Free · Historical exposure scenarios

Seafood Mercury Mass and Reference-Dose Comparison

Estimate mercury mass from a serving and compare it with seven days of the EPA methylmercury reference dose, using a dated pooled seafood dataset or entered concentration.

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Calculator inputs

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How to use this calculator

  1. Enter the known values in the units shown. Results update as you type.
  2. Where results are editable, change one to solve backwards. Lock a value to hold it fixed.
  3. Use the worked example to check the method. Reset restores the starting fields.

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Inputs and results stay in this browser tab. Bookify does not upload or store the values you enter.

Formula and method

The 100 g historical anchovy scenario contains 10.3 µg of mercury. For 70 kg, the seven-day reference mass is 49 µg; the serving equals approximately 21.02% of that arithmetic reference.

Mercury (µg) = serving mass (g) × concentration (ppm); seven-day reference mass (µg) = 0.1 × 7 × body weight (kg); comparison (%) = 100 × serving mercury / reference mass.

Worked example

Enter these known values and leave the other values blank.

Seafood preset (2012 pooled means)
Anchovies — 2012 pooled mean
Serving size
100 g
Your weight
70 kg
Mercury concentration
0.103 ppm
Mercury per serving
10.3 µg
Seven-day reference mass
49 µg
Percent of seven-day reference mass
21 %

Assumptions and limitations

  • The seafood presets are historical grand mean total-mercury concentrations across studies in Karimi, Fitzgerald and Fisher (2012), Table S1, on a wet-weight basis. They do not describe every fish or current local concentrations.
  • Pooled labels combine species or origin categories as stated in the study. The trout row is freshwater wild or unknown status; the light-tuna row is canned or packed tuna, rather than exclusively skipjack.
  • One ppm by wet mass equals one microgram per gram. The arithmetic uses total seafood mercury as a methylmercury exposure proxy; it does not identify mercury speciation in a particular sample.
  • The EPA chronic methylmercury reference dose is 0.0001 mg/(kg·day), or 0.1 µg/(kg·day). Multiplying by seven days is an arithmetic comparison reference, not an EPA weekly-serving recommendation.
  • A reference dose estimates long-term exposure with uncertainty. A percentage below 100 does not guarantee safety, and a single serving above 100 does not establish poisoning. This calculator does not account for all diet exposures, nutritional benefits or individual medical circumstances.
  • Use FDA/EPA fish advice and local advisories for choosing fish, especially during pregnancy, breastfeeding or childhood. The historical mass calculation does not replace that advice.
  • To solve a concentration from measured mercury mass, clear the concentration and unlock it, then lock serving mass. The dropdown may share a numerical value across species; an inverse concentration cannot uniquely identify a species.

Common questions

Does the percentage tell me how much fish to eat?

It is a ratio to a chronic-exposure reference mass. Fish-choice and serving guidance depends on the applicable FDA/EPA advice, age and local fish advisories.

Can I enter a laboratory concentration?

Yes. Enter wet-weight ppm in the concentration control. A chosen preset supplies a historical mean; clear the preset to work with your entered concentration.

References

Bookify permits a zero reference-dose percentage when the entered mercury concentration is zero. Bookify aligns six seafood mercury presets with the historical grand means in Karimi and colleagues’ 2012 Table S1; the original pooled-species scope is stated in the choices and guide.

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