Farmed norwegian salmon world’s most toxic food

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The Toxicity of Farmed Norwegian Salmon: A Comprehensive Review

Introduction to Farmed Norwegian Salmon and Contaminants

Farmed Norwegian salmon has been a subject of scrutiny due to concerns about its safety and contaminant levels. This article synthesizes findings from multiple studies to provide a clear picture of the toxicity levels in farmed Norwegian salmon, focusing on contaminants such as dioxins, PCBs, heavy metals, and other pollutants.

Decreasing Contaminant Levels Over Time

Trends in Contaminant Levels (1999-2011)

A comprehensive study spanning 13 years (1999-2011) analyzed over 2300 samples of Norwegian farmed Atlantic salmon for various contaminants. The results showed a significant decrease in the levels of mercury, arsenic, dioxins, dioxin-like PCBs, and DDT over the study period. However, levels of cadmium, lead, and several organochlorine pesticides were too low to establish trends. This indicates a positive trend towards safer consumption levels of farmed salmon.

Comparison with Wild Salmon

When comparing farmed salmon to wild salmon, it was found that farmed salmon generally had lower concentrations of dioxins, PCBs, and heavy metals. For instance, wild salmon had three times higher levels of dioxins and PCBs compared to farmed salmon, although both were below the EU's maximum levels for contaminants in food. This suggests that farmed salmon may be safer in terms of certain contaminants compared to their wild counterparts.

Persistent Organic Pollutants and Feed Sources

Impact of Feed on Contaminant Levels

The type of feed used in salmon farming plays a crucial role in the levels of persistent organic pollutants (POPs) found in the fish. Studies have shown that farmed salmon from regions using pelagic fish in their feed had higher levels of POPs compared to those using non-pelagic feeds. Norwegian salmon farms have shifted towards using terrestrial sources in their feed, resulting in lower concentrations of POPs and mercury. This shift has contributed to the overall reduction in contaminant levels in farmed Norwegian salmon.

Regional Variations in Contaminant Levels

A study comparing farmed salmon from different regions, including Norway, found that Norwegian farmed salmon had lower levels of PCBs and dioxins compared to salmon from other regions like Scotland and the Faroe Islands. This regional variation highlights the importance of feed composition and farming practices in determining contaminant levels.

Health Risks and Regulatory Standards

Tolerable Weekly Intake (TWI) and Safety Assessments

The levels of dioxins and dioxin-like PCBs in Norwegian farmed salmon have been evaluated against established Tolerable Weekly Intake (TWI) values. The findings suggest that the contaminant levels in 2011 allowed for the consumption of up to 1.3 kg of salmon per week without exceeding the TWI. This indicates that, based on current standards, Norwegian farmed salmon can be safely consumed within these limits.

Pathogen and Disease Concerns

While the overall health situation in Norwegian aquaculture is good, there are concerns about the spread of pathogens from farmed to wild fish populations. Salmon lice and other parasites are significant issues, and the use of pesticides like emamectin benzoate (EMB) is common in treating these infestations. The regulatory standards for pesticide residues vary by country, with Norway having a shorter withdrawal period compared to other regions.

Conclusion

In conclusion, the toxicity levels in farmed Norwegian salmon have generally decreased over the years, making it safer for consumption. The shift towards non-pelagic feeds and stringent regulatory standards have contributed to lower levels of harmful contaminants. While there are still concerns about pathogen spread and regional variations in contaminant levels, the overall trend indicates that farmed Norwegian salmon is not the world's most toxic food and can be safely consumed within established guidelines.