What Is Arsenic?

Arsenic is a naturally occurring element that is very toxic.  It is used in industry, found in products, and is used in agriculture, particularly for chickens, for its antimicrobial properties.   Arsenic has been found in soils at high concentrations where the land was previously used for industry, particularly the leather tanning industry.   It is also a common ingredient in rat poison.

  • Arsenic is a naturally occurring element in the earth’s crust.
  • Arsenic is usually found combined with one or more elements.
  • Arsenic compounds are classified as:
    • Inorganic Arsenic (usually combined with oxygen, chlorine, or sulfur)
    • Organic Arsenic (combined with carbon & hydrogen)
    • Organic arsenic is usually less harmful than inorganic arsenic.


  • Naturally occurring element
  • No smell
  • No taste
  • Silver-gray crystalline solid
  • Most arsenic compounds dissolve in water

Uses (Navy Environmental Health Center, January 2003 )

Past Uses

  • Insecticides
  • Herbicides
  • Paints
  • Dyes
  • Rat baits

Current Uses

  • Wood Preservative
  • Production of Glass
  • Electronics Industry
  • Manufacturing of copper and other metals
  • Medicines

Arsenic In The Environment What happens to arsenic when it enters the environment?

  • Arsenic does not evaporate
  • It gets into air when materials containing it are burned
  • It settles from the air to the ground
  • It doesn’t break down, but can change from one form to another
  • Organic arsenic builds up in the tissues of fish and shellfish, but most of the arsenic in fish is not harmful.

Arsenic is an element that occurs naturally in the earth’s crust. It is released to the environment from sources such as, volcanoes and erosion from mineral deposits. Arsenic can also be released to the environment from human activities, such as, burning oil, coal, gasoline, and wood. It is also released when metals and chemicals are manufactured, through the use of pesticides, treated wood and when these materials are discarded.

Health Effects Of Arsenic – How are People Exposed to Arsenic?

  • Eating food containing arsenic
  • Drinking water containing arsenic
  • Breathing ambient air
  • Breathing air at work sites
  • Cigarette smoke

Known Health Effects

  • Thickening and discoloration of the skin
  • Stomach pain
  • Nausea, vomiting, and diarrhea
  • Numbness in the hands and feet
  • Direct skin contact may cause redness and swelling.
  • Skin lesions are the hallmark of arsenic poisoning.

How Arsenic Enters/Exits the Body:

  • From the food we eat every day
  • By drinking water containing arsenic or eating food cooked in this water
  • By breathing air containing it
  • Arsenic is quickly absorbed into the bloodstream
  • Does not accumulate in the body
  • Arsenic is removed from the body in the urine

International Issues: Arsenic is an extreme problem in Bangladesh and other developing countries, where a substantial amount of the drinking water is contaminated with naturally-occurring arsenic. An international conference was convened in 2004.

Click here to review the conference program, links to scholarly papers, and transcripts of some of the talks.

Additional Resources:

US EPA: Arsenic in Drinking Water

US EPA: Chromated-copper Arsenate (CCA): Inorganic Arsenical Pressure-treated wood 

ATSDR: ToxFAQs for Arsenic

ATSDR: Patient Education and Care Instruction Sheet

NIEHS: Arsenic and Diabetes

WHO: Arsenic Fact Sheet

Health Care Without Harm: Feeding Arsenic to Poultry: Is this good medicine?

Fletcher Allen Healthcare: Doing what it takes to bring arsenic-free chicken to patients

Food and Water Watch report on arsenic in poultry