Global Assessment of Organic Contaminants in Farmed Salmon

TLDR

Farmed salmon production has surged 40‑fold over two decades, making it a year‑round, low‑cost food source, yet its human health risks remain under‑studied. Our analysis of >2 t of salmon worldwide shows farmed salmon, especially European‑raised, contain higher organochlorine levels than wild, and consumption of farmed Atlantic salmon may pose health risks that offset its benefits.

Abstract

The annual global production of farmed salmon has increased by a factor of 40 during the past two decades. Salmon from farms in northern Europe, North America, and Chile are now available widely year-round at relatively low prices. Salmon farms have been criticized for their ecological effects, but the potential human health risks of farmed salmon consumption have not been examined rigorously. Having analyzed over 2 metric tons of farmed and wild salmon from around the world for organochlorine contaminants, we show that concentrations of these contaminants are significantly higher in farmed salmon than in wild. European-raised salmon have significantly greater contaminant loads than those raised in North and South America, indicating the need for further investigation into the sources of contamination. Risk analysis indicates that consumption of farmed Atlantic salmon may pose health risks that detract from the beneficial effects of fish consumption.