According to an article entitled 'Risk Based Consumption Advice for Farmed Atlantic and Wild Pacific Salmon Contaminated with Dioxins and Dioxin-like Compounds' published in May 2005, (Foran et al., 2005, Environmental Health Perspectives, 113:552-556), substances such as PCBs, toxaphene, dieldrin, dioxins and polybrominated diphenyl ethers were found in much higher concentrations in salmon from European fish farms than in salmon from fish farms in North and South America.
Volgens een artikel met titel "Risk Based Consumption Advice for Farmed Atlantic and Wild Pacific Salmon Contaminated with Dioxins and Dioxin-like Compounds" dat in mei 2005 gepubliceerd is (Foran et al., 2005, Environmental Health Perspectives, 113:552-556) werden stoffen zoals PCB's, toxafeen, dieldrin, dioxines en polybroombifenylethers in veel hogere mate aangetroffen in zalm uit Europese viskwekerijen dan in zalm uit Noord- en Zuidamerikaanse viskwekerijen.