What is arsenic?

Arsenic is a naturally occurring chemical found in water, food and soil. It is toxic when someone is exposed to a large amount. It can also occur in the environment due to human activity, like agriculture and manufacturing.

Arsenic can either be organic or inorganic. Organic forms of arsenic are less toxic than inorganic forms.

Where is arsenic found?

Water

Arsenic is often found in ground water, and there are some parts of the world with drinking water that is contaminated with an unsafe level of arsenic. These include Argentina, Bangladesh, Cambodia, Chile, China, India, Mexico, Pakistan, the United States of America and Vietnam.

Australia's Drinking Water Guidelines set a limit of 0.01 milligrams/L, which is in line with the World Health Organization's Guidelines for drinking water quality.

Food

Because arsenic occurs naturally in water, air and soil, it can sometimes be found in food. Australia's Food Standards Code sets maximum levels of arsenic that can be in food to ensure that these are safe to eat.

Rice, seaweed, fish and shellfish are examples of food that may contain low levels of organic and inorganic arsenic.

Some types of seaweed may contain high levels of inorganic arsenic, such as hijiki seaweed. Hijiki seaweed is black in appearance and usually comes in shredded form. Imported hijiki seaweed products that do not meet the limit for arsenic in the Food Standards Code cannot be sold in Australia. However, people who regularly have a lot of hijiki seaweed — along with other food that contains arsenic — may be at a higher health risk than the general population.

Industry and consumer products

Mining and metal manufacturing are the largest sources of arsenic in Australia. Other manufacturing industries where arsenic may be used include:

• agriculture
• paper and paper products
• glass and glass products
• petroleum and coal products

Products containing arsenic include timber treatments, wood preservatives and pesticides.

The most common timber treatment in Australia is copper chrome arsenate (CCA), which is made with arsenic. CCA treated timber is often used for:

• framing
• landscaping
• building poles
• jetty piles
• fencing

What are the health effects of arsenic exposure?

Health problems from arsenic exposure can occur due to inhalation (breathing), absorption (through the skin) or ingestion (swallowing) of arsenic dust and fumes.

If you're exposed to too much arsenic it can cause stomach pain, nausea, vomiting, damage to blood vessels, abnormal heart rhythms, a 'pins and needles' feeling in the hands and feet, and liver and kidney damage. Exposure to very high levels of arsenic can be fatal.

Ingesting or inhaling low levels of inorganic arsenic for a long time can cause skin to darken and you may develop warts on the hands, feet and torso.

Ingestion of inorganic arsenic can also increase the risk of skin, lung, bladder, liver, kidney or prostate cancer.

Inhaled or ingested arsenic may also affect pregnant females and their unborn babies. If you're pregnant and become ill due to arsenic exposure, it can result in low birth weight, foetal malformations or foetal death.

When should I see my doctor?

If you're concerned that you've been exposed to a dangerous level of arsenic, speak to your doctor or call the Poisons Information Line on 13 11 26.

If someone has lost consciousness and you believe they've been exposed to arsenic, call triple zero (000) and ask for an ambulance.

Can arsenic exposure be prevented?

Arsenic occurs naturally in the Earth's water, soil and air, so exposure to small amounts cannot be avoided. It's important to remember that the human body can safely tolerate these very low levels of arsenic without it affecting your health.

Eating a balanced diet with a variety of food will minimise any risks of eating food containing arsenic. Food Standards Australia and New Zealand (FSANZ) constantly monitors Australia's food supply to ensure that food is safe and meets national standards for chemical contamination.

If you work in an industry that uses arsenic, make sure you follow the safety guidelines set by your employer.

Do not burn CCA treated wood in open fires, stoves, fireplaces, or residential boilers. When sawing or machining treated wood, always wear a dust mask and perform these tasks outside whenever possible.

Other uses for arsenic

Arsenic is the active ingredient in a drug called arsenic trioxide, which is used to treat acute promyelocytic leukaemia.