Mercury can damage the nervous system, kidneys and immune system, especially in unborn children. For this reason, pregnant women and children should avoid large predatory fish such as swordfish or tuna altogether. The large predatory fish contain the most mercury. Fish such as trout, char, salmon and herring, on the other hand, are only slightly contaminated with mercury.

The European Food Safety Authority (EFSA) has set a tolerable weekly intake for mercury. This is the amount of a substance that can be ingested per week over a lifetime without causing health effects.

You can easily find out how much fish you can safely eat with our mercury calculator :

• Enter the amount of fish you want to eat
• Enter your weight (the tolerable intake depends on your body weight). If you have gained some weight during pregnancy, enter your pre-pregnancy weight
• Under Fish type you can select which fish you want to eat

Click on the Calculate/Add portion button to see how much mercury you are taking in and how much of your tolerable intake you are consuming (as a percentage). You can also enter several portions of fish, including different types of fish: Just make sure that you stay below 100 %.