How do toxic chemicals get into fish in the supermarket?
Researchers have now found that fish in supermarkets may contain toxic chemicals. For example, these chemicals are associated with developmental problems in children. Affected fish came from farms that use feed containing some kind of synthetic flame retardant.
- In 2004, the United States and Europe banned a type of chemical called PDBEs.
- PDBEs can get into the environment and in food and cause hormone disorders in humans.
- Despite restrictions, a new study shows high concentrations of PDBE in salmon feed and also in the salmon itself, which is said to have been grown in a PDBE-free environment.
The University of Pittsburgh scientists found in their current study that farmed fish can sometimes contain hazardous chemicals that they ingest from their feed.
PDBE found in fish in a supermarket
The doctors were able to prove that salmon in supermarkets can contain the toxic chemical PDBE. Since 2004, the United States and most countries in Europe have been working to eliminate the chemical PDBE in all waters, farmed fish and wild fish. The chemical disrupts the hormones and developmental effects in humans, which they ignorantly ingest about fish. The University of Pittsburgh scientists have found evidence of PBDE in feed that is fed to farmed salmon - even salmon that are said to be free of PBDE.
Contamination arises from animal feed
The chemicals have been detected in such high concentrations that contaminated fish could get onto our plates and thus into human bodies. But where does the chemical in fish come from? The growers use feed that contains a type of synthetic flame retardant that has been imported from countries that do not have advanced food safety regulations, the doctors explain.
The food trading system is becoming increasingly global
The international trading system for food is becoming increasingly global, and this also applies to animal feed, says study author Dr. Carla Ng of the Swanson School of Engineering at the University of Pittsburgh in a press release. Fish farms are allowed to import their feed or feed ingredients from a number of countries, including those without advanced food safety regulations. The United States and a large part of Europe already banned several PBDEs in 2004 due to environmental and health problems, the expert further explains. PBDEs can act as so-called endocrine disruptors and impair developmental effects. Children are particularly at risk.
In which countries are there many PBDEs?
PBDEs continue to be found in areas that process large quantities of electronic waste and that have poor recycling regulations, such as China, Thailand and Vietnam. As a result, salmon that grow in environments without polybrominated diphenyl ether (PBDEs) but eat feed from such countries can still contain dangerous amounts of the chemical.
PDBEs in the feed of cattle and sheep?
The study also includes some models of how the chemical enters the food chain and also shows that PDBEs could also get into cattle and sheep feed. Conventional models for predicting human exposure to pollutants mostly only consider the risk of people in their local environment. Dr.'s model However, Ng takes into account factors such as pollutants inhaled through gills, how fish metabolize and break down pollutants and the concentration of pollutants in the feed.
Contaminated feed can also affect fish in a clean environment
It was found that animal feed plays a relatively minor role in areas that already have high concentrations of pollutants in the environment. However, in otherwise clean and well-regulated environments, contaminated feed can be thousands of times more important than the location of the farm to determine the PBDE content of salmon fillets, the author explains.
There are hot spots with high levels of pollutants
The model can also be applied to other fish species with large global markets, such as Red Snapper. The model can be used to predict the pollutant content in livestock or feed, which is produced in contaminated hot spots. Such so-called hot spots are places that have high levels of pollutants. As these chemicals circulate through our environment, a lot of PBDE ends up in the sea. It is extremely important to pay attention to areas with particularly high concentrations of pollutants, the experts emphasize.
How can the chemical pollution be dealt with?
Hopefully, the model will help develop better strategies to control contamination, such as the substitution of fish oil with vegetable substances or the decontamination of fish oil before human consumption, the researchers say. (as)