Ocean Pollutants In Fish Considerably Toxic To Our Children

by Sam Wong; PreventDisease

Ocean pollutants are estimated to soon cause half of all newborn birth defects. They contaminate our food and tamper with the body’s ability to cope with toxins. Recent findings make it more urgent to know how the pollutants act, especially as they are often found in combination.

Amro Hamdoun and Sascha Nicklisch at the University of California at San Diego and colleagues studied 37 organic pollutants and their effect on P-gp, a cell-membrane protein that recognises harmful molecules and boots them out.

In experiments on yeast cells expressing the mouse P-gp protein, 16 of the pollutants stopped it from working. Ten of these chemicals have been found in humans, implying they are in the food chain.

One of these is the pesticide DDT, which was banned by an international treaty in 2001. Others include chemicals used as industrial flame retardants.

The team looked for those 10 chemicals in yellowfin tuna, which are among the most widely eaten fish in the world. Nine were found in tuna from the Gulf of Mexico, sometimes at relatively high levels.

"P-gp is incredibly important for eliminating a wide range of drugs and toxins," says Hamdoun. "These widespread pollutants can inhibit this defence system."

Newborn babies may be among the most vulnerable to the toxic chemicals, since organic pollutants reach high concentrations in breast milk and infants have low levels of P-gp in their cells.

The pollutants usually appear as mixtures both in the environment and in our food, says Nicklisch. "We don’t know what effects the combined levels of these inhibitors will have on the body, particularly when taken together with other medications."

There should be more testing on pollutants to determine their effects on biological defences against toxins, the researchers say.