Reasons, Preparation & Procedure of Arsenic Poisoning Nails Test

Submitted on March 27, 2012

Arsenic Nail

Arsenic is a heavy metal that has toxic effects on human beings, similar to those seen in mercury and lead. In normal conditions, a minute amount of arsenic is absorbed by our bodies, which is then detoxified by the organs to harmless forms, or is excreted in the urine. However, arsenic can reach critical concentration in human tissues, where it is primarily stored in tissue with keratin, such as bones, nails, and hair. The presence of arsenic in nails can be detected in cases of long-term, low dosage exposure. This typically occurs in cases of accidental exposure due to hazardous working environments or contaminated drinking water. Such cases of arsenic poisoning in nails can be detected with some accuracy where the exposure has been continuing for more than 6 months. However, some cases of arsenic poisoning are also deliberate, especially in homicide cases. In fact, until the Marsh Test was developed in 1836, arsenic poisoning was practically undetectable in cases of suspected homicide. Up to a couple of hundred years ago, arsenic was also a part of many cosmetic products and patent medicines, often causing long-term damage to the users.

Reasons Why a Arsenic Poisoning Nails Test is Conducted

A doctor may ask for arsenic nails testing when symptoms and environmental conditions suggest long-term exposure to minute traces of the heavy metal. The typical symptoms include changes to skin color, presence of hardened patches on the skin, apnea (hair loss), abnormalities of the kidney and urinary tract, and certain kinds of cancer. If the presence of arsenic is detected early, treatment can begin to remove this highly toxic metal from the tissues. If left untreated, arsenic poisoning can lead to internal bleeding, coma, and even death.


While doing the arsenic poisoning nails test, the doctor needs to be careful to avoid contaminants. Sometimes, trace levels of arsenic on the nail surface can lead to misleading results. Patients are usually required to clean their nails just before the samples are collected. Typically, around 1 gram of fingernail clippings will be taken from the fingers and toes. These are then stored in sterile plastic containers for transportation to the laboratory.


The nail clipping undergo laboratory procedures required to detect arsenic levels. Normal values of arsenic concentration range from 100-180 mg/100 g and any results above this could indicate long-term exposure to harmful levels of arsenic. Common techniques used to measure arsenic levels include Inductively Coupled Plasma and Mass Spectrometry.