Arsenic in drinking water

Arsenic is a natural element that is widely found in the Earth’s soil. Arsenic compounds are used commercially and industrially in the manufacture of a variety of products such as transistors, lasers, semiconductors, glass production, pigments, textiles, paper, metal adhesives, ceramics, wood preservatives, explosives and pesticides. 

There are two forms of arsenic – organic and inorganic. High levels of organic arsenic occur naturally in many types of food such as seafood. When eaten it is quickly eliminated by the body and normally poses a low risk to human health. Inorganic arsenic is found naturally in soil or rock where it can enter surface and groundwater. Inorganic arsenic can pose a serious risk to health.

How does arsenic get into drinking water?

Drinking water can be contaminated with inorganic arsenic by either wind-blown dust, leaching or runoff from soil, rocks and sediment. Groundwater sources such as bores are usually at greater risk of contamination from inorganic arsenic than surface and rain water supplies.

What are the potential health effects of arsenic?

Consuming very high levels of arsenic can cause acute poisoning and death. However, exposure to lower levels can cause decreased production of red and white blood cells, damage to blood vessels and a sensation of “pins and needles” in hands and feet.

Swallowing or breathing low levels of inorganic arsenic for a long time can cause a darkening of the skin and the appearance of small “corns” or “warts” on the palms, soles, and body. Long term consumption of arsenic may increase the risk of skin cancer, cancer in the liver, bladder and lungs.

If you have consumed water that has been contaminated by arsenic the potential affect on your health will depend on the following factors:

• How much arsenic you have been exposed to.
• How long and how often you have been exposed.
• The type of arsenic you have been exposed to.
• Your health, nutrition, age and lifestyle.

It is possible for some people to be affected by lower levels of arsenic than others. Young children, the elderly, people with long-term illnesses, and unborn babies are at greatest risk. However, arsenic is not transferred through breast milk to babies.

How can I tell if arsenic levels in my drinking water are elevated?

It is not easy to tell if your drinking water is contaminated by arsenic as you cannot smell, taste or see it. The only way to know if your water contains arsenic is to have it professionally tested.

How do I test for arsenic in my drinking water?

Water testing for arsenic can be done by any National Association of Testing Authorities (NATA) accredited chemical laboratory. Check with the laboratory first to find out how to collect and transport the water sample. Laboratories can be found in the Yellow Pages telephone directory under the heading, “Analysts”.

Are elevated levels of arsenic found in Scheme drinking water supplies in WA?

No. Scheme drinking water supplies in WA do not contain elevated levels of arsenic. In Western Australia all scheme drinking water supplies are continually monitored by the Department of Health to ensure arsenic levels to not exceed the safe level set by the 2004 Australian Drinking Water Guidelines of 0.007 mg/L.

Which water supplies are at risk of being contaminated by Arsenic?

Some privately owned bore water sources in acid sulphate soil risk areas in the South West coastal areas of Western Australia have been contaminated by high levels of arsenic. For more information on Acid Sulphate soils please contact the Department of Environment and Conservation on ph (08) 6467 5000. In addition elevated levels of naturally occurring arsenic have been detected in a number of bores located in the North West, Pilbara and Murchison/Goldfield districts of Western Australia.

Can I reduce the level of arsenic in my drinking water?

Yes. It is possible to reduce the level of arsenic in your household drinking water by using a variety of treatment processes. However, these processes are not simple and it is strongly recommended that you obtain advice from a professional water treatment company. Water treatment companies can be found in the Yellow Pages telephone directory under the heading ‘Water Treatment and Equipment’.

Can I be tested for arsenic poisoning?

Yes. There are tests available to measure arsenic in your urine, hair and fingernails. The urine test is used to detect a recent arsenic exposure. Tests of your hair and fingernails may be used to detect continuing arsenic exposure over the past 6-12 months, but are less reliable. However, even though these tests may detect exposure to elevated levels of arsenic they cannot predict the affect on your health. It is best to discuss their significance with your doctor.

How can I reduce my exposure to arsenic?

If your drinking water is contaminated by arsenic do not drink or prepare any food with it. Seek another source of water e.g. bottled water, scheme drinking water or rain water.

What can I use my water for if it is contaminated by arsenic?

Arsenic is not easily absorbed through the skin. Water contaminated with arsenic can still be used for hand washing, bathing, washing clothes and in the garden. However, care should be taken if you want to water vegetables such as beetroot, turnips, carrots, and potatoes as they can concentrate arsenic in their skin. Also care should be taken to ensure that pets and other animals do not drink contaminated water.

Summary

  • Consuming very high levels of arsenic can cause poisoning and death.
  • You cannot smell, taste or see arsenic in water.
  • Arsenic is not easily absorbed through the skin.
  • Water contaminated with arsenic can still be used for hand washing, bathing, washing clothes and in the garden (with caution).
  • Tests are available to measure your exposure to arsenic. See your doctor if you are concerned about the level of arsenic in your body.
  • Elevated levels of arsenic in bore water have been found in some parts of Western Australia.
  • Bore water should never be used for drinking, bathing, filling swimming pools and paddling pools, food production or cooking unless it has been professionally tested and treated if necessary.
  • Water testing for arsenic can be done by any National Association of Testing Authorities (NATA) accredited chemical laboratory. Laboratories can be found in the Yellow Pages telephone directory under the heading, “Analysts”.
  • All scheme drinking water supplies are continually monitored by the Department of Health to ensure compliance with the 2004 Australian Drinking Water Guidelines and do not contain elevated levels of arsenic.
  • Professionally designed and maintained water treatment systems can reduce arsenic levels in water supplies.
Last reviewed: 24-06-2016
Produced by

Public Health