Analytical Chemistry Trinidad & 

Tobago Lab Resources


HOME Email

Arsenic Poisoning

All information presented are excerpts from "Mercury Free", by Dr. James Hardy.


Exposure to higher than average levels of arsenic happens mostly in the workplace, near hazardous waste sites, or in areas with high natural levels. Arsenic is a powerful poison. At high levels, it can cause death or illness. This chemical has been found in at least 781 of 1.300 National Priorities List sites identified by the Environmental Protection Agency.

Arsenic is found in nature at low levels. It's mostly in compounds with oxygen, chlorine, and sulfur. These are called inorganic arsenic compounds.
Arsenic in plants and animals combines with carbon and hydrogen. This is called organic arsenic. Organic arsenic is usually less harmful than inorganic arsenic.
Most arsenic compounds have no smell or special taste.
Inorganic arsenic compounds are mainly used to preserve wood.
They are also used to make insecticides and weed killers.
You can check the labels of treated wood and insecticides to see if they contain arsenic.
Copper and lead ores contain small amounts of arsenic.


It doesn't evaporate.
Most arsenic compounds can dissolve in water.
It gets into air when contaminated materials are burned.
It settles from the air to the ground.
It doesn't break down, but can change from one form to another.
Fish and shellfish build up organic arsenic in their tissues, but most of the arsenic in fish isn't toxic.


Breathing sawdust or burning smoke from wood containing arsenic.
Breathing workplace air.
Ingesting contaminated water, soil, or air at waste sites.
Ingesting contaminated water, soil, or air near areas naturally high in arsenic.

Health Effects

Inorganic arsenic is a human poison.
Organic arsenic is less harmful.
High levels of inorganic arsenic in food or water can be fatal.
A high level is 60 parts of arsenic per million parts of food or water (60 ppm).
Arsenic damages many tissues including nerves, stomach and intestines, and skin.
Breathing high levels can give you a sore throat and irritated lungs.

Lower levels of exposure to inorganic arsenic may cause:

Nausea, vomiting, and diarrhea
Decreased production of red and white blood cells
Abnormal heart rhythm
Blood vessel damage
A "pins and needles" sensation in hands and feet

Long term exposure to inorganic arsenic may lead to a darkening of the skin and the appearance of small "corns" or "warts" on the palms, soles, and torso.
Direct skin contact may cause redness and swelling.

The Department of Health and Human Services (DHHS)has determined that arsenic is a known carcinogen.
Breathing inorganic arsenic increases the risk of lung cancer.
Ingesting inorganic arsenic increases the risk of skin cancer and tumors of the bladder, kidney, liver, and lung.

Exposure Tests

Tests can measure your exposure to high levels of arsenic.
These tests are not routinely performed in a doctor's office.
Arsenic can be measured in your urine. This is the most reliable test for arsenic exposure. Since arsenic stays in the body only short time, you must have the test soon after exposure.
Tests on hair or fingernails can measure your exposure to highlevels of arsenic over the past 6-12 months. These tests are not very useful for low level exposures.
These tests do not predict whether you will have any harmful health effects.

The Environmental Protection Agency (EPA) sets limits on the amount of arsenic that industrial sources can release.
It restricted or canceled many uses of arsenic in pesticides and may restrict more.
EPA set a limit of 0.05 parts per million (ppm) for arsenic in drinking water.
EPA may lower this further.

The Occupational Safety and Health Administration (OSHA) established a maximum permissible exposure limit for workplace airborne arsenic of 10 micrograms per cubic meter (g/m).

All information presented are excerpts from "Mercury Free", by Dr. James Hardy.

anal-chem resources

Signature: Dhanlal De Lloyd, Chem. Dept, The University of The West Indies, St. Augustine campus
The Republic of Trinidad and Tobago.
Copyright: delloyd2000© All rights reserved.