Organochlorine residues in fish oil dietary supplements: Comparison with industrial grade oils

The market for fish oils as dietary supplements is of global importance. Although it is widely recognised that lipophilic organic chemicals, particularly organochlorines, can accumulate in fish oils, dietary supplements are not routinely considered when estimating average daily intakes for these contaminants. This paper reports levels of organochlorine residues in 44 fish oils, collected from 15 countries between 1994 and 1995, including 38 purchased over the counter as dietary supplements. Despite controls on the use of persistent organochlorine substances, appreciable quantities are found in oils sold as dietary supplements. Levels are discussed in relation to the significance of fish oil dietary supplements as contributors to daily intake of PCBs and pesticide residues.