Farmed salmon have significantly higher concentrations of environmental
contaminants such as polychlorinated biphenyls (PCBs) than their wild counterparts,
according to an analysis of about 700 salmon from around the world.
The study's authors caution that eating farmed salmon "might pose risks
that detract from the beneficial effects of fish consumption" (Science. 2004;303:226-229). But a debate has ensued over the take-home
message from the study, with critics disputing that contaminant levels in
salmon pose a health risk great enough for consumers to curb their appetite
for the fish.
Hampton T. Farmed, Wild Salmon Pollutants Probed. JAMA. 2004;291(8):929-930. doi:10.1001/jama.291.8.929