: Jouni Tuomisto, D.Med.Sc; Jouko Tuomisto, D.Med.Sc, PhD, prof; Marko Tainio, M.Sc; Marjo Niittynen, M.Sc; Pia Verkasalo, D.Med.Sc; Terttu Vartiainen, PhD, prof; Hannu Kiviranta, M.Sc; Juha Pekkanen, D.Med.Sc, prof
Funding: Academy of Finland; TEKES, Finland
Contact person: Jouni Tuomisto
Background & objectives: In their Report “Global assessment of organic contaminants in farmed salmon,” R. A. Hites and co-workers analyzed wild and farmed salmon samples from North and South America and Europe for organic pollutants (Science, 9 Jan. 2004, p. 226). The authors conclude that, because of chemical contaminants, farmed salmon should not be eaten more often than 0.25 to 1 times per month. However, the model used does not take into account any beneficial effects of eating fish. We analyzed both risks and benefits. We also performed a value-of-information analysis to see which uncertainties were relevant for decision-making.
Results: Excess cancer mortality due to pollutants in farmed salmon was estimated at 210 cases per year [90% confidence interval (CI) 110 to 340], supporting restrictive recommendations. The number of cancer deaths that could be prevented by the restrictive recommendation on farmed salmon use was estimated at 40 deaths per year (90% CI 2 to 110). However, the recommendation would worsen the net health effect (cancer and cardiac deaths combined) by 5200 deaths per year (90% CI 34 to 19,000). It is therefore clear that if the main concern is the net health benefit, the decision-maker will not recommend restrictions. We also analyzed a decision to lower the amount of pollutants in fish feed. This lowering was estimated to save 360 deaths per year (90% CI -3200 to +4100), mainly because of possible increase in consumption of salmon.
Conclusions: The question about restricting consumption of farmed salmon appears to be nonscientific, because the outcome of the analysis was totally driven by a political variable, whether to ignore the health benefits of fish. The question about fish feed regulation was partly scientific and would benefit from further research.
Analytica-based model: FARMED SALMON.ana (117 K). To view the model graphically, save it to your computer, download the free Analytica-program from Lumina and open the saved model with the program. The model identifier is: URN:NBN:fi-fe20042774.
Reference: Tuomisto JT, Tuomisto J, Tainio M, Niittynen M, Verkasalo P, Vartiainen T, Kiviranta H, Pekkanen J. Risk-benefit analysis of eating farmed salmon. Science. 2004 Jul 23;305(5683):476-7 Read the article