Mercury content in commercially available finfish in the United States.
Level 4 - case-series / case-control
Cross-sectional market basket surveillance study (by design analogy, non-clinical).
PubMed 25198598 · doi:10.4315/0362-028X.JFP-14-097
What was done
Researchers collected 300 composite samples (each comprising three fish) representing 77 finfish species from commercial vendors across six regions of the United States (Great Lakes, Mid-Atlantic, New England, Northwest, Southeast, and Southwest) and measured total mercury concentrations in muscle tissue.
What was found
Total mercury ranged from 1 ppb in channel catfish to 1,425 ppb in king mackerel. Among the top 10 most commonly consumed US seafoods, finfish had low mercury levels: salmon species (13 to 62 ppb), Alaskan pollock (11 ppb), tilapia (16 ppb), channel catfish (1 ppb), Atlantic cod (82 ppb), and swai/pangasius (2 ppb). Two large predatory species exceeded the US FDA action level of 1,000 ppb: king mackerel (up to 1,425 ppb) and swordfish (1,107 ppb).
Why it matters
These findings verify that the most widely consumed finfish in the United States contain low mercury levels, while confirming that species exceeding regulatory action limits remain accessible in commercial retail markets.
Limits
The abstract does not provide variance, confidence intervals, or sample sizes per individual species. Total mercury was measured rather than specifically methylmercury, and the sampling represents commercial retail stock rather than subsistence or recreational catch.
Cited by
- supports Wild Alaskan salmon has among the lowest mercury contamination levels of seafood.