October 23, 2002 – According to a recent American study1 carried out in California, people who eat fish (mainly tuna, salmon and swordfish) more than twice a week have high levels of mercury in their blood.
The researchers took blood samples from 116 people who reported eating more than two meals of fish per week, or more than the two weekly servings recommended by the US Environmental Protection Agency (EPA). After one year, the tests showed that 89% of the subjects had, in their blood, a level of mercury higher than five parts per million which is the safe threshold recognized by the American National Academy of Sciences. In the group, 63 people had a mercury level more than twice the established standard and 19 had a level four times higher. More than two-thirds of the 116 study participants had ingested tuna (more than three meals per month), salmon (more than four meals per month) and swordfish (more than one meal per month).
Excessive mercury concentrations in the blood damage the nervous system and the fetus. It is not known, however, how much mercury-contaminated fish must be ingested to trigger such problems. This contamination places nutritionists in a delicate situation, because for some time they have been encouraging the consumption of fish, a food whose flesh is low in fat and rich in omega-3 fatty acids.
The mercury found in fish comes mainly from the combustion of fossil fuels and more particularly from coal-fired power stations. Although in North America and Europe, mercury emissions declined significantly in the 1980s through the use of cleaner electricity generation processes, they increased significantly in Asia. In China, for example, where coal is used extensively to generate electricity and heat, mercury emissions represent a quarter of global emissions.
Stéphane Gagné – PasseportSanté.net
According to Associated Press, October 21, 2002.
1. The study was presented at a symposium on environmental health, organized by theAmerican Fisheries Society and the EPA and held in Burlington, VT on October 20-22.