Health Guide

Arsenic measurement

What is this test?

This test measures the amount of arsenic in the hair or nails[1][2]. This test screens for arsenic exposure in the workplace and in the environment. It is also used to help diagnose arsenic poisoning[2][3][4].

Why do I need this test?

Laboratory tests may be done for many reasons. Tests are performed for routine health screenings or if a disease or toxicity is suspected. Lab tests may be used to determine if a medical condition is improving or worsening. Lab tests may also be used to measure the success or failure of a medication or treatment plan. Lab tests may be ordered for professional or legal reasons. You may need this test if you have:

  • Toxic effect of arsenic AND/OR its compounds

When and how often should I have this test?

When and how often laboratory tests are done may depend on many factors. The timing of laboratory tests may rely on the results or completion of other tests, procedures, or treatments. Lab tests may be performed immediately in an emergency, or tests may be delayed as a condition is treated or monitored. A test may be suggested or become necessary when certain signs or symptoms appear.

Due to changes in the way your body naturally functions through the course of a day, lab tests may need to be performed at a certain time of day. If you have prepared for a test by changing your food or fluid intake, lab tests may be timed in accordance with those changes. Timing of tests may be based on increased and decreased levels of medications, drugs or other substances in the body.

The age or gender of the person being tested may affect when and how often a lab test is required. Chronic or progressive conditions may need ongoing monitoring through the use of lab tests. Conditions that worsen and improve may also need frequent monitoring. Certain tests may be repeated to obtain a series of results, or tests may need to be repeated to confirm or disprove results. Timing and frequency of lab tests may vary if they are performed for professional or legal reasons.

How should I get ready for the test?

Ask the healthcare worker for information about how to prepare for this test.

Tell the healthcare worker if you have chemically (dyed, tinted, permanently waved) processed hair[2].

How is the test done?

A hair sample or a sample of nail clippings will be collected for this test.


Prior to collection of a hair sample, your hair needs to be washed[5]. At least 1 gram of hair will be collected for this test. The hair will be cut close to the scalp, and taken from several areas at the nape of your neck[2].


Prior to collection of nail clippings, your nails need to be washed[5]. Nails will be collected from clippings of all of your fingernails and toes[5].

If you have questions or concerns about this test, talk to the healthcare worker.

How will the test feel?

The amount of discomfort you feel will depend on many factors, including your sensitivity to pain. Communicate how you are feeling with the person doing the test. Inform the person doing the test if you feel that you cannot continue with the test.

This test usually causes no discomfort.

What should I do after the test?

Instructions for what to do after hair or nails are collected for this test may vary. Ask the healthcare worker what you should expect after this test is completed. If you have questions or concerns about what to expect after the test is completed, talk to the healthcare worker.

What are the risks?

Ask the healthcare worker to explain the risks of this test or procedure to you before it is performed.

What are normal results for this test?

Laboratory test results may vary depending on your age, gender, health history, the method used for the test, and many other factors. If your results are different from the results suggested below, this may not mean that you have a disease. Contact your healthcare worker if you have any questions. The following are considered to be normal results for this test:

  • Normal Concentration:
    • Adults: Hair <1 mcg/g dry weight [2]
  • Acceptable Range for Industrial Exposure [5]:
    • Adults: Hair <65 mcg/100 g dry weight (<8.65 nmol/g dry weight)
    • Adults: Nail <180 mcg/100 g dry weight (<23.94 nmol/g dry weight)

What follow up should I do after this test?

Ask your healthcare worker how you will be informed of the test results. You may be asked to call for results, schedule an appointment to discuss results, or notified of results by mail. Follow up care varies depending on many factors related to your test. Sometimes there is no follow up after you have been notified of test results. At other times follow up may be suggested or necessary. Some examples of follow up care include changes to medication or treatment plans, referral to a specialist, more or less frequent monitoring, and additional tests or procedures. Talk with your healthcare worker about any concerns or questions you have regarding follow up care or instructions.

Where can I get more information?

Related Companies

  • Agency for Toxic Substances and Disease Registry -


[1] Samanta G, Sharma R, Roychowdhury T, et al: Arsenic and other elements in hair, nails, and skin-scales of arsenic victims in west bengal, india. Sci Total Environ 2004; 326:33-47.

[2] Hindmarsh JT: Caveats in hair analysis in chronic arsenic poisoning. Clin Biochem 2002; 35:1-11.

[3] Saad A & Hassanien MA: Assessment of arsenic level in the hair of the nonoccupational egyptian population: pilot study. Environ Int 2001; 27:471-478.

[4] Karagas MR, Tosteson TD, Blum J, et al: Measurement of low levels of arsenic exposure: a comparison of water and toenail concentrations. Am J Epidemiol 2000; 152:84-90.

[5] Tietz NW (Ed): Clinical Guide to Laboratory Tests, 3rd ed. W. B. Saunders, Philadelphia, PA, 1995.

Last Updated: 7/4/2018
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