contaminant Level (MCL) specific to the hexavalent chromium. Instead, the national drinking water standard is set for “total chromium.” 

Both hexavalent and trivalent chromium are covered under the same drinking water standard because chromium may convert between CrIII and CrVI states in water and the human body depending on the environmental conditions. 

The EPA currently limits total chromium at 100 PPB.

However, at the time when the total chromium Maximum Contaminant Level was established (1991), hexavalent chromium associated with consumption of drinking water was not considered to pose a cancer risk.

A 2008 study by National Institutes of Health, however has led to new goals and recommendations. While the federal MCL remains at 100 PPB for total chromium, scientists at the California Office of Environmental Health Hazard Assessment recommended a public health goal of 0.02 PPB of hexavalent chromium in drinking water.

Health Effects of Chromium in Drinking Water

While there are many industrial uses for hexavalent chromium, human inhalation or ingestion of the chemical is known to cause cancer. It affects the human liver and kidney and is known to cause circulatory disorders and nerve damage.

How Do I Know If There Is Chromium in My Drinking Water? 

Like many metals in drinking water, chromium cannot be seen, tasted or smelled. Knowing if it’s in your drinking water is near impossible if you haven’t tested it. But, if Erin Brockovich is in your local newspaper, it’s definitely time to raise your concern level.

How to Remove Chromium from Drinking Water 

Both total chromium and hexavalent chromium can be reduced by reverse osmosis technology.

Copper contamination in drinking water

What Is Copper and How Does It Get into Drinking Water?

Copper, while seldom occurring naturally in the water supply, is one of the most commonly detected heavy metals in tap water

Corrosion of pipes, faucets and other plumbing fixtures is the most common source of copper in American homes. Changes in water chemistry can dissolve these metals from old pipes and deposit them in your drinking water. Running your water for a minute before drinking can reduce copper buildup at your tap.

How Much Copper Is Safe in Drinking Water?

Small amounts of copper are necessary to our health and the EPA has set a (non-enforceable) health goal of 1.3 parts per million (PPM).

Health Effects of Copper in Drinking Water

Copper is an essential element for your health. However, too much of it—especially in young children—can cause vomiting, diarrhea and stomach cramps. Copper has also been associated with liver and kidney disease.

How Do I Know if There Is Copper in My Drinking Water? 

Above 1 PPM, copper can cause a distasteful, bitter/metallic flavor in your water and leave blue-green stains on fixtures.

How to Remove Copper from Drinking Water

Similarly to the hyperlocal causes of lead contamination, copper can often enter your water directly from the plumbing and fixtures in your home.

Point-of-use filters are often suggested to address copper contamination. 

Nickel in tap water

What Is Nickel and How Does it Get into Drinking Water?

Nickel is a naturally occurring element and is most often exposed to drinking water during mining and smelting activities.

How Much Nickel Is Safe in Drinking Water?

Currently, there are no EPA enforced limits on nickel levels in drinking water. 

Nickel was regulated from 1992 until 1995 with a level set at 100 PPB. However, the EPA removed the limits when the Nickel Development Institute challenged the methodology used to establish the Maximum Contaminant Level in a petition to the U.S. Court of Appeals.

Health Effects of Nickel in Drinking Water

The most frequent concern regarding nickel in water is skin irritation. About 10-20% of the U.S. population is sensitive to nickel and may experience a rash or other dermal irritation after having contact in water (i.e. shower or bath) that contains nickel. 

Nickel can be a potent human carcinogen at high doses. In lower doses it can lead to decreased lung function and allergic reaction. 

How Do I Know if There Is Nickel in My Drinking Water? 

Nickel is another contaminant that doesn’t always make itself easily known. If you think you are suffering from a nickel allergy and notice skin irritation after a shower or bath, the best thing to do is test! 

Each of the tests below include analysis for nickel (and the rest of the metals on this list too!):

How to Remove Nickel from Drinking Water 

Nickel contamination is often resultant of nickel-plated faucets and fixtures. Replacing any fixtures that are leaching nickel into your water supply is typically the most surefire way to reduce nickel exposure and limit skin irritation. 

Aluminum in drinking water

What Is Aluminum and How Does it Get into Drinking Water?

Aluminum can come into contact with drinking water sources from natural formations underground or after use as a water treatment coagulant and additive. It may also be released by metal refineries and mining operations.

How Much Aluminum Is Safe in Drinking Water?

The federal Secondary Maximum Contaminant Level (SMCL) for aluminum is set between 50 to 200 PPBwhich means at or above these levels certain aesthetic effects (such coloration of water) can occur.

Health Effects of Aluminum in Drinking Water

Aluminum is a known nervous system toxicant with possible links to dementia and Alzheimer’s Disease.

Aluminum in Drinking Water: Everything You Need to Know—SimpleLab Tap Score

How Do I Know if There Is Aluminum in My Drinking Water? 

While elevated levels of aluminum may result in bluish-tinged water, concentrations of aluminum may be high without presenting any aesthetic effects.

How to Remove Aluminum from Drinking Water? 

Reverse osmosis systems have demonstrated up to 98% removal of aluminum from drinking water.

Should You Filter Drinking Water For Aluminum?—SimpleLab Tap Score

Arsenic in tap water

What Is Arsenic and How Does it Get into Drinking Water?

Arsenic is a common element in the earth's crust and is quite toxic to humans.

Natural erosion of arsenic from soil and rocks is the most common pathway for arsenic to get into your tap water. It is also present in agricultural runoff from orchards and waste streams from metals and electronics industry activities.

Arsenic: The Ultimate Guide—SimpleLab Tap Score

How Much Arsenic Is Safe in Drinking Water?

The EPA recommends an MCL (Maximum Contaminant Level) for arsenic of < 10 PPB. However, the MCL recommendation remains arguably insufficient.

A recent study demonstrated that arsenic levels well below the MCL have adverse health impacts, as children drinking well water with levels as low as 5 PPB of arsenic had significant reductions in IQ and perceptual reasoning relative to children exposed to less than 5 PPB of arsenic.

Health Effects of Arsenic in Drinking Water

Short term effects of arsenic exposure include skin discoloration, stomach pain, nausea, vomiting and diarrhea. Long term effects include impacts to the heart, lung, liver, kidney, eye, dermal gastrointestinal, hematological (blood), immune, and nervous system, developmental effects, diabetes and various types of cancer.

How Do I Know if There Is Arsenic in My Drinking Water? 

There are no obvious signs of arsenic contamination. However, a Natural Resources Defense Council (NRDC) study reported that nearly 77 million Americans receive drinking water from systems that violate federal regulations for arsenic (> 10 PPB). They also noted that western states tend to have a higher incidence and elevated average levels of arsenic in their water systems. 

Additionally, it is estimated that 43 million Americans use private wells as their drinking water source. While community water systems are mandated to test for the toxic metalloid, routine testing for private wells does not usually include assessing arsenic levels.

How to Remove Arsenic from Drinking Water 

Similar to the other metals in this list, testing is the only sure fire way to know what’s in your water. This is especially crucial when it comes to arsenic because the form of arsenic in your water determines how best to remove it. Different oxidative states of arsenic respond to treatment technology in different ways. 

Before spending money on a treatment product that may not be designed to target the specific form of arsenic in your water, test your water with Tap Score and our team of treatment experts will provide an unbiased and personalized list of treatment product recommendations tailored to exactly what’s in your water. 

Contact us for questions about water testing

Sources and References

The Lead Series: Flint, Michigan and Corrosive River Water

Heavy Metals And Bioaccumulation: What You Need to Know

Secondary Drinking Water Standards: Guidance for Nuisance Chemicals | US EPA

Manganese in Drinking-water 

Soil Contamination: Impacts on Human Health

Chloramine, Chlorine, Lead and Pipes: How Water Treatment Turned Toxic

National Primary Drinking Water Regulations | US EPA

The Weight of Lead: Effects Add Up In Adults

Lead Poisoning (for Parents) - Nemours KidsHealth

Protect Your Family from Exposures to Lead | Lead | US EPA

The Ultimate Guide to Lead

Arsenic Poisoning. Symptoms of arsenic poisoning and causes

Chronic arsenic poisoning

Arsenic: Everything You Need to Know

Arsenic in drinking water EPA fact sheet 

A cross-sectional study of well water arsenic and child IQ in Maine schoolchildren

Threats on Tap: Widespread Violations Highlight Need for Investment in Water Infrastructure and Protections

Arsenic in Private Wells: An Under-recognized Hazard - WCP Online

Erin Brockovich: The Ongoing Fight for Clean Water

Chromium in Drinking Water Causes Cancer

Hexavalent Chromium

Public Health Goals (PHGs) | OEHHA

Frequently Asked Questions about Hexavalent Chromium in Drinking Water

Hexavalent Chromium Water Test | SimpleLab

General Chemistry of Water | SimpleLab

Copper in Drinking Water

The Complete Guide to Discolored Water


Nickel Institute: Knowledge for a brighter future

Metal Allergy--A Review on Exposures, Penetration, Genetics, Prevalence, and Clinical Implications

What Is The Difference Between MCLG and MCL?

Secondary Drinking Water Standards: Guidance for Nuisance Chemicals | US EPA

Relation Between Aluminum Concentrations in Drinking Water and Alzheimer's Disease: An 8-year Follow-Up Study

Will the EPA’s Updated Lead and Copper Rule Make School Drinking Water Safer?

Intellectual Impairment in Children with Blood Lead Concentrations below 10 µg per Deciliter

Late to Regulate | SimpleLab Tap Score

The All-in-One-Guide to Arsenic | SimpleLab Tap Score

Safety and Health Topics | Hexavalent Chromium - Health Effects

The Drinking Water Taste Guide | SimpleLab Tap Score

Aluminum and Alzheimer’s Disease: Is There a Link?

How To Spot Well Water Contamination | SimpleLab Tap Score

Example Tap Score Report 

Should You Filter Drinking Water For Aluminum? | SimpleLab Tap Score

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About The Author


Kate leads operational strategy as COO at Tap Score and SimpleLab. She oversees daily, as well as long-term logistics for tens of thousands of environmental samples across hundreds of certified laboratories. However, she started her environmental testing career by way of scientific blog writing at Tap Score and it continues to be one of her favorite aspects of the business. Outside of Tap Score, Kate loves making homemade pasta, floral arranging, and singing along to Dolly Parton tunes.
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