Reasons, Preparation & Procedure For Conducting a Arsenic Hair Test

Submitted on March 27, 2012

Arsenic Hair

Arsenic is a naturally occurring heavy metal that is normally present in very small quantities in our bodies. Small quantities can be detoxified by the body and converted to non-toxic forms, or excreted in the urine. However, excess arsenic can be absorbed by the body via accidental exposure or deliberate poisoning. Arsenic was also widely used in cosmetic products until a couple of hundreds years ago, since its toxic nature was not clear. In modern times, arsenic poisoning is usually linked to hazardous workplace environments and presence of arsenic in drinking water. Any excess arsenic collects in several tissues, mainly those having keratin, a natural protein. This means the hair and nails usually have some levels of arsenic.

Reasons Why Arsenic Hair Test is Conducted

Exposure to arsenic has serious effects on the human body, depending on length of exposure, and concentration of absorbed arsenic. Short term exposure can cause swelling of the face and severe gastrointestinal problems, including vomiting, diarrhea, and stomach convulsions. In higher dosages, even short term exposure can lead to internal bleeding, coma, and death. However, most cases of unintentional arsenic exposure are of long-term duration to minute quantities. These can results in symptoms including changes to skin color and texture, nerve damage, hair loss, and cancers of the kidney, urinary bladder, and lungs. Since these serious complications develop slowly over years, testing for the presence of arsenic in the tissues is important in identifying poisoning, and starting early treatment. The arsenic hair test can be especially useful, since it can detect exposure to high levels of arsenic over the past 6-10 months. However, urine arsenic tests are preferred to detect cases of exposure to lower levels of arsenic.


Testing for arsenic in hair can be complicated, especially since there is a significant risk of environmental contamination of the sample. The doctor should also be made aware of usage of hair coloring or styling products. The patient is usually expected to wash the hair before the test without the use of chemical shampoos. In most cases, about half a gram of hair is cut off from near the scalp, usually from the base of the neck. This should immediately be sealed in a plastic container to avoid contamination.


Detection of arsenic in hair is possible using laboratory methods such as Inductively Coupled Plasma and Mass Spectrometry. The results are usually available within a week. Normal values are around 65mg/100 g of arsenic in hair.