Lead and mercury are still part of everyday life. They sit in the paint of older apartments, in shooting ranges and fishing weights, in the solder of a stained-glass hobby and in the tuna steak on your plate. Most people carry small traces of both. A heavy metal blood test answers a more useful question than "is there any?": is something in your life adding to it right now?
That question matters because lead mainly affects the nervous system, kidneys, heart and blood vessels, and mercury mainly the nervous system. Both can build up without symptoms that point to them. The World Health Organization is clear on lead: no level of exposure is known to be without harmful effects . The encouraging part is that exposure almost always has a source, and a source can be found and removed.
Where lead and mercury come from in everyday Swiss life
Swiss blood lead levels have fallen sharply. Across three population surveys in western Switzerland between 1984 and 1993, average blood lead dropped by about 40% , and the researchers named the switch to unleaded petrol as the main cause. Today, most people take in small amounts of lead through ordinary food such as cereals, dairy products and vegetables. What pushes an individual's level up is usually a more personal source. That is exactly why a population average tells you little about your own levels.
Lead
- Older buildings. Old paint on window frames, doors and walls, and older water fittings. Sanding, stripping or renovating releases fine lead dust.
- Hobbies. Casting fishing weights or bullets, soldering with lead solder and making stained glass are all recognized sources of lead exposure .
- Shooting. Indoor ranges concentrate lead fumes and dust. In a small German study of seven marksmen, all had blood lead well above the general population, with a median roughly six times higher . Those who swept the range after training were the most exposed.
- Game meat. Animals shot with lead ammunition can carry fragments into the meat. The Federal Food Safety and Veterinary Office (FSVO) advises that children up to seven, pregnant and breastfeeding women, and women planning a pregnancy avoid game where possible . For most Swiss, who eat game one to three times a year, the contribution is small. In hunting households, it can be much larger.
- Where you live or spend time. Exposure can be higher near active industry or former mining and metal-processing sites, in Switzerland and abroad. In south-western Sardinia, for example, people living near an industrial metallurgy site had about twice the blood lead of a control group . If you have lived abroad or split your time between several homes, mention it in your questionnaire.
- Smoking. In the same Swiss surveys, smoking was one of several factors linked to higher blood lead, alongside age and, at the time, wine drinking.
- Work. Renovation of older buildings, demolition, metal recycling and battery work. In Switzerland, workers with known exposure are covered by Suva's occupational medical prevention, which includes medical check-ups .
Mercury
For most people, blood mercury reflects one thing: fish. Mercury in lakes and seas is converted to methylmercury, which builds up along the food chain. Large, long-lived predators carry the most, especially shark and swordfish, and to a lesser extent tuna. Smaller, faster-growing fish like herring, mackerel, trout and salmon carry far less .
The European Food Safety Authority (EFSA) set a tolerable weekly intake for methylmercury of 1.3 micrograms per kilogram of body weight, and noted that people who eat a lot of fish can exceed it several times over . EFSA also concluded that one to four servings of fish a week bring real health benefits . The practical answer is to choose your species well, not to stop eating fish.
| Lead | Mercury | |
|---|---|---|
| Common sources | Old paint and dust, older fittings, shooting, casting and soldering, stained glass, game shot with lead ammunition, some workplaces | Mainly large predatory fish (shark, swordfish, some tuna) |
| Main systems affected | Nervous system, kidneys, cardiovascular system, blood formation | Nervous system, kidneys |
| Where it is stored | Over 90% in bone, where it stays for decades | Not stored long term; cleared over weeks to months |
| What blood shows | Exposure over the recent weeks to months | Mostly your recent fish intake |
What a heavy metal blood test measures
The test measures lead and mercury in whole blood. Whole blood matters here: about 99% of the lead in blood sits in the red blood cells , so a serum or plasma test would miss most of it. For mercury, blood mainly reflects methylmercury from fish. Mercury vapor from some workplaces or dental amalgam is better assessed with a urine test , so a blood test can underestimate that kind of exposure.
Blood is a window into the recent past. The half-life of lead in adult blood is about 28 to 36 days, while bones and teeth hold about 94% of an adult's total lead. In practice, this means:
- A raised value points to an ongoing source. Something in your environment, diet or hobbies is adding lead or mercury now.
- A value in the reference range means there's no sign of significant ongoing exposure to lead, or to mercury from fish. It does not measure lead stored in bone from decades ago, or mercury vapor from work or old dental fillings.
Your results are compared with reference values for the general population. For lead, the WHO's 2021 clinical guideline uses a blood lead of 50 micrograms per liter (5 micrograms per deciliter) as the trigger for a thorough review of exposure sources. Ahead physicians read your values against these benchmarks and in the context of your questionnaire, so a number comes with an explanation.
Lead and mercury are not part of a standard blood panel. They are usually tested when a doctor already suspects exposure. At Ahead Health, you can add them to the same blood draw as your yearly check-up.
Who should consider a heavy metal blood test
A heavy metal blood test is most useful when there is a plausible source in your life. Consider it if you:
- Eat shark, swordfish or tuna more than once a week
- Are renovating an older home, or live in a building with original paint and fittings
- Shoot regularly, especially indoors, cast your own bullets or weights, or hunt and eat your own game
- Have hobbies such as stained glass, soldering or restoring old furniture
- Work in renovation, demolition, metal recycling or with batteries
- Live, or have lived, near active industry or former mining sites, in Switzerland or abroad
- Are planning a pregnancy. Lead stored in bone is released into the blood during pregnancy , and methylmercury is a key reason for the fish advice given in pregnancy: choose low-mercury fish such as herring, mackerel, trout or salmon, and avoid swordfish and shark.
If you have acute symptoms after a known exposure, such as abdominal pain, headaches or confusion, see your GP or call Tox Info Suisse on 145 rather than waiting for a preventive test.
What happens if a value is raised
A raised value is a reason to act, not to panic. It is the most useful result a test like this can give, because it hands you a starting point.
- Find the source. Your Ahead physician reviews your result alongside your diet, home, work and hobbies, and suggests where to look first.
- Remove or reduce it. Switching fish species, changing range habits, using lead-free ammunition or managing renovation dust often makes the difference.
- Retest. Because lead in blood halves roughly every month once exposure stops, a follow-up test after two to three months usually shows whether the change is working. In some people, especially later in life, lead released from bone can keep blood levels raised for longer.
For clearly elevated values, your action plan includes a recommendation to see your GP, who can coordinate further assessment with specialists in occupational or environmental medicine where needed.
Heavy metal blood test at Ahead Health
The Heavy metals (lead and mercury) add-on measures lead and mercury in whole blood from the same sample as your check-up. You don't need a separate appointment. It covers lead and mercury only: other metals such as cadmium and arsenic are better measured in urine, and "provoked" urine tests after chelation are not validated.
You can add it to any Ahead check-up:
- Ahead check-up: advanced blood test with 80+ biomarkers, a personal report and action plan from Swiss physicians
- Full-body MRI: organs, vessels and spine, without radiation
- Full-body MRI Advanced: adds prostate or ovaries imaging and longevity and body composition markers
- Full-body MRI Pro: adds brain age analysis, hip and knee MRI, and hormone and B-vitamin blood tests
Heavy metals affect nerves, kidneys and blood vessels in ways a scan can't show, so they're measured in blood. See the full list of biomarkers we check .
Conclusion
Lead and mercury rarely announce themselves, and they almost always come from somewhere specific. A heavy metal blood test turns a vague worry into a number, and a raised number into a clear place to start. If you eat a lot of fish, shoot, renovate or work with metals, adding it to your next check-up is a simple way to know where you stand. Questions first? Book a free advisory call with our team.
