Mercury is a naturally occurring element found in the environment, but its presence in food—especially seafood—raises health concerns. While most people are exposed to small amounts of mercury through air, water, and food, excessive exposure can be harmful, particularly for pregnant individuals and young children.
At Test Needs, we provide accurate and reliable food contamination testing, including mercury analysis, to help businesses and consumers ensure food safety. In this article, we’ll explore mercury’s presence in food, its potential health risks, and how you can minimise exposure.
What Is Mercury, and How Does It Get into Food?
Mercury exists in three forms:
- Elemental (Metallic) Mercury – Found in old thermometers, industrial processes, and fossil fuels.
- Inorganic Mercury Compounds – Found in mining, skin-lightening creams, and some traditional medicines.
- Organic Mercury (Methylmercury) – The most toxic form, found in fish and seafood due to environmental pollution.
When mercury enters water bodies, bacteria convert it into methylmercury, which is then absorbed by aquatic organisms. Predatory fish, such as shark, swordfish, and tuna, accumulate higher levels of mercury because they eat smaller contaminated fish over time.
Health Risks of Mercury Exposure
High levels of mercury exposure can lead to:
- Neurological damage (memory loss, tremors, mood changes)
- Lung and kidney damage
- Digestive issues, nausea, and vomiting
- Vision and hearing impairments
For pregnant individuals and young children, mercury exposure is particularly concerning. Methylmercury can cross the placenta and blood-brain barrier, affecting fetal brain development. Potential effects include:
- Learning and memory problems
- Speech and motor skill delays
- Vision and hearing impairments
How Much Mercury Is Too Much?
According to global health standards, safe mercury levels in food are determined by tolerable weekly intake (TWI) guidelines. The European Food Safety Authority (EFSA) has set a limit of 1.3 µg/kg body weight per week for methylmercury.
For a 70 kg adult, this means a limit of 91 µg of methylmercury per week. For a 30 kg child, the limit is 39 µg per week.
Which Foods Contain the Most Mercury?
High-Mercury Fish (Limit Intake)
- King mackerel
- Marlin
- Orange roughy
- Shark
- Swordfish
- Tilefish
- Tuna (Albacore, Bigeye, Yellowfin)
Low-Mercury Fish (Safer Choices)
- Salmon
- Trout
- Tilapia
- Sole
- Sardines
- Shrimp
- Oysters
How to Reduce Mercury Exposure
- Choose low-mercury seafood – Stick to salmon, trout, shrimp, and sardines.
- Follow dietary guidelines – Pregnant individuals should eat 2-3 servings (8-12 oz) of low-mercury fish per week.
- Check local advisories – Some water sources may have higher contamination levels.
- Test food for mercury contamination – Test Needs provides food testing services to ensure compliance with safety regulations.
Ensure Food Safety with Test Needs
At Test Needs, we specialise in food contamination testing, including mercury analysis in fish, seafood, dairy, grains, and baby food. Our laboratory helps businesses meet food safety standards and protects consumers from harmful contaminants.
To learn more about our food testing services, contact us at:
Phone: 03 9005 8578
Email: info@testneeds.com.au
