What is arsenic?
Arsenic is a chemical found naturally in soils, rocks, and water. There are 2 types:
- organic arsenic, which is found in fish and shellfish
- inorganic arsenic, which is found in minerals, rocks, and mine tailings.
Both types can be toxic at high levels. But inorganic arsenic is much more toxic.
Environments with higher arsenic levels
All soils contain arsenic but levels can be higher because of:
- past use of pesticides containing arsenic
- nearby industrial sources, like smelters or coal-fired power plants
- volcanic activity.
Why arsenic is in food
Most foods contain small amounts of arsenic. Food accumulates arsenic from the environment. For example, plants absorb arsenic from the soil.
How can arsenic affect health
Regularly eating foods with high levels of inorganic arsenic can increase the risk of:
- skin lesions
- cancer
- diabetes
- heart disease.
Food with high levels of arsenic
Arsenic levels in most foods are very low and not a risk to health. Some foods contain higher levels, and there is more risk.
Foods with high levels of inorganic arsenic are:
- watercress grown near the Waikato River and in geothermal regions
- rice products that still have their husk – such as brown rice
- some seaweeds and seaweed products – such as hijiki.
For information on harvesting watercress safely, download our marae food safety guide.
The Te Kai Manawa Ora marae food safety guide [PDF, 13 MB]
Fish and seafood are low risks
Fish and seafood can contain high amounts of organic arsenic. It's not a health risk, though, because it's not absorbed into your body.
Safe levels in New Zealand diets
The New Zealand Total Diet Study runs every 5 to 6 years. It tests exposure to chemical residues, contaminants, and selected nutrients. More than 120 common foods are in the study. Results show that arsenic levels are low in New Zealand.
The New Zealand Total Diet Study
The Food Standards Code sets maximum limits for inorganic arsenic in foods.
Arsenic – Food Standards Australia New Zealand
Find out more
Arsenic fact sheet – World Health Organization
Who to contact
If you have questions about arsenic levels in food, email info@mpi.govt.nz
