Arsenic testing measures exposure to this toxic element, found in contaminated water, rice-based foods, certain seafood, and some pesticide residues.
Chronic low-level arsenic exposure is associated with cardiovascular disease, diabetes, and certain cancers. From a longevity perspective, any detectable arsenic warrants attention. Even low-level chronic exposure compounds over decades. Well water testing is important in areas with known groundwater contamination. Organic arsenic from seafood is less toxic than inorganic forms from water or contaminated foods, but still registers on total urine panels.
Optimal Arsenic (Urine Total): 0-10 µg/L.
Typically re-tested every 16 weeks.
That single number is a screening signal. It tells you how much arsenic passed through recently, and it sets up the next question, which is what kind of arsenic it was.
Arsenic (urine total) is a urine test that reports the combined concentration of every arsenic species the kidneys excreted, usually in micrograms per litre (µg/L).
Arsenic is a naturally occurring element found in rock, soil, groundwater and, from there, in the food chain. It exists in two broad families that behave very differently in the body. Inorganic arsenic, the form found in groundwater, some soils and several industrial settings, is the species of main health concern. Organic arsenic, mainly arsenobetaine from fish, shellfish and seaweed, is absorbed and excreted largely unchanged and is generally regarded as far less reactive.
Once inorganic arsenic is absorbed, the liver methylates it in a series of steps, producing monomethylarsonic acid and dimethylarsinic acid, which the kidneys clear into urine over a matter of days. Because of that short clearance window, a urine measurement is a picture of recent intake rather than a lifetime accumulation. Blood arsenic clears faster still, which is why urine is the usual medium for exposure screening, while hair and nails are sometimes used to look further back.
A total result does not separate the species. When a total value sits above the standard range, laboratories often follow with a speciation test that reports inorganic arsenic and its methylated metabolites separately, so that a seafood meal is not confused with a contaminated water supply.
It matters because chronic inorganic arsenic exposure is one of the better-characterised environmental risks in the toxicology literature, and urine is the practical way to see whether current exposure is low.
A systematic review and meta-analysis of occupational cohorts reported an association between workplace arsenic exposure and genitourinary cancers[1], and a separate systematic review examined the carcinogenic role of arsenic in head and neck cancers[2]. Molecular work on arsenic-associated lung tumours has described distinctive genomic and expression features compared with tumours arising without that exposure[3].
Reviews of arsenic-mediated carcinogenesis describe epigenomic reprogramming, including changes in DNA methylation and altered gene expression patterns[4], and further work has mapped arsenic-induced epigenetic changes during cancer development[5]. Other reviews describe effects that extend beyond epigenetic modification, including oxidative stress and interference with cellular signalling[6], and a review of molecular targets catalogues the enzymes and pathways arsenic species bind and disrupt[7].
Beyond cancer, studies indicate associations with cardiovascular disease, with one review describing how arsenic exposure may promote vascular and cardiac pathology[8]. Research in the neuroscience literature has examined mechanisms behind cognitive and behavioural impairment following arsenic exposure[9], and a review of male reproductive toxicity describes molecular and biochemical effects on testicular tissue and sperm parameters[10].
None of that is a prediction about one person from one number. It is the reason the marker is worth measuring: exposure is modifiable, and the only way to know your current level is to test.
Most laboratories regard a total urine arsenic result below roughly 35 µg/L as within the standard reference range, while FitScript's optimal band is tighter.
| Measure | Typical lab reference range | FitScript optimal range |
|---|---|---|
| Arsenic, urine total | 0 to 35 µg/L | 0 to 10 µg/L |
These are typical lab reference ranges, and they vary by laboratory, by analytical method, by age and by sex, so always read your result against the range printed on your own report. FitScript's optimal range is an optimization target, not a diagnostic cut-off, and a value outside it is information to discuss, not a diagnosis.
Two practical notes on units. Some laboratories report in µg/L on a spot sample, others correct for urine concentration and report micrograms per gram of creatinine, and a few run a timed collection. The numbers are not interchangeable, so compare like with like when you track results over time.
A high total urine arsenic result means a meaningful amount of arsenic, of some form, passed through your kidneys in the days before collection. It does not identify the species, and it does not by itself describe harm.
Common causes. Seafood is the single most frequent explanation for an isolated elevation in people with no occupational exposure, because fish, shellfish and seaweed carry organic arsenic that is excreted quickly. Private well water drawn from arsenic-bearing geology is a classic chronic source. Food is another route, and a review of arsenic in crops, vegetables, animals and food products describes how rice and rice-based products concentrate arsenic from soil and irrigation water more readily than many other staples[11]. Occupational sources include smelting and metal refining, glass and semiconductor manufacturing, some pesticide handling and work with older pressure-treated timber. Some imported herbal or traditional preparations contain arsenic by design, and arsenic-containing formulations have been studied in medicine, including an oral preparation investigated for myelodysplastic syndromes[12].
Symptoms people report. With ongoing higher-level exposure, people describe gastrointestinal upset, fatigue, headache, and tingling, burning or numbness in the hands and feet. Many people with a modestly raised total result report nothing at all, which is exactly why screening exists.
Long-term impact. Where elevation reflects genuine ongoing inorganic exposure rather than a seafood meal, the associations described above become the concern: cancer risk at several sites[1],[2], cardiovascular disease[8], cognitive and behavioural effects[9] and reproductive effects in men[10]. The sensible sequence is observation, then explanation, then action: confirm the result, identify the likely source, and decide with a clinician whether speciation testing or a change in water or diet is the right next step. A markedly elevated result, or one accompanied by neurological or skin symptoms, is worth discussing with a clinician promptly, and no abnormal result should be set aside without review.
A low total urine arsenic result generally means recent exposure was low, and that is the outcome you want.
Symptoms. There are none associated with a low value. Arsenic is not an essential nutrient in humans, and there is no recognised deficiency state, so nothing about a low number calls for correction.
Common causes. Low results usually reflect municipal water with low arsenic content, little recent seafood, a diet that is not rice-heavy and no occupational contact. A low value can also be a sampling artefact. A very dilute sample, from heavy fluid intake shortly before collection, can pull a spot concentration down, which is one reason laboratories may correct for creatinine. Because arsenic clears within days, a low result also cannot rule out an exposure that ended weeks earlier.
Long-term impact. A consistently low result over repeat testing is reassuring about current exposure and is one of the cleaner signals you can collect on your environment. It says nothing about past exposure, so where there is a known occupational or well-water history, that context still belongs in the conversation with your clinician.
Several everyday factors move a total urine arsenic number, and most of them have nothing to do with harm.
FitScript measures total urine arsenic within its Heavy Metals panel, alongside the other metals most often implicated in environmental exposure, as part of a membership built on 150+ biomarkers tested per year.
The value of running it inside a broader panel is context. One metal above its optimal band in isolation reads differently from a pattern across several, and a pattern often points toward a shared source such as a water supply, an occupational setting or a dietary habit. Atlas, FitScript's AI health advisor, reads the result against the standard laboratory range and the optimal band, places it beside your other markers and your history, and writes the interpretation into your FitScript, the personalized output generated from your own biology. Repeat testing over the year is what turns a single reading into a trend, which matters for a marker that reflects only the last few days.
Where a result is outside the optimal band, the practical steps are usually investigative rather than pharmacological: confirming with a repeat sample taken under controlled conditions, requesting speciation to separate inorganic from seafood-derived arsenic, and testing the water at source. Any therapy that might be considered for a confirmed significant exposure sits firmly with a licensed provider, who evaluates whether it is appropriate after reviewing the person, the history and the laboratory data. This article is educational and is not medical advice. Discuss your results and any treatment decision with a clinician or licensed provider who can see your full picture.
Arsenic is most informative when read with the other metals and the nutrients that share its pathways.
The closest companions are Lead (Whole Blood), Mercury (Whole Blood) and Cadmium (Whole Blood), since overlapping sources such as seafood, older housing stock, industrial work and tobacco often lift more than one at a time. On the nutritional side, Vitamin B12 sits in the one-carbon pathway that supplies methyl groups used in arsenic metabolism, Ferritin tracks iron status and can help separate fatigue caused by low iron from fatigue attributed to an exposure, and Vitamin D (25-OH) rounds out a baseline picture that is worth having before drawing conclusions from any single metal.
Total urine arsenic answers a narrow, useful question: how much arsenic cleared your kidneys in the last few days. Below roughly 35 µg/L is within the typical laboratory range, and FitScript's optimal target is 0 to 10 µg/L. A high result most often traces back to seafood, rice or a water source, and speciation is what separates the harmless from the meaningful. A low result is reassuring and needs no correction. Either way, the number is a starting point for a conversation with a clinician, not a verdict.
Yes, and it is the most common reason for an unexpected elevation. Fish, shellfish and seaweed contain organic arsenic, mainly arsenobetaine, which is absorbed and excreted quickly and counts toward a total urine measurement. Laboratories commonly ask people to avoid seafood for several days before collection, so follow the preparation instructions your laboratory provides and mention any recent seafood when you review the result.
Total arsenic reports everything the kidneys cleared, both the organic forms from seafood and the inorganic forms from water, soil and industry. Speciation separates them and reports inorganic arsenic along with its methylated metabolites. Because the health concern centres on inorganic arsenic, speciation is the usual follow-up when a total result sits above the standard laboratory range.
Days, not years. Absorbed arsenic is methylated in the liver and cleared by the kidneys over a short window, so a urine result reflects recent intake. That makes it good for detecting ongoing exposure and poor for detecting exposure that stopped weeks or months earlier. Hair and nail testing are sometimes used when a longer look-back is needed.
Most laboratories regard a total urine arsenic result below roughly 35 micrograms per litre as within the standard reference range, and FitScript's optimal range is 0 to 10 micrograms per litre. Ranges vary by laboratory, method, age and sex, and the optimal band is an optimization target rather than a diagnostic cut-off, so read your number against the range printed on your own report.
It can contribute. Rice takes up arsenic from soil and irrigation water more readily than many other staples, which carries through to rice bran, rice cakes and rice-based syrups. A rice-heavy diet is one of the dietary patterns worth mentioning when you discuss a raised result with a clinician.
No. Arsenic is not an essential nutrient in humans and there is no recognised deficiency state, so a low result needs no correction and causes no symptoms. It simply indicates low recent exposure. Keep in mind that a very dilute sample can also lower a spot concentration, which is one reason some laboratories correct results for urine creatinine.
Start with investigation rather than conclusions. A sensible sequence is repeating the sample under controlled conditions, requesting speciation to separate seafood-derived arsenic from inorganic arsenic, and testing drinking water at source if you use a private well. Share the result with a clinician, and if it is markedly elevated or accompanied by numbness, tingling or skin changes, raise it promptly.
Lead, mercury and cadmium are the natural companions, since overlapping sources such as seafood, older housing, industrial work and tobacco often move more than one metal together. Vitamin B12 is relevant because the one-carbon pathway supplies methyl groups used in arsenic metabolism, and ferritin helps distinguish fatigue from low iron rather than from an exposure.