Marine Math: Calculating the Risks of Seafood Consumption

Lay summary by Rachel Shaffer

Seafood provides important health benefits to the population, yet it can also result in exposure to numerous environmental contaminants. Public health officials and policy-makers often face the challenge of determining the overall risks from seafood consumption. This study provides a new framework to integrate chemical data and exposure data, thus allowing a standardized way to understand risk and prioritize policy interventions across different populations.

Heavy metals, such as mercury and lead, are perhaps the most common chemical contaminants found in seafood. Additional groups of chemicals, collectively known as persistent organic pollutants (POPs), are also common, particularly in large fish species with high fat content. Yet risk is not only determined by the presence of a contaminant; it is equally important to consider the specific health effects of the chemicals and how often the population eats different types of fish.

The authors of this study sought to develop a way to combine these three key types of data: fish contamination (how much of the chemical is present in each species?), chemical toxicity (how harmful is the chemical?), and fish consumption patterns (how much and what types of fish do different populations consume?). Together, these factors form the “integrated risk index from seafood consumption” (IRISC) for specific regions and specific chemicals.

To test this newly developed IRISC framework, the authors conducted a case study based on five European countries (Belgium, Ireland, Spain, Italy, and Portugal) and four fish species (sardines, canned tuna, salmon, and mussels). Using existing data on contamination, toxicity, and consumption, they calculated the overall IRISC for each country. They were also able to determine the most problematic contaminants for each regional population. Portugal and Spain had the highest IRISC, and metals were the most important contributors to the risk index for all five countries.

This case study demonstrates that the IRISC framework can be an effective tool for health officials and policy-makers. By incorporating region-specific information, regulators in other parts of the world can begin to use this tool to understand health risks and develop standards to better protect the population.

Read the Environmental Research original research article which this summary is based on Integrated risk index for seafood contaminants (IRISC): Pilot study in five European countries (March 2015).

Visit the profile of the research ambassador, Rachel Shaffer, who wrote this summary.

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