Heavy Metals Screening (Arsenic Lead Mercury): Detecting Toxic Metals in Your Blood

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The Heavy Metals Screening, Whole Blood test measures three toxic metals in your blood at once: arsenic, lead, and mercury. These metals can enter the body through food, water, air, older homes, and certain jobs, and over time they can harm the nervous system, the kidneys, and the heart and blood vessels.

Because it reads whole blood, this test shows the arsenic, lead, and mercury circulating in your body now, which reflects recent and ongoing exposure. You can order it online without a doctor’s visit and see your results in a clear report. If you eat a lot of fish or seafood, ask about timing your blood draw, since a recent seafood meal can briefly raise blood arsenic and mercury.

What This Test Is Looking For

This screen checks for three of the most common toxic metals people are exposed to. A raised result means enough of that metal is circulating in your blood to be worth acting on, whether the source is your water, your home, your work, or your food.

Whole blood is the right sample when the question is current exposure. It shows what is in your body now rather than what passed through months ago, so it is the usual choice for checking a recent or continuing source. For a longer window or a wider set of metals, other tests fit better, and those are covered below.

The Three Metals This Test Measures

Each metal comes from a different set of sources and affects the body in a different way.

Arsenic: Arsenic turns up in some well water, in certain foods such as rice, and in air near industrial activity. Long-term exposure raises the risk of skin changes, lung disease, and some cancers.
Lead: Lead is common in homes built before 1978, through lead-based paint and older plumbing, and in some imported pottery, cosmetics, and remedies. It harms the developing brain in children and, in adults, is linked to kidney problems, higher blood pressure, and reproductive effects.
Mercury: Mercury builds up in large predatory fish such as swordfish, king mackerel, and some tuna, and it also comes from mining and manufacturing. Long-term exposure can affect the nervous system, causing tremor, memory trouble, and difficulty concentrating, and it can affect the kidneys.

Who Should Consider This Test

This screen is most useful when you have a reason to suspect exposure. These situations carry the strongest reason to test, in rough order.

A known source at home or in your water: a home built before 1978 with old paint or lead pipes, well water or soil that may be contaminated, or regular use of imported pottery, cosmetics, or traditional remedies that can contain lead or mercury. These are the most common everyday sources.
Work or hobbies that involve these metals: construction, painting, plumbing, welding, mining, manufacturing, battery or electronics work, and farming or gardening where older pesticides may contain arsenic. Dust, fumes, and contaminated materials are the exposure route here.
Frequent high-mercury fish: eating large predatory fish such as swordfish, king mackerel, or bigeye tuna often enough that mercury can build up over time.
Pregnancy, or a young child in the home: lead, arsenic, and mercury can affect a developing baby, and children absorb more lead than adults. Lead lowers children’s intellectual function even at low blood levels (PMC1257652), so testing is worth it when exposure is possible.
Unexplained symptoms, or following up a known exposure: ongoing issues such as nerve symptoms, fatigue, or digestive trouble without a clear cause, a past occupational or environmental exposure, or tracking your levels after you reduce a source. A result gives you and your provider something concrete to act on.

Reading Your Results: Normal vs. Optimal

For toxic metals, a result inside the lab’s range is reassuring, but lower is better across the board. These metals have no helpful role in the body, so the aim is the lowest level you can reach, not simply a passing mark. Exact cut points come with your report and vary by lab, so read each result against your own report rather than a fixed number.

Metal	What the Reference Range Says	The Optimal Picture
Lead	For children, the CDC uses a blood lead reference value of 3.5 micrograms per deciliter to flag the most exposed. The exact cut point on your report comes from the lab, and public-health reference values have kept dropping over the years.	Researchers have not found a blood lead level low enough to call safe, so lower is always better. Even levels within the usual range track with a higher risk of death in the years that follow (PMID 29544878). The goal is the lowest level you can reach, not simply a result inside the range.
Arsenic	Reference cut points come with your report. A recent seafood meal can raise blood arsenic, so timing matters when you read the number.	Lower is better. Long-term arsenic exposure raises the risk of skin changes, lung problems, and some cancers (PMC3621177), so a raised result is a reason to find and cut the source.
Mercury	Reference cut points come with your report, and the number rises with regular fish intake.	Lower is better. Even low-level methylmercury from fish can affect health (PMC3385440). Most everyday mercury comes from high-mercury fish, so a raised result usually points to a fish choice you can change.

What to Do With Your Results

A result is a starting point, and the most useful ones point to a source you can reduce and a food change you can make. Share your numbers with your healthcare provider, and use the metal that came back raised to guide your next step.

Find and Reduce the Source

Lowering exposure is the step that changes your levels over time. If you have a well, test the water for arsenic and lead. For arsenic, cooking rice in extra water and draining it lowers the arsenic it holds (PMID 19137137), and varying your grains helps too. For mercury, choose lower-mercury fish such as salmon, sardines, or light canned tuna over swordfish and king mackerel. In an older home, control paint dust and have paint and pipes checked, and keep young children away from peeling paint. Avoiding tobacco smoke and checking any imported pottery, cosmetics, or remedies rounds out the common sources.

Support Your Body With Food First

What you eat changes how much metal your body takes in. Enough iron, calcium, and zinc in your food lowers how much lead your gut absorbs, because these minerals use the same uptake path lead does. An eating pattern that meets your mineral needs is protective for that reason. NutriScape’s guide to reducing heavy metals through food and supplements covers the food-first options in depth.

When to Bring In a Professional

A clearly raised result is worth reviewing with your healthcare provider promptly, and a raised lead level in a child is a standard reason to involve a provider right away. For the nutrition side, building an eating pattern that supports mineral status and lowers absorption is individual work, and a registered dietitian can walk through your results with you at nourish.com.

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Related Tests and When Each Makes Sense

This screen checks arsenic, lead, and mercury in whole blood, which reflects current exposure. When you want to focus on one metal, see a longer window, or add minerals, these tests each answer a more specific question.

For Lead Alone

A lead test measures lead by itself and is the standard check for children. It is the right pick when lead is your main concern.

For a Longer Window or a Wider Panel

A hair elements profile shows the pattern of metals over the past few months rather than a single moment. A 21 toxic metals urine test measures a much wider set of metals at once, and a 21 toxic and 16 nutritional elements urine test adds your essential minerals to that picture.

For Metals and Minerals From One Blood Draw

A red blood cell toxic and nutrient elements test reads both toxic metals and essential minerals from inside your red cells, which reflects your levels over the past few months.

If a current-exposure check for arsenic, lead, and mercury is what brought you here, you can order the screen above.

To Sum It Up

The Heavy Metals Screening, Whole Blood test reads arsenic, lead, and mercury circulating in your blood now, so it is the usual choice for checking a recent or ongoing source. For toxic metals, lower is always better, and there is no blood lead level low enough to call safe, so the goal is the lowest level you can reach rather than simply a passing result.

When a metal comes back raised, the first move is finding and reducing the source, while an eating pattern that meets your iron, calcium, and zinc needs lowers how much lead your body absorbs. A clearly raised result, and any raised lead level in a child, is worth reviewing with your healthcare provider. If that current-exposure picture is what you want, the order button is above.

The information provided in this article is for educational purposes only and is not intended to diagnose, treat, cure, or prevent any disease. Functional medical tests and nutrition-related labs should be used as tools to support health and wellness under the guidance of a qualified healthcare provider. Results from these tests should not replace professional medical advice or be interpreted without consulting a licensed practitioner familiar with your health history and needs. Always consult your doctor or dietitian before making changes to your diet, supplements, or health management plan.